Cessna 402 prop feathering time
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Cessna 402 prop feathering time
Back in 1987 in Australia, a Cessna 402 crashed shortly after take off when one engine failed. The pilot was using a hand held microphone and was engrossed in talking to ATC after they saw him passing lower than expected over the departure threshold. The aircraft eventually got into a VMCA situation and flicked and spun. The investigation revealed he spent 18 seconds of the 25 second flight time answering ATC concerns. One hand flying and the other holding a mike. All aboard were killed.
The investigation discovered the pilot had not feathered the failed engine prop. The question arose about the length of time in takes for the prop to feather in a Cessna 402. Various figures were quoted including one figure of 15 seconds from the time the feather lever is actuated to the time the prop is feathered. On the other hand in a Seneca 2, the prop feathering time is three seconds.
Does anyone have reliable information on how long it should take to feather a prop from initial actuation of lever to prop stopped for the Cessna 402?
The investigation discovered the pilot had not feathered the failed engine prop. The question arose about the length of time in takes for the prop to feather in a Cessna 402. Various figures were quoted including one figure of 15 seconds from the time the feather lever is actuated to the time the prop is feathered. On the other hand in a Seneca 2, the prop feathering time is three seconds.
Does anyone have reliable information on how long it should take to feather a prop from initial actuation of lever to prop stopped for the Cessna 402?
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The answer isn't so simple as "how long." The nature of the reason the engine is being feathered has a lot to do with "how long."
I've feathered engines after failures or other engine problems, which didn't feather, ever. Others that partially feathered. Others which went into feather and came back out again. I've had engines that couldn't be feathered; one in particular resulted in a forced landing three years ago, when all engine oil was pumped overboard...and the propeller didn't feather.
If the engine is properly shut down and everything works as published, the feathering should take place in several seconds...but it may be substantially longer.
The time involved in feathering isn't particularly relevant in the case you've described, however. Whereas the aircraft eventually was lost not due lack of climb performance, but assymetrical thrust (and thus failure to fly the airplane)...concentrating on the time to feather is concentrating on the wrong area. An engine failure on departure is not the time to be talking on the radio.
I've feathered engines after failures or other engine problems, which didn't feather, ever. Others that partially feathered. Others which went into feather and came back out again. I've had engines that couldn't be feathered; one in particular resulted in a forced landing three years ago, when all engine oil was pumped overboard...and the propeller didn't feather.
If the engine is properly shut down and everything works as published, the feathering should take place in several seconds...but it may be substantially longer.
The time involved in feathering isn't particularly relevant in the case you've described, however. Whereas the aircraft eventually was lost not due lack of climb performance, but assymetrical thrust (and thus failure to fly the airplane)...concentrating on the time to feather is concentrating on the wrong area. An engine failure on departure is not the time to be talking on the radio.
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Does anyone have reliable information on how long it should take to feather a prop from initial actuation of lever to prop stopped for the Cessna 402?
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The time involved in feathering isn't particularly relevant in the case you've described, however
Hence the original post. What is the certified feathering time of a C402...
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What is the certified feathering time of a C402...
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Maybe - maybe not. If the prop is not fully feathered then presumably it is windmilling and creating significant drag. In the case of the accident described, the drag of the windmilling prop was a direct cause of the reduction of airspeed until Vmca was reached and control was lost. If the prop had been feathered immediately the engine failure was confirmed, chances are there would have been a better outcome. If the certified feathering time of the C402 propeller/engine combination is lengthy (15-17 seconds), this has serious ramifications - that is the drag is there for much longer than for a another type which may have a certified feathering time of 3-5 seconds (Piper Seminole or Seneca 2).
Hence the original post. What is the certified feathering time of a C402...
Hence the original post. What is the certified feathering time of a C402...
It wasn't a 402, but I did a feather and restart on a 414 today. In this case it partially feathered and I had to pull it sharply to the stop to get it to go. At that point it feathered quickly.
The windmilling propeller isn't the cause of the assymetrical thrust loss; it's the failure to retard the engine still producing power, and that's the cause of the loss of control. In a piston airplane such as the 402, drag on the windmilling propeller causes a performance loss, but it's a failure of the pilot to maintain control that leads to a mishap...not the windmilling propeller.
I've flown four engine airplanes in which the failure of a single engine to feather caused an inability to maintain altitude using the remaining three; certainly performance loss can be significant. However, is a loss of directional control occurs, this is a failure to fly the airplane. The propeller may or may not feather; one may take action to achieve a feather...but one still needs to keep flying the airplane all the same. This may very well require retarding power on the operative engine to keep directional control.
The time to feather...depends. It may never feather, depending on the problem. This never obviates the responsibility to fly the airplane, and the time it takes is largely irrelevant in consideration of this responsibility.
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This may very well require retarding power on the operative engine to keep directional control.
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Had an engine failure (piston and cylinder departed through cowling) immediately after take-off before even the gear was up. Single pilot ops.
Prop feathered in much less than 5 seconds and told ATC "Engine failure, standby." Munich ATC wanted to know a lot, I simply did not reply and did my job, after about 2 minutes and all under control I spoke to ATC and we arranged the circuit to return....recalled like it was yesterday and not about 20,000 hrs ago....
Prop feathered in much less than 5 seconds and told ATC "Engine failure, standby." Munich ATC wanted to know a lot, I simply did not reply and did my job, after about 2 minutes and all under control I spoke to ATC and we arranged the circuit to return....recalled like it was yesterday and not about 20,000 hrs ago....
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I think we are going around in circles on this one in more ways than one. If you then pull back the power on the operating engine to avoid a Vmca situation then chances are you will lose further speed and certainly as you say a loss of performance. Eventually you will crash somewhere but not due to Vmca. And it all started from the propeller failing either to feather after windmilling and subsequent loss of performance. End of thread.
It's one thing to try to blame the airplane for failing to feather in a timely manner (a poor carpenter blames his tools). It's entirely another to take responsibility as the pilot in command for ensuring control of the aircraft (and yes, this frequently means retarding the power on the good engine in a light piston twin like the 402). One does not equate to the other. If one loses control and crashes as a result of a propeller failing to feather...it's not the propeller, and there's no good excuse for having lost control...that's a pilot problem, not a propeller problem.
Most certainly with loss of power on one engine, performance is lost. Most of us understand that with a light twin, not 50% of the performance is lost with one of two engines failing, but closer to 80% or greater. We have two engines in a light twin for performance, rather than redundancy or safety...it's axiomatic that the other remaining, functioning engine may do serve only to help drift down to the scene of a forced landing.
That performance is lost isn't the question. That control is lost, is. Certainly with loss of a motor, performance will substantially diminish. However, maintaining control of the airplane is a key issue; it's the only issue, in fact. With a drift down or descent with reduced power, a given outcome may be inevitable or may not...but maintaining control of the airplane vs. allowing the airplane to depart controlled flight are two very different things...not at all talking in circles about the same thing.
Even if a propeller never feathers, and this is possible...losing directional control should never occur. This isn't a function of the time it takes to feather a prop. It's a function of pilot failure to maintain control. Rule #1 is always fly the airplane. This is a given. This is what we can control. We may not be able to control the feathering of the propeller, but we can certainly control the airplane.
Again, the question is how long does a 402 propeller take to feather. There's no such thing as a 402 propeller...the same propeller is used on other aircraft, and the same engine propeller combination is used on other airplanes. In fact different powerplants and different propellers are used, depending on the model of 402, within the same family of aircraft. It's not a "402" propeller. It's a McCauley propeller on a Continental engine.
The question isn't whether a McCauley prop feathers quickly on a full functioning motor...but whether it feathers or not, in an emergency during a malfunction. Of course the time may be extended...it may not feather at all...and the time, and the function, depends on what's wrong.
Whether it feathers or not, however, isn't the cause of a loss of control. It's a pilot problem. Ask not how long to feather, but how dedicated the pilot is to maintaining control.
End of thread? Not.
