Russian Water Landing & Sinking
 

Link here.

how do you check for leaks???
 

Apparently this accident was caused by water leaking into the hull such that when the pilot applied a touche of nose-down the whole lot ran forward and tipped him over. How do you check for leaks .... before you take your amphibian swimming that is?

C.K-D

This thread was around a couple of years ago. First scene, helo has single engine failure, blades cone up, sinks onto water.
To stabilise the aircraft, he lowers the gear to keep the cg low.

Some time later, he attempts a single-engine takeoff, but has forgotten to raise the gear, so the drag tips him over. Should have stopped when his window went under the first time, but the scene continues and over he goes.:sad:

Here on Mi-14s the crew chief (flight engineer) is the one to prevent pilots from doing stupid things. I know of one occasion when a pilot submerged whole nose on take of and tried do get out of the situation by applying more collective (not a good thing) - crew chef stepped into action reducing power on both engines allowing the machine to float up, and avoiding main rotor blades from striking the water.

The whole idea of amphibious helicopter is not very good - it was prised by USCG in the days of Pelican, but on Mi-14 it just make it dissolve faster, as the water landings are part of routine training, even though I don't remember if in the last 25 years they had to do this operationally. Kind think of it, the same goes for the life rafts inside - there are 5-6 oil-drum-sized rafts stored, and they were last time used during Hevelius sinking in 14th January 1993 (didn't do anything good, but that's a different story).

Ascend Charlie

Doesn't make much sense that, how can he take off if the engine has already failed :p

What happened the machine at the start, did he get into VRS??

Dave

Combination of rough sea...gear down....low power margin (if any)...and a major brain infarction all at the same time!

The gear does not provide that much drag in reality....the Chinook does a grand running landing and running takeoff to water....smooth water...with both engines running. Not sure I would want to try a single engine takeoff however...unless you can hover.

If one takes on water inside the aircraft...then lowers the nose.....I can see where it might get awfully nose heavy in a hurry! I know of at least one UH-1H that was lost that way in Vietnam. Monsoon rain flooded the landing site....filled the low lying spot until there was about six inches of water inside the cabin and cockpit. Upon attempting a takeoff....the pilot lowered the nose and enough water flowed forward to cause the aircraft to nose into the water again but this time with substantial forward speed. Result was very similar to the video of this Russian aircraft.

We wound up slinging out a pile of wreckage instead of a wet soaked aircraft.

ONE engine out of two failed! So an SEWTO ( Single Engine Water Take Off ) would eventually be possible. The danish and canadians practised that for training even with a real helicopter ( Seaking/ S61 ) and it works fine. It was a standard procedure during our simulatortraining on the Seaking.
After reducing the weight to the calculated SEWTO weight Speedselector full forward, gain max. waterspeed ( approx. 15 kts ) and pull collective to min. NR.

skadi

I didn't seen crash report on that Russian Mi-14 so will not go to why it happened.

But:
Sea King is a lightweight helicopter, compared to Haze. Haze is more than twice as heavy while empty, with only around 18% more power. It can not take off on one engine. Not from water, not from airstrip.

Actually you can't maintain altitude above 1400 feet, and speed is reduced to 60 kts. 2225 HP* will only give you that much in 12 metric ton airftrame.

* The TW3-117M-III series engines have 5 distinct operation regimes:
1 and 2 - Cruise - producing 1200, and 1500 HP
3 - Nominal - producing 1700 HP - 60 minutes limit
4 - TakeOff-limited - 1950 HP - in this mode engine work if the other is inop, but with 6 minutes limit it will probably only get you to the ground/water, longer - it's a gamble.
5 - TakeOff - 2225 HP for limited period of time - as long as exhaust temp. is below 990*C (usually measured in seconds)

Somehwere it was written that floats located forward of the sponsons on the fuselage would have prevented nose plowing during water taxiing.

No, no where near it.

smoke and mirrors
 

When this video first came into the public spotlight the two different camera angles were neatly and seamlessly edited so that it appeared the elapsed time between initial impact and attempted takeoff was just a few seconds.

If there is a cut or change of angle we should not assume the action is continuous.


Mickjoebill

Water spouting from 'radome'.
 

I noticed that when it turns over and the nose bobs partially out of the water that a jet of water comes out a what appears to be a circular hole, perhaps a few inches in diameter, on the bottom of the 'radome'.

I wondered if the cause of the take-off failure was that the radome contained a significant amount of water that had leaked past a displaced inspection cover or somesuch.

The water spout can be seen clearly on the video at second 13 (counts down) just above (on the image) the front port (on the machine) gear leg. Later at second 7, as the radome bobs out again the water has stopped and the hole can be seen as a black spot.

Perhaps the water can be seen earlier too (say second 16) but with the general splashing and the less tight camera zoom it is less certain.

Maybe its sonar and is designed to flood?

That was Mi-14 PS - search and rescue version - no sonar, MAD or sonobuoy launch tubes on those, the bomb-bay is also reduced, although the radar is on its place. If that hole was the only one in the fiberglass radome it couldn't fill with water - it is watertight, and without a way for air to vent elsewhere - its pressure would minimize the leakage.

Will try to look for crash report on Russian sites, maybe it will shed some light.

I don't speak Russian and the Cyrillic alphabet looks to me like hieroglyphics, therefore I use online translators while searching eastern web sites. I will send it to someone who can... but don't get your hopes high, as this material is fresh after the crash, and what I understand (from similarieties between Polish and Rusian language) at that time their prosecutor was about to start investigation to find out if the cause of crash was a mechanic malfunction, and if the safety regulation were crossed.

I searched for crash report although as that aircraft belong to military - none was given to the public, for civilian crash investigation you can find info on Mak.rusite. For military.... well you need to be in it ;)

@Dan Reno - I don't think any additional floats would do anything more than add drag, this construction floats by itself, inflatable bladders on sponson sides are for more stability in such conditions (a side note: although they can be inflated with a bottle, the main system is compressed air from compressor - they will slowly deflate if the engines stop running). The limitations for performing water running takeoffs are:
- waves up to 2°
- wind speed up to 20kts
- forward speed no more than 8 kts
- weight no more than 12000kg (no load except for equipment and some fuel)

I've looked the manual for any note that lowering landing gear will increase stability on water and found none... and I don't think it will work that way.

One of the things not mentioned here so far is the sea state. All the SEWTO practice done by the Canadians was with very small waves. I think the pilot got out of phase with the waves, and didn't realize that with the nose going down so far, he was out of options very quickly.
Increasing collective would only drive the nose down further - dynamic pitchover if we can coin a phrase.
This has also happened to two OH-58s on floats at the US Naval Test Pilot School, trying to do running takeoffs on the water (don't ask why - it was noted in at least one country's flight manuals as a prohibited maneuver) and the front of the skids got underwater, and over they went.

nose down attitude of Mil Choppers
 

The mils, especially the Mi 8 and Mi 17, have a very very nose down attitude when taking off, and for the uninitiated it looks like the main rotors are about to touch ground when moving forward ...:}

The Mi8/17 has steps for the forward door, while the rear doors can be almost walk-in height ..

I was always amazed when these choppers transitioned, fearing they are gonna loose it ....

That's why manual advises to keep 1/4th of rearward cyclic during takeoff, and perform running takeoffs with level attitude, especially avoiding rising main gear, but still rolling on the front, as in Mi-14 it is not very strong and may be damaged this way.

A lot of don'ts in those machines.

When that sort of Heli has the sort of power being quoted, why was the pilot not able to just get up to max power similar to that required for a towering take off, and gently lift off?

Peter R-B
Vfr

Only obvious reasons come to mind. Either they couldn't pull off so much power - any mechanical failure, or engines already running hot. Or it wouldn't do anything - overweight.