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Mastery of Flight
When Would You...?
by Thomas P. Turner
Flying a twin, you have a lot of capabilities that your friends in single-engine airplanes do not have. You also have a lot more choices to make. Most of the additional options are a direct result
of having that second engine. Let’s take a look at some of the unique options presented to the multiengine pilot and when you might actually use them.
Precautionary shutdown
One option available to the pilot of a twin that is not usu- ally considered an alternative for the single-engine flyer is a precautionary shutdown. A precautionary shutdown means just that—shutting one of the engines down before it might fail. You might do this for one of two reasons:
1. To prevent or minimize damage to an engine as a result of indications that suggest additional damage may occur, and/or
2. To make the engine failure happen on your terms instead of just as you’re turning inbound on the approach or entering the traffic pattern.
Personally, I think reason #2 is at least as important as the first reason, at least from a safety standpoint.
So, when would you perform a precautionary shutdown? The most likely reason is a loss of oil pressure combined with an increase in oil temperature (which confirms the oil loss), especially if there is a visible oil leak on the cowl- ing of the engine in question. Whereas in a single-engine airplane, similar indications would suggest reducing power, staying high (for greater glide radius if the engine seizes) and aiming for the nearest suitable airport; in the twin, you can shut down the ailing engine, transition to single-engine flight, then fly an almost-normal descent, approach and landing on one engine at the nearest good option...including flight to an airport with better weather within the one-engine range of the fuel left on board if conditions at closer airports aren’t good.
Other possibilities include a surging propeller, a pro- peller overspeed, or a severe vibration that suggests a propeller problem that could quickly lead to blade sepa- ration. Vibration could also be the result of a mechanical
20 • TWIN & TURBINE / February 2024