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Steve Glasgow

Joined: 10 Jan 2006
Posts: 674

Posted: Wed Sep 17, 2008 6:21 am Post subject: Closure Rates

Before I begin let me ask two questions.  How many times have you been given 

traffic at three miles and you never saw the traffic?  How much traffic do 

we miss seeing because we are VFR and/or ATC has not pointed out the 

traffic?



To keep the numbers simple lets use an RV traveling at 180 mph and a Jet 

traveling at 540 mph.



With two RV’s closing head on, we have 180 + 180 = 360 mph or 6 

miles/minute.   This means if there was another RV three miles ahead, both 

aircraft would have 30 seconds to see and avoid the each other.



With an RV and a Jet closing head on, we have 180 + 540 = 720 mph or 12 

miles/minute.  This means if there was traffic three miles ahead, both 

aircraft would have only 15 seconds to see and avoid the each other.



With a Jet directly behind an RV, we have 540 -180 = 360 mph or 6 

miles/minute.   This means the Jet would only have 30 seconds to see and 

avoid running the RV.  Assuming he/she is looking, now only one pilot has 

just 30 seconds to see and avoid!



Except for takeoff and landings where they are restricted to 250 knots, Jets 

and other faster planes generally fly above 10,000’.  Additionally, many 

Jets and other faster planes regularly fly between 10,000’ and 17,500’ 

without positive control or VFR.



Therefore, unless there are rocks to avoid, my personal preference is to 

stay below 10,000’.



I’m not telling anyone how to fly their airplane or suggesting flying above 

10,000’ is unsafe.  I’m just pointing out some facts that might be food for 

thought.



Steve Glasgow - Cappy

willfly(at)carolina.rr.com

_________________
Steve Glasgow-Cappy
Cappy's Toy
RV-8 N123SG

rv8a2001(at)yahoo.com
Guest

Posted: Wed Sep 17, 2008 7:08 am Post subject: Closure Rates

I like to fly 10k to 12.5k to keep away from all the other traffic that flies below 10k. I understand your point, but at 12.5k I would guess you have at least 50% less traffic than you do at 8k. So which is better.......faster traffic up high but less of them, or slower traffic down low and more of them?



 Scott 



---

rgf(at)dcn.davis.ca.us
Guest

Posted: Wed Sep 17, 2008 7:22 am Post subject: Closure Rates

"Except for takeoff and landings where they are restricted to 250 knots,

Jets and other faster planes generally fly above 10,000'.  Additionally,

many Jets and other faster planes regularly fly between 10,000' and 17,500' 

without positive control or VFR."



So pick up flight following above 10K. Even if other aircraft aren't talking

to Center, at that altitude they will have their Mode-C on and Center can

give you avoidance alerts.

skydive80020(at)yahoo.com
Guest

Posted: Wed Sep 17, 2008 7:41 am Post subject: Closure Rates

Steve, let me repond as an RV6A pilot and an En Route controller with over 20 years experience. The numbers you quote are close on closing times. Most controllers try to call traffic soon enough to give either pilot time to respond, additionally you should know that we spend a great deal of time comparing ground tracks, climb or descent rates, etc to determine if close proximity is imminent. It is not our discretion to decide if we wish to call traffic to you, but it may be based upon controller workload. If the controller feels two aircraft may be too close and either not see each other, they will recommend a course of action to alleviate the problem, it will not be surprise to you. I am completely comfortable flying VFR in class B, C or D airspace while receiving flight following that ATC will keep me appraised of potential traffic problems. 

  

 M. Phipps



--- On Wed, 9/17/08, Steve Glasgow <willfly(at)carolina.rr.com> wrote:



  	  Quote: 	
		  From: Steve Glasgow <willfly(at)carolina.rr.com>

Subject: Closure Rates

To: "RV-List" <rv-list(at)matronics.com>

Date: Wednesday, September 17, 2008, 8:20 AM



 	  Quote: 	
		  --> RV-List message posted by: "Steve Glasgow"

<willfly(at)carolina.rr.com>



Before I begin let me ask two questions.  How many times have you been given 

traffic at three miles and you never saw the traffic?  How much traffic do 

we miss seeing because we are VFR and/or ATC has not pointed out the 

traffic?



To keep the numbers simple lets use an RV traveling at 180 mph and a Jet 

traveling at 540 mph.



With two RV¢s closing head on, we have 180 + 180 = 360 mph or 6 

miles/minute.   This means if there was another RV three miles ahead, both 

aircraft would have 30 seconds to see and avoid the each other.



With an RV and a Jet closing head on, we have 180 + 540 = 720 mph or 12 

miles/minute.  This means if there was traffic three miles ahead, both 

aircraft would have only 15 seconds to see and avoid the each other.



With a Jet directly behind an RV, we have 540 -180 = 360 mph or 6 

miles/minute.   This means the Jet would only have 30 seconds to see and 

avoid running the RV.  Assuming he/she is looking, now only one pilot has 

just 30 seconds to see and avoid!



Except for takeoff and landings where they are restricted to 250 knots, Jets 

and other faster planes generally fly above 10,000¢.  Additionally, many 

Jets and other faster planes regularly fly between 10,000¢ and 17,500¢ 

without positive control or VFR.



Therefore, unless there are rocks to avoid, my personal preference is to 

stay below 10,000¢.



I¢m not telling anyone how to fly their airplane or suggesting flying above 

10,000¢ is unsafe.  I¢m just pointing out some facts that might be food for



thought.



Steve Glasgow - Cappy

willfly(at)carolina.rr.com



	
	


           [quote][b]

ronlee(at)pcisys.net
Guest

Posted: Wed Sep 17, 2008 7:46 am Post subject: Closure Rates

 	  Quote: 	
		   Except for takeoff and landings where they are restricted to 250 knots, 

 Jets and other faster planes generally fly above 10,000’.  Additionally, 

 many Jets and other faster planes regularly fly between 10,000’ and 17,500’ 

 without positive control or VFR.



 I’m not telling anyone how to fly their airplane or suggesting flying 

 above 10,000’ is unsafe.  I’m just pointing out some facts that might be 

 food for thought.



 Steve Glasgow - Cappy


	


My home airport is at 6840 feet so I rarely fly below 10,000'  Over the

mountains 12,500' minimum and often 14,500' to 17,500'.  Even when I

flew in Florida I was above 10,000'.



I use fly following and other than a FedEx plane leaving Memphis and

another airline flying into Orlando I have never seen a jet.  The only other

called out jet was a F-117 (?) near White Sands.  I did not see it.  OK,

I just remember that flying over Denver Class B I see airliners.  My point

relates to areas away from airports.



I stay above 10,000' to avoid other GA aircraft.  I don't expect many other

aircraft of any sort in the areas I fly (between 10,000' and 17,500') and my

experience where I fly supports that.  My limited time back east also 

supports

that view but with less experience.



Ron Lee

n212pj(at)gmail.com
Guest

Posted: Wed Sep 17, 2008 8:18 am Post subject: Closure Rates

I love flight following.  Even if it's a no-joy, at least I know they

spotted something and will stay on top of it.  Once going from Boston to

White Plains they cut me loose during a heavy traffic situation, and man, I

tell you, that got my attention.  Right smack dab in the middle of the

busiest airspace in the country, being let go from radar services, going

into a busy airport on a hazy summer day, VFR, after seeing all sorts of

traffic at all sorts of altitudes, hearing all kinds of chatter over the

frequencies, it gets the old ticker pumping.  And, it makes you realize just

how valuable flight following is for the VFR only pilot.  



Out here in the west, I fly anywhere from 1,500 to 12,500 going over the

mountains, and anytime I'm above 3,000 and going any distance, I usually get

hooked up with them.  Highly recommend it.  



John J 



--

rickpegser(at)yahoo.com
Guest

Posted: Wed Sep 17, 2008 10:33 am Post subject: Closure Rates

steve 



   if you keep asking these question and we will all be required to have tcas. occasiobally i have to fly to the SF bay area, and have never liked it. but the big boys are not the ones that i worry about. we have a large collection of migs and l-39s here. those are the guys that are tough to see. While it does seem to happen the odds that you put your aircraft in the same fifty foot box as somebody else enroute, is very slim. the odds of this happening though, see pic is much higher



rick

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pitts_pilot(at)bellsouth.
Guest

Posted: Thu Sep 18, 2008 5:27 am Post subject: Closure Rates

I don't fly that high ...... yet ......... so my question is ...... is 

the  problem due to 'vfr' traffic not holding to the odd/even +500 

enroute or is the system mucked up by climbing/descending aircraft ..... 

of all types????



Other than filing a VFR flight plan, what else can we do???

Linn



Steve Glasgow wrote:

 	  Quote: 	
		   



 Scott, your question "which is best" implies a known quantity of which 

 you have determined by a guess.  One thing that is not a guess is 

 every one of the planes that go above 10,000' will come back down at 

 some time.



 As pointed out by the controller, positive control of both aircraft on 

 a collision course is very helpful. Flight Following may or may not 

 help. Those that use Flight Following are well aware that you are on 

 the bottom of the totem pole, and many times are told Flight Following 

 is canceled swank 1200.  Also there are many areas where it is not 

 available.



 Over my many years or airline flying, I can't tell you how may times I 

 have been vectored away from slower aircraft above 10,000' who were 

 not in positive control.   The guy we were vectored around never even 

 knew he had created a problem because he was VFR, not looking or did 

 not see us.



 Just because we can't see them doesn't mean they are not there.  The 

 skies are very crowded and there are more and more light jets in the 

 air every day.



 But as my original posts stated, "Additionally, many Jets and other 

 faster planes regularly fly between 10,000 and 17,500 without positive 

 control or VFR".  Note: I said, "without positive control or VFR".  

 These are the ones I am primarily concerned about.



 Again as stated in my previous post, "I'm not telling anyone how to 

 fly their airplane or suggesting flying above

 10,000 is unsafe.  I'm just pointing out some facts that might be food 

 for thought."



 Steve Glasgow-Cappy

 willfly(at)carolina.rr.com

 704-362-0005 Home

khorton01(at)rogers.com
Guest

Posted: Thu Sep 18, 2008 6:41 am Post subject: Closure Rates

Well, an IFR aircraft on autopilot could easily be 150 ft high or low 

from the nominal altitude, once you consider normally seen static system 

position errors, altimeter errors, autopilot altitude hold tolerances, 

and differences in altimeter settings from region to region.  If the 

aircraft is not on autopilot, you can add another 100 ft to that, for 

plus or minus 250 ft.



If we have an amateur-built aircraft, the vast majority have completely 

unknown static system position errors, as most builders don't take the 

time to learn how to determine them.  I've seen reports from several RV 

builders who report static system position errors of more than 100 ft.  

For VFR traffic not using flight following, they may very well be using 

a different altimeter setting than the IFR traffic.



Even if the IFR and VFR traffic are making reasonable efforts to fly the 

correct altitudes, they could easily be less than 200 ft apart in 

altitude, maybe even closer.



Thing you can do:



1. Use flight following.  This ensures you are using the same altimeter 

setting as the IFR traffic.  It also helps cue to where to look for some 

traffic.



2. Determine the static system position error of your aircraft.  If it 

is large, either make some mods to reduce it, or at least deliberately 

fly an indicated altitude so as to be at the correct real altitude.  For 

example, if you determine that your altimeter will be reading 100 ft too 

low due to static system position error, you could deliberately fly 8400 

ft indicated, instead of 8500 ft, to account for this static system 

position error.  Of course there is no way to correct the altitudes 

reported by the transponder for static system position error, so the 

best approach is to make mods to the static system to reduce the error.



How to determine static system position error:



http://www.kilohotel.com/rv8/rvlinks/ssec.html



Kevin Horton



linn Walters wrote:

 	  Quote: 	
		   



 I don't fly that high ...... yet ......... so my question is ...... is 

 the  problem due to 'vfr' traffic not holding to the odd/even +500 

 enroute or is the system mucked up by climbing/descending aircraft 

 ..... of all types????



 Other than filing a VFR flight plan, what else can we do???

 Linn



 Steve Glasgow wrote:

> 

>

> Scott, your question "which is best" implies a known quantity of 

> which you have determined by a guess.  One thing that is not a guess 

> is every one of the planes that go above 10,000' will come back down 

> at some time.

>

> As pointed out by the controller, positive control of both aircraft 

> on a collision course is very helpful. Flight Following may or may 

> not help. Those that use Flight Following are well aware that you are 

> on the bottom of the totem pole, and many times are told Flight 

> Following is canceled swank 1200.  Also there are many areas where it 

> is not available.

>

> Over my many years or airline flying, I can't tell you how may times 

> I have been vectored away from slower aircraft above 10,000' who were 

> not in positive control.   The guy we were vectored around never even 

> knew he had created a problem because he was VFR, not looking or did 

> not see us.

>

> Just because we can't see them doesn't mean they are not there.  The 

> skies are very crowded and there are more and more light jets in the 

> air every day.

>

> But as my original posts stated, "Additionally, many Jets and other 

> faster planes regularly fly between 10,000 and 17,500 without 

> positive control or VFR".  Note: I said, "without positive control or 

> VFR".  These are the ones I am primarily concerned about.

>

> Again as stated in my previous post, "I'm not telling anyone how to 

> fly their airplane or suggesting flying above

> 10,000 is unsafe.  I'm just pointing out some facts that might be 

> food for thought."

>

> Steve Glasgow-Cappy

> willfly(at)carolina.rr.com

> 704-362-0005 Home

>

>




	




-- 

Kevin Horton

RV-8 (Flight Test Phase)

Ottawa, Canada

http://www.kilohotel.com/rv8

mr.sun

Joined: 30 Jan 2007
Posts: 85

Posted: Thu Sep 18, 2008 7:19 pm Post subject: Closure Rates

Just out of curiosity...  Is it a real problem?  I mean are there near misses out there?  Has a C-17 wiped out any RV's?  Anybody hear of any bent metal lately?  I don't want to downplay the issue but just gauge my worry factor.   I fly my -7 up and down the left coast and have never seen another aircraft at all when I'm at 12,500 (or 11,500 depending on whether I'm going N or S).  I guess I need to look harder and or thank my stars.  

 

do not archive



On Thu, Sep 11, 2008 at 6:25 AM, linn Walters <pitts_pilot(at)bellsouth.net (pitts_pilot(at)bellsouth.net)> wrote:

[quote] --> RV-List message posted by: linn Walters <pitts_pilot(at)bellsouth.net (pitts_pilot(at)bellsouth.net)>

 

 I don't fly that high ...... yet ......... so my question is ...... is the  problem due to 'vfr' traffic not holding to the odd/even +500 enroute or is the system mucked up by climbing/descending aircraft ..... of all types????

  

 Other than filing a VFR flight plan, what else can we do???

 Linn

 

 

 

 Steve Glasgow wrote:

  	  Quote: 	
		   --> RV-List message posted by: "Steve Glasgow" <willfly(at)carolina.rr.com (willfly(at)carolina.rr.com)>

 

 Scott, your question "which is best" implies a known quantity of which you have determined by a guess.  One thing that is not a guess is every one of the planes that go above 10,000' will come back down at some time.

  

 As pointed out by the controller, positive control of both aircraft on a collision course is very helpful. Flight Following may or may not help. Those that use Flight Following are well aware that you are on the bottom of the totem pole, and many times are told Flight Following is canceled swank 1200.  Also there are many areas where it is not available.

  

 Over my many years or airline flying, I can't tell you how may times I have been vectored away from slower aircraft above 10,000' who were not in positive control.   The guy we were vectored around never even knew he had created a problem because he was VFR, not looking or did not see us.

  

 Just because we can't see them doesn't mean they are not there.  The skies are very crowded and there are more and more light jets in the air every day.

 

 But as my original posts stated, "Additionally, many Jets and other faster planes regularly fly between 10,000 and 17,500 without positive control or VFR".  Note: I said, "without positive control or VFR".  These are the ones I am primarily concerned about.

  

 Again as stated in my previous post, "I'm not telling anyone how to fly their airplane or suggesting flying above

 10,000 is unsafe.  I'm just pointing out some facts that might be food for thought."

 

 Steve Glasgow-Cappy

 willfly(at)carolina.rr.com (willfly(at)carolina.rr.com)

 704-362-0005 Home

 

 

 

 

 

 

 

 

 

 

 

 

 	
 

 

 

 

 

 [b]

_________________
Greg RV-7

wdleonard(at)gmail.com
Guest

Posted: Thu Sep 18, 2008 7:41 pm Post subject: Closure Rates

Mr. Gsun,



I am with you on this one.  The skys are WAY less crowded above 10'k and all the big iron have TCAS to keep themselves away from us bug smashers.  Only the rare minority of aircraft spend any time between 12k and 30k.   That IS the safest place to avoid collision bar none!  There are probably a few collisions I dont know about, but collisions between aircraft above 10k are so rare you could count them on one hand.  I only know of 2.  Two airliners over Europe where the controller was messed up, and a lear hitting a sail plane (without a transponder) on approach to Reno.  Compare that to the Hundreds of collisions below 10k.  IMHO - that is by far the safest place to avoid a collision...  Above 10k! 

-- 

David Leonard



Turbo Rotary RV-6 N4VY

http://N4VY.RotaryRoster.net

http://RotaryRoster.ne



 On Thu, Sep 18, 2008 at 8:18 PM,  <mr.gsun(at)gmail.com (mr.gsun(at)gmail.com)> wrote:

 	  Quote: 	
		   Just out of curiosity...  Is it a real problem?  I mean are there near misses out there?  Has a C-17 wiped out any RV's?  Anybody hear of any bent metal lately?  I don't want to downplay the issue but just gauge my worry factor.   I fly my -7 up and down the left coast and have never seen another aircraft at all when I'm at 12,500 (or 11,500 depending on whether I'm going N or S).  I guess I need to look harder and or thank my stars.  

  

do not archive



On Thu, Sep 11, 2008 at 6:25 AM, linn Walters <pitts_pilot(at)bellsouth.net (pitts_pilot(at)bellsouth.net)> wrote:

  	  Quote: 	
		   --> RV-List message posted by: linn Walters <pitts_pilot(at)bellsouth.net (pitts_pilot(at)bellsouth.net)>

 

 I don't fly that high ...... yet ......... so my question is ...... is the  problem due to 'vfr' traffic not holding to the odd/even +500 enroute or is the system mucked up by climbing/descending aircraft ..... of all types????

   

 Other than filing a VFR flight plan, what else can we do???

 Linn

 

 

 

 Steve Glasgow wrote:

  	  Quote: 	
		   --> RV-List message posted by: "Steve Glasgow" <willfly(at)carolina.rr.com (willfly(at)carolina.rr.com)>

 

 Scott, your question "which is best" implies a known quantity of which you have determined by a guess.  One thing that is not a guess is every one of the planes that go above 10,000' will come back down at some time.

   

 As pointed out by the controller, positive control of both aircraft on a collision course is very helpful. Flight Following may or may not help. Those that use Flight Following are well aware that you are on the bottom of the totem pole, and many times are told Flight Following is canceled swank 1200.  Also there are many areas where it is not available.

   

 Over my many years or airline flying, I can't tell you how may times I have been vectored away from slower aircraft above 10,000' who were not in positive control.   The guy we were vectored around never even knew he had created a problem because he was VFR, not looking or did not see us.

   

 Just because we can't see them doesn't mean they are not there.  The skies are very crowded and there are more and more light jets in the air every day.

 

 But as my original posts stated, "Additionally, many Jets and other faster planes regularly fly between 10,000 and 17,500 without positive control or VFR".  Note: I said, "without positive control or VFR".  These are the ones I am primarily concerned about.

   

 Again as stated in my previous post, "I'm not telling anyone how to fly their airplane or suggesting flying above

 10,000 is unsafe.  I'm just pointing out some facts that might be food for thought."

 

 Steve Glasgow-Cappy

 willfly(at)carolina.rr.com (willfly(at)carolina.rr.com)

 704-362-0005 Home

 

 

 

 

 

 

 

 

 

 

 

 

 	
 

 

 

 

 

 

	
	




t

 

  [quote][b]

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