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CJ-6 Questions

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727gs(at)att.net
Guest

Posted: Sun Nov 08, 2015 3:51 pm Post subject: CJ-6 Questions

Got our CJ flying after sitting a few years and have been flying the heck out of it. A few issues have cropped up that maybe someone could shed some light on.

First, I was flying this morning (kind of cool out, high 30's, low 40's) and when I selected gear up, got three red lights and selected neutral, the gear slowly fell back down. I tried up twice more and they came back down to lock in neutral and I got them to stay up after selecting gear down then up. The gear operated normally through six or seven cycles the rest of the day.

A potential gear selector handle problem?

Secondly, after parking it, I put some catch pans beneath each exhaust and behind the nose gear and open the intake manifold drain valve. I generally don't get anything out of the manifold drain unless it's been sitting a while. This time when I opened the drain, I got a splash of fuel leaking out. It had been flying about 40 minutes with a normal lean run-up before shut-down.

Is this normal?

Thanks in advance,

Steve near Chicago

dsavarese0812(at)bellsout
Guest

Posted: Mon Nov 09, 2015 3:58 am Post subject: CJ-6 Questions

Why are you putting the gear in neutral after you select UP?  If it is to "reduce the back pressure on the compressor", that simply is ludicrous.  The pneumatic system already has a device to "reduce the back pressure" and that is called the pop off valve or pressure relief valve.  When you put the gear selector in NEUTRAL you completely depressurize the landing gear actuators, thus requiring you to move the gear selector to the UP position before you put the selector in the DOWN position.  That in itself is a unnatural action.  I don't think there is a single airplane manufactured with retractable landing gear that requires two complete movements of the gear selector (first back to the UP position before going to the DOWN position).  In the case of the CJ, if you do not put the gear selector back in the UP position from NEUTRAL before you move it to the DOWN position, the landing gear will slam down due to no back pressure on the actuators.

If your airplane has uplocks, make sure they are properly functioning.   The uplocks are designed to lock the gear in the UP position until the gear selector is moved to the DOWN position.  The uplocks are unlocked by either placing the gear selector in the DOWN position or opening the emergency air valve after you place the gear selector in NEUTRAL.

Dennis



        From: Stephen Jones <727gs(at)att.net>

 To: Yak-list <yak-list(at)matronics.com> 

 Sent: Sunday, November 8, 2015 6:47 PM

 Subject: CJ-6 Questions

  

 

  Got our CJ flying after sitting a few years and have been flying the heck out of it. A few issues have cropped up that maybe someone could shed some light on.

First, I was flying this morning (kind of cool out, high 30's, low 40's) and when I selected gear up, got three red lights and selected neutral, the gear slowly fell back down. I tried up twice more and they came back down to lock in neutral and I got them to stay up after selecting gear down then up. The gear operated normally through six or seven cycles the rest of the day.

A potential gear selector handle problem?

Secondly, after parking it, I put some catch pans beneath each exhaust and behind the nose gear and open the intake manifold drain valve. I generally don't get anything out of the manifold drain unless it's been sitting a while. This time when I opened the drain, I got a splash of fuel leaking out. It had been flying about 40 minutes with a normal lean run-up before shut-down.

Is this normal?

Thanks in advance,

Steve near Chicago

727gs(at)att.net
Guest

Posted: Mon Nov 09, 2015 4:19 am Post subject: CJ-6 Questions

The Yakkity-Yaks check-list that came with the airplane says to move the gear handle to neutral after the gear is retracted and three red indicators are illuminated.

The same as EVERY Boeing I've ever flown except for the Stearman.

The airplane has uplocks. They worked as advertised until yesterday. It seems to me that if you're relying on air pressure to keep the gear up, (handle left in up), you wouldn't need uplocks.

Excuse my ignorance.

Steve near Chicago 

  



     On Monday, November 9, 2015 5:50 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net> wrote:

  

  



 Why are you putting the gear in neutral after you select UP?  If it is to "reduce the back pressure on the compressor", that simply is ludicrous.  The pneumatic system already has a device to "reduce the back pressure" and that is called the pop off valve or pressure relief valve.  When you put the gear selector in NEUTRAL you completely depressurize the landing gear actuators, thus requiring you to move the gear selector to the UP position before you put the selector in the DOWN position.  That in itself is a unnatural action.  I don't think there is a single airplane manufactured with retractable landing gear that requires two complete movements of the gear selector (first back to the UP position before going to the DOWN position).  In the case of the CJ, if you do not put the gear selector back in the UP position from NEUTRAL before you move it to the DOWN position, the landing gear will slam down due to no back pressure on the actuators.



If your airplane has uplocks, make sure they are properly functioning.   The uplocks are designed to lock the gear in the UP position until the gear selector is moved to the DOWN position.  The uplocks are unlocked by either placing the gear selector in the DOWN position or opening the emergency air valve after you place the gear selector in NEUTRAL.



Dennis



        From: Stephen Jones <727gs(at)att.net> To: Yak-list <yak-list(at)matronics.com>  Sent: Sunday, November 8, 2015 6:47 PM Subject: CJ-6 Questions  

   Got our CJ flying after sitting a few years and have been flying the heck out of it. A few issues have cropped up that maybe someone could shed some light on.



First, I was flying this morning (kind of cool out, high 30's, low 40's) and when I selected gear up, got three red lights and selected neutral, the gear slowly fell back down. I tried up twice more and they came back down to lock in neutral and I got them to stay up after selecting gear down then up. The gear operated normally through six or seven cycles the rest of the day.

A potential gear selector handle problem?



Secondly, after parking it, I put some catch pans beneath each exhaust and behind the nose gear and open the intake manifold drain valve. I generally don't get anything out of the manifold drain unless it's been sitting a while. This time when I opened the drain, I got a splash of fuel leaking out. It had been flying about 40 minutes with a normal lean run-up before shut-down.

Is this normal?



Thanks in advance,

Steve near Chicago

pa3arw(at)ziggo.nl
Guest

Posted: Mon Nov 09, 2015 4:26 am Post subject: CJ-6 Questions

With all due respect Steve, you don’t know how the system works.....

 Who told you to put the gear selector in neutral after the gear is up?

 This doesn’t make sense at all. Leave it in up when flying and in down position when landing/on the ground.

 

 I’d suggest to read the manual again on this particular topic....

 

 Again: with all respect.

 

 Hans

 

 

 Op 09-11-15 00:47, Stephen Jones <[url=727gs(at)att.net]727gs(at)att.net[/url]> schreef:

 

  	  Quote: 	
		    Got our CJ flying after sitting a few years and have been flying the heck out of it. A few issues have cropped up that maybe someone could shed some light on.

 

 First, I was flying this morning (kind of cool out, high 30's, low 40's) and when I selected gear up, got three red lights and selected neutral, the gear slowly fell back down. I tried up twice more and they came back down to lock in neutral and I got them to stay up after selecting gear down then up. The gear operated normally through six or seven cycles the rest of the day.

 A potential gear selector handle problem?

 

 Secondly, after parking it, I put some catch pans beneath each exhaust and behind the nose gear and open the intake manifold drain valve. I generally don't get anything out of the manifold drain unless it's been sitting a while. This time when I opened the drain, I got a splash of fuel leaking out. It had been flying about 40 minutes with a normal lean run-up before shut-down.

 Is this normal?

 

 Thanks in advance,

 Steve near Chicago

dsavarese0812(at)bellsout
Guest

Posted: Mon Nov 09, 2015 5:13 am Post subject: CJ-6 Questions

Ahhh.  Now I understand where the procedure came from.

Question for you Stephen.  In the Boeings you have flown, after you retract the gear and the 3 red indicators are illuminated and you move the gear selector to neutral, is the procedure in the Boeing to move the gear selector to the UP position before you move the gear selector to the DOWN position to extend the gear?

Dennis



        From: Stephen Jones <727gs(at)att.net>

 To: "yak-list(at)matronics.com" <yak-list(at)matronics.com> 

 Sent: Monday, November 9, 2015 7:16 AM

 Subject: Re: CJ-6 Questions

  

 

The Yakkity-Yaks check-list that came with the airplane says to move the gear handle to neutral after the gear is retracted and three red indicators are illuminated.

The same as EVERY Boeing I've ever flown except for the Stearman.



The airplane has uplocks. They worked as advertised until yesterday. It seems to me that if you're relying on air pressure to keep the gear up, (handle left in up), you wouldn't need uplocks.



Excuse my ignorance.



Steve near Chicago 

  

     On Monday, November 9, 2015 5:50 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net> wrote:  

   Why are you putting the gear in neutral after you select UP?  If it is to "reduce the back pressure on the compressor", that simply is ludicrous.  The pneumatic system already has a device to "reduce the back pressure" and that is called the pop off valve or pressure relief valve.  When you put the gear selector in NEUTRAL you completely depressurize the landing gear actuators, thus requiring you to move the gear selector to the UP position before you put the selector in the DOWN position.  That in itself is a unnatural action.  I don't think there is a single airplane manufactured with retractable landing gear that requires two complete movements of the gear selector (first back to the UP position before going to the DOWN position).  In the case of the CJ, if you do not put the gear selector back in the UP position from NEUTRAL before you move it to the DOWN position, the landing gear will slam down due to no back pressure on the actuators.



If your airplane has uplocks, make sure they are properly functioning.   The uplocks are designed to lock the gear in the UP position until the gear selector is moved to the DOWN position.  The uplocks are unlocked by either placing the gear selector in the DOWN position or opening the emergency air valve after you place the gear selector in NEUTRAL.



Dennis



        From: Stephen Jones <727gs(at)att.net> To: Yak-list <yak-list(at)matronics.com>  Sent: Sunday, November 8, 2015 6:47 PM Subject: CJ-6 Questions  

   Got our CJ flying after sitting a few years and have been flying the heck out of it. A few issues have cropped up that maybe someone could shed some light on.



First, I was flying this morning (kind of cool out, high 30's, low 40's) and when I selected gear up, got three red lights and selected neutral, the gear slowly fell back down. I tried up twice more and they came back down to lock in neutral and I got them to stay up after selecting gear down then up. The gear operated normally through six or seven cycles the rest of the day.

A potential gear selector handle problem?



Secondly, after parking it, I put some catch pans beneath each exhaust and behind the nose gear and open the intake manifold drain valve. I generally don't get anything out of the manifold drain unless it's been sitting a while. This time when I opened the drain, I got a splash of fuel leaking out. It had been flying about 40 minutes with a normal lean run-up before shut-down.

Is this normal?



Thanks in advance,

Steve near Chicago

migfighter42(at)gmail.com
Guest

Posted: Mon Nov 09, 2015 5:52 am Post subject: CJ-6 Questions

 FYI

MiG-15/-17 procedure us to move gear and flap handles back to neutral after use for all operations except landing. Leaving them up or down holds pressure on the hydraulic rams and will overheat the hydraulic pump causing pump failure if left too long. I have often wondered if the yaks have this feature as a training aids for the MiGs.

Bill

Red Star Aero Services





Sent from my T-Mobile 4G LTE Device



-------- Original message --------

From: "A. Dennis Savarese" <dsavarese0812(at)bellsouth.net> 

Date: 11/9/2015  7:07 AM  (GMT-06:00) 

To: yak-list(at)matronics.com 

Subject: Re: Yak-List: CJ-6 Questions 



Ahhh.  Now I understand where the procedure came from.

Question for you Stephen.  In the Boeings you have flown, after you retract the gear and the 3 red indicators are illuminated and you move the gear selector to neutral, is the procedure in the Boeing to move the gear selector to the UP position before you move the gear selector to the DOWN position to extend the gear?

Dennis



        From: Stephen Jones <727gs(at)att.net>

 To: "yak-list(at)matronics.com" <yak-list(at)matronics.com> 

 Sent: Monday, November 9, 2015 7:16 AM

 Subject: Re: Yak-List: CJ-6 Questions

  

 

The Yakkity-Yaks check-list that came with the airplane says to move the gear handle to neutral after the gear is retracted and three red indicators are illuminated.

The same as EVERY Boeing I've ever flown except for the Stearman.



The airplane has uplocks. They worked as advertised until yesterday. It seems to me that if you're relying on air pressure to keep the gear up, (handle left in up), you wouldn't need uplocks.



Excuse my ignorance.



Steve near Chicago 

  

     On Monday, November 9, 2015 5:50 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net> wrote:  

   Why are you putting the gear in neutral after you select UP?  If it is to "reduce the back pressure on the compressor", that simply is ludicrous.  The pneumatic system already has a device to "reduce the back pressure" and that is called the pop off valve or pressure relief valve.  When you put the gear selector in NEUTRAL you completely depressurize the landing gear actuators, thus requiring you to move the gear selector to the UP position before you put the selector in the DOWN position.  That in itself is a unnatural action.  I don't think there is a single airplane manufactured with retractable landing gear that requires two complete movements of the gear selector (first back to the UP position before going to the DOWN position).  In the case of the CJ, if you do not put the gear selector back in the UP position from NEUTRAL before you move it to the DOWN position, the landing gear will slam down due to no back pressure on the actuators.



If your airplane has uplocks, make sure they are properly functioning.   The uplocks are designed to lock the gear in the UP position until the gear selector is moved to the DOWN position.  The uplocks are unlocked by either placing the gear selector in the DOWN position or opening the emergency air valve after you place the gear selector in NEUTRAL.



Dennis



        From: Stephen Jones <727gs(at)att.net> To: Yak-list <yak-list(at)matronics.com>  Sent: Sunday, November 8, 2015 6:47 PM Subject: Yak-List: CJ-6 Questions  

   Got our CJ flying after sitting a few years and have been flying the heck out of it. A few issues have cropped up that maybe someone could shed some light on.



First, I was flying this morning (kind of cool out, high 30's, low 40's) and when I selected gear up, got three red lights and selected neutral, the gear slowly fell back down. I tried up twice more and they came back down to lock in neutral and I got them to stay up after selecting gear down then up. The gear operated normally through six or seven cycles the rest of the day.

A potential gear selector handle problem?



Secondly, after parking it, I put some catch pans beneath each exhaust and behind the nose gear and open the intake manifold drain valve. I generally don't get anything out of the manifold drain unless it's been sitting a while. This time when I opened the drain, I got a splash of fuel leaking out. It had been flying about 40 minutes with a normal lean run-up before shut-down.

Is this normal?



Thanks in advance,

Steve near Chicago

727gs(at)att.net
Guest

Posted: Mon Nov 09, 2015 6:58 am Post subject: CJ-6 Questions

No, Dennis, it doesn't under normal procedures.

When we bought the airplane from Fred Ehlenburg at Yakkity-Yaks in 1997, that was the procedure his check pilots taught and is the procedure in the checklist they distributed with the airplane. I can't recall why, my assumption was to relieve the pressure on the actuators and I had seen this done on Boeings, MiGs and some British airplanes. It does note to raise the handle to the up position before lowering the gear, which I thought was unusual but I didn't have any time in Chinese equipment.

Rest assured that I didn't invent a procedure because I had seen it in something else I flew.

Steve

  



     On Monday, November 9, 2015 7:07 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net> wrote:

  

  



 Ahhh.  Now I understand where the procedure came from.



Question for you Stephen.  In the Boeings you have flown, after you retract the gear and the 3 red indicators are illuminated and you move the gear selector to neutral, is the procedure in the Boeing to move the gear selector to the UP position before you move the gear selector to the DOWN position to extend the gear?

Dennis



        From: Stephen Jones <727gs(at)att.net> To: "yak-list(at)matronics.com" <yak-list(at)matronics.com>  Sent: Monday, November 9, 2015 7:16 AM Subject: Re: CJ-6 Questions  

 The Yakkity-Yaks check-list that came with the airplane says to move the gear handle to neutral after the gear is retracted and three red indicators are illuminated.

The same as EVERY Boeing I've ever flown except for the Stearman.



The airplane has uplocks. They worked as advertised until yesterday. It seems to me that if you're relying on air pressure to keep the gear up, (handle left in up), you wouldn't need uplocks.



Excuse my ignorance.



Steve near Chicago 

  

     On Monday, November 9, 2015 5:50 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net> wrote:  

   Why are you putting the gear in neutral after you select UP?  If it is to "reduce the back pressure on the compressor", that simply is ludicrous.  The pneumatic system already has a device to "reduce the back pressure" and that is called the pop off valve or pressure relief valve.  When you put the gear selector in NEUTRAL you completely depressurize the landing gear actuators, thus requiring you to move the gear selector to the UP position before you put the selector in the DOWN position.  That in itself is a unnatural action.  I don't think there is a single airplane manufactured with retractable landing gear that requires two complete movements of the gear selector (first back to the UP position before going to the DOWN position).  In the case of the CJ, if you do not put the gear selector back in the UP position from NEUTRAL before you move it to the DOWN position, the landing gear will slam down due to no back pressure on the actuators.



If your airplane has uplocks, make sure they are properly functioning.   The uplocks are designed to lock the gear in the UP position until the gear selector is moved to the DOWN position.  The uplocks are unlocked by either placing the gear selector in the DOWN position or opening the emergency air valve after you place the gear selector in NEUTRAL.



Dennis



        From: Stephen Jones <727gs(at)att.net> To: Yak-list <yak-list(at)matronics.com>  Sent: Sunday, November 8, 2015 6:47 PM Subject: CJ-6 Questions  

   Got our CJ flying after sitting a few years and have been flying the heck out of it. A few issues have cropped up that maybe someone could shed some light on.



First, I was flying this morning (kind of cool out, high 30's, low 40's) and when I selected gear up, got three red lights and selected neutral, the gear slowly fell back down. I tried up twice more and they came back down to lock in neutral and I got them to stay up after selecting gear down then up. The gear operated normally through six or seven cycles the rest of the day.

A potential gear selector handle problem?



Secondly, after parking it, I put some catch pans beneath each exhaust and behind the nose gear and open the intake manifold drain valve. I generally don't get anything out of the manifold drain unless it's been sitting a while. This time when I opened the drain, I got a splash of fuel leaking out. It had been flying about 40 minutes with a normal lean run-up before shut-down.

Is this normal?



Thanks in advance,

Steve near Chicago

dsavarese0812(at)bellsout
Guest

Posted: Mon Nov 09, 2015 7:18 am Post subject: CJ-6 Questions

And therein is the key difference.  Hydraulic versus pneumatic.  The compressor continues to run regardless of whether the gear selector is UP, DOWN or in Neutral.  Once the pressure in the air tanks reaches the preset pressure set by the pressure relief valve (pop off valve), approximately 50 atmospheres, the pressure relief valve opens and dumps the excess air overboard or until the pressure relief valve closes and begins to repressurize the system back to the preset pressure.

I believe the person who wrote the procedure was applying a hydraulic system operational procedure to the pneumatic system.

On the CJ or Yak 52, if the gear selector is placed in the neutral position after retracting the gear, if the actuators are not repressurized before putting the gear down by moving the gear selector back to the UP position, the gear will slam down and it can eventually cause damage to the actuators because the back pressure in the actuators acts as a "shock absorber" when the gear selector is moved from the UP position to the DOWN position.  ie:  the pressure on the UP side is being forced out of the gear handle (that is the woosh sound you hear in the cockpit) by the air pressure being applied to the DOWN position.  Works the opposite way when you move from the DOWN position to the UP position. 



Dennis



        From: migfighter42 <migfighter42(at)gmail.com>

 To: yak-list(at)matronics.com 

 Sent: Monday, November 9, 2015 8:49 AM

 Subject: Re: CJ-6 Questions

  

 

 FYI



MiG-15/-17 procedure us to move gear and flap handles back to neutral after use for all operations except landing. Leaving them up or down holds pressure on the hydraulic rams and will overheat the hydraulic pump causing pump failure if left too long. I have often wondered if the yaks have this feature as a training aids for the MiGs.



Bill

Red Star Aero Services



Sent from my T-Mobile 4G LTE Device





-------- Original message --------

From: "A. Dennis Savarese" <dsavarese0812(at)bellsouth.net> 

Date: 11/9/2015  7:07 AM  (GMT-06:00) 

To: yak-list(at)matronics.com 

Subject: Re: CJ-6 Questions 

Ahhh.  Now I understand where the procedure came from.



Question for you Stephen.  In the Boeings you have flown, after you retract the gear and the 3 red indicators are illuminated and you move the gear selector to neutral, is the procedure in the Boeing to move the gear selector to the UP position before you move the gear selector to the DOWN position to extend the gear?

Dennis



        From: Stephen Jones <727gs(at)att.net> To: "yak-list(at)matronics.com" <yak-list(at)matronics.com>  Sent: Monday, November 9, 2015 7:16 AM Subject: Re: CJ-6 Questions  

 The Yakkity-Yaks check-list that came with the airplane says to move the gear handle to neutral after the gear is retracted and three red indicators are illuminated.

The same as EVERY Boeing I've ever flown except for the Stearman.



The airplane has uplocks. They worked as advertised until yesterday. It seems to me that if you're relying on air pressure to keep the gear up, (handle left in up), you wouldn't need uplocks.



Excuse my ignorance.



Steve near Chicago 

  

     On Monday, November 9, 2015 5:50 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net> wrote:  

   Why are you putting the gear in neutral after you select UP?  If it is to "reduce the back pressure on the compressor", that simply is ludicrous.  The pneumatic system already has a device to "reduce the back pressure" and that is called the pop off valve or pressure relief valve.  When you put the gear selector in NEUTRAL you completely depressurize the landing gear actuators, thus requiring you to move the gear selector to the UP position before you put the selector in the DOWN position.  That in itself is a unnatural action.  I don't think there is a single airplane manufactured with retractable landing gear that requires two complete movements of the gear selector (first back to the UP position before going to the DOWN position).  In the case of the CJ, if you do not put the gear selector back in the UP position from NEUTRAL before you move it to the DOWN position, the landing gear will slam down due to no back pressure on the actuators.



If your airplane has uplocks, make sure they are properly functioning.   The uplocks are designed to lock the gear in the UP position until the gear selector is moved to the DOWN position.  The uplocks are unlocked by either placing the gear selector in the DOWN position or opening the emergency air valve after you place the gear selector in NEUTRAL.



Dennis



        From: Stephen Jones <727gs(at)att.net> To: Yak-list <yak-list(at)matronics.com>  Sent: Sunday, November 8, 2015 6:47 PM Subject: CJ-6 Questions  

   Got our CJ flying after sitting a few years and have been flying the heck out of it. A few issues have cropped up that maybe someone could shed some light on.



First, I was flying this morning (kind of cool out, high 30's, low 40's) and when I selected gear up, got three red lights and selected neutral, the gear slowly fell back down. I tried up twice more and they came back down to lock in neutral and I got them to stay up after selecting gear down then up. The gear operated normally through six or seven cycles the rest of the day.

A potential gear selector handle problem?



Secondly, after parking it, I put some catch pans beneath each exhaust and behind the nose gear and open the intake manifold drain valve. I generally don't get anything out of the manifold drain unless it's been sitting a while. This time when I opened the drain, I got a splash of fuel leaking out. It had been flying about 40 minutes with a normal lean run-up before shut-down.

Is this normal?



Thanks in advance,

Steve near Chicago

dsavarese0812(at)bellsout
Guest

Posted: Mon Nov 09, 2015 7:33 am Post subject: CJ-6 Questions

I know you didn't invent the procedure and you are correct, it is unusual to have to move the gear selector from the neutral to up position.

I tried to explain the pneumatic system  a bit better in another post a few minutes ago so as to help folks understand how that procedure was possibly created and why it is flawed.  Again as you or someone else said, the reason for moving the gear selector to neutral on hydraulic system aircraft is to shut the hydraulic pump down, which makes perfect sense.  But in the hydraulic system aircraft, one does not have to move the gear selector from neutral back to UP before moving the gear selector to the down position because the actuators remain pressurized.  On our pneumatic system aircraft, once the gear selector is placed in neutral the actuators are depressurized.  The compressor, being physically attached to the engine, always runs as long as the engine is running.

Hope this makes sense.

Dennis



        From: Stephen Jones <727gs(at)att.net>

 To: "yak-list(at)matronics.com" <yak-list(at)matronics.com> 

 Sent: Monday, November 9, 2015 9:54 AM

 Subject: Re: CJ-6 Questions

  

 

No, Dennis, it doesn't under normal procedures.



When we bought the airplane from Fred Ehlenburg at Yakkity-Yaks in 1997, that was the procedure his check pilots taught and is the procedure in the checklist they distributed with the airplane. I can't recall why, my assumption was to relieve the pressure on the actuators and I had seen this done on Boeings, MiGs and some British airplanes. It does note to raise the handle to the up position before lowering the gear, which I thought was unusual but I didn't have any time in Chinese equipment.



Rest assured that I didn't invent a procedure because I had seen it in something else I flew.



Steve

  

     On Monday, November 9, 2015 7:07 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net> wrote:  

   Ahhh.  Now I understand where the procedure came from.



Question for you Stephen.  In the Boeings you have flown, after you retract the gear and the 3 red indicators are illuminated and you move the gear selector to neutral, is the procedure in the Boeing to move the gear selector to the UP position before you move the gear selector to the DOWN position to extend the gear?

Dennis



        From: Stephen Jones <727gs(at)att.net> To: "yak-list(at)matronics.com" <yak-list(at)matronics.com>  Sent: Monday, November 9, 2015 7:16 AM Subject: Re: CJ-6 Questions  

 The Yakkity-Yaks check-list that came with the airplane says to move the gear handle to neutral after the gear is retracted and three red indicators are illuminated.

The same as EVERY Boeing I've ever flown except for the Stearman.



The airplane has uplocks. They worked as advertised until yesterday. It seems to me that if you're relying on air pressure to keep the gear up, (handle left in up), you wouldn't need uplocks.



Excuse my ignorance.



Steve near Chicago 

  

     On Monday, November 9, 2015 5:50 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net> wrote:  

   Why are you putting the gear in neutral after you select UP?  If it is to "reduce the back pressure on the compressor", that simply is ludicrous.  The pneumatic system already has a device to "reduce the back pressure" and that is called the pop off valve or pressure relief valve.  When you put the gear selector in NEUTRAL you completely depressurize the landing gear actuators, thus requiring you to move the gear selector to the UP position before you put the selector in the DOWN position.  That in itself is a unnatural action.  I don't think there is a single airplane manufactured with retractable landing gear that requires two complete movements of the gear selector (first back to the UP position before going to the DOWN position).  In the case of the CJ, if you do not put the gear selector back in the UP position from NEUTRAL before you move it to the DOWN position, the landing gear will slam down due to no back pressure on the actuators.



If your airplane has uplocks, make sure they are properly functioning.   The uplocks are designed to lock the gear in the UP position until the gear selector is moved to the DOWN position.  The uplocks are unlocked by either placing the gear selector in the DOWN position or opening the emergency air valve after you place the gear selector in NEUTRAL.



Dennis



        From: Stephen Jones <727gs(at)att.net> To: Yak-list <yak-list(at)matronics.com>  Sent: Sunday, November 8, 2015 6:47 PM Subject: CJ-6 Questions  

   Got our CJ flying after sitting a few years and have been flying the heck out of it. A few issues have cropped up that maybe someone could shed some light on.



First, I was flying this morning (kind of cool out, high 30's, low 40's) and when I selected gear up, got three red lights and selected neutral, the gear slowly fell back down. I tried up twice more and they came back down to lock in neutral and I got them to stay up after selecting gear down then up. The gear operated normally through six or seven cycles the rest of the day.

A potential gear selector handle problem?



Secondly, after parking it, I put some catch pans beneath each exhaust and behind the nose gear and open the intake manifold drain valve. I generally don't get anything out of the manifold drain unless it's been sitting a while. This time when I opened the drain, I got a splash of fuel leaking out. It had been flying about 40 minutes with a normal lean run-up before shut-down.

Is this normal?



Thanks in advance,

Steve near Chicago

rocketerf1(at)yahoo.ca
Guest

Posted: Mon Nov 09, 2015 9:51 am Post subject: CJ-6 Questions

I find this a very interesting discussion.

A friend of mine does this on his CJ6 and was convincing me I should as well (place handle back to neutral after gear up to ensure no pressure on the system).  My placard on the dash even reads "Gear down - Place handle up then down".  This had me convinced he was probably right.  This after flying the CJ6 for 6 years where I just put the handle up when flying and down when landing.

Personally I think it is better that way as I do know of one CJ6 where the owner landed gear up and swears he put the handle down, but he never did, he just had it in the neutral position.

So my question to the whole group is:  Will it hurt the system at all to have pressure on the UP side of the gear for a whole flight?  If not I won't be doing it.

Jeff

  



     On Monday, November 9, 2015 8:42 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net> wrote:

  

  



 I know you didn't invent the procedure and you are correct, it is unusual to have to move the gear selector from the neutral to up position.



I tried to explain the pneumatic system  a bit better in another post a few minutes ago so as to help folks understand how that procedure was possibly created and why it is flawed.  Again as you or someone else said, the reason for moving the gear selector to neutral on hydraulic system aircraft is to shut the hydraulic pump down, which makes perfect sense.  But in the hydraulic system aircraft, one does not have to move the gear selector from neutral back to UP before moving the gear selector to the down position because the actuators remain pressurized.  On our pneumatic system aircraft, once the gear selector is placed in neutral the actuators are depressurized.  The compressor, being physically attached to the engine, always runs as long as the engine is running.



Hope this makes sense.

Dennis



        From: Stephen Jones <727gs(at)att.net> To: "yak-list(at)matronics.com" <yak-list(at)matronics.com>  Sent: Monday, November 9, 2015 9:54 AM Subject: Re: CJ-6 Questions  

 No, Dennis, it doesn't under normal procedures.



When we bought the airplane from Fred Ehlenburg at Yakkity-Yaks in 1997, that was the procedure his check pilots taught and is the procedure in the checklist they distributed with the airplane. I can't recall why, my assumption was to relieve the pressure on the actuators and I had seen this done on Boeings, MiGs and some British airplanes. It does note to raise the handle to the up position before lowering the gear, which I thought was unusual but I didn't have any time in Chinese equipment.



Rest assured that I didn't invent a procedure because I had seen it in something else I flew.



Steve

  

     On Monday, November 9, 2015 7:07 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net> wrote:  

   Ahhh.  Now I understand where the procedure came from.



Question for you Stephen.  In the Boeings you have flown, after you retract the gear and the 3 red indicators are illuminated and you move the gear selector to neutral, is the procedure in the Boeing to move the gear selector to the UP position before you move the gear selector to the DOWN position to extend the gear?

Dennis



        From: Stephen Jones <727gs(at)att.net> To: "yak-list(at)matronics.com" <yak-list(at)matronics.com>  Sent: Monday, November 9, 2015 7:16 AM Subject: Re: CJ-6 Questions  

 The Yakkity-Yaks check-list that came with the airplane says to move the gear handle to neutral after the gear is retracted and three red indicators are illuminated.

The same as EVERY Boeing I've ever flown except for the Stearman.



The airplane has uplocks. They worked as advertised until yesterday. It seems to me that if you're relying on air pressure to keep the gear up, (handle left in up), you wouldn't need uplocks.



Excuse my ignorance.



Steve near Chicago 

  

     On Monday, November 9, 2015 5:50 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net> wrote:  

   Why are you putting the gear in neutral after you select UP?  If it is to "reduce the back pressure on the compressor", that simply is ludicrous.  The pneumatic system already has a device to "reduce the back pressure" and that is called the pop off valve or pressure relief valve.  When you put the gear selector in NEUTRAL you completely depressurize the landing gear actuators, thus requiring you to move the gear selector to the UP position before you put the selector in the DOWN position.  That in itself is a unnatural action.  I don't think there is a single airplane manufactured with retractable landing gear that requires two complete movements of the gear selector (first back to the UP position before going to the DOWN position).  In the case of the CJ, if you do not put the gear selector back in the UP position from NEUTRAL before you move it to the DOWN position, the landing gear will slam down due to no back pressure on the actuators.



If your airplane has uplocks, make sure they are properly functioning.   The uplocks are designed to lock the gear in the UP position until the gear selector is moved to the DOWN position.  The uplocks are unlocked by either placing the gear selector in the DOWN position or opening the emergency air valve after you place the gear selector in NEUTRAL.



Dennis



        From: Stephen Jones <727gs(at)att.net> To: Yak-list <yak-list(at)matronics.com>  Sent: Sunday, November 8, 2015 6:47 PM Subject: CJ-6 Questions  

   Got our CJ flying after sitting a few years and have been flying the heck out of it. A few issues have cropped up that maybe someone could shed some light on.



First, I was flying this morning (kind of cool out, high 30's, low 40's) and when I selected gear up, got three red lights and selected neutral, the gear slowly fell back down. I tried up twice more and they came back down to lock in neutral and I got them to stay up after selecting gear down then up. The gear operated normally through six or seven cycles the rest of the day.

A potential gear selector handle problem?



Secondly, after parking it, I put some catch pans beneath each exhaust and behind the nose gear and open the intake manifold drain valve. I generally don't get anything out of the manifold drain unless it's been sitting a while. This time when I opened the drain, I got a splash of fuel leaking out. It had been flying about 40 minutes with a normal lean run-up before shut-down.

Is this normal?



Thanks in advance,

Steve near Chicago

dsavarese0812(at)bellsout
Guest

Posted: Mon Nov 09, 2015 10:09 am Post subject: CJ-6 Questions

Won't hurt the system one bit. 

Dennis



Sent from my iPhone



On Nov 9, 2015, at 12:46 PM, Jeff Deuchar <rocketerf1(at)yahoo.ca (rocketerf1(at)yahoo.ca)> wrote:

 	  Quote: 	
		  I find this a very interesting discussion.

A friend of mine does this on his CJ6 and was convincing me I should as well (place handle back to neutral after gear up to ensure no pressure on the system).  My placard on the dash even reads "Gear down - Place handle up then down".  This had me convinced he was probably right.  This after flying the CJ6 for 6 years where I just put the handle up when flying and down when landing.

Personally I think it is better that way as I do know of one CJ6 where the owner landed gear up and swears he put the handle down, but he never did, he just had it in the neutral position.

So my question to the whole group is:  Will it hurt the system at all to have pressure on the UP side of the gear for a whole flight?  If not I won't be doing it.

Jeff

  



     On Monday, November 9, 2015 8:42 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net (dsavarese0812(at)bellsouth.net)> wrote:

  

  



 I know you didn't invent the procedure and you are correct, it is unusual to have to move the gear selector from the neutral to up position.



I tried to explain the pneumatic system  a bit better in another post a few minutes ago so as to help folks understand how that procedure was possibly created and why it is flawed.  Again as you or someone else said, the reason for moving the gear selector to neutral on hydraulic system aircraft is to shut the hydraulic pump down, which makes perfect sense.  But in the hydraulic system aircraft, one does not have to move the gear selector from neutral back to UP before moving the gear selector to the down position because the actuators remain pressurized.  On our pneumatic system aircraft, once the gear selector is placed in neutral the actuators are depressurized.  The compressor, being physically attached to the engine, always runs as long as the engine is running.



Hope this makes sense.

Dennis



        From: Stephen Jones <727gs(at)att.net (727gs(at)att.net)> To: "yak-list(at)matronics.com (yak-list(at)matronics.com)" <yak-list(at)matronics.com (yak-list(at)matronics.com)>  Sent: Monday, November 9, 2015 9:54 AM Subject: Re: CJ-6 Questions  

 No, Dennis, it doesn't under normal procedures.



When we bought the airplane from Fred Ehlenburg at Yakkity-Yaks in 1997, that was the procedure his check pilots taught and is the procedure in the checklist they distributed with the airplane. I can't recall why, my assumption was to relieve the pressure on the actuators and I had seen this done on Boeings, MiGs and some British airplanes. It does note to raise the handle to the up position before lowering the gear, which I thought was unusual but I didn't have any time in Chinese equipment.



Rest assured that I didn't invent a procedure because I had seen it in something else I flew.



Steve

  

     On Monday, November 9, 2015 7:07 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net (dsavarese0812(at)bellsouth.net)> wrote:  

   Ahhh.  Now I understand where the procedure came from.



Question for you Stephen.  In the Boeings you have flown, after you retract the gear and the 3 red indicators are illuminated and you move the gear selector to neutral, is the procedure in the Boeing to move the gear selector to the UP position before you move the gear selector to the DOWN position to extend the gear?

Dennis



        From: Stephen Jones <727gs(at)att.net (727gs(at)att.net)> To: "yak-list(at)matronics.com (yak-list(at)matronics.com)" <yak-list(at)matronics.com (yak-list(at)matronics.com)>  Sent: Monday, November 9, 2015 7:16 AM Subject: Re: CJ-6 Questions  

 The Yakkity-Yaks check-list that came with the airplane says to move the gear handle to neutral after the gear is retracted and three red indicators are illuminated.

The same as EVERY Boeing I've ever flown except for the Stearman.



The airplane has uplocks. They worked as advertised until yesterday. It seems to me that if you're relying on air pressure to keep the gear up, (handle left in up), you wouldn't need uplocks.



Excuse my ignorance.



Steve near Chicago 

  

     On Monday, November 9, 2015 5:50 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net (dsavarese0812(at)bellsouth.net)> wrote:  

   Why are you putting the gear in neutral after you select UP?  If it is to "reduce the back pressure on the compressor", that simply is ludicrous.  The pneumatic system already has a device to "reduce the back pressure" and that is called the pop off valve or pressure relief valve.  When you put the gear selector in NEUTRAL you completely depressurize the landing gear actuators, thus requiring you to move the gear selector to the UP position before you put the selector in the DOWN position.  That in itself is a unnatural action.  I don't think there is a single airplane manufactured with retractable landing gear that requires two complete movements of the gear selector (first back to the UP position before going to the DOWN position).  In the case of the CJ, if you do not put the gear selector back in the UP position from NEUTRAL before you move it to the DOWN position, the landing gear will slam down due to no back pressure on the actuators.



If your airplane has uplocks, make sure they are properly functioning.   The uplocks are designed to lock the gear in the UP position until the gear selector is moved to the DOWN position.  The uplocks are unlocked by either placing the gear selector in the DOWN position or opening the emergency air valve after you place the gear selector in NEUTRAL.



Dennis



        From: Stephen Jones <727gs(at)att.net (727gs(at)att.net)> To: Yak-list <yak-list(at)matronics.com (yak-list(at)matronics.com)>  Sent: Sunday, November 8, 2015 6:47 PM Subject: CJ-6 Questions  

   Got our CJ flying after sitting a few years and have been flying the heck out of it. A few issues have cropped up that maybe someone could shed some light on.



First, I was flying this morning (kind of cool out, high 30's, low 40's) and when I selected gear up, got three red lights and selected neutral, the gear slowly fell back down. I tried up twice more and they came back down to lock in neutral and I got them to stay up after selecting gear down then up. The gear operated normally through six or seven cycles the rest of the day.

A potential gear selector handle problem?



Secondly, after parking it, I put some catch pans beneath each exhaust and behind the nose gear and open the intake manifold drain valve. I generally don't get anything out of the manifold drain unless it's been sitting a while. This time when I opened the drain, I got a splash of fuel leaking out. It had been flying about 40 minutes with a normal lean run-up before shut-down.

Is this normal?



Thanks in advance,

Steve near Chicago

jblake207(at)comcast.net
Guest

Posted: Mon Nov 09, 2015 11:16 am Post subject: CJ-6 Questions

Jeff,



  

 When I first got my CJ, I was told to move the gear handle to the neutral position to relieve backpressure.  I thought about it a little and since the system already incorporates a relief valve I decided to NOT move it to the neutral position... Have been doing that for over 10 years now with ZERO issues.  As Dennis alluded to in his message, the movement back to the UP position is un-natural and is introducing a negative (or in my opinion a WRONG) habit and will damage gear components if repeated over time.  My advice is to think of the gear handle with only 2 positions... 

  

 I'd be very interested and surprised to hear of anyone having issues due to only using two positions.

  

 JB

  

  

 



   From: "Jeff Deuchar" <rocketerf1(at)yahoo.ca>

To: yak-list(at)matronics.com

Sent: Monday, November 9, 2015 11:46:04 AM

Subject: Re: CJ-6 Questions

 



  I find this a very interesting discussion.

 A friend of mine does this on his CJ6 and was convincing me I should as well (place handle back to neutral after gear up to ensure no pressure on the system).  My placard on the dash even reads "Gear down - Place handle up then down".  This had me convinced he was probably right.  This after flying the CJ6 for 6 years where I just put the handle up when flying and down when landing.

 Personally I think it is better that way as I do know of one CJ6 where the owner landed gear up and swears he put the handle down, but he never did, he just had it in the neutral position.

 



 So my question to the whole group is:  Will it hurt the system at all to have pressure on the UP side of the gear for a whole flight?  If not I won't be doing it.

 



 Jeff



 

 

    On Monday, November 9, 2015 8:42 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net> wrote:

 



     I know you didn't invent the procedure and you are correct, it is unusual to have to move the gear selector from the neutral to up position.

 

 I tried to explain the pneumatic system  a bit better in another post a few minutes ago so as to help folks understand how that procedure was possibly created and why it is flawed.  Again as you or someone else said, the reason for moving the gear selector to neutral on hydraulic system aircraft is to shut the hydraulic pump down, which makes perfect sense.  But in the hydraulic system aircraft, one does not have to move the gear selector from neutral back to UP before moving the gear selector to the down position because the actuators remain pressurized.  On our pneumatic system aircraft, once the gear selector is placed in neutral the actuators are depressurized.  The compressor, being physically attached to the engine, always runs as long as the engine is running.

 

 Hope this makes sense.

 Dennis

 

      From: Stephen Jones <727gs(at)att.net>To: "yak-list(at)matronics.com" <yak-list(at)matronics.com> Sent: Monday, November 9, 2015 9:54 AMSubject: Re: CJ-6 Questions

     No, Dennis, it doesn't under normal procedures.

 

 When we bought the airplane from Fred Ehlenburg at Yakkity-Yaks in 1997, that was the procedure his check pilots taught and is the procedure in the checklist they distributed with the airplane. I can't recall why, my assumption was to relieve the pressure on the actuators and I had seen this done on Boeings, MiGs and some British airplanes. It does note to raise the handle to the up position before lowering the gear, which I thought was unusual but I didn't have any time in Chinese equipment.

 

 Rest assured that I didn't invent a procedure because I had seen it in something else I flew.

 

 Steve

 

     On Monday, November 9, 2015 7:07 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net> wrote:

     Ahhh.  Now I understand where the procedure came from.

 

 Question for you Stephen.  In the Boeings you have flown, after you retract the gear and the 3 red indicators are illuminated and you move the gear selector to neutral, is the procedure in the Boeing to move the gear selector to the UP position before you move the gear selector to the DOWN position to extend the gear?

 Dennis

 

      From: Stephen Jones <727gs(at)att.net>To: "yak-list(at)matronics.com" <yak-list(at)matronics.com> Sent: Monday, November 9, 2015 7:16 AMSubject: Re: CJ-6 Questions

     The Yakkity-Yaks check-list that came with the airplane says to move the gear handle to neutral after the gear is retracted and three red indicators are illuminated.

 The same as EVERY Boeing I've ever flown except for the Stearman.

 

 The airplane has uplocks. They worked as advertised until yesterday. It seems to me that if you're relying on air pressure to keep the gear up, (handle left in up), you wouldn't need uplocks.

 

 Excuse my ignorance.

 

 Steve near Chicago 

 

     On Monday, November 9, 2015 5:50 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net> wrote:

     Why are you putting the gear in neutral after you select UP?  If it is to "reduce the back pressure on the compressor", that simply is ludicrous.  The pneumatic system already has a device to "reduce the back pressure" and that is called the pop off valve or pressure relief valve.  When you put the gear selector in NEUTRAL you completely depressurize the landing gear actuators, thus requiring you to move the gear selector to the UP position before you put the selector in the DOWN position.  That in itself is a unnatural action.  I don't think there is a single airplane manufactured with retractable landing gear that requires two complete movements of the gear selector (first back to the UP position before going to the DOWN position).  In the case of the CJ, if you do not put the gear selector back in the UP position from NEUTRAL before you move it to the DOWN position, the landing gear will slam down due to no back pressure on the actuators.

 

 If your airplane has uplocks, make sure they are properly functioning.   The uplocks are designed to lock the gear in the UP position until the gear selector is moved to the DOWN position.  The uplocks are unlocked by either placing the gear selector in the DOWN position or opening the emergency air valve after you place the gear selector in NEUTRAL.

 

 Dennis

 

 

 

 

 

      From: Stephen Jones <727gs(at)att.net>To: Yak-list <yak-list(at)matronics.com> Sent: Sunday, November 8, 2015 6:47 PMSubject: CJ-6 Questions

     Got our CJ flying after sitting a few years and have been flying the heck out of it. A few issues have cropped up that maybe someone could shed some light on.

 

 First, I was flying this morning (kind of cool out, high 30's, low 40's) and when I selected gear up, got three red lights and selected neutral, the gear slowly fell back down. I tried up twice more and they came back down to lock in neutral and I got them to stay up after selecting gear down then up. The gear operated normally through six or seven cycles the rest of the day.

 A potential gear selector handle problem?

 

 Secondly, after parking it, I put some catch pans beneath each exhaust and behind the nose gear and open the intake manifold drain valve. I generally don't get anything out of the manifold drain unless it's been sitting a while. This time when I opened the drain, I got a splash of fuel leaking out. It had been flying about 40 minutes with a normal lean run-up before shut-down.

 Is this normal?

 

 Thanks in advance,

 Steve near Chicago

cjpilot710(at)aol.com
Guest

Posted: Mon Nov 09, 2015 11:36 am Post subject: CJ-6 Questions

My airplane came from China without up locks.  For 21 years now I've  flown without them.  I look at it this way - 3 less failure points.   The only time the gear will fall without the up locks, 1. You have massive air  leak in the main system. and  2. The engine air compressor fails. 

  

 Yes all Boeing's had the gear handle moved to the neutral position AFTER  SELECTING UP, WITH GEAR UP AND LOCKED, but none required that it be moved to the  "up" position before going to the "down" position. This was done because at  point in abnormal gear situations, the gear handle was required to be moved to  the neutral position and there was stop point in the handle travel.  If one  left the gear handle "up" in a normal situation nothing is going to happen to  the system (same in the CJ with or without up locks).  However there is  a real chance in a Boeing of pilot in a "normal" situation going from the  "up" position to "neutral" position, thinking he had moved to the "down"  position.  I saw it happen a number of times in the early days at  PAA.

  

 Jim "Pappy" Goolsby

  

  In a message dated 11/9/2015 7:20:18 A.M. Eastern Standard Time,  727gs(at)att.net writes:

  	  Quote: 	
		        The Yakkity-Yaks check-list that came with    the airplane says to move the gear handle to neutral after the gear is    retracted and three red indicators are illuminated.

   The same as EVERY Boeing I've ever    flown except for the Stearman.

   



   The airplane has uplocks. They worked as    advertised until yesterday. It seems to me that if you're relying on air    pressure to keep the gear up, (handle left in up), you wouldn't need    uplocks.

   



   Excuse my    ignorance.

   



   Steve near    Chicago 



   

            On Monday, November 9, 2015 5:50 AM, A.    Dennis Savarese <dsavarese0812(at)bellsouth.net>    wrote:



               Why are you    putting the gear in neutral after you select UP?  If it is to "reduce the    back pressure on the compressor", that simply is ludicrous.  The    pneumatic system already has a device to "reduce the back pressure" and that    is called the pop off valve or pressure relief valve.  When you put the    gear selector in NEUTRAL you completely depressurize the landing gear    actuators, thus requiring you to move the gear selector to the UP position    before you put the selector in the DOWN position.  That in itself is a    unnatural action.  I don't think there is a single airplane manufactured    with retractable landing gear that requires two complete movements of the gear    selector (first back to the UP position before going to the DOWN    position).  In the case of the CJ, if you do not put the gear selector    back in the UP position from NEUTRAL before you move it to the DOWN position,    the landing gear will slam down due to no back pressure on the  actuators.

   

   If your airplane    has uplocks, make sure they are properly functioning.   The uplocks    are designed to lock the gear in the UP position until the gear selector is    moved to the DOWN position.  The uplocks are unlocked by either placing    the gear selector in the DOWN position or opening the emergency air valve    after you place the gear selector in NEUTRAL.

   

   Dennis

   

   

   

   

   

                  From:    Stephen Jones <727gs(at)att.net>To: Yak-list    <yak-list(at)matronics.com> Sent: Sunday, November 8, 2015 6:47 PMSubject: Yak-List:    CJ-6 Questions

               Got our CJ flying after sitting a few years and have been flying the heck    out of it. A few issues have cropped up that maybe someone could shed some    light on.

   

   First, I was flying this morning (kind of cool out, high 30's, low 40's)    and when I selected gear up, got three red lights and selected neutral, the    gear slowly fell back down. I tried up twice more and they came back down to    lock in neutral and I got them to stay up after selecting gear down then up.    The gear operated normally through six or seven cycles the rest of the    day.

   A potential gear selector handle problem?

   

   Secondly, after parking    it, I put some catch pans beneath each exhaust and behind the nose gear    and open the intake manifold drain valve. I generally don't get anything    out of the manifold drain unless it's been sitting a while. This time when I    opened the drain, I got a splash of fuel leaking out. It had been flying about    40 minutes with a normal lean run-up before shut-down.

   Is this normal?

   

   Thanks in advance,

   Steve near    Chicago

dantpayne(at)icloud.com
Guest

Posted: Mon Nov 09, 2015 11:56 am Post subject: CJ-6 Questions

As per Dennis's prior post:

I picked up a Yak (52) out of KEVB.

The aircraft had been sitting for approx 8 months before I took off on the ferry flight to Valdosta.

Made two touch and goes, on the last "gear up...no runway remaining" I returned the gear handle to neutral. Flew 175nm and then put the gear selector to down. Gear slammed down. Forward gear handle immediately starting hissing air out. Never stopped till I returned it neutral on base...

The gear slamming down shook the airplane as well as blowing one of the nose gear seals in the actuator.

The air bypassing through the gear handle (as well as the air guage indicating a leak as it continually dwindled down) made me think it was a handle problem...

I returned the handle to neutral, and the air gauge stopped falling.

Landed. Called Dennis. He told me an actuator seal was likely. 

He was right.

The only time you should return it to neutral is when you have selected either UP or DOWN and notice the air gauge continues to fall...otherwise expect a BLOW down that will hurt the aircraft.

Again, listen to Dennis. He knows his shit.  

Keep 'em Flyin!



On Nov 9, 2015, at 2:13 PM, jblake207(at)comcast.net (jblake207(at)comcast.net) wrote:

 	  Quote: 	
		  Jeff,



  

 When I first got my CJ, I was told to move the gear handle to the neutral position to relieve backpressure.  I thought about it a little and since the system already incorporates a relief valve I decided to NOT move it to the neutral position... Have been doing that for over 10 years now with ZERO issues.  As Dennis alluded to in his message, the movement back to the UP position is un-natural and is introducing a negative (or in my opinion a WRONG) habit and will damage gear components if repeated over time.  My advice is to think of the gear handle with only 2 positions... 

  

 I'd be very interested and surprised to hear of anyone having issues due to only using two positions.

  

 JB

  

  

 



   From: "Jeff Deuchar" <rocketerf1(at)yahoo.ca (rocketerf1(at)yahoo.ca)>

To: yak-list(at)matronics.com (yak-list(at)matronics.com)

Sent: Monday, November 9, 2015 11:46:04 AM

Subject: Re: CJ-6 Questions

 



  I find this a very interesting discussion.

 A friend of mine does this on his CJ6 and was convincing me I should as well (place handle back to neutral after gear up to ensure no pressure on the system).  My placard on the dash even reads "Gear down - Place handle up then down".  This had me convinced he was probably right.  This after flying the CJ6 for 6 years where I just put the handle up when flying and down when landing.

 Personally I think it is better that way as I do know of one CJ6 where the owner landed gear up and swears he put the handle down, but he never did, he just had it in the neutral position.

 



 So my question to the whole group is:  Will it hurt the system at all to have pressure on the UP side of the gear for a whole flight?  If not I won't be doing it.

 



 Jeff



 

 

    On Monday, November 9, 2015 8:42 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net (dsavarese0812(at)bellsouth.net)> wrote:

 



     I know you didn't invent the procedure and you are correct, it is unusual to have to move the gear selector from the neutral to up position.

 

 I tried to explain the pneumatic system  a bit better in another post a few minutes ago so as to help folks understand how that procedure was possibly created and why it is flawed.  Again as you or someone else said, the reason for moving the gear selector to neutral on hydraulic system aircraft is to shut the hydraulic pump down, which makes perfect sense.  But in the hydraulic system aircraft, one does not have to move the gear selector from neutral back to UP before moving the gear selector to the down position because the actuators remain pressurized.  On our pneumatic system aircraft, once the gear selector is placed in neutral the actuators are depressurized.  The compressor, being physically attached to the engine, always runs as long as the engine is running.

 

 Hope this makes sense.

 Dennis

 

      From: Stephen Jones <727gs(at)att.net (727gs(at)att.net)>To: "yak-list(at)matronics.com (yak-list(at)matronics.com)" <yak-list(at)matronics.com (yak-list(at)matronics.com)> Sent: Monday, November 9, 2015 9:54 AMSubject: Re: CJ-6 Questions

     No, Dennis, it doesn't under normal procedures.

 

 When we bought the airplane from Fred Ehlenburg at Yakkity-Yaks in 1997, that was the procedure his check pilots taught and is the procedure in the checklist they distributed with the airplane. I can't recall why, my assumption was to relieve the pressure on the actuators and I had seen this done on Boeings, MiGs and some British airplanes. It does note to raise the handle to the up position before lowering the gear, which I thought was unusual but I didn't have any time in Chinese equipment.

 

 Rest assured that I didn't invent a procedure because I had seen it in something else I flew.

 

 Steve

 

     On Monday, November 9, 2015 7:07 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net (dsavarese0812(at)bellsouth.net)> wrote:

     Ahhh.  Now I understand where the procedure came from.

 

 Question for you Stephen.  In the Boeings you have flown, after you retract the gear and the 3 red indicators are illuminated and you move the gear selector to neutral, is the procedure in the Boeing to move the gear selector to the UP position before you move the gear selector to the DOWN position to extend the gear?

 Dennis

 

      From: Stephen Jones <727gs(at)att.net (727gs(at)att.net)>To: "yak-list(at)matronics.com (yak-list(at)matronics.com)" <yak-list(at)matronics.com (yak-list(at)matronics.com)> Sent: Monday, November 9, 2015 7:16 AMSubject: Re: CJ-6 Questions

     The Yakkity-Yaks check-list that came with the airplane says to move the gear handle to neutral after the gear is retracted and three red indicators are illuminated.

 The same as EVERY Boeing I've ever flown except for the Stearman.

 

 The airplane has uplocks. They worked as advertised until yesterday. It seems to me that if you're relying on air pressure to keep the gear up, (handle left in up), you wouldn't need uplocks.

 

 Excuse my ignorance.

 

 Steve near Chicago 

 

     On Monday, November 9, 2015 5:50 AM, A. Dennis Savarese <dsavarese0812(at)bellsouth.net (dsavarese0812(at)bellsouth.net)> wrote:

     Why are you putting the gear in neutral after you select UP?  If it is to "reduce the back pressure on the compressor", that simply is ludicrous.  The pneumatic system already has a device to "reduce the back pressure" and that is called the pop off valve or pressure relief valve.  When you put the gear selector in NEUTRAL you completely depressurize the landing gear actuators, thus requiring you to move the gear selector to the UP position before you put the selector in the DOWN position.  That in itself is a unnatural action.  I don't think there is a single airplane manufactured with retractable landing gear that requires two complete movements of the gear selector (first back to the UP position before going to the DOWN position).  In the case of the CJ, if you do not put the gear selector back in the UP position from NEUTRAL before you move it to the DOWN position, the landing gear will slam down due to no back pressure on the actuators.

 

 If your airplane has uplocks, make sure they are properly functioning.   The uplocks are designed to lock the gear in the UP position until the gear selector is moved to the DOWN position.  The uplocks are unlocked by either placing the gear selector in the DOWN position or opening the emergency air valve after you place the gear selector in NEUTRAL.

 

 Dennis

 

 

 

 

 

      From: Stephen Jones <727gs(at)att.net (727gs(at)att.net)>To: Yak-list <yak-list(at)matronics.com (yak-list(at)matronics.com)> Sent: Sunday, November 8, 2015 6:47 PMSubject: CJ-6 Questions

     Got our CJ flying after sitting a few years and have been flying the heck out of it. A few issues have cropped up that maybe someone could shed some light on.

 

 First, I was flying this morning (kind of cool out, high 30's, low 40's) and when I selected gear up, got three red lights and selected neutral, the gear slowly fell back down. I tried up twice more and they came back down to lock in neutral and I got them to stay up after selecting gear down then up. The gear operated normally through six or seven cycles the rest of the day.

 A potential gear selector handle problem?

 

 Secondly, after parking it, I put some catch pans beneath each exhaust and behind the nose gear and open the intake manifold drain valve. I generally don't get anything out of the manifold drain unless it's been sitting a while. This time when I opened the drain, I got a splash of fuel leaking out. It had been flying about 40 minutes with a normal lean run-up before shut-down.

 Is this normal?

 

 Thanks in advance,

 Steve near Chicago

barryhancock

Joined: 09 Oct 2008
Posts: 285

Posted: Wed Nov 25, 2015 8:25 pm Post subject: Re: CJ-6 Questions

I believe (but it's been awhile since I checked) that the Chinese manual comes with the direction to put the handle in neutral.  It does make sense as this is the procedure in the MiGs for the aforementioned reasons.  That being said...



There is simply no good reason to put the handle in neutral.  If anything it increases the number of cycles on the system.  But in the dozens of CJ's I've flown and over 1000 hours in type I have yet to see a reason that putting the lever in neutral is of benefit to the operation of the aircraft.  



Hope this helps...



Cheers,



Barry

_________________
Barry Hancock
Worldwide Warbirds, Inc.
www.worldwidewarbirds.com

Egon

Joined: 01 Jul 2012
Posts: 23
Location: Australia

Posted: Thu Nov 26, 2015 12:49 pm Post subject: Re: CJ-6 Questions

Another good reason to leave the gear selector handle in the up position is that if your up locks are not correctly adjusted, your gear leg could just fall down if the unlock releases. ( Iv'e seen it happen ) I would hate to think what would happen if a gear leg deployed at 180 knots pulling 5 G. At least with the gear selected up, the air system will keep your gear retracted.

Cheers Egon.

cjowner15
Guest

Posted: Fri Nov 27, 2015 6:23 pm Post subject: Re: CJ-6 Questions

for the record, newer boeings don't have a neutral gear handle position....

JL2A

Joined: 07 Apr 2015
Posts: 113
Location: Australia

Posted: Sun Dec 13, 2015 3:51 am Post subject: Re: CJ-6 Questions

I must confess I have been a gear to neutral CJ driver for over 3000 cycles.. because way back that is how I was shown.



In that time I have never, not once, selected down from the neutral position so don't entirely buy that as the primary argument for leaving handle in up position... However I am open to anything that is simpler and more fool proof especially when showing others how to fly the CJ so think I might change my ways.



One point is bugging me though, why did they put up locks in them?! 



Was it just to get pilots familiar with Mig (hydraulic) operating procedures? Would seem strange as someone already mentioned, in the MIG you don't have to re pressurise the up lines. Therefor it doesn't even achieve that design goal...

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