I was wondering this while idly clicking around Wikipedia, and looking at old Navy and Coast Guard helos such as the SH-3, I noticed that there seemed to be a period around the 1960’s and 70’s where amphibious helicopters became very popular, and then were replaced by a series of non-amphibious helicopters.
Were there any particular drawbacks to a water-tight or boat hull? Any particular advantages to just not messing with them? (I suppose I can see a definite cost advantage to making minimal design changes to a land-based design, and maybe they just figured that landing in the water wasn’t terribly useful?)
I’ll make a WAG that experience showed that landing a chopper in the sea to pick someone or something up was much less safe than hovering and picking them/it up with a winch, and that making emergency landings in the sea tended to be pretty much a one-shot affair. Hence you’d be better off with a ship/shore based chopper, and spend your engineering time on better winches and emergency flotation bags rather than amphibious hulls.
It’s also worth noting that the necessary changes to navalise a land-based helicopter are non-trivial (swapping out lots of alloys that are prone to saltwater corrosion, etc), even without the challenge of trying to land the thing in water.
This sort of thing may be a factor.
Yeah, it occurs to me that an aircraft is inherently safer the farther from the surface it can stay while doing its job. I find myself wondering if those air ambulances would have fewer problems if they used winches and slings instead of landing to get to injured hikers.
Since playing Call of Duty 4, helicopters (and heli crashes, on occasion) has become a larger interest of mine.
There are a few helicopters still in servuce with the Russian military, IIRC, that have at least some amphibious capability. The Mi-14, for example.
Perhaps it became cheaper to retrofit existing designs with pontoon floats?
I couldn’t watch that without yelling, “No, NO, NOOO!” when he starts trying to take off the second time and pitches forward. It’s not clear if he’s just been sucking in sea spray and had a flameout in one engine or what his basic malfunction is, but once he started going nose down he should have just dropped power on the rotor to just enough to maintain pitch and yaw control in the moderate seas. Instead, it looks like he tried to power out as he was taking on water and did a header. I wonder if there were any survivors; that’s looked like a pretty catastrophic roll.
To answer the o.p., you can only land helicopters and airplanes on water when the seas are very, very moderate (i.e. Sea State 2 or less). Any more than that, and the chop and roll makes landing and taking off impossibly hazardous. Of course, most rescue scenarios occur in much higher seas.
Stranger
I wonder if the pilot was having trouble lifting off (power loss from spray suck or possibly excess weight) and decided instead to treat the aircraft as a boat and “push” it to shore, not realizing that would tip the nose down like that.
That’s what I thought at first, but why would he do it? There’s a ship right there for rescue of the occupants and recovery of the helicopter. Every helicopter pilot knows that pushing the cyclic forward pushes the nose down. If he was ‘boating’ he pushed too far. But why? If he was trying to take off he should have brought the ship into a hover before pushing over. Unless he was heavy and wanted some air flowing over the rotors and he was trying a running take-off. I tend toward an attempted running take-off.
FWIW, helicopters are usually top-heavy. Sure, they have a hull; but with the engine and rotors on top the hull and outriggers are the only things keeping it upright. In rough water I think you’d have to keep the rotors turning to provide lift to keep the machine upright. In a piston-engine light helicopter the CG is a bit lower since the engine is mounted lower, and the pontoons have a wider stance than a hull and a greater ‘footprint’ than the outriggers on an amphibian.