There wouldn't be a pilot who, during asymmetric training on his initial light twin-engine aircraft, that did not have the mantra drummed into him of: Pitch up, mixture up, power up, flap up, gear up, identify, dead side dead leg, throttle close to confirm identification then feather. Maybe not in exactly the same order depending on aircraft type and instructor preference.
Chances are for the rest of your career on light twins that order of actions will be stuck in your mind. It is almost certain your instructor in those early years would not have told you that the above sequence of actions take time and that you should never hurry them. Take your time Bloggs, lest you inadvertently identify the wrong engine and close down the good one.
That may be good general advice especially for a cruise engine failure but does the same order of things apply to an engine failure after take off where the cause of the engine failure could be a major mechanical fault; for example seizing bearings due to loss of oil?
Back in 1980, Aviation Safety Digest published the following article entitled Propeller feathering on light twin-engine aircraft. It introduced the article thus:
The following article was produced as Aeronautical Information Circular 9/1979 by the Civil Aviation Authority, United Kingdom. It concerns the possibility of feathering difficulties with propellers fitted to light twin-engine aircraft. The message it contains is applicable anywhere in the aviation world
Most feathering propellers (hydraulically actuated, constant speed, such as the Hartzell and McCauley types) fitted to twin-piston engine light aircraft are designed in such a way that it is not possible to feather the blades below a certain low rpm (typically 700-1000 rpm). This is because at these low rpm centrifugal latches operate to hold the blades in fine pitch to ensure that when the engine is shut down on the ground, the subsequent restart is not made with the propellers feathered.
In cases where the normal windmilling rpm at low airspeed may fall low enough to prevent feathering, the Flight Manual, Owner's handbook or Pilot's Operating Handbook warns the pilot that feathering cannot be accomplished below a certain rpm. However, the full implications of the situation may not always be clear, and other factors of which the pilot should be aware of are:
(a) In the event of an engine failure caused by a major mechanical fault (e.g. seizing bearings due to loss of oil), the rate of deceleration of the engine can be rapid and it is thus imperative that the pilot take immediate action to feather the propeller before the rpm falls to the 1000 rpm region.
(b) On most twins the usual procedure when shutting down an engine which has failed is initially close the throttle of the inoperative engine. This serves to confirm which engine has failed before commencing the feathering actions. However, if the windmilling rpm has reduced towards the critical region where feathering may not be successful, then re-opening the throttle will usually increase the rpm slightly and improve the probability of being able to feather.
(c) In the event of an engine failure, it is important not to let the airspeed reduce below the scheduled engine-out climb speed. This will help ensure that the propeller continues to windmill at sufficiently high rpm for feathering to be successful. if optimum performance is required it is vital to achieve and maintain this best engine-out climb speed.
(d) The loss of performance associated with a stopped propeller in fine pitch or more importantly with a windmilling propeller is potentially serious. The additional drag will considerably reduce the single-engine climb performance from that available with a fully feathered propeller. The directional control will also be reduced, though adequate control should still be available down to the minimum control speed (Vmca), as Vmca is determined with the propeller in the condition existing prior to feathering action by the pilot (i.e. normally with a windmilling propeller). It will probably not be possible to trim the aircraft on the rudder trim at the best rate-of-climb speed and considerable foot force may have to be held to maintain heading. However, it cannot be over-emphasised that, if it is necessary to gain or conserve altitude, the best available performance is essential and for this the best engine-out rate of climb must be maintained.
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Paragraph (a) bears repeating:
(a) In the event of an engine failure caused by a major mechanical fault (e.g. seizing bearings due to loss of oil), the rate of deceleration of the engine can be rapid and it is thus imperative that the pilot take immediate action to feather the propeller before the rpm falls to the 1000 rpm region.
Centaurus comment: Flying school instructors qualified to instruct on light multi-engine piston aircraft should bring the attention of their students to the above UK CAA AIC 9/179 and explain that with an engine failure shortly after take-off caused by a major mechanical fault, the subsequent actions prior to feathering may have to be modified in order expedite feathering before the rpm drops below a critical figure.
The current updated CAA advice can be located in the following link:
http://www.ead.eurocontrol.int/eadba...2005-12-08.pdf