Engine Failure in Flight

[QueensPilot]

I've also read that if you are flying a carbureted airplane it might be a good idea to put on carb heat simultaneously as you pitch for best glide. Why? Because if ice is the reason for the failure, the engine may cool down too much for that checklist item, when completed later, to do much good.

 

[dhc8fo]

I do it in this order. If I knew what caused the failure i.e. carb ice, forgot to adjust the mixture on climb/descent, need to change fuel tanks, I'd do that action before pitching for best glide.

Agree with this, but I do it AS I am also pitching as some others have said.

 

[icefr8dawg]

Your school is wrong. Engine failure or fire is a memory item in most planes. Especially single pilot! If you're not familiar enough with the operation of the engine without using a checklist then you're not ready to fly it alone.

 

[avbug]

(Avbug? You've flown enough different aircraft; certainly far more than me. With my limited experience, I have never come across a single that didn't approximate best glide by simply putting it into a cruise level pitch attitude. Have you?)

I don't honestly know. I've never thought about the pitch attitude during an engine failure.

Unless I'm on intruments, most of the time it's strictly a feel issue, and I probably am not looking inside the cockpit. One airplane I regularly fly, a single, has a flight manual which is placarded on the cover "Nothing in this manual is to be believed." It's a foriegn airplane with a foriegn flight manual, and none of the numbers or speeds are close to the book, even if it were believable, due to numerous mods. I have no idea what the "best glide" speed is, and don't really care. I know where it feels right, and that's where I'll fly it, eyes outside.

The airplane has no checklist, and attempting to use one would be a really bad idea, especially in an emergency. It's a very "hands-on" airplane that you really don't want to let go of, especially when things aren't going well.

From a practical point of view, however, one intuitively knows that if one is trimmed for a speed higher than best glide, one is going to have to hold back pressure at best glide...until it's trimmed off. I can't see any value in pitching up to obtain best glide speed...doing as you say and holding the present attitude until the speed bleeds down to best glide is probably a much more preferable choice, but it needs to be temperated with consideration for obstacles, terrain, etc. When I've experienced engine failures before, much of the time they've been within a few feet of the surface, up to a couple hundred feet, because that's where the airplane is operated much of the time. It's operated often in very cut up mountainous terrain, and therefore a prime consideration isn't how far I can glide, but avoiding trees, powerlines, rocks, etc.

I think too much emphasis is put on best glide speed, too. How often are you going to need to stretch the glide in a single, vs. always keeping the airplane over a decent landing spot? Perhaps more important, especially if one is going to execute checklists, attempt restarts or relights, and so on, is minimum sink speed...which is not the same as best glide speed, and is often not taught.

Best glide provides the greatest possible distance, but minimum sink provides the greatest possible time to impact. Distance isn't always the critical issue, but often as not, time is. It may afford more time to relight, more time to communicate, etc. Minimum sink is also the preferable speed in white-out forced landings, water landings, etc. Especially glassy water landings.

But back to your question...I have no idea what the pitch attitude is of any airplane I fly, respective of best glide. I'd say it depends a lot on the center of gravity and loading, etc. I can tell you what it sounds like and feels like, though.

 

[Dr Pokenhiemer]

Best Glide is the most important part. The school that i used to teach at always wanted to teach the student that best glide is 80kts intead of 70kts in a C172. (I think that's right--it's been a while.) Anyway, by pitching for a slower or faster speed, the gliding distance is reduced. What if someone were to pitch for 80 and end up 50 yards short of a suitable landing area? Even in the Lear I do a lot of power off decents to conserve fuel and pitch for Vref +60 for best glide.

 

[USMCmech]

I've also read that if you are flying a carbureted airplane it might be a good idea to put on carb heat simultaneously as you pitch for best glide. Why? Because if ice is the reason for the failure, the engine may cool down too much for that checklist item, when completed later, to do much good.

That is the reason that some people say to run the checklist first. It is a valid concern, but like many of these arguments it is a case of people overthinking to problem.

I agree with waht everybody else is saying. Pitch for best glide, run the checklist, and look for a landing site simutaniously. The engine failure checklist in almost any single only takes about 30 seconds max. You should have praticed this enough times to do it by feel and memory. All the while holding the airplane level and slowing to best glide, while looking for a landing site.

 

[Cutlass1287]

I dont think its likely that your engine would go from perfect health to totally dead instantly from carb ice anyhow.

 

[USMCmech]

I dont think its likely that your engine would go from perfect health to totally dead instantly from carb ice anyhow.

Think again.

Carb Ice is probably the second most comon reason for engine failure (right behind fuel exaustion/starvation).

The most likely scenerio is where you are flying along on a nice fall or spring day with the OAT about 50F. Your carb is slowly iceing up, and when you reduce power to start your descent the throttle plate (which is covered in ice) completely chokes off all airflow in the iced up venturi. THis is why I always add "full throttle" to my engine failure checklist even if the checklist in the POH dosen't mention it.

It happens all the time. Look at the NTSB reports where "engine falied because of undetermined reason" is part of the cause. If you look closely at the weather conditions you will see they are useually an OAT of 55-30F, the most dangerous temps for carb ice. By the time the investigators get there, the ice has melted, and the culprit is never found.

 

[MauleSkinner]

I agree 100% with the general consensus...fly the airplane, pitch to best glide, and run the appropriate checklist (memory or paper, depending on the situation).

While Avbug's comment about the applicability of best glide is probably true for the most part (the only one I had quit cold in a single was at 75 feet and Vx...not sure what I pitched to, but it worked), unfortunately the PTS is worded "Establishes and maintains the recommended best-glide airspeed, ±10 knots."

With regard to Midlife's question, higher-drag airplanes tend to have a lower nose attitude for best glide speed...holding a Stearman in a level flight attitude with the engine out will seriously degrade its already rock-like gliding qualities

Fly safe!

David

 

[midlifeflyer]

I don't honestly know. I've never thought about the pitch attitude during an engine failure.

Unless I'm on instruments, most of the time it's strictly a feel issue, and I probably am not looking inside the cockpit.

Neither am I. I'm talking about cruise level pitch based on visual cues, not the AI (unless in IMC where it works just as well).

The concept is that I've seen many student and low-time pilots spend a heck of a long time (as much as 3-5 seconds) getting to best glide when all they have to do is keep looking out the window as they establish (or maintain) a cruise level pitch attitude while they look for a place to put down and start their troubleshooting.

Thanks. Guess you've been flying long enough that it's so automatic that you don't need to think about it for yourself and aren't worried about how to teach it to others.