Wheels up landing, to feather or not PART 2

[Marauder]

Peter F and Much Ado, with all due respect it is not quite so simple,

If the AFM has a procedure follow it,

by way of example, the SA227 (Metro 3/23) Manual, directs to feather the engines prior to touchdown,

to do otherwise would have you answering pretty sicky questions to
1) your company, but more importantly
2) a courtroom full of (wise after the event) legal counsell, particully if death
or serious injury ensued

[Grogmonster]

Maurader,

I am in very late here but have a question re the metro. Does it say to specifically feather both engines prior to landing with gera up or is this a ditching? What circumstances? I have to agree that it has to ba as per the book.

Groggy

[Marauder]

Groggy, as requested

From the SA227 QRH


NOTE
• If either main gear will not extend, land with
all three gear up if possible. If the nose gear
will not extend, land on the mains.
• Depressurise the aeroplane so that escape
hatches will be available after landing.


LANDING GEAR UP (ALL THREE UP)
1. Use full flap
2. Pull EGPWS C/B (Ideally, once in VMC conditions).
3. Approach at 5-10 kts above normal approach speed.
4. Do not feather propellers until landing is assured.
5. Shut off electrical power just prior to touchdown. Leave
batteries on at night to permit use of landing lights.
6. Touch down in flat attitude on runway centre-line.
7. Use rudder for directional control.


The rational being that a feathered prop is less likely to produce flying debris which may puncture the cabin, and will also be completely stopped during the subsequent evacuation.

Unlike a PT6, a TPE 331 ( as fitted to the Metro) there is an engine STOP and FEATHER knob, first detent shuts off fuel, second feathers the prop, so the gas generator by virtue of this be shut down as part of the Feather process.

[Howard Hughes]

Turbine blades tend to move quite freely in the feathered position, so will move to the position of least resistance, piston blades sometimes will not!

As others have said, do what it says in the manual, there is no single correct answer...:ok:

[Mach E Avelli]

I saw an Aztec landed in the UK gear up with both props feathered. Because they were 2 blade props, the pilot had the presence of mind to crank them to horizontal. Did a nice job with the landing too. Minimal damage.
But yes, do whatever the book says. If no book statement, use your own judgement.

[Peter Fanelli]

Certainly IF it is covered in the book then follow the book.
If it is not in the book DO NOT feather.

There was another Aztec in the UK in which the pilot feathered and the aircraft flipped on it's back killing the five occupants.
I watched a duchess at Parafield almost go on it's back due to feathered props but fortunately the engine concerned departed the airframe just before the aircraft went past vertical and it settle back the right way up.
There's no guarantee that you will be able to get the propellor into an appropriate position when gliding and two props and engine inspections must be cheaper than the effects from tearing the engine mount out.

[ForkTailedDrKiller]

There was another Aztec in the UK in which the pilot feathered and the aircraft flipped on it's back killing the five occupants.

There was another Aztec in Fiji tried the same trick - didn't get it quite right - flipped on its back crushing the cabin and killing the pilot.

Dr :8

[Capt Claret]

I'm not familiar with the Metro, though as a mate from aeons ago was want to say, I would recognise one if I saw one. :\

4. Do not feather propellers until landing is assured. is not the same as an instruction to feather the propellers. The express instruction to feather doesn't appear in the QRH extract above.

[Peter Fanelli]

Some might say that landing is not assured until the wheels (or the belly) are on the ground.

[Capt Fathom]

Peter,

While you quote certain disasters, I have seen many feathered arrivals that have been quite successful.

There is no one answer that fits all scenarios!

So you really cannot say.... If it is not in the book DO NOT feather.


If there is no guidance in the POH, the pilot in command decides what is required to achieve the desired outcome.

[Peter Fanelli]

And if, as I mentioned before, you cannot get a prop to stay in a suitable position so it will not drag on the ground then you've committed yourself to a high risk touchdown.

I just don't think it's worth the risk.

[Capt Fathom]

Peter,

They may stuff up the takeoff, so won't have to worry about feathering for the gear up landing!

What are your thoughts on takeoffs?

[Peter Fanelli]

If all propellors were feathered for take off there'd be fewer accidents.

:E

[grade-3]

Capt Claret (quite correctly) said:
I'm not familiar with the Metro, though as a mate from aeons ago was want to say, I would recognise one if I saw one.


4. Do not feather propellers until landing is assured.
is not the same as an instruction to feather the propellers. The express instruction to feather doesn't appear in the QRH extract above.

I agree, the devil is in the detail, and the extract from the QRH Marauder posted above lacks specific instructions to feather the props. However, the Metro 23 (sa227dc) AFM says (page 3-20 in my copy):

Propeller blades contacting the surface while turning under
power tend to disintegrate and throw shrapnel which may
puncture the fuselage. Blades contacting the surface when
feathered, or nearly feathered, will bend slightly and wear away
but most likely will not shatter and will aid in holding the wings
and nacelles off the runway.


and for partial gear landings, the AFM says:

LANDING WITH NOSE GEAR AND ONE MAIN GEAR EXTENDED:

...

3. Feather propellers after landing on the runway is assured.


The intent in the Metro 23 AFM appears to be that there is a preference to feather the propellers for a gear up landing, and a directive to do so for a partial gear (one main hung up) landing.

So, yes, follow the AFM, and I believe that Marauder is quite right about the Metroliner.

grade-3