Russian Water Landing & Sinking
Moderator
The gear does not provide that much drag in reality
I cannot see how the helicopter could manage any better that the flying boat. If you tried a wheels down takeoff in a flying boat or float plane it would go over, though probably with some warning to the pilot. He would have pitch control to use to resist the nose over, while he reduced the power.
With all the drag on the bottom, all the thrust at the top, and no ability to control forces in the whole aircraft pitch axis, it seems pitching over is inevitible for the helicopter, if you tried a running takeoff on water with the wheels down (those long looking dual nose wheels can't help either). Perhaps the Chinook can manage better because it is tandem rotor, and I presume has much greater pitch control.
I recall a spectacular photo of a Vertol 107 towing a load on the surface, it had an incredible nose low pitch attitude, and I presume was in stable flight. That photo makes me think that with a high "drag" force on the lower portion of the helicopter, it would like to assume a very nose low attitude to fine stable flight. This helicopter just found the water with the blades before it got to the stabilized nose low attitude. The forward sponsons of the Sea King having the bouyant effect forward of the C of G, is an interesting observation in light of the other considerations.
Pilot DAR
Couple of points...
The BV-107 photo taken on the North Slope provided a visual illiusion as the actual pitch angle was was less than it appeared.
The drag the landing gear would have at the 10-15 knots of water speed would be far less than at an airplane's takeoff speed of 70-90 knots.
On a Chinook....the allowable center of gravity travel is on the order of 144 inches depending upon the model of the aircraft....thus it has a full 12 feet of CG range. Add in the quad gear....spaced a long way apart and it does not want to tip forward like a tricycle geared aircraft.
In a boat hulled helicopter like the S-61.....I would imagine drag would be the issue and not control limitations. Perhaps Crab or some other 61 or Sea King pilot could enlighten us on that.
Perhaps control touch is more important than anything.....
YouTube - cubdriver749er.com - demo video 1
YouTube - Landing on water without floats!
The BV-107 photo taken on the North Slope provided a visual illiusion as the actual pitch angle was was less than it appeared.
The drag the landing gear would have at the 10-15 knots of water speed would be far less than at an airplane's takeoff speed of 70-90 knots.
On a Chinook....the allowable center of gravity travel is on the order of 144 inches depending upon the model of the aircraft....thus it has a full 12 feet of CG range. Add in the quad gear....spaced a long way apart and it does not want to tip forward like a tricycle geared aircraft.
In a boat hulled helicopter like the S-61.....I would imagine drag would be the issue and not control limitations. Perhaps Crab or some other 61 or Sea King pilot could enlighten us on that.
Perhaps control touch is more important than anything.....
YouTube - cubdriver749er.com - demo video 1
YouTube - Landing on water without floats!
Last edited by SASless; 20th Jan 2009 at 04:07.
Join Date: Jul 2007
Location: Canada
Posts: 228
Likes: 0
Received 0 Likes
on
0 Posts
Yup, the 61 does a single engined water take-off just fine if you get the weight down a bit and you have the 140-1 or 2 engines. I don't know about the 110's.
At least the OKie 61's did.
And probably pulling the gear up for take-off would be good plan, too!
This is because the puppy can be notoriously nose heavy when taxiing (depending, of course, on cabin loading) for example, through snow or muck - which is kind of like taxiing on water. It is really easy to scuff the forward belly light under these conditions.
Anyway, trying a water take-off with the gear down requires a technique I don't have.
At least the OKie 61's did.
And probably pulling the gear up for take-off would be good plan, too!
This is because the puppy can be notoriously nose heavy when taxiing (depending, of course, on cabin loading) for example, through snow or muck - which is kind of like taxiing on water. It is really easy to scuff the forward belly light under these conditions.
Anyway, trying a water take-off with the gear down requires a technique I don't have.
Last edited by oleary; 20th Jan 2009 at 05:47.
As far as i remember, the procedure for SEWTO ( Sea King ) was allways "gear up" to reduce drag / nose down moment! It was recommended to put the gear down if you have to float in the water to increase the stability ( lower C of G ), but for landing/ takeoff in the water allways gear up!
skadi
skadi
Join Date: Aug 2007
Location: Texas
Posts: 65
Likes: 0
Received 0 Likes
on
0 Posts
I have about 130 hours in a ASW Mi-14 and one of the systems on the aircraft is a door, window, radome, and bomb bay pneumatic seal that is supposed to be activated anytime over water. If the system is not activated, the radome will fill with water when you land in the drink and at 8.5 lbs. per gallon the weight it takes on will preclude any kind of take off. There is simply no way that enough aft cyclic control is available to stop the nose down pitching moment. Also, notice that the sponsone floats were inflated at some point which will allow for some lateral water stabilty, but not help a bit with pitch control. It appears that the seal, if installed and working was not operating since in one frame the left door is partially open. The pneumatic system seals all of the aircraft doors/openings at once.
I suspect that once she went into the water, it didn't matter what the crew did. The nose was going down.
I suspect that once she went into the water, it didn't matter what the crew did. The nose was going down.
Join Date: Nov 2007
Location: Poland
Posts: 178
Likes: 0
Received 0 Likes
on
0 Posts
Can you please show me that pneumatic seal on this main door frame ?
To my knowledge the whole radome is one piece - fiberglass composite, mounted to the fuselage with around 10 screws - between radome and fuselage there is rubber-like substance neatly sealling it off. The radar/avionics compartment is also sealed, just like the hydraulics that operate the bomb-bay door, that are located behind it. I may be wrong, but I think I would notice it.
To my knowledge the whole radome is one piece - fiberglass composite, mounted to the fuselage with around 10 screws - between radome and fuselage there is rubber-like substance neatly sealling it off. The radar/avionics compartment is also sealed, just like the hydraulics that operate the bomb-bay door, that are located behind it. I may be wrong, but I think I would notice it.
Join Date: Feb 2008
Location: midlands
Age: 63
Posts: 61
Likes: 0
Received 0 Likes
on
0 Posts
Tenpennorth
Looks like he had insufficient power to hover, hence the heavy landing in the drink.
Was he possibly trying to achieve tranlational lift to get off again? The sea state didnt help him either.
Easy to be wise after the event but an abandoned take-off, followed by a significant offloading of weight - ships nearby etc. - might have saved the day.
He might well have been taking on water though, and took the decision to go as opposed to losing the aircraft.
It would be interesting to read a tranlation of the pilots report. Anybody know the telephone code for Siberia?
JB
Was he possibly trying to achieve tranlational lift to get off again? The sea state didnt help him either.
Easy to be wise after the event but an abandoned take-off, followed by a significant offloading of weight - ships nearby etc. - might have saved the day.
He might well have been taking on water though, and took the decision to go as opposed to losing the aircraft.
It would be interesting to read a tranlation of the pilots report. Anybody know the telephone code for Siberia?
JB
Join Date: Aug 2007
Location: Texas
Posts: 65
Likes: 0
Received 0 Likes
on
0 Posts
LT FUBAR
I don't see it in this picture and it may be that this is a different version, I don't know. Ours had seals in the one and only passenger door. The door seal was mounted in the frame and surrounded the door. It, as well as the others, was activated by the pilot (left seat) using a round knob. The seals were swelled by compressed air from a tank that was fed by the compressor mounted on the main transmission. (Compressed air also powered the wheel brakes) These seals were located around each window in the cockpit, the radome, the bomb bay, as well as the door. Our aircraft was the ASW version and I assumed, perhaps wrongly that the accident aircraft also had the seals. I know that there was a SAR version of the MI-14 and I would think that they would want the seals also. Ours had no inspection port.
As for the radome, you are right about the numerous screws or bolts holding the fiberglass dome. But ours had the inflatble seal.
When we flew overwater, the drill was to shut all the openings, seal them, and insert air conditioner hoses into our flight suits since we didn't have the appropriate air conditioned suits.
In my opinion, if there was nothing more than just rubber gunk around the dome to seal out water, just a little deterioration and some hefty water pressure would cause a major leak.
I don't see it in this picture and it may be that this is a different version, I don't know. Ours had seals in the one and only passenger door. The door seal was mounted in the frame and surrounded the door. It, as well as the others, was activated by the pilot (left seat) using a round knob. The seals were swelled by compressed air from a tank that was fed by the compressor mounted on the main transmission. (Compressed air also powered the wheel brakes) These seals were located around each window in the cockpit, the radome, the bomb bay, as well as the door. Our aircraft was the ASW version and I assumed, perhaps wrongly that the accident aircraft also had the seals. I know that there was a SAR version of the MI-14 and I would think that they would want the seals also. Ours had no inspection port.
As for the radome, you are right about the numerous screws or bolts holding the fiberglass dome. But ours had the inflatble seal.
When we flew overwater, the drill was to shut all the openings, seal them, and insert air conditioner hoses into our flight suits since we didn't have the appropriate air conditioned suits.
In my opinion, if there was nothing more than just rubber gunk around the dome to seal out water, just a little deterioration and some hefty water pressure would cause a major leak.
Join Date: Nov 2007
Location: Poland
Posts: 178
Likes: 0
Received 0 Likes
on
0 Posts
The picture I posted is from Polish Navy Mi-14PS (#1016) - SAR version similar to the one that crashed (manufactured in 1983). There are no inflatable seals around doors. It is probable there is positive pressure inside the avionics (radar) compartment, but no inflatable seals there as well. Although our ASW Mi-14PLs do have a seal around the door, but I have no klowledge if it is in fact inflatable (didn't looked that way).
Join Date: Aug 2007
Location: Texas
Posts: 65
Likes: 0
Received 0 Likes
on
0 Posts
Lt. Fubar
I honestly don't remember the designation of ours. It has been several years since I flew it. The ones I have seen on the internet don't show enough detail to solve the confusion. Maybe some one you know around these aircraft will remember the seal inflation. On youtube there are several videos showing Mi-14's in various stages of water landings and they show a lot of water coming up to the windshield when moving forward in the water. That big radome doesn't help much.
I honestly don't remember the designation of ours. It has been several years since I flew it. The ones I have seen on the internet don't show enough detail to solve the confusion. Maybe some one you know around these aircraft will remember the seal inflation. On youtube there are several videos showing Mi-14's in various stages of water landings and they show a lot of water coming up to the windshield when moving forward in the water. That big radome doesn't help much.
I suspect Dark Horse was flying an ex-East German Mi-14 ,several of which were sold for potential firefighting and other uses ,although all/most ended up abandoned.However I am not aware that the East german aircraft were any different from the Polish examples
Lt Fulbar...How about bringing one to the HeliDays event in the UK this year....I know the organisers always welcome a Polish contingent .
Lt Fulbar...How about bringing one to the HeliDays event in the UK this year....I know the organisers always welcome a Polish contingent .
Join Date: Jun 2007
Location: 1°21'10.20"N - 103°56'36.21"E
Posts: 294
Likes: 0
Received 0 Likes
on
0 Posts
Join Date: Nov 2007
Location: Poland
Posts: 178
Likes: 0
Received 0 Likes
on
0 Posts
Heli1, It would be interesting to show those machines there, unfortunately it is a bit late. It's becoming a problem to keep them running, they're a bit short on life span, spares and crews.
For ASW ones, from 11 available - 3 were modernized so far, 2 others are worked on, so maybe one of those could fly there, if a spare crew would be find. The SAR ones are off the limits, although showing one beside S-92, or Irish S-61 would be interesting. Unfortunately last year one (#5137) reached its life limit (28 years) and had to be scraped, two other (#1013 and #1016), are not far behind it, they should be decommissioned next year. One newer ASW was sent to be rebuild to perform SAR missions, but it was siting there waiting for parts from the scraped one - I asume it will get its doors, winch, and comunication equipment, but the whole thing is not set in stone yet.
There is going to be a purchase of new helicopters soon, meant for ASW/ASuW, SAR, CSAR and troop transport roles, but it's geting late
. There were some talks about making the lifespan of SAR machines 4 years longer - to equal to the ASW variant which can fly for 32 years, but with all the politics crap right now - it's not likely. Currently the whole Polish coast is secured by two Mi-14PS, and 7 W-3RM "Anaconda", unfortunatly those W-3 were not design to work in that corosive environment, and are a bit small, and not very ergonomic (next one who say AW139 is not suited for maritime SAR - think off those 
).
For ASW ones, from 11 available - 3 were modernized so far, 2 others are worked on, so maybe one of those could fly there, if a spare crew would be find. The SAR ones are off the limits, although showing one beside S-92, or Irish S-61 would be interesting. Unfortunately last year one (#5137) reached its life limit (28 years) and had to be scraped, two other (#1013 and #1016), are not far behind it, they should be decommissioned next year. One newer ASW was sent to be rebuild to perform SAR missions, but it was siting there waiting for parts from the scraped one - I asume it will get its doors, winch, and comunication equipment, but the whole thing is not set in stone yet.
There is going to be a purchase of new helicopters soon, meant for ASW/ASuW, SAR, CSAR and troop transport roles, but it's geting late
. There were some talks about making the lifespan of SAR machines 4 years longer - to equal to the ASW variant which can fly for 32 years, but with all the politics crap right now - it's not likely. Currently the whole Polish coast is secured by two Mi-14PS, and 7 W-3RM "Anaconda", unfortunatly those W-3 were not design to work in that corosive environment, and are a bit small, and not very ergonomic (next one who say AW139 is not suited for maritime SAR - think off those ).
CH-47A Water Ops
In 1964, I picked up a new Chinook in Philadelphia that had been modified for water operations. It had a small dam that could be temporarily installed in the rear, thus allowing the ramp to be lowered while on the water and disembark a raft etc.
Part of the exercise was to conduct some simulated single engine landings and takeoffs. The landings were uneventful, with the large undersurface acting as a terrific brake. Lots of water spray up near the engine intakes, but no stalls. The takeoff was a problem, though, because just as you got to about 15 kts, the lower right cockpit window failed, and with that aft-slanting metal surface just forward and below the pedals, the water was efficiently sluiced right into the pilots chest. End of simulated single engine takeoff evaluation.
Thanks,
John Dixson
Part of the exercise was to conduct some simulated single engine landings and takeoffs. The landings were uneventful, with the large undersurface acting as a terrific brake. Lots of water spray up near the engine intakes, but no stalls. The takeoff was a problem, though, because just as you got to about 15 kts, the lower right cockpit window failed, and with that aft-slanting metal surface just forward and below the pedals, the water was efficiently sluiced right into the pilots chest. End of simulated single engine takeoff evaluation.
Thanks,
John Dixson
Join Date: Aug 2007
Location: Texas
Posts: 65
Likes: 0
Received 0 Likes
on
0 Posts
ecureilx,
That video is the one. There are a few others. Our aircraft was definitely ASW. It had all sorts of ASW stuff in the back and no rescue hoist. Also, It appears from the video that the crew/passenger door on the left side is bigger on the SAR than on our ASW aircraft.
As you can tell from the video, the nose gets a good washing at just about any forward speed in the water. If the crew in the crash video didn't have the front sealed she is going to take on water. Just stating the obvious.
That video is the one. There are a few others. Our aircraft was definitely ASW. It had all sorts of ASW stuff in the back and no rescue hoist. Also, It appears from the video that the crew/passenger door on the left side is bigger on the SAR than on our ASW aircraft.
As you can tell from the video, the nose gets a good washing at just about any forward speed in the water. If the crew in the crash video didn't have the front sealed she is going to take on water. Just stating the obvious.
There is going to be a purchase of new helicopters soon, meant for ASW/ASuW, SAR, CSAR and troop transport roles, but it's geting late
I would say, you are overoptimistic, but only time will tell.
Regarding the Mi-14 crash, after the Haze overturned, fortunately it stayed afloat. 12 out of 13 pax/crew onboard survived the crash.
Arrakis
Last edited by ARRAKIS; 22nd Jan 2009 at 10:24.
Join Date: Dec 2006
Location: Here and there...
Age: 58
Posts: 854
Likes: 0
Received 0 Likes
on
0 Posts
Considering that he looked like he was taxying at the time could it not be something like nose-tuck that caused the prang? I remember talking to an old 61 pilot who had done water landings and he mentioned nose-tuck as a potential problem in water ops.
If the pilot is not experienced or trained for it, then he could fall for that one.
If the pilot is not experienced or trained for it, then he could fall for that one.
Join Date: Aug 2007
Location: Texas
Posts: 65
Likes: 0
Received 0 Likes
on
0 Posts
Actually, the real number is 8.345 lbs./gallon. I round up to 8.5 to safe side weight calculations when I don't have a calculator or side rule handy. Anyway, you UK guys have bigger gallons by 20%! That's why you're at 10lbs./gallon. That's really nice if you're measuring out scotch!
