Alpine operations - Question

[Nipper2]

I'm just back from some early season skiing in the alps. Lots of helicopter activity, possibly early season training. As a simple fixed wing flyer, I'm trying to expand my knowledge of rotary flight limitations....

The ship of choice seems to be an AS350 (though I'm not smart enough to tell the variant). The SAR ones are fitted with an external winch. The guys I watched doing cliff rescue (either for real or as a practice) seemed to have superb skills flying close and slow at what must be near to the limits of the machine in very gusty conditions.

There are also a fair few AS355's though not it seems in the SAR role.

At first sight, it seems strange to be using a single-engined machine in a highly risky SAR environment but a quick look at the Eurocopter data sheets seems to suggest that at the kind of altitudes these guys are working at (up to around 12,000 feet) the second engine is not much use - if the lights go out on one, the remaining engine barely has enough grunt to keep you flying.

As far as I can see they prefer the better high-altitude performance of the singe with its attendant risks to the inferior performance of the twin with marginal single-engine performance.

Can any of you thrashing-wing types enlighten me further?

[ShyTorque]

I think you've enlightened yourself ;)

[FLY 7]

Always thought the Allouette 'Lama' was the helicopter of choice in the mountains.

[Nipper2]

Fly

Quite so.... There was one on the ground at the landing site near Val d'Isere. More for fun than serious action as far as I could see.

[FLY 7]

Air Zermatt have several still performing stirling service.

[621andy]

Lamas are still in extensive use, both for 'trips round the bay' and for serious work- watched one lifting replacement electric pylons for the railway line through Chateau D'Oex for example.

All the major players have at least one Lama- Air Glaciers, BoHag, Heliswiss, Air Zermatt etc.

For the heavier stuff, then the Kamov Ka-32 is the one to use;)

The various Eurocopters are also quite popular especially with REGA, and the Swiss Air Force are now replacing their Allouette IIIs with the EC135.

Zermatt;

http://i250.photobucket.com/albums/gg244/621andy/HB-XND0012.jpg

Lauterbrunnen;
http://i250.photobucket.com/albums/gg244/621andy/HB-XRF0032.jpg

Sion;
http://i250.photobucket.com/albums/gg244/621andy/HB-XRL0082.jpg

Gruyere;
http://i250.photobucket.com/albums/gg244/621andy/DSC004562.jpg

Bex;
http://i250.photobucket.com/albums/gg244/621andy/HB-ZGV0002.jpg

Allouette III @ Alpnach;
http://i250.photobucket.com/albums/gg244/621andy/V-2452.jpg

EC135 @ Alpnach;
http://i250.photobucket.com/albums/gg244/621andy/T351000.jpg

Ka32;
http://i250.photobucket.com/albums/gg244/621andy/HB-XKE0012.jpg

[birrddog]

621andy, I see no "snow shoes" for the skids on the Kamov... don't they intend on putting them down in the snow, or was this photo just taken in another config/season?

[GenuineHoverBug]

Nipper 2 wrote:

At first sight, it seems strange to be using a single-engined machine in a highly risky SAR environment but a quick look at the Eurocopter data sheets seems to suggest that at the kind of altitudes these guys are working at (up to around 12,000 feet) the second engine is not much use - if the lights go out on one, the remaining engine barely has enough grunt to keep you flying.

Some would say that in mountainous terrain the difference between “barely flying” and not (flying) after an engine failure might be rather significant. As the years have gone by, I believe I have learnt to appreciate the difference between:
1-1=0
2-1=1

There may however be some other aspects that could play a role in this:
1) Do the twins have the required AEO performance at that DA?
2) Could it be that a twin is considered too expensive?
3) Tradition/culture?

[621andy]

Birddog- Al the pics were taken during the summer, so can't comment about snowshoes. However I'll be back there in march, so I'll have a look:ok:

[Lutefisk989]

Culture (inertia) is hard to change ... though it seems to me that all SAR ops are moving towards twins, particularly if Category-A design may be a consideration (JAR-OPS requirement?).

Operating costs of twins would certainly be an issue...

Even with today's engines, a engine failure during OGE/hoisting ops at a high DA could be just as ugly as having only one engine. But if the engine failure occurred during any other phase of flight, then a twin is the way to go... I'll take the twin!

[/random thoughts]