Single-engine Endurance and Performance

[hharney]

My opinion is based on limited single engine work, just enough to know how the aircraft will handle. I have shut down an engine several times but this was for practice and can't say what the loads were exactly but here's a good attempt at remembering.

Out in the mountain states years ago with 2JF dad and I practiced the SE stuff several times. I can remember being at around 10K MSL but don't remember the temperature. I would guess that it was at least standard or maybe less. For load the mains were full, not sure on the aux's but it's a good chance that they were full too. Myself at 200 lbs and dad at 265 lbs. We maintained 10K for some time but it was a little sluggish. The rear was better than the front. I lost a cylinder over Lake Michigan several years ago and pulled the front back to minimal and flew it for about an hour with no problems. I would say that I was at 6500 ft. I did not know what had happened to the engine while in flight but I watched my vitals and limped into the airport. Cylinder separated from the base.

At 5,000 ft and 2/3 load I would estimate that you could maintain altitude. You didn't mention that your experienced source had actual factual info on this or if it was just an opinion based on POH.

[Ernie Martin]

The source was basing it on recollections of practices/simulations and conversations he had with others, not on a specific incident.

Ernie

[Cole5Oh5]

Follow the POH
Feather the engine that doesn't work, because if you feather the engine that was working, you got a lousy glider.
Close the cowl flap doors on the engine that isn't working.
Open the cowl flap doors on the engine that does work.
Go to max throttle, lean for performance. At full load, or pretty close to it, you can maintain altitude, at least at 5K, even on a warm day.
keep in mind, however, that you don't want to do this for very long, and you'll be down to blue line or pretty close to it, which is why it is there.
I was able to maintain altitude for a short period of time, on the front engine, but it was an emergency, and we headed for an airport right smartly.

[Cole5Oh5]

you wanted to do it at 25/25, or reduced power.
Not the wise thing to do. POH says max power. Do that, you can stay up.

[Ernie Martin]

The issue of power and extended endurance is precisely the question. These engines are not rated for extended operation at full (i.e., take-off) power. If your closest landing is 1 or 2 hours away, you want to go to full cruise power, which is the top of the green band or 25/25. I believe that the engines are designed to operate at this power for extended periods. Can we start with that? Do you all agree or disagree? Then, will it maintain 5,000 ft at 2/3 load on a warm day?

I think this aircraft -- and all twins -- are designed to do that. Am I wrong?

In a single-engine aircraft, you have to promptly find a landing spot if the engine quits. Are we saying that our second engine simply extends briefly (5 - 15 minutes) the time we have to pick a landing spot?

Ernie

[skymstr02]

Originally Posted by Cole5Oh5

you wanted to do it at 25/25, or reduced power.
Not the wise thing to do. POH says max power. Do that, you can stay up.

Thats max continuous power (25/25), not full power.

On my O-2, I am able to maintain 4K, configured single engine, rear engine operating, near full gross wt.

And what the hell is blue line on a center line thrust airplane?

[Ernie Martin]

Come on, people. No more views? I'm seeking your opinion whether or not you ever did this. It's real simple and probably at the core of why you bought a Skymaster. The choices are:

1. Yes, a 2/3 loaded Skymaster on one engine will maintain 5,000 ft even on a hot day. That's what twins are supposed to do.

or

2. No, you will bleed altitude to maintain a safe speed. It's just like a single, where you've got to start looking for a place to put it down as soon as you lose an engine, except here you have more time to look.

Please vote.

Ernie

[tropical]

The best rule of thumb in any multi engine aircraft is once you have lost an engine land as soon as practical.