Helicopters and frost

[Groundpounder]

If your helicopter is sitting outside and gets covered in frost, do you have to worry about making sure the blades are clear of frost, or can you just start up and have it sublimate off? Any other critical surfaces I'm not thinking of?

 

[kep5niner]

Frost is a no-go. Control surfaces in particular (M/R blades, T/R blades, stabilator), but I would be leery of it anywhere on the airframe. Move it into a heated hangar, or wait for the sun to come out and take care of it.

 

[Groundpounder]

Frost is a no-go. Control surfaces in particular (M/R blades, T/R blades, stabilator), but I would be leery of it anywhere on the airframe. Move it into a heated hangar, or wait for the sun to come out and take care of it.

OK, thanks for that info!

 

[Bell206]

do you have to worry about making sure the blades are clear of frost, or can you just start up and have it sublimate off?

If talking about a light frost from overnite cooling it depends. In most cases it would sublimate off during a ground run. However, depending on type ops you may have to follow a different procedure as there are contamination checks required for 135. In areas where there is persistent morning frost some people will use blade covers... just never put them on wet.

Any other critical surfaces I'm not thinking of?

Windshields. A small heater left in the cabin overnight works wonders. Scraping frost and plexiglass/lexan don't play together well. However, any frost/ice beyond a light frost requires additional measures depending on the helicopter.

 

[Sac Arrow]

Man, and to think I was about ready to fire up the helicopter this morning...

 

[jayhawk74]

If your helicopter is sitting outside and gets covered in frost, do you have to worry about making sure the blades are clear of frost, or can you just start up and have it sublimate off? Any other critical surfaces I'm not thinking of?

The blades are essentially wings so my question to you would you take off with frost on the wings of an airplane?

 

[Skip Miller]

The blades are essentially wings so my question to you would you take off with frost on the wings of an airplane?

No I wouldn’t. But helo blades prior to take off are already at a high airspeed, so presumably sublimation will occur quickly and well before it would on an iced up fixed wing... so the answer is I dunno. Any helo pilots care to comment?

-Skip

 

[455 Bravo Uniform]

On an airplane, the effects of frost on lift won’t be understood until rotation speed, initial climb, turns, etc. At that point any surprises in lack of performance could be dangerous.

On a helicopter, isn’t the highest loading right at “lift off”? Would the pilot be able to tell performance is affected just prior to lift off and safely abort the takeoff? I am clueless, just asking.

 

[Velocity173]

The frost sublimates with the blades spinning and if a turbine, it’s assisted by the heat of the exhaust. Probably some slight affects from aerodynamic heating and blade flex from static to 100 % Nr as well.

Never seen even the slightest performance issue with the aircraft completely covered in thick frost or even snow / ice. Then again, never got out to check to see if any was still attached. Only time I’ve seen any rise in torque was icing (light) in flight and even then it was minor.

Part 135, you have to ensure there’s no frost attached to certain components of the aircraft prior to departure. That means either fluid to melt it or run it up for a couple minutes, shutdown and inspect. No frost and you’re good to go. Generally not an efficient practice in for hire ops so hangaring the aircraft is prudent.