T.C. is quite correct in that the EC 135 doesn't have a C of G problem. It has a landing gear position problem.

PANews spoke of the shot of one ship that had landed across a levee or similar and it had pivoted about the rear of the skids and was stuck tail down nearly vertical down the embankment. Probably happened as the pilot stepped out. Great shot but what an embarrassment.

Pity EC can't move the rear cross-tube back another 6 inches or so though as it seems it is currently positioned directly on the C of G. Even picking the bird up with a Tug-a-lug generally requires placing some ballast on the front of the skids to prevent it from tipping backwards.

Tigerfish
 

STL - Try a TLC Heli Lift. What an incredible piece of kit. It seems to lift anything. ( & I am not connected!). Seiously they are worth looking at if you have a lift & shift problem.

i haven't said that the EC135 have a CG problem ;)

Lima Oscar

I agree that you didn't say it had a problem, just that it "is really on the rear". I was simply agreeing with TC that it didn't. Other than the nasty trait of wanting to sit on its tail on the ground, it is a delightful little machine.

Mass of tail boom = 60kg if I remember a comment by the Essex Air Ambulance correctly.

Just a thought, if the pilot had test the density of the snow during landing, by "jerking" the collective up and down in a gentle manner, maybe he could avoid the situation.

Cheers
Dick

Ok no problem ;)

I always wished EC had moved the skid 6 inches rearward, it would have stopped it appearing in the camera lens!

Artist formerly known as FNW.

EC-135 landing an take-off
 

Hi folks,:)
this is Gilbert, the Austrian EC135 pilot (shown in action on the video)!


Of course, I did! I also told the HEMS-crew to get out and report, wether the snow-skids where fully on the ground and how the surface is. He reported: "both skids well on ground, surface is hard"!
I shut down and when the rotor stopped, I went out normally. Just when my feet touched the ground, I heard a "sort of scratching" noise and the EC sunk rearwards, until the Fenestron-housing stopped it!
Actually the surface was frozen hard, but there was sort of powder-snow down under. The snow-skids would sink, including a greater piece of the hard surface!
Never experienced this before - flying EC135 since 1997 in mountainous areas of Austria.:ooh:
I have checked the situation of the Fenstron eagerly and decided, NOT to dig it out because I was afraid, it could sink even deeper?
We also tried to pull the aircraft into it`s normal attitude - no way!

The "recovery" maneuver was not a real problem - despite I should have made it a bit less harsh!? No limit on mast-moment, no uncommon feeling - she moved a bit too fast but, well, that was it! (No such training ever before!)

Losses: the tail-bumper was slightly damaged, replaced and a special-check was carried out. No further damages.
Reliable aircraft? I guess....

Kind regards,

old Gil. :D

Welcome Gilbert !

Thanks for the explications and well done ;)

Regards

LO

Hi Gilbert, sorry I didn't want to offence you. But you are right I saw similar thing happen in Canada. An Astar land by a lake, where the snow seem to be ok but when the rotor stop and the pilot disembark, the A/C sunk in the snow. I was flying by and the pilot call me to look during he attemp a take off, same as yours. Basically good job.
Cheers
Dick

Hello Gilbert

Thanks for those explanations. One thing still bothers me. Why didn't you dig away the snow from the top of the skids? Wasn't that the main obstacle sticking you to the ground?

EC135 take-off
 

Hi Phoinix:)

yeah, was thinking about this (even the snow on top of the skid was not the real reason for "sinking")
Finally, I decided, not to remove snow or dig somehow for not to destabilise the tricky ground!
Seen retrospectively, I would move more slowly (but I had to consider the mast-moment limit, of course) !:hmm:

Lesson learned: TAKE ADDITIONAL CARE - NEVER TRUST THE SNOW TOO MUCH!

Kindest regards,

old Gil.:)

We all make mistakes and we all learn; from our own experiences and from others. Thank you for sharing that one with us :)

In the end, everything turned out OK, that's important :ok:

Regards

Old Gil
 

Like the others said, thanks for the narrative, and we're all glad everything worked out well!

Hey Gilbert!

Someone over here wishes to know, if you are still wearing those big moustache :}

Hi Phoinix:)

yes,yes - part of me! (Helps to balance....!)

Kind regards,

Gilbert, the senior

Good onya Gil! Tricky terrain, tricky surface and tricky recovery.Well done!

Hi Warrigal:)

Yeah - my wording! Thank you!
Another lesson learned, yes!
This time, tricky terrain and conditions every day!
Foggy weather, fresh snow, poor visibility - many missions!
Last weekend, we had stormy northwind - up to 80 kts max. in 12000ft!
Hard winter this year!
You`re better off in Australia, rather than in Austria, at the time beeing?
I dream so....

Kind regards,

old Gil:) :)

Q's about flying in snow
 

Hello,
Anyone have any rules of thumb about flying in snow. More like when icing may occur, ie...temps, relative humidity freezing level? I fly vfr and am familiar with when icing may occur when in the clouds, but there isn't much info I can find on icing when it comes to flying while it's snowing.

Thanks for your help

S

Never picked up any ice in snow. Let me define icing in a helicopter as picking up enough ice on the blades to register an increase in torque. Snow will build up everywhere else that it can, like the wiper blades, windshield, crosstubes, etc, but won't affect the operation of the helicopter. There are some restrictions on snow operations that require baffles or other deflectors to keep the snow away from the engine intakes but that is not an "icing" problem.

Rule of thumb is if you can see the next tree or the next powerpole you keep going, otherwise you sit and wait in a hover at said tree until you can see the next one. Heavy snowfall tends to come in showers, so if you can wait out the worst for 20-30 minutes you can carry on. If I had a concern about snow it is the variable visibility - a few feet one minute, 10 miles the next.

malabo

"Rule of thumb is if you can see the next tree or the next powerpole you keep going, otherwise you sit and wait in a hover"



Increase that to about 6 poles you might be nearer the mark. And I would be on the ground, not hovering.

Scotto, if you're not in precipitation, you won't get icing, and the time to start looking out is when you have to turn the anti-icing on, which is 4 degrees or so in the 206. I seem to remember something about the 206 (in UK anyway) not being able to fly in snow anyway, but I may be wrong.

As malabo says, you may need baffles or deflectors, or even snow kits to protect the engine, depending on the machine, but dry powdery snow is otherwise not a problem for the airframe, until it starts to restrict your vis.

Wet, clingy snow won't get off the windcscreen and won't blow off in flight (downwash in the hover is best) so don't even try. Get yer backside on the ground with a coffee in your hand at the nearest hostelry first!

Phil

Scotto,
Anytime you're flying in wet snow around freezing, as Paco says, you either want to be keeping a close eye on things, or having said coffee. That said, we do a LOT of work in these conditions on the West Coast, you just have to monitor them closely, and bear in mind an Astar will be different to a 500 or 206 etc etc. Know your flight manual and you'll be fine a far as an type specific issues/limitations.

Flying in colder, falling snow, is actually preferable to rain for me in many instances. A) It doesn't stick to the window or distort your vision as rain does, and B) you usually don't have fogging issues on the inside of the wind screen. However, and this is a really big however, in very low vis operations as Malabo is talking about, you have to be very careful about flying over open, or completely snow covered areas. This can lead to "whiteout" situations, that in a VFR ship, can and will lead to a nasty accident.

There are a few "rules of thumb" I use, but mainly when operating below the treeline, don't attempt to transit an area you cannot see across such as a frozen lake, or even open fields when the vis is right down in the one power pole example. This is a sure way to get disoriented, and leads to a number of accidents every year. Fly the edge of lakes or fields along the tree-line.

The other thing, is to be very aware of the "snowball" on approach and departure in fresh snow. This is the cause of a number of rollovers every season, and there are a few things you can do to mitigate the effects of blowing on liftoff or dept. First, ALWAYS land next to something dark in colour, a rock or bush will work, and be close, even if you land ON the bush. This is often your only point of reference. Same goes for dept, choose a dark ref point close to the machine, and maintian contact with it until you are either able to rise above the snowball, or transition forward from it. Your choice of dept will be governed by an number of things that I really can't type out at this speed....lol

I wouldn't worry about above the tree-line work right now, that's a bit further down the road for you judging by your question, But, if you do find youreself going there, make sure you've got very good weather until you get some training and more experience in those areas.

Good luck, and remember this is by no means a complete lesson on snow flying, get some training with an experienced pilot if at all possible.

RH

Scotto...

There's some useful info here?

http://www.caa.govt.nz/fulltext/Safe...g_Handbook.pdf

Be careful out there ;) ...170'

Use the Landing light to give you a clue to where the snow surface is, when landing

206 in snow is allowed with particle separator and snow deflector plates. Otherwise I beleive that "flight in visible percipitation below 4 deg C" is not allowed.

/perfrej

I have not done a lot of flying in snow but one thing I have noticed is that thicker snow started to stick and remain on the screen at about +2°C where as rain or thin powdery snow needs a temperature of 0°C or less to stick.

Before I saw this I always thought you would have to have a tempreture of 0°C or less for snow to stick.

You can fly below 4.4C (40 deg F) without the deflectors and separators (but not falling or blowing snow) but the engine anti-ice has to be on in visible moisture. Has to be off if OAT is over 4.4C. Take your pick of 4 or 5 if you've got a fancy digital thermometer in C.

For flight in falling or blowing snow you need FMS10 and 12 (particle separator and snow deflectors) installed, and then there are some limits on how long you can hover, idle, etc.

Good idea to have the Engine Automatic Re-Ignition (FMS18) installed too. It will also make a "tvarich" or true believer out of you when you're hovering over somewhere inhospitable on a dark dreary day and the little orange light tells you that it's done you a favor and relit the engine.

malabo

My comment about hovering was to avoid the whiteout situation.

Thanks for the tips about the 206.

Phil

Thanks for your input. The BH407 I fly has the intake baffles that will be installed soon. I have flown UH-1's in Germany for three years, but I didn't fly that much in actual snowing conditions. Done plenty of whiteout training and so on. I was just wonding if snow sticking on the acft during flight would accumulate into ice. Any experience with snow melting on the acft (after you push it out of the hanger) and refreezing on it in flight.

Thanks for you input again.

S

Thats the time, when to start thinking about alternate means of transport ;-)
10 nm further east was sunshine - thats what my boss said...

http://www.uheeren.de/images/Schalke0.jpg

No, but having landed in dry powder snow there was a liberal amount over the windscreen. Came back 30 mins later to find that it had melted due to the warmth of the screen, then quickly refrozen due to the sub zero temperatures. Allways cleared the screen after landing from then on.

Hi FlyingBull,

did you land in- or outside the arena???:eek:

Errr - he's flying on instruments! He has an AI to tell him where the horizon is.

Ah I see where you are coming from now ampan.

However reviewing a video won't help you understand because you have none of the physiological factors present.

The propreoceptive feedback (seat of the pants feelings) from muscles and nerves allied with the semi-circular canals in the ears provide powerful orientation signals - the brain will interpret these (possibly erroneously) and calculate what it thinks is the local vertical and therefore where the horizon is.

In the accident you refer to the illusion was optical, not created within the brain. See here for some more http://www.erebus.co.nz/Portals/4/Do...Phenomenon.pdf

No, the visual perception and interpretation of what is actually there is the problem and that lies fairly and squarely within the brain. By definition any optical illusion is the brain incorrectly interpreting the visual cues.

This type of whiteout, where texture cannot be defined, is observable when skiing in flat light - you don't see the bumps until you ski into them.

'Hidden' rideglines are also a problem on NVG (it is lack of depth perception and texture information again) - I encountered it last year in the Falklands (very dark) and was saved by the rad-alt.

During my time as a Army Pilot as soon as the snow arrived we were rebriefed about snow landings and take-offs etc,also we had to fly with a QHI and demonsrate we could carry out this type of flying,what happens as a civilian or do you learn the hard way.