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What is your Altitude loss in a 180 degree turn?
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grantr

Joined: 12 Sep 2007
Posts: 217

Posted: Sun Dec 07, 2008 5:17 pm Post subject: What is your Altitude loss in a 180 degree turn?

I tested my plane MK III C with 503  today to see how much Altitude loss would occur in a 180 degree turn at idle flying solo.



Todays temp was 56 degrees. My plane lost 300 feet in the turn by making a 45o turn at 55 mph IAS. 



I preformed the maneuver 4 times with the same result.



This is great since one end of  our runway is  full of trees and those Big metal tower High voltage transmission lines!



I usually cross the end  of the runway at 700 to 800 feet AGl.

lcottrell

Joined: 29 May 2006
Posts: 1494
Location: Jordan Valley, Or

Posted: Sun Dec 07, 2008 5:27 pm Post subject: What is your Altitude loss in a 180 degree turn?

[quote] ---

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ropermike

Joined: 28 Aug 2006
Posts: 40
Location: West Texas, South Mississippi

Posted: Sun Dec 07, 2008 6:08 pm Post subject: Re: What is your Altitude loss in a 180 degree turn?

My Mk II looses 300' also on a 180* turn. I practice this turn often in case of a flame out on take off. I know I must be at least 350' high to turn back to runway. I practice at a safe altitude of course...

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John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Mon Dec 08, 2008 1:32 pm Post subject: What is your Altitude loss in a 180 degree turn?

> What I read suggest making a 45o turn at best glide speed to lose the 

least altitude in a 180o turn.





Grant:



You are saying, "45 degree turn" and I think you mean "45 degree bank".



There are a whole lot of varibles when it comes to gliding turns and 

altitude loss.  The faster you are flying when you begin the glide has a lot 

to do with how much altitude will be lost.  Also, how aggressive you turn 

will make a big difference.  A Kolb will turn on its wing tip, or so it 

seems when you really honk it around using a lot of up elevator in a steep 

bank.



I haven't flown in almost three months.  Next time I fly, probably tomorrow, 

if I can get the 912 cranked and knock off most of the dust, bug crap, ect, 

I'll see what my altitude loss is in a 180 degree turn with a dead stick. 

Dead stick will produce less altitude loss than an idling prop.



Good flying weather at hauck's holler, alabama, this afternoon, but I don't 

know about tomorrow.



Take care,



john h

mkIII

_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama

slyck(at)frontiernet.net
Guest

Posted: Mon Dec 08, 2008 2:30 pm Post subject: What is your Altitude loss in a 180 degree turn?

My guess is a hastily begun step angle turn would yield the best  

results.  Less exposure time to drag.



Sure easy to prove but I'm not going to do it today.

BB



On 8, Dec 2008, at 4:04 PM, grantr wrote:



 	  Quote: 	
		   

 <grant_richardson25(at)yahoo.com>



 That almost seems impossible. How did you only loss 100 feet in a  

 180o turn?



 What I read suggest making a 45o turn at best glide speed to lose  

 the least altitude in a 180o turn.





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p 18285#218285

slyck(at)frontiernet.net
Guest

Posted: Mon Dec 08, 2008 2:36 pm Post subject: What is your Altitude loss in a 180 degree turn?

steep angle (bank)

On 8, Dec 2008, at 5:29 PM, robert bean wrote:



 	  Quote: 	
		   



 My guess is a hastily begun step angle turn would yield the best  

 results.  Less exposure time to drag.



 Sure easy to prove but I'm not going to do it today.

 BB



 On 8, Dec 2008, at 4:04 PM, grantr wrote:



> 

> <grant_richardson25(at)yahoo.com>

>

> That almost seems impossible. How did you only loss 100 feet in a  

> 180o turn?

>

> What I read suggest making a 45o turn at best glide speed to lose  

> the least altitude in a 180o turn.

>

>

> Read this topic online here:

>

> http://forums.matronics.com/viewtopic.php?p 18285#218285

>

>

grantr

Joined: 12 Sep 2007
Posts: 217

Posted: Mon Dec 08, 2008 4:12 pm Post subject: Re: What is your Altitude loss in a 180 degree turn?

John,



Yes I meant 45o bank not turn.   Please do let us know how much you loss in an engine out  180. I don't have the nerve to kill a perfectly good running engine yet.



My test was for the purpose of determining how high i would need to be to turn back to the runway if I had an engine failure on take off.



The 300 feet lost was from entering the turn to exiting wings level. I know it will take a little more during a turn back due to the fact a 180 will not have the plane aligned with the runway.

John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Mon Dec 08, 2008 4:31 pm Post subject: What is your Altitude loss in a 180 degree turn?

>  I don't have the nerve to kill a perfectly good running engine yet.

 	  Quote: 	
		  

 My test was for the purpose of determining how high i would need to be to 

 turn back to the runway if I had an engine failure on take off.



 The 300 feet lost was from entering the turn to exiting wings level. I 

 know it will take a little more during a turn back due to the fact a 180 

 will not have the plane aligned with the runway.


	




Grant:



Turning back to the runway kills lot of good folks.  This maneuver 

introduces a lot more ways to hurt your airplane and yourself.



My first engine out, in a fixed wing, was my Ultrastar.  I was so dead set 

on getting back to where I had come from, I mushed the little Ultrastar in, 

experiencing a very hard landing.  Engine quit dead about 100 feet on 

takeoff.  In my effort to get turned around, I did not see the several 

thousand feet of taxiway almost directly in front of me.



Hard maneuvering with a dead engine during an emergency situation makes it 

so easy to try to turn harder than the plane will fly, and try to stretch 

the glide by slowing down airspeed.  All the previous are inviting a stall, 

spin accident.



I think I will shoot straight ahead, deviating left or right to make the 

best landing I can.  My primary purpose is to survive with as little damage 

to me as possible.  The airplane can be repaired or replaced if necessary.



Flying off a "real" airport, always us all of the runway, whether 3,000 feet 

or 6,000 feet.  At the rate our Kolbs climb, and the speed they climb, there 

is generally always room to land if you experience an engine out on takeoff.



john h

mkIII

_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama

grantr

Joined: 12 Sep 2007
Posts: 217

Posted: Mon Dec 08, 2008 7:36 pm Post subject: Re: What is your Altitude loss in a 180 degree turn?

John,



Thanks for the advice. 



I do use the entire runway each time I fly and I don't plan on turning back unless I have plenty of altitude say 700 + and no other options. Looking at the end of runway 23 or 27 there are no good options that I would consider safe to try to land in.  Fairly dense tall trees, houses and large power lines! 27 is 3600 feet and 23 is 6000 so I never use 27/9.



Each time I make my departure I am constantly observing the runway left over ahead of me and any other option to the left and right of me and thinking what  would I do if the engine quit now. I do the same when I am away from the airport flying  over the fields and trees.



I know making that turn under the stress of losing the engine will not be the same as practicing the turn at altitude.

pj.ladd(at)btinternet.com
Guest

Posted: Tue Dec 09, 2008 2:29 am Post subject: What is your Altitude loss in a 180 degree turn?

Turning back to the runway kills lot of good folks.>>



Hi John,



One Christmas Day many years ago when I had been learning to glide for about 

a couple of months this happened.



A friend who joined the club at the same time that I did strapped into our 

old tandem seat Slingsby trainer. The instructor was in the back and they 

were practicing `cable breaks`.

For those with no gliding experience. We were pulled into the air by an old 

Allard sports car.  The piano wire launch cable broke about every 4th 

launch. Learning `cable breaks` was the gliding equivalent of `engine 

failure`in the powered flying world.

The last thing anyone heard was the instructor sasying  "OK Now Safety above 

everything`.  The Allard pulled away and the glider trundled down the runway 

and into the air. At around 500 feet the instructor pulled the bung and 

detached the cable to simulate a cable break. At that point the glider had a 

mile of runway ahead and cracking the brakes and landing straight ahead was 

the obvious drill. To the surprise of the watchers on the ground, the glider 

turned back through 180 degrees. Even then it would have been OK. He could 

have landed downwind with no trouble BUT.. when he got abreast of the launch 

point he tried to turn back into wind. By this time he was low and was 

afraid to put his wing down so he banked slightly and put in a bootful of 

rudder, skidded into the turn and of course the inside wing stalled, the 

plane dropped into an incipient spin for about 50 feet and dived straight 

into the tarmac.

The pupil was killed outright. The instructor lingered a couple of days and 

then died.

No one knows what happened. Presumably the pupil froze on the controls and 

the instructor couldn`t over ride him.



Pat

Jean Pillaudin

Joined: 30 Oct 2008
Posts: 26
Location: France

Posted: Tue Dec 09, 2008 4:32 am Post subject: What is your Altitude loss in a 180 degree turn?

Thom Riddle

Joined: 10 Jan 2006
Posts: 1597
Location: Buffalo, NY, USA (9G0)

Posted: Tue Dec 09, 2008 5:58 am Post subject: Re: What is your Altitude loss in a 180 degree turn?

Kolbers,



The time to turn an airplane depends primarily on the bank angle of the turn and the airspeed being flown. It is a mathematical relationship that is a function of the tangent of the angle of bank. Attached is an image of a spreadsheet table I put together to show this relationship at various airspeeds and bank angles. The first table shows the turn radius (not diameter) in feet for a given bank angle and airspeed. 



The second table uses this data to derive the time in seconds to make a turn of 270 degrees. I used 270 degrees because to get back to the runway you have to turn 180 to get the right heading but then you are two radii away from the runway so then you have to keep turning, say another 45 degrees then turn back 45 degrees to get re-aligned with the runway, for a total of 270 degrees of turning.



The third table takes the second tables data and ASSUMING a 600 FPM descent rate, calculates the loss of altitude in the 270 degree turn.



NOTE: This is not a recommendation for or against turning back to the runway at any time. It is simply showing the mathematical relationship amongst bank angle, true airspeed, time to turn and altitude lost in doing so.

turnback.jpg

Description:

270 degree turn data

Filesize:

117.66 KB

Viewed:

527 Time(s)

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Thom Riddle

Joined: 10 Jan 2006
Posts: 1597
Location: Buffalo, NY, USA (9G0)

Posted: Tue Dec 09, 2008 6:07 am Post subject: Re: What is your Altitude loss in a 180 degree turn?

I did not use very steep bank angles in the previous table posted so I am posting another with steeper bank angles, for your amusement and perhaps amazement.

steepturnback.jpg

Description:

Steeper bank turn back data

Filesize:

113.66 KB

Viewed:

502 Time(s)

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John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Tue Dec 09, 2008 6:25 am Post subject: What is your Altitude loss in a 180 degree turn?

 	  Quote: 	
		   I did not use very steep bank angles in the previous table posted so I am 

 posting another with steeper bank angles, for your amusement and perhaps 

 amazement.


	


 	  Quote: 	
		   Thom Riddle


	


Thom:



Are these Kolb numbers, or a generalization?



I'm not surprised at the results of steep bank angles and higher airspeeds. 

I believe I mentioned in a previous email, agressive turns take less time 

and use less altitude.  The problem with that maneuver is attaining and 

maintaining the increased airspeed at low altitudes, and how hard can I 

crank it around, at very low altitudes, without stalling.



If I get a chance to fly today, I will practice some of this stuff at 

altitude to see how it works out.



john h

mkIII

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John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama

Thom Riddle

Joined: 10 Jan 2006
Posts: 1597
Location: Buffalo, NY, USA (9G0)

Posted: Tue Dec 09, 2008 6:43 am Post subject: Re: What is your Altitude loss in a 180 degree turn?

John H,



The first two tables are mathematical relationships that are independent of the airplane being flown. This means that the turn radius and time to turn are the same for any airplane at these bank angle and airspeed combinations. Ever notice how big a radius it takes to turn a jet fighter flying at high speed? It takes many miles to turn around at high speed, even in a near 90 degree bank angle. Ever wonder why gyroplanes (and helicopters for that mater) can turn on a dime? Because of their very low speed capability. At higher speeds they cannot turn so quickly or in such short distances. It is pure math.



The third table, ASSUMES a 600 FPM descent rate. This table depends upon that assumption. If your airplane descends at a different rate then the altitude loss numbers will differ linearly. In other words if your airplane descends at say 450 FPM then the altitude loss will be 3/4 of those in the table shown for a 600 FPM descent rate.

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Buffalo, NY (9G0)

Don't worry about old age... it doesn't last very long.
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slyck(at)frontiernet.net
Guest

Posted: Tue Dec 09, 2008 6:49 am Post subject: What is your Altitude loss in a 180 degree turn?

My Aeronca chief, when experimenting this series of turns, would eat  

up a lot of energy in a hurry.

It wasn't very good without the prop helping it around.  Straight  

ahead glide wasn't too bad.

The MkIII, to my pleasant surprise, seems much happier in a steep  

turn.  I gave  demo rides

this past summer to a couple of young lads and did steep bank turns  

to show what a small circle we could turn.

The extra passenger load made little difference.  Pretty amazing.

BB

On 9, Dec 2008, at 9:24 AM, John Hauck wrote:

 	  Quote: 	

> I did not use very steep bank angles in the previous table posted  

> so I am posting another with steeper bank angles, for your  

> amusement and perhaps amazement.

> Thom Riddle

 Thom:

 Are these Kolb numbers, or a generalization?

 I'm not surprised at the results of steep bank angles and higher  

 airspeeds. I believe I mentioned in a previous email, agressive  

 turns take less time and use less altitude.  The problem with that  

 maneuver is attaining and maintaining the increased airspeed at low  

 altitudes, and how hard can I crank it around, at very low  

 altitudes, without stalling.

 If I get a chance to fly today, I will practice some of this stuff  

 at altitude to see how it works out.

 john h

 mkIII

John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Tue Dec 09, 2008 7:01 am Post subject: What is your Altitude loss in a 180 degree turn?

Ever wonder why gyroplanes (and helicopters for that mater) can turn on a 

dime? Because of their very low speed capability. At higher speeds they 

cannot turn so quickly or in such short distances. It is pure math.



 	  Quote: 	
		   Thom Riddle


	




Thom:



Helicopters are much more adept at making 180s than fixed wing.  The primary 

reason, rotary wing aircraft build rotor rpm in turns.  The tighter the 

turn, the more rotor rpm.  Sometimes it took quite a bit of collective to 

prevent overspeed and maintain rotor rpm in the green. Very low speeds 

during autorotation will prove hazardous to your health in a helicoper.  The 

Army helicopters I flew were amazingly agile.  They handled quick turns and 

steep bank angles quite well.



john h

mkIII

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John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama

John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Tue Dec 09, 2008 7:04 am Post subject: What is your Altitude loss in a 180 degree turn?

 	  Quote: 	
		   The MkIII, to my pleasant surprise, seems much happier in a steep  turn. 

 I gave  demo rides

 this past summer to a couple of young lads and did steep bank turns  to 

 show what a small circle we could turn.

 The extra passenger load made little difference.  Pretty amazing.

 BB


	




Bob B:



You are quite right.



It took a pretty good sized passenger in the the factory MKIII to get into 

an accelerated stall during demonstrations.  That, of course, was in the 

clean configuration, no flaps.



During a demo in my mkIII a few years ago at Lakeland, I blanked out the 

elevators during a hard pull up with full flaps.  Would not do it clean, but 

with full flaps, the elevators went away.  This caused me to be a lot mor 

cautious during steep approaches and landings with full flaps.



john h

mkIII

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MKIII/912ULS
hauck's holler
Titus, Alabama

slyck(at)frontiernet.net
Guest

Posted: Tue Dec 09, 2008 7:17 am Post subject: What is your Altitude loss in a 180 degree turn?

(those demo turns were WITH power)  

BB



On 9, Dec 2008, at 9:49 AM, robert bean wrote:



 	  Quote: 	
		   



 My Aeronca chief, when experimenting this series of turns, would  

 eat up a lot of energy in a hurry.

 It wasn't very good without the prop helping it around.  Straight  

 ahead glide wasn't too bad.



 The MkIII, to my pleasant surprise, seems much happier in a steep  

 turn.  I gave  demo rides

 this past summer to a couple of young lads and did steep bank turns  

 to show what a small circle we could turn.

 The extra passenger load made little difference.  Pretty amazing.

 BB



 On 9, Dec 2008, at 9:24 AM, John Hauck wrote:



> 

>

>> I did not use very steep bank angles in the previous table posted  

>> so I am posting another with steeper bank angles, for your  

>> amusement and perhaps amazement.

>

>> Thom Riddle

>

> Thom:

>

> Are these Kolb numbers, or a generalization?

>

> I'm not surprised at the results of steep bank angles and higher  

> airspeeds. I believe I mentioned in a previous email, agressive  

> turns take less time and use less altitude.  The problem with that  

> maneuver is attaining and maintaining the increased airspeed at  

> low altitudes, and how hard can I crank it around, at very low  

> altitudes, without stalling.

>

> If I get a chance to fly today, I will practice some of this stuff  

> at altitude to see how it works out.

>

> john h

> mkIII

>

>

Thom Riddle

Joined: 10 Jan 2006
Posts: 1597
Location: Buffalo, NY, USA (9G0)

Posted: Tue Dec 09, 2008 7:26 am Post subject: Re: What is your Altitude loss in a 180 degree turn?

John H,



You bring up a good point. The tables I posted assume 1 G flight because the original question was about turning back with engine out. In a descending turn without power or attempt to hold altitude it is easy enough to maintain 1 G or less. 



What gets a lot of airplane pilots in trouble is pulling back on the stick during a power out descending turn in the vain hope that some magic will be performed. The vast majority of CFIs and the FAA pubs teach that Gs increase in high banked turns. Of course this is true if you are maintaining altitude. In a power out situation any attempt to maintain altitude in an airplane will eventually result in exceeding the critical angle of attack and a stall. The trick to quick descending power out turns in an airplane is maintaining 1 G or less loading. If this is done you can get turned around pretty quickly at slow speeds. Load it up with back stick and you are asking for a stall/spin fatality.

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Buffalo, NY (9G0)

Don't worry about old age... it doesn't last very long.
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