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Eddie P -> RE: Single engine maiden save B25 !! (3/14/2013 6:52 AM)
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quote:
ORIGINAL: Lnewqban
As I have not flown more than single engine models, please excuse me the ignorant question:
If location regarding runway, wind and altitude is favorable; wouldn't be safer to kill the engine that remains working (eliminating that disturbing off-center force) and to perform a dead stick landing?
Just for some feedback, your question is a great one and your instincts are solid! You should be flying multiengine models ;) Most anyone would do this if they could (unless they don't know). What happens that prevents this.. is if,
1) The engine failure goes unnoticed before a snap roll and spin causes a crash even at idle power due to altitude, ideas and airspeed running below survivable levels all at once, or:
2) The engine attempted dead stick landing would immediately cause utter destruction due to underlying terrain, altitude and airspeed... and let's say, the initial try at handling the engine failure goes well enough to justify the attempt to fly a pattern to a point where a controlled dead stick approach can be made.
Most guys who make successful engine out approaches are either trained on engine failures, lucky, or they were fat dumb and happy enough in airspeed, altitude and position to manage a safe low power landing to the runway. In my case my model was a 4 engine model and that helped - it was also modestly powered, and that also helped (modest meaning low power, this may run against instincts but more on this in the next paragraph). My rudder was plenty big enough to manage the one of four engines that died. In my case as well, the terrain ahead would have shredded my model to bits if I just gave up, pulled power and landed straight ahead. I was handling the problem well enough and made the decision to continue handling the problem all the way around the pattern until a controlled low power approach could be made to the runway.
Most scale model airplanes let alone sporty ones have far more power (power to weight) than their full scale counterparts. A full scale airplane can be safely managed with an engine failed due to the minimum controllable airspeed being fairly reasonably low compared to operational airspeed normally flown - that's due to reasonable and modest power available. A multiengine model airplane with a huge power to weight ratio compared to full size (and that's typical for models) may not actually have a minimum controllable airspeed with one engine out that is below it's cruise speed at full power!! Engine failures in model airplanes almost always need an immediate power reduction to even have a hope in controlling the model aerodynamically due to the normally high levels of power available and the asymmetrical issue with such high power. Dead stick may not be necessary if flown well but it may be if the design is such (thin airfoils, small control surfaces, short coupled) and power levels are such (lots of power and hard to fine tune) that it's too tricky to try otherwise.
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