What would you do if…

[sfGnome]

This thread is just a result of a diseased imagining in the early hours of the morning, but if it prompts some useful questions and discussion, then the restless night was worth it. 🙂

 

Imagine that you’re cruising on a long distance flight, say at 5500’, plenty of fuel, CAVOK, then the engine goes to wide open throttle and you can’t reduce it. What would you do?

[facthunter]

At that Height the engine would be at about 75% Power so just climb a bit and keep going. Nev

[Neil_S]

Hi SFG,

 

Happened to my mate a number of years ago (throttle cable broke, I believe, and Rotax went to full, as it should).

As Facthunter says, keep going. When at your destination (or a suitable airfield en route)  conduct a circuit and then when certain of making the runway cut the engine and glide in to land.

That's what my mate did and landed without any dramas. 

 

Cheers,

Neil

[Thruster88]

In a "proper" aircraft one could use the red knob to control the engine.

[facthunter]

You Might have to explain that. Nev

[BurnieM]

1 hour ago, Thruster88 said:

In a "proper" aircraft one could use the red knob to control the engine.

Don’t proper engines have ECUs ?

 

[skippydiesel]

IF ? you have a Constant Speed prop:

Even if throttle cable broke, prop likly to remain at or close to, selected rpm.

If above not true, select for courser pitch to govern rpm down to a less heart stopping rpm.😈

[facthunter]

Sorry I've never seen coloured Pitch Levers that I can recall if that's what you are referring to. So far the concern has been about Max cruise "continuous"  POWER. Introducing a CSU is  or an in flight variable pitch complicates things a bit . The POH would Have MP/ RPM relationship limits. Level gives MP at WOT then adjust the RPM to what you need and see as optimum for continued flight.  WOT on a supercharged engine is a good thing for efficiency. Nev

[sfGnome]

I will admit that my diseased imaginings didn’t include a constant speed prop (that would be more like a dream), but Neil hit the nail on the head. The issue isn’t what to do right now (apart from “don’t panic”), but what to do when you get to a suitable airport (hence my “plenty of fuel” specification in the original post). We all train for engine failure (don’t we?), so landing dead stick from above the strip shouldn’t be a major issue, but the only other thing I would add is, after cutting the engine and while still at height, attempt a restart just to see if it is possible so that a go-around is an option if the landing goes pear-shaped. 

[KRviator]

19 hours ago, Thruster88 said:

In a "proper" aircraft one could use the red knob to control the engine.

Spot on.

Use the mixture as your new throttle lever. Pull it well beyond LOP to reduce power, increase the mixture if you need more. Do not, under any circumstances where you have a pilot-adjustable mixture control, compound your 'emergency' by adding an engine failure to it, even if such an action is generally considered reversible. 

[facthunter]

I certainly would NOT be doing that. . Nev

[FlyBoy1960]

you can further the grade the engine performance slightly in this situation by turning off one ignition circuit.   It's not much but it helps

[facthunter]

 That will make it run hotter. How can you manage a motor at low level and descending on WOT? (full Power) It will capture all of your attention trying to Manage it when you should be flying the Plane. I'd get over a Large field and shut it down by turning the fuel off.  Nev

[djpacro]

When it happened to me … full throttle …. PAN call to Moorabbin Tower and they gave me the whole airport. Orbited overhead, descending. Low and fast on base then final … very fast. Got my student in the front seat to pull the mixture to idle cutoff. Nose up then sideslipped to reduce energy. On the ground at normal landing speed before halfway down the runway and easily stopped well before the end.

[facthunter]

Some aircraft will exceed VNE , turbulence Penetration, Flap extension speed limits  in Level flight at WOT. With any descent It will compound the Problem. With a fixed pitch Prop is May easily overspeed the Motor. If this is Likely shutting down  the Motor is the Only way to avoid it. Risks are too high otherwise BUT you can Pick the Point where you do this, and do it wisely. Starting some engines on full throttle is Unlikely to succeed. Your main task is to successfully do an engine out landing and that's not rocket science. It's a good question to consider .It could happen. . Nev