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Jetpipe.
10th May 2011, 11:52
Assuming an aircraft with landing gear stuck down or with no retractable gear.. and the only thing left possible to do is to ditch it in the sea (calm sea?). Which do you think is the best-safest way of doing it?

In many discussions people often talk about a possible flip-over because of the gear down .. So being close to Vso when hiting the water ( lucky us flaps are still working! ;) ) is I suppose one correct thing to do but I m not 100% sure.. hmm ..???

Jp

lomapaseo
10th May 2011, 16:48
Your question has way too many controversial presumptions in it to be answered..

best that you start over with more basic questions

Oktas8
11th May 2011, 03:11
Which do you think is the best-safest way of doing it?

The way the flight manual says to do it...

More helpfully, if the flight manual doesn't say, you can look up the manual of an aircraft of similar design. The usual phrasing is to land at minimum speed with some amount of flap down, along the primary swell, only into wind if the wind is so strong that a crosswind (along-swell) landing cannot be contemplated... etc. There are variations on this theme.

I have heard many pilots express concern about the aircraft flipping over. However, the accident record of recent years suggests that this is unlikely. Springing to mind in my part of the world are ditchings of a Piper Warrior near Kaikoura NZ, a Cessna 172 near Auckland NZ, and a PAC750XL between Hawaii & SFO. All fixed gear, none flipped on landing. Other ditchings have occurred but I can't positively recall whether they flipped. I think not though. The most common outcome seems to be either swimming a short distance to shore, or death by drowning / hypothermia if not close to shore. The PAC750 is the exception to this - death in the cockpit of a floating aeroplane.

PS - there was that Cessna in a sewage pond, if that counts... No flipping either, thank goodness for the pilot! I wonder if the increased viscosity of sewage more than compensates for the decreased speed on entry from a runway overrun? :yuk:

V1... Ooops
11th May 2011, 04:53
Below is an image of the guidance provided in the AFM for the Twin Otter, which is a 12,500 pound, high-wing, fixed gear, twin-turboprop aircraft.

As the text states, the guidance is speculative and generic, because no ditching trials were carried out. Several Twin Otters have been ditched due to fuel exhaustion with no injury or loss of life.

http://i979.photobucket.com/albums/ae275/Paneuropean/TwinOtterDitching.jpg

Jetpipe.
11th May 2011, 12:35
Many thanks for the replies guys!

Lomapaseo, yes you re right I should have been more specific about my thoughts but it seems like Oktas8 and V1..ops managed to get into my thinking! :)

So the question is.. Up to what factor is gear down affecting the technique used at a potential ditching?

From the answers i got i assume that the technique is not affected in any way, it is the same we would have used with retracted gear..

My fear for a possible flip-over was for small, light piston aircraft with fixed gear. I thought that less weight would increase the probability but then stalling speeds can be really low for these planes which in this case counteracts that probability.. Maybe this explains why they dont flip-over!

Thanks again, ;)
Jp

V1... Ooops
11th May 2011, 18:53
From the answers i got i assume that the technique is not affected in any way, it is the same we would have used with retracted gear...

I agree with that conclusion.

For sure, it is not an advantage to have gear down, but if it has to be down - as is the case with fixed-gear aircraft - then there is nothing much you can do about it.

I think that the key point is "don't stall it in".

Michael

EDLB
11th May 2011, 19:22
One additional point they trained in Hawaii. Before impact unplug and throw all headsets in the back that nobody gets entangled when geting out.

lynn789
13th May 2011, 03:13
a high speed touchdown on the surface of smooth water might appeal but when this was tried with the amphibious catalina, it never worked

Torqueman
13th May 2011, 10:07
I'll take a really bad landing any day over a good ditching! :ooh:

bubbers44
13th May 2011, 10:52
Sully did a great demo on video on how to ditch properly. Half flaps, gear up and don't stall it in. Use airspeed to stop descent and let it touch down with minimum descent rate.

Checkboard
13th May 2011, 11:05
A float plane has a very high CofG, but this at least shows the deceleration when landing with the wheels down on water!

YouTube - Float Plane forgets "wheels up" when landing on water

Jetpipe.
14th May 2011, 16:48
bubbers44, yes that was textbook! But what do you have to say about the Ethiopian airlines flight 961? The situation these pilots faced was indeed a lot different, with hijackers in the cockpit.. They never managed to get the plane leveled before impact and the rapid deceleration riped the 767 apart as the left wing and engine dugg into the sea first..

Checkboard, Clearly a pilot having both land & sea class rating! pretty confusing, hehe!

-Gear down!
-Check!!

or should it be..

-Gear up!
-Check!!

or was it down..?? :confused: :E

Pugilistic Animus
15th May 2011, 01:25
I also guess much depend on if you have engines or not...in either case it would be important not to let catastrophic vertical speed rates develop in an attempt at minimizing airspeed

Checkboard...what a sad way for her to go out...:{