Flight limits in falling snow
Thread Starter
Joined: Feb 2001
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From: Europe
Flight limits in falling snow
With widespread snow the UK at the moment be interesting to know what limits apply to flight in falling snow in various helos, in terms of minutes flying permitted in a given vis. Any offers and views?
Joined: Jan 2003
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From: CYPG
the Jetbox requires Eng anti ice, Particle separator, snow baffles and automatic Re-ignition.
there should be 4 items anyhow.
Hovering limited to 15 minutes in falling snow.
Don't recall that there are any other limits.
The AS355F2 (FX2) was only a eng anti ice limit if I recall correctly
Cheers
edit: corrected the 4th element of the ice...
there should be 4 items anyhow.
Hovering limited to 15 minutes in falling snow.
Don't recall that there are any other limits.
The AS355F2 (FX2) was only a eng anti ice limit if I recall correctly
Cheers
edit: corrected the 4th element of the ice...
Last edited by Winnie; 2nd February 2009 at 15:21.
Thread Starter
Joined: Feb 2001
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From: Europe
It's a while ago now, but seem to recall that the AS350 had no limit on time over 1500m vis, 10 minutes 800-1500m and was not permitted less than 800m. FM I've seen for AS355 doesn't specify anything. A109? AS365? S76?
Joined: Jan 2009
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From: Sweden
Falling snow is not icing condition in (at least) 99.9% ot the cases.
Falling snow and limitations in flight often refers to risk of flame out if lot of snow has formed on roof of heli or at engine inlets. This could make the engine flame out if a lot of 'clogged' snow comes loose and goes into the engine.
Bell jetranger: snow defelction plates should be mounted.
MBB bo105: min 800 meter visibility. Possible to mount continous ignition probably allows lower vis. (dont know the civilian POH to 100%, but flew a military version).
AS332 super puma: no restriction in snow visibility, but about how long time ground run as allowed without check on roof(max 20min in 400m or less)
Falling snow and limitations in flight often refers to risk of flame out if lot of snow has formed on roof of heli or at engine inlets. This could make the engine flame out if a lot of 'clogged' snow comes loose and goes into the engine.
Bell jetranger: snow defelction plates should be mounted.
MBB bo105: min 800 meter visibility. Possible to mount continous ignition probably allows lower vis. (dont know the civilian POH to 100%, but flew a military version).
AS332 super puma: no restriction in snow visibility, but about how long time ground run as allowed without check on roof(max 20min in 400m or less)
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From: On the big blue planet
Joined: Aug 1999
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From: Gold Coast, Australia
I can't recall the 212 limits, but the early days of the Brent Field we found the particle separator worked pretty well in passing snow showers 
FWIW, the external door hinges were/are the best ice accretion indicator on the 212. The wiper blade arm shows ice early, but is difficult to monitor compared to the door hinges.
FWIW, the external door hinges were/are the best ice accretion indicator on the 212. The wiper blade arm shows ice early, but is difficult to monitor compared to the door hinges.
Joined: Feb 2007
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From: Canada
As far as I know as per my POH the A-Star limitations (D,BA,B2, FX2 ammendment) as previously stated are correct although god/God knows why as sometimes the limited visibility is not always created by "falling snow" but also embedded fog.
That being said if you are running an FDC filter don't forget that once the light goes on in falling precip/snow you are GROUNDED! Just a little hint here... if your light goes on in flight pay attention to your T's and P's and you may not have to land "immediatly" and may be able to land at a spot that's a little more convenient. (Note:if you are questioning what I said just follow the book)
Don't forget to DI the workings of your bypass doors prior to each flight as well. If they don't work you are grounded and is not CLEARLY mentioned in the POH. Also, when landing for any length of time in falling snow when running the FDC filter, don't forget to put a cover on it....if you get a build-up of snow on it you can/will activate the low-flow light on start-up (Could also be indicated by T4) or just after lift-off. Don't mean to be a smart-ass but once you put the cover on don't forget to WALK AROUND YOUR A/C to make sure you took it off!!!
That being said does anyone know where the limited visibility flying in snow came to pass in the POH. Just curious as I fly in Northern Canada all the time, with and without FDC filters down to 1/2 mile and have never had an issue.
Any input from you boys over on the other side of the Pond would be greatly appreciated as here in Canada, no-one can get a straight "not covering my ass" answer from the "Makers"
Fly Safe ALL
Backward Blade
That being said if you are running an FDC filter don't forget that once the light goes on in falling precip/snow you are GROUNDED! Just a little hint here... if your light goes on in flight pay attention to your T's and P's and you may not have to land "immediatly" and may be able to land at a spot that's a little more convenient. (Note:if you are questioning what I said just follow the book)
Don't forget to DI the workings of your bypass doors prior to each flight as well. If they don't work you are grounded and is not CLEARLY mentioned in the POH. Also, when landing for any length of time in falling snow when running the FDC filter, don't forget to put a cover on it....if you get a build-up of snow on it you can/will activate the low-flow light on start-up (Could also be indicated by T4) or just after lift-off. Don't mean to be a smart-ass but once you put the cover on don't forget to WALK AROUND YOUR A/C to make sure you took it off!!!
That being said does anyone know where the limited visibility flying in snow came to pass in the POH. Just curious as I fly in Northern Canada all the time, with and without FDC filters down to 1/2 mile and have never had an issue.
Any input from you boys over on the other side of the Pond would be greatly appreciated as here in Canada, no-one can get a straight "not covering my ass" answer from the "Makers"
Fly Safe ALL
Backward Blade
Joined: Apr 2000
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From: EGDC
Our Sea King limits (we have a particle separator) depend on OAT and visibility; if the vis is above 2000m or the OAT below minus 6 degC then there is no limit.
The most restrictive limit is with vis less than 500m and the OAT above minus 6 degC when we have a 10 minute limit. This follows the idea that warm wet snow is the most hazardous due to accretion/blocking intakes etc.
The most restrictive limit is with vis less than 500m and the OAT above minus 6 degC when we have a 10 minute limit. This follows the idea that warm wet snow is the most hazardous due to accretion/blocking intakes etc.
Joined: Aug 2000
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500
Falling snow is fine as long as auto relight is on and their is no centre seat pax. Not the same in an E model, presume this is because the switch for auto relight in an E is half way up the panel, not at the bottom in pre e machines, where center seat pax foot may turn it off. Unless anyone knows better ???
Falling snow is fine as long as auto relight is on and their is no centre seat pax. Not the same in an E model, presume this is because the switch for auto relight in an E is half way up the panel, not at the bottom in pre e machines, where center seat pax foot may turn it off. Unless anyone knows better ???
Joined: Sep 2004
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From: Canada
412 Snow deflectors???
Hi TunaSandwich:
Stupid question perhaps but why would a 412 require snow deflectors and a 212 not?
I have lots of time in a 212 in snow but all my 412 time is in the hot.
If the 412 requires deflectors could someone post a photo of them.
Just curious
Stupid question perhaps but why would a 412 require snow deflectors and a 212 not?
I have lots of time in a 212 in snow but all my 412 time is in the hot.
If the 412 requires deflectors could someone post a photo of them.
Just curious
Joined: Oct 2007
Posts: 147
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From: USA
Never heard of a falling snow limit before. The 60 is basically retard proof. Just turn on the anti-ice when encountering "visible moisture" below 4* C and you're good. I guess an inlet that heats to above 93* C helps. The power loss sucks though.