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Air start on 912ULS

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clint_bazzill(at)hotmail.
Guest

Posted: Sat Feb 18, 2006 8:00 pm Post subject: Air start on 912ULS

With all the talk about engine out, decided to try a dead engine condition.  

Up to 3500 ft over Half Moon Bay airport.  Shut engine down, checked glide 

at 65 & 70 mph.  At 70 was even 500 ft/min prop stopped.  Could not get an 

airstart.  Air speed up to 140, prop turned through compression about 3 

times, down to 1200 feet, started engine with starter.  No air start with 

those high compression engines.  Clint

spaghettiohead(at)hotmail
Guest

Posted: Sat Feb 18, 2006 9:28 pm Post subject: Air start on 912ULS

Half Moon Bay?! Would that be in California? I've heard of the airport - if 

you take-off and head west from it in FlightSimulator, you'll hit an 

aircraft carrier in the Pacific...



Anywho, I routinely shut-down in the air just because I like the feeling of 

gliding...don't ever count on air-restart with these engines (and I have a 

582). It's starter or ropestart only!



It was a surprise then when I started my Multi-Engine training some months 

ago to find that after a complete shut-down of the right engine (including 

prop-feather), the engine WILL airstart once you bring the props forward out 

of feather!



Andrew

 	  Quote: 	
		  From: "Clint Bazzill" <clint_bazzill(at)hotmail.com>

Reply-To: kitfox-list(at)matronics.com

To: kitfox-list(at)matronics.com

Subject: Air start on 912ULS

Date: Sun, 19 Feb 2006 03:57:49 +0000




<clint_bazzill(at)hotmail.com>



With all the talk about engine out, decided to try a dead engine condition.

Up to 3500 ft over Half Moon Bay airport.  Shut engine down, checked glide

at 65 & 70 mph.  At 70 was even 500 ft/min prop stopped.  Could not get an

airstart.  Air speed up to 140, prop turned through compression about 3

times, down to 1200 feet, started engine with starter.  No air start with

those high compression engines.  Clint

chenoweth(at)gwi.net
Guest

Posted: Sun Feb 19, 2006 7:38 am Post subject: Air start on 912ULS

Andrew,

One of the reasons I posted my first ever shut down was my surprise at the

difference in stall speed between an idling and stopped engine.  That hasn't

seemed to have surprised anyone - at least no one has expressed surprise.

Have you found the same difference in stall speeds in your shutdowns?  Also,

do you have best glide speeds for a stopped engine glide?

Bill



---

lcfitt(at)sbcglobal.net
Guest

Posted: Sun Feb 19, 2006 8:25 am Post subject: Air start on 912ULS

This is an interesting subject.



Several years ago during one of the Idaho back contry trips, we were flying 

over some pretty unfriendly ground - lots of trees and low mountains - and 

needing something to occupy my mind, I started thinking of the in air 

restart and was tempted to shut down to experience what Clint mentioned.  I 

didn't do it, wisely as I learned.   Our next landing was at Cavanaugh Bay 

and my heart was in my throat as we prepared to depart, I hit the starter 

and nothing happened.  A little corrosion on the spade terminal on the 

starter solenoid essentially rendered the start circuit inop.



Clint's try over the airport showed some wise planning.



Lowell



---

spaghettiohead(at)hotmail
Guest

Posted: Sun Feb 19, 2006 10:16 am Post subject: Air start on 912ULS

Yep - a prop spinning at idle should, in my experience, increase the 

stall-speed.  In multi-engine training, you don't always shut-down and 

feather one motor for practice. Instead, you idle the engine (which causes a 

lot of drag), and then increase the throttle slightly to simulate 

zero-thrust (also, minimum of drag, such as when the prop is feathered).



As far as a best-glide speed is...In my Model 3, I find my Min-Sink airspeed 

first. That gives me the lowest rate of descent, but not best-glide. Now 

Best-glide is usually just a little faster, so if my min-sink speed is 50, 

I'll add a few mph and fly at 55, a good rough speed.



In my primary training a couple years ago I flew a motorglider a few times. 

With some manuevering, you can plot data points on a graph to make a Power 

Required/Power Available curve. Then it's very easy to find the exact speeds 

you're looking for (for your actual aircraft, not generic!). I'd have to dig 

around my notes somewhat because I forget the exact way to get the data in 

the aircraft...



Andrew

[quote]From: "Chenoweth" <chenoweth(at)gwi.net>

Reply-To: kitfox-list(at)matronics.com

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

Subject: Re: Air start on 912ULS

Date: Sun, 19 Feb 2006 10:33:58 -0500






Andrew,

One of the reasons I posted my first ever shut down was my surprise at the

difference in stall speed between an idling and stopped engine.  That 

hasn't

seemed to have surprised anyone - at least no one has expressed surprise.

Have you found the same difference in stall speeds in your shutdowns?  

Also,

do you have best glide speeds for a stopped engine glide?

Bill



---

smokey_bear_40220(at)yaho
Guest

Posted: Sun Feb 19, 2006 12:11 pm Post subject: Air start on 912ULS

Hi Bill,



OK, to respond to the stall speed changes....



This is one of the things I had to be very careful of

when I did my stall testing with a CAP prop.  You

could get very different stall speeds with different

prop pitch settings that would throw off all your

other data.



This is also when an angle of attack system really

helps.  The same AOA should give you best results with

all other changes.  Your glide path will vary with

conditions, but with AOA, you can always find the best

glide given your current condition.  Make sense?



I think that the fuselage and wing root section lift

can be greatly infleuenced by prop blast or

windmilling prop wake.  You face both the problem of

prop drag and steeper glide from a windmilling prop,

with the greater stall speed of the destroyed lift

behind the windmilling prop.  Then you add the false

impression of good glides from idle prop thrust with

the engine running.  All this makes for a more

difficult time in judging engine out practice landings

from real ones.



When I got my KitFox tailwheel checkout in an S-4, I

was surprised at how steep a glide I needed.  Engine

out patterns had to be close to the runway!  I was

always low and short at first.



I would suggest that any engine out testing be done at

higher altitudes with a planned restart by 2000`AGL. 

Make sure to be over a landing place in case of no

restart.  The 2000` will give you more time to set up

for landing and then try the restart.  Plan to land

engine out, then restart.  Quit trying to restart

whenever you need to pay attention to landing.



Make sure you don`t have an engine failure again down

low after you have overflown your runway.  We lost one

KitFox pilot in Mexico from that and I have heard of

other pilots being caught the same way.  They power

away from their landing, then the engine quits.



Instead, start the engine on descent and land anyway.



There is a lot more that can be covered on this

subject.  Maybe that is why no one jumped right in. 

It can get very complex, but is necessary to know.



Kurt S.  S-5/NSI turbo

Jim Shumaker

Joined: 09 Jan 2006
Posts: 106

Posted: Sun Feb 19, 2006 5:02 pm Post subject: Air start on 912ULS

Bill

   

  Yes I had the same reaction from the list several years ago.  There had been two or three off field landing where the pilots had reported that they had the landing made and then over ran the landing field and hit a ditch or something.  I went up and test with idle prop and engine off and discovered that the stall is much higher and the glide was much better with the prop stopped  (about 5 mph and about 2 points in glide).  I guess everyone else already knew this or they did not believe me because I got virtually no response.  Or maybe they just went out and practiced.  So, no, we are not surprised by the increase in stall or the increase in glide.  The MAGNITUDE of the difference is what cathes us off guard.

   

  Jim Shumaker

   

  Chenoweth <chenoweth(at)gwi.net> wrote:

  



Andrew,

One of the reasons I posted my first ever shut down was my surprise at the

difference in stall speed between an idling and stopped engine. That hasn't

seemed to have surprised anyone - at least no one has expressed surprise.

Have you found the same difference in stall speeds in your shutdowns? Also,

do you have best glide speeds for a stopped engine glide?

Bill

_________________
Jim Shumaker

temco(at)telusplanet.net
Guest

Posted: Sun Feb 19, 2006 9:37 pm Post subject: Air start on 912ULS

Kurt



Thanks for the excellent points about the restarts and continue on to land. 

Makes a lot of sense.



DO NOT ARCHIVE



Ted Palamarek

Edmonton Ab (Temporarily in Dubai)

------------------SNIP----------------



 	  Quote: 	
		   I would suggest that any engine out testing be done at

 higher altitudes with a planned restart by 2000`AGL. 

 Make sure to be over a landing place in case of no

 restart.  The 2000` will give you more time to set up

 for landing and then try the restart.  Plan to land

 engine out, then restart.  Quit trying to restart

 whenever you need to pay attention to landing.

 

 Make sure you don`t have an engine failure again down

 low after you have overflown your runway.  We lost one

 KitFox pilot in Mexico from that and I have heard of

 other pilots being caught the same way.  They power

 away from their landing, then the engine quits.

 

 Instead, start the engine on descent and land anyway.

 

 There is a lot more that can be covered on this

 subject.  Maybe that is why no one jumped right in. 

 It can get very complex, but is necessary to know.

 

 Kurt S.  S-5/NSI turbo

chenoweth(at)gwi.net
Guest

Posted: Mon Feb 20, 2006 5:23 am Post subject: Air start on 912ULS

Kurt,

Back when I was building I looked into an AOA system and decided against it

mostly due to cost.  There were some issues with mounting it on a fabric

covered plane, too.  Kind of wish I'd bought one now because I think it

would be interesting to have some precise information on best speeds.  A

friend has one on his RV7A and finds it very helpful.

Great advice on the engine starts.  I'm guessing that the folks you describe

as loosing their engines after restart and powering away are flying

two-strokes, right?  I certainly gave that particular point a lot of thought

when working out my plans though I do have the blue head 582 which has a

thermostat.  Even so I did approach the application of power after the

restart with a lot of caution.

Bill

do not archive

---

chenoweth(at)gwi.net
Guest

Posted: Mon Feb 20, 2006 5:23 am Post subject: Air start on 912ULS

Jim,

Thanks for your comments.  In my case it appears that I'm getting a lot more

help from my idling engine than I'd thought possible.  In fact, I think my

descent rate was a lot more than one should expect with a stopped prop.

Since this was my first run at this I'm planning to go back and do it some

more just to confirm my glide speeds and ranges.

Bill

do not archive

---

chenoweth(at)gwi.net
Guest

Posted: Mon Feb 20, 2006 5:23 am Post subject: Air start on 912ULS

Andrew,

Back when I was doing my 40 hours I found that my sink rate (as timed, not

as per VSI) got lower the slower I flew (a bit like what I experienced

during my glider training) down to about 45 mph where I quite measuring.

Given what I know now re the engine out performance I'd say the speeds and

performance I came up with then are highly suspect.  Ergo, the plan to re do

them with the engine stopped.

Bill

---

spaghettiohead(at)hotmail
Guest

Posted: Mon Feb 20, 2006 7:36 am Post subject: Air start on 912ULS

45 doesn't seem too far off, Bill...what model are you flying and with what 

powerplant?



Andrew



do not archive

[quote]From: "Chenoweth" <chenoweth(at)gwi.net>

Reply-To: kitfox-list(at)matronics.com

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

Subject: Re: Air start on 912ULS

Date: Mon, 20 Feb 2006 07:30:19 -0500






Andrew,

Back when I was doing my 40 hours I found that my sink rate (as timed, not

as per VSI) got lower the slower I flew (a bit like what I experienced

during my glider training) down to about 45 mph where I quite measuring.

Given what I know now re the engine out performance I'd say the speeds and

performance I came up with then are highly suspect.  Ergo, the plan to re 

do

them with the engine stopped.

Bill

---

MichaelGibbs(at)cox.net
Guest

Posted: Mon Feb 20, 2006 9:27 am Post subject: Air start on 912ULS

 	  Quote: 	
		  I guess everyone else already knew this or they did not believe me 

because I got virtually no response. Or maybe they just went out and 

practiced.


	


I guess what you guys experienced jives with my understanding of the 

physics involved, so I didn't find it surprising.  It does underscore 

the need to practice these things periodically so you will be 

prepared if the situation ever arises.



Mike G.

N728KF

smokey_bear_40220(at)yaho
Guest

Posted: Tue Feb 21, 2006 11:56 pm Post subject: Air start on 912ULS

Hi Bill,



I seem to remember "Chenoweth" as an Indian name, but

googling it came up with all women???  Just courious

as to the origion....



Anyway, the first case I remember of a plane

overflying the landing zone was a C-150 with an

instructor testing a student.  They did a practice

engine out by killing the engine.  Set up nicely for a

landing and then tried to restart.  When it didnt,

the instructor shut off the fuel.  Then the student

got it started and.... guess what?  It ran long enough

to get them to the far end of the field.  Too many

cooks in the kitchen.



Another was an engine failure in Mexico with one of

our great KitFox listers.  He made history in Mexico

twice with his plane.  It was while testing another

builders plane that the engine quit.  I dont know

which engine it was.  He got a restart, but it quit

again leaving him in a bad spot.  We lost him only a

few years ago from that.



I would rather if no one did that again!



Elbie, on this list, makes a reasonable priced AOA

system that I bought and like.  The probe attaches to

the jury strut, but you have to run wire thru the wing

to it.  I think his is the lowest priced out there,

last I saw.  (I dont count the BaconSaver since you

have to look over at it instead of flying your plane.)



Cant look it up now, but I think he had it in

Aircraft Spruce for sale.  Havent checked his latest

price either, but it really can make setting best

climb/glide speeds easy.  In fact, I had to turn it

off during testing so I didnt cheat on myself and

ignore the airspeed indicator when I needed it for

data.  If you have AOA and a GPS for ground

speed/navigating, the ASI is hardly useful or looked

at.



Anyway, AOA is a reasonable thing to have, safety

wise.



Kurt S.



--- Chenoweth <chenoweth(at)gwi.net> wrote:



 	  Quote: 	
		   Kurt,

 Back when I was building I looked into an AOA system

 and decided against it

 mostly due to cost.  There were some issues with

 mounting it on a fabric

 covered plane, too.  Kind of wish I'd bought one now

 because I think it

 would be interesting to have some precise

 information on best speeds.  A

 friend has one on his RV7A and finds it very

 helpful.

 Great advice on the engine starts.  I'm guessing

 that the folks you describe

 as loosing their engines after restart and powering

 away are flying

 two-strokes, right?  I certainly gave that

 particular point a lot of thought

 when working out my plans though I do have the blue

 head 582 which has a

 thermostat.  Even so I did approach the application

 of power after the restart with a lot of caution.

 Bill

 do not archive

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