Engine Failure on Takeoff

[jesse]

At my home airport. After running the numbers of my takeoff distance, climbout speed, and climb rate. There is no way I can possibly do a 180 turn back to the runway if I lose the engine on takeoff. It doesn't matter what altitude I try it at there is no way I'm going to make it back to the runway (3200 ft runway) Give me a 5000 ft runway and it wouldn't be an issue. My climb out distance is longer than my glide distance back. Of course with a strong headwind this would be different. But that's too many variables to even consider it.

After figuring this all out I tried it in Flight Sim and touched down pretty much about where I predicited I would.
http://youtube.com/watch?v=uAQgXd8uwq0

Satalite image of airport:
http://maps.google.com/maps?f=q&hl=en&q=crystal,+mn&ie=UTF8&z=15&ll=45.061882,-93.351903&spn=0.021431,0.054245&t=k&om=1

Video of what you see at night:
http://www.jesseangell.com/downloads/crystal.wmv



So. Based on what I've calculated and that video. If I lose the engine on takeoff in the day I'll have a chance at going for a road or maybe that lake. If I lose an engine on takeoff at night. I'm dead.

How much thought have you put towards engine failures on takeoff?

 

[SkyHog]

as I've said in chat before, I have not put enough thought into it. For the most part, a failure on takeoff would always be a straight out for me unless it was less hospitable than the possible attempt to turn back or I felt I was high enough (my limit is currently 800ft because I haven't practiced lower).

I really should go out and figure it out.

 

[jesse]

as I've said in chat before, I have not put enough thought into it. For the most part, a failure on takeoff would always be a straight out for me unless it was less hospitable than the possible attempt to turn back or I felt I was high enough (my limit is currently 800ft because I haven't practiced lower).

IMO If straight out is an option. Take it. Turning around is *not* something you want to attempt without practice. It requires a very steep nose low turn that most pilots have never done.

I can do 500 ft in a 172 without an issue. That I know from practice. But I don't think I would have made it the very first time that I tried it. The issue is if I'm too far from the runway to make it back at this point. 5000 ft runway, I'll probably make it back. 3000 ft is not going to happen. But I'm not going to even consider turning back unless straight out isn't an option. All of this I decide before I take the runway.

 

[Skip Miller]

http://youtube.com/watch?v=uAQgXd8uwq0

Good on ya for thinking about this!

Your simulation also included an almost simultaneous turnback when the engine failed. In reality, there would likely be a several second hesitation (we pilots can't say "what the ***k" and turn the yoke at the same time, it seems! ) which would only make the situation worse.

-Skip

 

[Ken Ibold]

The issue is if I'm too far from the runway to make it back at this point. 5000 ft runway, I'll probably make it back. 3000 ft is not going to happen. But I'm not going to even consider turning back unless straight out isn't an option. All of this I decide before I take the runway.

Hey, you just need to get an airplane that climbs better. On occasion I have made pattern altitude by the time I was 3000 feet from brake release.

OK, maybe a slight exaggeration!

 

[flykelley]

Hi Guys
Straight out is about the only option where Im based at (PTK) Going west is a good size lake, going to the east is a nice field that the airport bought for a saftey zone. A turn back to the field, I wouldn't try that unless I was a good 800 ft AGL. That is something I will need to go out to the practice area and try to see what the numbers will be. This is a great topic and something for all of us to think about. Jessie thanks for giving us something to think about.

Regards Mike

 

[gismo]

IMO If straight out is an option. Take it. Turning around is *not* something you want to attempt without practice. It requires a very steep nose low turn that most pilots have never done.

I can do 500 ft in a 172 without an issue. That I know from practice. But I don't think I would have made it the very first time that I tried it. The issue is if I'm too far from the runway to make it back at this point. 5000 ft runway, I'll probably make it back. 3000 ft is not going to happen. But I'm not going to even consider turning back unless straight out isn't an option. All of this I decide before I take the runway.

I suspect you'll find that your options improve in the colder months due to higher climb rates. Did you work this assuming Vy from rotation to pattern altitude?

 

[tonycondon]

i also wish you would test it out with even a 5 or 10 knot wind. i think the difference will surprise you.

headwinds really help your climb angle, and tailwinds really really help your glide. Take it from a low performance glider owner.

 

[jesse]

I suspect you'll find that your options improve in the colder months due to higher climb rates. Did you work this assuming Vy from rotation to pattern altitude?

I did this with Vx from rotation. The better the angle means the closer to the runway I'll be when the engine quits.

Even if you do the math on 700 FPM (this would be a very nice winter climb in a 172.. I wouldn't bet on getting this often). It's still not looking good

700 FPM / 60 = 11.66 feet per second

500 AGL / 11.66 = 42.88 seconds to turn around altitude

42.88 seconds at 74 mph = 4716.8 feet forward over the ground

I lost 800 ft to rotation and climb.

Runway is 3266 feet. I lost at least 800 of that to rotation and climb. That leaves me with 2466 ft of runway left after rotation.

4717-2466 = 2251 feet

That means when the engine quits at 500 AGL I am 2251 feet from the runway going the wrong direction. I have to turn the airplane around. I'm going to lose 300 ft doing this.. Now I'm pointed back at the runway at 200 AGL.

200 AGL & 8:1 glide ratio = 1600 ft of glide. 651 feet short of the runway.

Now this is all assuming *perfect pilot*. I'm not. I'd say oh ****. I'd take a few seconds. I wouldn't turn around perfectly at night like I can do in the day when I'm ready for it. This is assuming a 172 climbing at 700 FPM.. Which I don't really see much.

I'll try it tonight with a 10 knot head wind.


In the day I have a fighting chance at surviving. I'd say I'm more likely to live than get killed. At night though.. It's not gonna be pretty.

 

[tonycondon]

the maths not that hard. with 10 knot headwind, your groundspeed will be 62 mph. so in 42.88 seconds you will go 3899.22 feet. Lets play devils advocate and say you still take 800 feet to get in the air, although it will probably be shorter.

3900-2466 = 1434 off the end of the runway at engine failure. with a 300 feet loss to get turned around (which sounds reasonable) and even a pitiful 8:1 glide back you will make it with a couple hundred feet to spare. BUT your glide ratio will be much better than 8:1. Best glide of about 65 knots usually gives me around a 700 fpm descent, for a 9:1 ish glide, no wind. with a 10 knot tailwind you will have a groundspeed of 75 but still be sinking at 700 fpm with 65 knot airspeed. so you are pushing 11:1 then. should be able to glide something like 2100 feet forward from 200 AGL. So, you should be able to make it with just a 10 knot wind.

 

[tonycondon]

ya know i think Ed made a spreadsheet about this a while back. he got really into it, factoring turn radius descent rate climb speed and rate, wind etc. ill try to dig it up

edit: Found it. his was for a power off approach and landing, how far out can you run the downwind.

 

[lurker]

Jesse,

Without watching your video, what bank angle were you using in the turn? I attended a WINGS seminar a couple of months back where the presenter gave a demonstration using MSFS. The gist of the demo was that if you are going to attempt a turn back to the airport, the steeper the bank angle the better.

 

[Ken Ibold]

Jesse,

Without watching your video, what bank angle were you using in the turn? I attended a WINGS seminar a couple of months back where the presenter gave a demonstration using MSFS. The gist of the demo was that if you are going to attempt a turn back to the airport, the steeper the bank angle the better.

The bank was plenty steep. But I couldn't read the airspeed. Jesse, how close were you to stall speed in the bank?

 

[Steve]

Analysis by a Navy academy professor...

http://jeremy.zawodny.com/flying/turnback.pdf

A simplified model of the turnback maneuver after engine failure during the take-off climb segment has been developed. The model shows that optimum conditions for returning to the departure runway result from climbing at

Vymax , executing a gliding turn through a 190-220° heading change, using a 45° bank angle at 5% above the stall velocity in the turn using a teardrop shaped flight path.​

Additional discussion by the author at

http://www.nar-associates.com/technical-flying/impossible/possible.html

 

[TMetzinger]

Whether you turn or not, if you maintain control of the airplane all the way to ground contact, and that ground contact occurs at the slowest speed that lets you maintain control, you've done the best you can, and you'll have the best chance of survival.

 

[NC Pilot]

Hey, you just need to get an airplane that climbs better. On occasion I have made pattern altitude by the time I was 3000 feet from brake release.

OK, maybe a slight exaggeration!

THEN you need a plane with a glide ratio better than a brick...

 

[ApacheBob]

The fatal Cessna crash that I witnessed at Chicago-DuPage re-inforces Jesse's point. He was too low to make it back, but the temptation to try and save the airplane was too great.
He stalled two-thirds of the way through the 180 and crashed one block from the departure end of the runway. He and his teenage daughter perished.
I wish I could promise that I could resist the temptation. It would take a leap of faith to willingly sacrifice my "baby" to save my life.
But Jesse's calculations are excellent fuel for thought.
1957 ApacheBob

 

[jesse]

The bank was plenty steep. But I couldn't read the airspeed. Jesse, how close were you to stall speed in the bank?

I was right around 65 knots for most of it and at one point I went up to maybe 70 or so and corrected again. The problem with a turn like this is you are so damn steep with so little airspeed that there is no room for error. Pulling on the yoke and loading the wings up would most certainly result in a very bad day. Flightsim does a really crappy job in doing a steep power off turn like that. It's much more nose high than what I've observed simulating this in real airplanes.

 

[KennyFlys]

Jesse is thinking. This is cause for concern!

At a seminar a few months ago in Atlanta, AOPA's Mark Grady showed us a few simulation videos of turn-backs. If I recall, they all started at 700' AGL but varied by 30, 45 and 60 degree banks (No wind, if I recall correctly). The 45 got it back on the field safely. But, as was mentioned, there's that delay that will happen for whatever reason the body may not be reacting to the brain telling it to do something.

I've thought about this often. Although it may not be quite as safe to try it for real, a close real-life effort would be a power-off 180. I'd think the better you can run that scenario, the more successful you'd be in a turn back on takeoff departure.

 

[jesse]

Although it may not be quite as safe to try it for real, a close real-life effort would be a power-off 180. I'd think the better you can run that scenario, the more successful you'd be in a turn back on takeoff departure.

BTDT. Not exactly sure what you accomplish though. I also wouldnt reccomend you try it until you've done it at a *very* safe altitude several times until there is no possible way you'll mess it up. It'd be pretty silly to kill yourself testing something that is not that likely to occur with proper maintance. Because there is no room to mess up at 500 ft since you'll be at 300 ft as you roll out.

All I discovered is that on that day from 500 ft with that runway and those winds with that temperature I would make it. This does very little though considering how every day that I fly is different. I don't like to convince myself that just because I was able to do it without an issue once means I'll always be able to.

I'm going to mess with some wind yet and finally come up with some procedures for this airport (KMIC) that I will use.

 

[TangoWhiskey]

Fun stuff, Jesse, and good to think about. Rolling through the airport boundary fence on the rollout (2:00 in the video) would be painful.

Did you open a can of pop right after rotation? I heard a sound I couldn't identify.

 

[jesse]

Did you open a can of pop right after rotation? I heard a sound I couldn't identify.

Not sure. I had a video camera pointed at the monitor. I've never found a better way to record it. Any software solutions I've tried were way jerky.

 

[cwyckham]

I'm a bit concerned that many of the posters in this thread have identified an altitude at which they would turn back. What matters is the angle down to the touchdown point, not the altitude you're at. If you're at 800 feet 2 miles from the runway, that's different from 800 feet just off the departure end.

The safe altitude depends on the aircraft, winds, and length of runway. In a typical trainer type aircraft such as a 172 with no winds and a shortish runway, turning back is never an option from a straight out departure, no matter what altitude you're at. The climb angle is much shallower than the glide angle, so even if you ignore the fact that you have to turn around, you won't make it back.

If you have a headwind, you'll get a better climb rate and a better glide ratio. It would be simple to calculate what headwind component you need to allow a turnback for your particular aircraft at the typical length field you fly from (though I've never done it). In my case, I looked at the dismal results for no wind and decided to always land straight ahead no matter what. It would probably do for me to revisit the calculation.

Chris

 

[tonycondon]

Chris, I set up a pretty simple excel spreadsheet to figure it out. I even got all aerospace engineerish and factored in turn radius. Wind is definitely a huge factor and I found that on a 3500 foot runway with typical trainer performance, 5 mph wind will just barely get you back, calm and you come up short.

hopefully the thing that people get out of this thread is that you cant have a specific altitude no matter what and that it really does depend on the conditions.