Engine Poweroff Mid-Flight

Here’s The Situation:

You are flying an aircraft to a destination that is far beyond the capabilities of the aircraft with full fuel and no PAX or Cargo.


My Question:

Does powering off half, 1/3, and/or 1/4 of the engines reduce fuel usage, letting you be able to get to the destination?


Example:

Flying non-stop from KBWI to PHNL in a Southwest 737-800. The Southwest -800 (and all -800s) has 8-9 hours of fuel and the flight is 10-11 hours at Mach 0.76-0.80 (cruising speed in the 737-800). Does shutting off one of the engines allow you to maintain your speed at a lower altitude, and reduce fuel usage?

Turning off an engine on a dual engine plane will make little to no difference on the range. The remaining engine will have to ramp up power to maintain speed therefore fuel used is more or less then same. The only viable way to make a distance well above the range is to plan a stop over half way and refuel.

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Wouldn’t powering off all engines at a very high altitude and gliding for a while, before turning them back on help with the range?

That would cause a stall and a loss of altitude, which is not what I want to do. Also, engine startup of both engines would take time, so I would try to stay away from gliding.

This is something I will try once on Casual, as there the device can run and run and run

In theory that would work. However, climbing up to the original altitude uses more fuel and you might as well cruise normally. If you went up to like FL420 and started gliding down to like FL380 and then cruising and gliding some more you might have a chance. Still, it probably won’t work.

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How about when you get about 30 minutes of fuel, you shut off the engines and glide for about 20min, then restart engines…idk if that would work…

When the RAF operated the Nimrod they would shut down two of the four engines to increase endurance. However, increasing endurance doesn’t necessarily increase range.

If you want to maximise your range then you should fly at long range cruise speed (if you have a way or working that out).

Although the Nimrod did do this, it was actually to increase efficiency and will have had an effect on its range, however, this operation was part of the design of the plane, no plane we have in Infinite Flight is designed in that way, and no pilot would dream of purposely shutting down an engine for fuel efficiency.

No, it was nothing to do with range. It was to increase endurance.

The principles of doing so apply to any multi engined aircraft.

I think that this would only work if your in a 4 engine plane. If you’re in a less than 4 engine plane, you might stall. Correct me if I’m wrong, but I think that you would still be able to fly a 4 engine plane with 2 engines.

You wouldn’t stall if you shut down one engine on a twin. They are all designed to be flown at maximum take off weight on one engine to comply with performance certification.

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