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Instrument panel

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GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Fri Feb 19, 2010 7:27 pm Post subject: Instrument panel

I'm going to try attaching a pic of an instrument panel I did in a Cheetah.  If it doesn't come through, let me know and I'll send you a pic.

Corls_panel.jpg

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Gary
AuCountry Aviation
Home of Team Grumman

rdp123(at)verizon.net
Guest

Posted: Fri Feb 19, 2010 8:21 pm Post subject: Instrument panel

Came through just fine.  I need one Gary!

On Feb 19, 2010, at 7:26 PM, TeamGrumman(at)aol.com (TeamGrumman(at)aol.com) wrote:

[quote]I'm going to try attaching a pic of an instrument panel I did in a Cheetah.  If it doesn't come through, let me know and I'll send you a pic.

 

  

  <Corls_panel.jpg>[b]

md11strejo(at)YAHOO.COM
Guest

Posted: Fri Feb 19, 2010 8:33 pm Post subject: Instrument panel

Needs an Aspen EFD1000 Pro



Scott Trejo



On Feb 19, 2010, at 9:26 PM, teamgrumman(at)AOL.COM (teamgrumman(at)AOL.COM) wrote:

[quote]I'm going to try attaching a pic of an instrument panel I did in a Cheetah.  If it doesn't come through, let me know and I'll send you a pic.

 

  

  <Corls_panel.jpg>[b]

Discover

Joined: 26 Feb 2007
Posts: 429

Posted: Fri Feb 19, 2010 8:45 pm Post subject: Instrument panel

Gary V does awesome panels!

  

 Wow that's a great looking one  Gary.

   [quote][b]

v1rotate(at)verizon.net
Guest

Posted: Fri Feb 19, 2010 9:39 pm Post subject: Instrument panel

Hey, this looks great.  Kind of reminds me of  my panel.  The only thing I would have done differently is swap the  positions of the nav head and JPI for a better scan when shooting an approach in  the clouds.  I like the style of the yokes too.  The pebbled look sort  of hints of spots on a real Cheetah's coat.  I see the Mitchell  gauges.  That reminds me, don't know if I ever mentioned it or not, but  since you changed the connector style on my fuel pressure tranducer I've never  had a questionable needle fluctuation again.  I will save this pic to my  Grumman favorites.

  

 Bill

 [quote]   ---

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Fri Feb 19, 2010 10:11 pm Post subject: Instrument panel

I'm sure as soon as Corl gets enough money he'll put another indicator in his plane.  Corl wanted his indicators there.  He's an airline pilot also.  Did you notice the circuit breakers?  There are additional locations, pre-drilled for more if needed.  His panel also has idiot lights for low voltage and low vacuum.   

 

  I'm glad to hear the fuel pressure problem was that spade connector.  Easy fix.

 

  

 

 

  --

_________________
Gary
AuCountry Aviation
Home of Team Grumman

haveblue1(at)mac.com
Guest

Posted: Sat Feb 20, 2010 4:08 am Post subject: Instrument panel

Gary,



Freakin' awesome!

Bruce Smith



On Feb 19, 2010, at 10:26 PM, teamgrumman(at)aol.com (teamgrumman(at)aol.com) wrote:

 	  Quote: 	
		  I'm going to try attaching a pic of an instrument panel I did in a Cheetah.  If it doesn't come through, let me know and I'll send you a pic.

 

  

  <Corls_panel.jpg>

flyv35b(at)minetfiber.com
Guest

Posted: Sat Feb 20, 2010 6:19 am Post subject: Instrument panel

Nice looking panel!  The only thing I would add  would be a manifold pressure gauge to the right of the tach, and swap the JPI  and nav head as Bill suggested.

  

 I assume the yokes are powdercoated?  What do you  call that textured finish?

  

 Cliff

 [quote]   ---

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Sat Feb 20, 2010 9:54 am Post subject: Instrument panel

The yokes are powder coated in hammer tone.  The instrument panel is too.  Just a different color.  

 

  

 

 

  --

_________________
Gary
AuCountry Aviation
Home of Team Grumman

cwleach

Joined: 11 May 2009
Posts: 11

Posted: Sat Feb 20, 2010 6:26 pm Post subject: Re: Instrument panel

 	  flyv35b(at)minetfiber.com wrote: 	
		  Nice looking panel!  The only thing I would add  would be a manifold pressure gauge to the right of the tach, and swap the JPI  and nav head as Bill suggested. 	


I put the Nav head next to the ... NAV RADIO! What a concept, huh! 



"In the clouds" I have GPS 1 showing the CDI and numerical ground track and desired track information while GPS 2 shows the moving map display. In this way I can simply match the #1 displayed Actual Track with Desired Track numbers, check the deviation from Course on the adjacent CDI, then adjust heading 1 or 2 degrees to change the actual track to correct any error. I've found the "digital approach procedure" to be far more accurate than chasing needles anyway. YMMV.



I only purchased 1 Nav head because eventually an HSI (Aspen?) will replace the DG leaving the CDI for Nav 2. Why buy two when you'll be replacing one soon-ish? My airplane seems to be getting heavy despite leaving stuff out!



... just curious what true benefit a manifold pressure gauge would serve other than to give Gary a little more $$ for installation costs?

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Sat Feb 20, 2010 8:47 pm Post subject: Instrument panel

Corl, I have a CHT in my plane.  It also shows on my JPI 800.  Other than comparing book values, I rarely use it.   

 

  

 

  

 

 

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_________________
Gary
AuCountry Aviation
Home of Team Grumman

flyv35b(at)minetfiber.com
Guest

Posted: Sun Feb 21, 2010 6:49 am Post subject: Instrument panel

I think that Bill suggested putting the nav CDI next to the flight 

instruments is probably because when using it for an ILS approach you want 

to keep your scan confined to as small and area as possible.  You are 

constantly looking at the CDI and comparing that with the DG and AI and VSI, 

so closer is better.



As far as the MP gauge is concerned it is hard to explain the value of it 

unless you have flown a plane with a CS prop for awhile, which most Grumman 

owners have not.  It is a more precise way to set power and it reacts 

instantly and is beneficial even with a fixed pitch prop.  Granted, it is 

not mandatory, just useful.  For instance, what is your power setting and 

how much did it change when you drop the nose significantly and start a 

decent from altitude when you were near redline at cruise?  A manifold 

pressure gauge will tell you that whereas your tachometer will stay right at 

2700 rpm for a maximum speed descent.  It's pretty much accepted practice 

that you want to maintain at least 15" MP at least so as to no unduly cool 

the cylinders and not backdrive the engine.  Also during climb if you choose 

to make a power reduction, how far back to you pull the throttle as the rpm 

doesn't react immediately or change much.  Manifold pressure tells you 

exactly how far to pull the throttle back - 2" hg, 3" or whatever.



And finally, if you have a modified plane such as a 2 place with a bigger 

engine then the POH is of little help in determining what the power setting 

is.  With a MP gauge you can go to Lycoming's curves for a specific engine 

and determine that, but you must know MP.  Make up a little chart of MP vs. 

RPM vs. fuel flow and % power.  I have a Lynx with an O-320 engine and a MP 

gauge and I use it all the time to adjust power.  The tachometer just 

follows along and ends up wherever and is mainly used to prevent excessive 

RPM.



Cliff

---

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Sun Feb 21, 2010 11:49 am Post subject: Instrument panel

A couple of things.   	  Quote: 	
		  I think that Bill suggested putting the nav CDI next to the flight instruments is probably because when using it for an ILS approach you (he, SIC) want to keep your (his) scan confined to as small and area as possible. You (he) are (is) constantly looking at the CDI and comparing that with the DG and AI and VSI, so closer is better. 	
 CDI Location:  The factory put the VOR indicators next to the avionics stack.  I wonder if they new about scan techniques. But, then, I asked that same question when I bought my first plane 26 years ago.  The first thing I did was to exchange the ADF/tach and VOR indicators.  I liked it closer to my center-of-interest.  Personally, I'd like to have a GMX 200 in the middle of my scan.  The Horizon gyro and the DG (or HSI) side-by-side above it.

  

 

  	  Quote: 	
		  It's pretty much accepted practice that you want to maintain at least 15" MP at least so as to no unduly cool the cylinders and not backdrive the engine. 	
 15" MAP:  This is interesting.  I've been flying for 30 years. I've never heard that the manifold pressure should be above 15 inches for a fixed pitch prop.  

  

 

  To unduly cool:  This assumes that there is such a thing as shock cooling.  I don't buy the myth of shock cooling.  Shock heating maybe, but not shock cooling.  There is just too much empirical evidence against the myth.  

  

 

  	  Quote: 	
		  As far as the MP gauge is concerned it is hard to explain the value of it unless you have flown a plane with a CS prop for awhile, which most Grumman owners have not. It is a more precise way to set power and it reacts instantly and is beneficial even with a fixed pitch prop. 	
 More precise way to set power (using MAP):  I don't buy this either.  This may be true in a plane with a constant speed prop, but not for a fixed pitch.  If you use MAP to set power, it's only because the EI tach has 10 rpm resolution.  Then, of course a small change in MAP will show up faster than rpm.  A digital Horizon tach is a lot more useful than just being there to tell me if I go over redline.  I can fine tune less than 5 rpm without a vernier.  All of my power charts, in the Grumman handbook, are based on altitude and rpm.  There is no mention of manifold pressure.  

  

 

  Interesting side note:  During the Climb-Cooling and carb-heat-rise flight tests for the Jaguar cowling, the FAA kept asking what the manifold pressure was for a given flight test.  It took six months for them to read, absorb and accept the fact that the POH only had altitude and rpm.  When I extrapolated between altitudes and rpms I had to explain to them just what the process was that allowed me to find a point not in the chart.  Seriously, they did not understand extrapolation.  

  

 

    	  Quote: 	
		  For instance, what is your power setting and how much did it change when you drop the nose significantly and start a decent from altitude when you were near redline at cruise? A manifold pressure gauge will tell you that whereas your tachometer will stay right at 2700 rpm for a maximum speed descent. 	


 Power setting:  Question: why do I care what power setting I use during a descent?  If I were at 80% in cruise do I care if I'm at 78% (or even 60%) during a descent?  Some pilots might.  I don't.  Again, with a constant speed prop, I might.  I don't know.  

  

 

  I have a JPI 800 in my Tiger.  It displays percent power all the time without the need to look up anything.  Do I use the percent power feature?  Not really.  I do look at it and think about it while leaning above 75% power.  I watch CHTs the most.  And, that means, keeping the CHTs under 470 degrees.  I know there are those of you who will think that is insane.  The EI I used for a year told me that 470 on my JPI was about 390 to 400 on the EI.  We'll see when I pull the cylinders.

  

 

  The only real use of percent power, aside from leaning, is for computing fuel burn.  In the old days, it was really important to know fuel burn because fuel gauges were so inaccurate (imagine inaccurate fuel gauges being accepted procedure in automobiles).  With fuel flow displaying current fuel burn, fuel used, and fuel remaining, there is seldom doubt what is in the tanks.  

  

 

  The dozen or so times I flew N254 (after I installed the first MT constant speed prop on a Grumman in the United States; sorry, had to throw that in) I still flew it at redline during a descent.  I still climbed at WOT and as near to 2700 rpm as I could.  Perhaps over a long time of flying it, I might rely on MAP.  

 

 

   	  Quote: 	
		  And finally, if you have a modified plane such as a 2 place with a bigger engine then the POH is of little help in determining what the power setting is. With a MP gauge you can go to Lycoming's curves for a specific engine and determine that, but you must know MP. Make up a little chart of MP vs. RPM vs. fuel flow and % power. I have a Lynx with an O-320 engine and a MP gauge and I use it all the time to adjust power. The tachometer just follows along and ends up wherever and is mainly used to prevent excessive RPM. 	
  No POH for an O320 in an AA1x:  OK Bill, tell us, what do you do for percent power in your O320 powered 2-seater?  If you had a JPI 800, it would display percent power for you.  In fact, if you let my put in a JPI 830, you will have, at all times, in one unit:

  RPM, Manifold Pressure, EGT/CHT, Oil Temp, Oil Pressure, OAT, Volts, Carb Temp, % power, EGT delta, Fuel Flow, Gallons used, Gallons remaining, AND miles per gallon.  And it takes up a lot less space than you are currently occupying.  

 

 

  

 

   	  Quote: 	
		  The tachometer just follows along and ends up wherever and is mainly used to prevent excessive RPM. 	
 

 

  Question:  What is excessive rpm?  What is excessive CHT?  

  

 

  At my current rate of flying my plane, I will have 1000 hrs on my LyCon massaged cylinders in about 3 years.  At that time, 7 years since installation, the engine will have about 2100 hours and 35 years on it.  It's never been off the plane.  I plan on having LyCon do a complete tear down and thorough inspection at that time.  Why?  Because most of that 1000 hours will be at CHTs in the neighborhood of 420 to 430 degrees (on a JPI) and at rpms in the neighborhood of 2800.  My engine/prop combination has a sweet spot at about 2825 rpm.  

  

 

  Questions?  Comments?  Let's hear them . . . . . 

  

 

   

   

      

 

 

   [quote][b]

_________________
Gary
AuCountry Aviation
Home of Team Grumman

v1rotate(at)verizon.net
Guest

Posted: Mon Feb 22, 2010 10:49 pm Post subject: Instrument panel

Good question. Because there is no official  POH performace reference for an O320 AA1X, I created my own  charts. Our plane has a 62 inch pitch prop.  I don't remember what the  stock Cheetah prop pitch is, but the closest I could get (and I  figured it would be close enough) was to scab the % power data out of my old  Cheetah manual which I converted to an easy to read card I carry in the  cockpit.  That's what I use, plus the old standard of full rich to 5000' DA  (conveniently displayed on my EI Super Clock), and thereafter lean for all full  throttle operations.  Under 5000' DA I refer to the scabbed Cheetah data  for leaning below 75% RPM settings. I think it works.

  

 As for the rest of the data, like takeoff  distances, cruise speeds and fuel flows, and rates of climb, being an obsessive  former flight test engineer I undertood a mini program using a combination of  many flights and accepted formulas to create what has been a reliable reference  card which presents all this information.  Takeoff distance for weights  from 1450# to 1684# and DA's from sea level to 8000' are in a table.   Cruise speeds and fuel flows are listed for DA's from 4000' to 15000' and rates  of climb for the entire weight range are listed from DA's of sea level to  15000'. I have added a safety buffer to the calculations where it seemed prudent  and have had not had any surprises.  Last year my wife and I departed  the Grand Canyon airport early in the morning.  For the reported conditions  we lifted off and climbed out very close to the performance predicted on  the card.  It was the first time we had the airplane in a truly high DA  situation at max weight and, at least on that day, it did a good  job..

  

 Bill K.

 [quote]   No POH for an    O320 in an AA1x:  OK Bill, tell us, what do you do for percent    power in your O320 powered 2-seater?  If you had a JPI 800, it    would display percent power for you.  In fact, if you let my put in a JPI    830, you will have, at all times, in one unit:

            RPM, Manifold Pressure, EGT/CHT, Oil Temp, Oil Pressure, OAT, Volts, Carb    Temp, % power, EGT delta, Fuel Flow, Gallons used, Gallons remaining, AND    miles per gallon.  And it takes up a lot less space than you are    currently    occupying.  



[b]

flyv35b(at)minetfiber.com
Guest

Posted: Tue Feb 23, 2010 6:31 am Post subject: Instrument panel

Bill,

  

 Can I get a copy of your performance chart  (card)?

  

 I've also taken off from the Grand Canyon at over  1600 lb weight and climbed out very well.  I took off once on a grass strip  at 5000 ft msl (Johnson Creek, ID) at around 40F and 1684+ lb weight and had no  problem.  Got off the ground in about 2000 ft. as I recall.  My prop  pitch is 63".

  

 Cliff

 [quote]   ---

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Tue Feb 23, 2010 12:09 pm Post subject: Instrument panel

Cliff and Bill, What are your True Air Speeds at, say, 4500 feet and 2700 rpm?  I'm curious if the 1 inch makes much difference.

 

  

 

 

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_________________
Gary
AuCountry Aviation
Home of Team Grumman

flyv35b(at)minetfiber.com
Guest

Posted: Tue Feb 23, 2010 2:00 pm Post subject: Instrument panel

I don't know without doing some more flying.  I  suspect it would be close to 140 kts.  The weather is to crapy to check it  out today!

  

 Cliff

 [quote]   ---

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