Ditching: Gear up or down

[athonite]

Just wondering if any of the instructors have any thoughts on forced lands onto water in low wing retractable gear types, such as the Piper Arrow or similar. Even better has anyone got first hand experience?

My thoughs are:

(a) Landing with gear up made develop into a series of bounces, compounded by the possible separation of a flap since this will make contact first the water first, inducing roll or pitch.

(b) Landing with gear down, would be a faster deceleration, but may induce some pitching as the gear touches the water.

Let me know what you think.

[Daysleeper]

What does the Aeroplane Flight Manual say?

[2close]

Fella at Swansea had to do this 2 years back in an Arrow.

He chose to keep the legs up and made a safe ditching onto very calm waters; picked up by a fishing boat very quickly and the aircraft went down shortly afterwards - still down there! Here's the AAIB report.

http://www.aaib.gov.uk/cms_resources/Piper%20PA-28RT-201T,%20G-JANG%208-05.pdf

I also recall a C-152 going into Tampa Bay back in '94 on the approach into Albert Whitted. The moment the wheels touched the water they just dug in and flipped the a/c over on its back. Both pilots got out safely.

As has been already suggested, reference should probably be made to the POH but as a generalisation I would have thought that leaving the u/c retracted would be the correct technique when landing on water or dense, deep or tough undergrowth - there may be less chance of flipping over.

[huckleberry58]

Gear up definitely.

[Caboclo]

Always gear up. A guy in my class in flight school had a cockpit fire, chose to ditch into a lake, and put the gear down. The autopsy showed he died not of fire or drowning, but blunt trauma. Water is extremely hard if you hit it fast enough. Leaving the gear down decelerates you much too fast; in that case the best you can hope for is being flipped upside down. If you leave the gear up and get a "series of bounces" so much the better, because each bounce will dissipate energy, making the final stop that much gentler. In that situation, the last thing you should worry about is flap separation. In an emergency, you should consider the plane to already be destroyed, and use it to absorb the energy of the crash so you don't have to absorb that energy in your body.

[Whopity]

IF you ditch with gear down, water will ingress into the wheel bays with possible disastrous consequences. Turned a C130 into a submarine!

Plan to land crosswind, along the swell rather than into it.

[DaveW]

The CAA Safety Sense leaflet (SSL21b) on ditching (http://www.caa.co.uk/docs/33/SRG_GAD_WEBSSL21.PDF) is worth reading.

That says:

h. Retractable gear aircraft should be ditched with the gear retracted (beware of automatic lowering systems). The Flight Manual/ Pilot’s Operating Handbook may provide suitable advice.

[maxdrypower]

Now recently had this discussion at length with some steely eyed types . The consensus of opinion is if retractable , gear definately up no question for reasons already mentioned. Now what are peoples thoughts on this , in fixed gear I was taught by a very experienced FI , although I say taught more like was discussed as Im sure he hasnt actually done it. He stated that due to the flipping characteristic safest form of arrival on terra wet would be to stall the aircraft on . This may give a heavier impact but the aircraft would not flip , any thoughts

[DaveW]

This is an interesting read: Ditching Myths (http://www.equipped.com/ditchingmyths.htm)

Myth 5: In A Retractable, It's Better to Ditch With the Gear Up Than the Gear Down

This one has sparked more hangar arguments than debating over pitch and power. Here's our view: It probably doesn't make much measurable difference. Or, put another way, if you think it does, show us some data.

Unfortunately, the accident records shed no useful light on this controversy. Pilots often don't remember whether they extended gear and/or flaps; they don't recall if they landed with the swells or upwind or crosswind. Even if they do remember, this detail often doesn't make it into the accident summary.

We think the best you can do is to examine the big picture: Irrespective of aircraft configuration, do the pilots and crew get out of the airplane after impact? Yes, overwhelmingly. How often does the airplane flip over because the gear caught in the water? We don't really know. But even if all the airplanes flipped--highly unlikely--the occupants still manage to egress safely. Conclusion: It may not matter much.

From films of live ditchings and interviews with survivors, our impression is that most airplanes don't flip, but dig in one wing, turn and settle upright or settle straight ahead with a bit of nose under moment. But, we simply don't have enough reliable information to make a definitive judgement on this. Our best advice is make your own assessment and configure the airplane accordingly.

More critical than configuration, in our view, is touching down parallel to the swells, or if that isn't an issue in calmer water, landing into the wind or with the river's current to yield the lowest possible touchdown speed.

Worth noting is that 9 of the 22 fatal ditchings involved retractables. As with the high wing versus low wing controversy, these numbers are too small to draw any meaningful conclusions.

[Keygrip]

I do recall attendance at a safety seminar, one particular session of which was hosted by a Search and Rescue pilot (Blackhawk/Pavehawk helicopters).

He firmly suggested that you do not stall the aircraft into the water ...... as the sudden upward force on the underside of the fuselage in a tail strike could easily exceed design limitations.

This "MAY" cause the aircraft to break apart and suddenly fill with water from behind - taking all concerned by surprise.

I later, whilst doing some reasearch on Engine Failure After Take Off, discovered that for an aircraft to be certficated as airworthy, the cabin must be able to accept a deceleration of 9G's without structural damage.

The two items together did make me reconsider my earlier taught plan of stalling onto liquids.

[OpenCirrus619]

Myth 5: In A Retractable, It's Better to Ditch With the Gear Up Than the Gear Down

Well the wheels certainly snatched and caused a big pitch forwards here (http://www.youtube.com/watch?v=i2rtWsGt91Y). I guess this will start a discussion about whether it would have flipped had the bow of the floats not dug in - personally I reckon it would.

I'm certainly going to stick to what I was taught for retractables: Forced landings on water or rough / v. soft ground should always be wheels up.

OC619

[xsbank]

A friend of mine, flying a Grumman Tracker, had an opportunity to ditch in a river after a double flame-out (don't ask) and he chose the water with the gear up as opposed to a poor field because he figured with the clean bottom of the a/c, he would just skip along the water, stop and climb out in a dignified manner.

Wrong. The a/c touched the water, pitched forward on its nose and the nose cone came off, breaking the panel off and landing it in his lap. The cockpit "immediately" filled with water then the a/c immediately sank. He released his harness, couldn't find the escape handle (wrong order, but he was understandably stressed), and he very nearly drowned until he could find it, open it and swim to the surface.

A/c don't just skip along on their bottoms, gear up or down...

He should have chosen the field because not much would have burnt!

[JW411]

I have only met three pilots who have ditched.

The first one ended up in the water on finals to Gan Island in a Handley Page Hastings (large 4-engine taildragger). He had full flap and the gear down at the time. All on board survived.

The second one ended up in the water on finals to Khormaksar in Aden in an HS Argosy (4-turboprop with nose gear). Once again, he went in the water with flaps and the gear down. All on board survived.

The third one went into the water in an Auster. The gear was down and welded and he survived.

Pick the bones out of that.

[Keygrip]

There aren't any bones - they all survived!!

[Cap'n Arrr]

A couple ideas, although keep in mind I have never ditched, or met anyone who has.

In an Arrow, my concern would be (I would assume anyway) to clean up the underside. A 152 I can imagine to be more flip-safe than an Arrow:ouch:. So having decided that I would be putting up the gear and locking the Emergency Extension all the way up (to turn of auto extend, although all the Arrows I've flown have had them disabled anyway).

Next I would think about flaps. From what I remember about the Arrow, the flaps hang down below the underside when extended, so if the approach is conducted flapless, there would be less risk of them reducing the controllability of the aircraft after touchdown, as well as possibly keeping the wings intact:}. Also, I'm fairly sure the Arrow touches down fairly flatly in a flapless as compared to normal approach (I may be wrong, it's been a while :(), and I would be going for a slightly nose high touchdown (not too high, just enough to make sure the nose doesn't dig in initially).

Speaking of the nose digging in, if I had time, stopping the prop would be crossing my mind (I'm unsure as to what effect a windmilling prop would have on touchdown), as well as unlatching the door, in case it jams otherwise.

On that note, I've evidently had too much time to think about this, so I'll leave it there.:bored:

Arrrr!