WIND

[rotormandan]

So today a flight got cancelled because of thunderstorms brewing up out of nowhere (They seem to do that just as you're preflighting) Any way it was calm all day and it just started blowing semi decent. It only got to about 15 kts maybe but it wasn't the wnd we cancelled for. It did however get me thinking. What is the strongest wind any one has flown in. I'm especially curious about the Robinson pilots out there. We have no wind limitations (maybe 102kts but that's insane) so what's the worst it's been? I know we cancel between 25-30 kts depending on the students level of training. Any off shore pilots out there? What's your wind max? I bet those waves look pretty crazy with some strong winds out there. I couldn't imagine a precautionary landing or an auto into any size of big waves. Would you even do a precautionary landing in the middle of the ocean? I'm having a hard time picturing a "Land Immediately" situation with 20' waves and the closest helipad 20min away.

[Gomer Pylot]

For single-engine, it's generally 40 knots offshore. That's based mainly on startup and shutdown problems, with the possibility of the blades flapping down and chopping off the tailboom. It has happened. For medium and large ships, there is generally no maximum, it's whatever the PIC thinks he can handle. I've flown up to about 60, and have done 40+ in a 206, when I got caught in unforecast winds and couldn't shut down. The limit might be lower, depending on the offshore heliport, and how the wind swirls on the helipad. I've seen a few platforms I wouldn't crank on if the winds were above 25 knots or so, depending on where and how I'm parked.

 

If I have to land when the seas are really heavy, it's probably going to be on a platform. I've seen seas over 50' offshore, with the waves washing the cellar deck of the platform I was on. When the seas get up to 20' or so, most small single-engine ships stop flying, but it's not a hard and fast rule.

Edited July 23, 2008 by Gomer Pylot

[TimW68]

At about 50hrs I got my instructor to take me up in 25 gusting to 34 it was a great experience. LTE was not a problem at all as I was very careful to keep in trim and was mindful of the left crosswind (robbies don't have allot of LTE issues). My instructor had me pick-up and set-down in each direction, cross & tail wind took a little more time then normal but was'nt to bad. All in all it was not as bad as I thought it would be and I definately wanted the experience incase I got caught in those conditions while solo. If you keep the nose into the wind it's not a problem at all. Best of luck and if you get the opportunity to go up in strong winds (within reason) by all means do it!

 

 

Tim

[ADRidge]

So today a flight got cancelled because of thunderstorms brewing up out of nowhere (They seem to do that just as you're preflighting) Any way it was calm all day and it just started blowing semi decent. It only got to about 15 kts maybe but it wasn't the wnd we cancelled for. It did however get me thinking. What is the strongest wind any one has flown in. I'm especially curious about the Robinson pilots out there. We have no wind limitations (maybe 102kts but that's insane) so what's the worst it's been? I know we cancel between 25-30 kts depending on the students level of training. Any off shore pilots out there? What's your wind max? I bet those waves look pretty crazy with some strong winds out there. I couldn't imagine a precautionary landing or an auto into any size of big waves. Would you even do a precautionary landing in the middle of the ocean? I'm having a hard time picturing a "Land Immediately" situation with 20' waves and the closest helipad 20min away.

 

 

Robbies do have a wind limit. Don't have my POH handy, but it's in there.

 

The highest I've ever been in was 29g35 or something ridiculous like that. It was funny, because before that I'd been really nervous about any wind over 15ish. Well, my dad's buddy is a pretty high time CFI (6000rw, something like 12k TT) and when I expressed my doubts, he just looked me in the eye and said he believed I could do it. Given that he's Chief Mx Test Pilot for a rather large agency, I believed him. We hopped into a -22, and off we went. I don't think I'd have done it with anyone that didn't have his credentials and ability, but getting out there really showed me that wind isn't a huge deal as long as you stay within your limits.

[Darren Hughes]

Yeah Robbies have a limitation of 25kts for pilots under 200hrs or something like that.

 

One night while working towards my commercial and with a whopping 100hrs I got caught out on a solo night x-country from Fresno,CA to Byron,CA with winds that were 22 gusting 35(can't remember exact figure). The wind information I used to make my GO decision from Fresno was Stockton(Metar & TAF) which was only about 10miles away(reporting Variable at 3). But the local terrain features create havoc right around Byron at night.

 

To top things off, when I was about 2 miles out(and just starting to feel the full effects of the wind) I had a small elecrical fire(that originated in the instrument panel) that filled the cockpit with a nice layer of smoke. That's the reason I didn't divert to Stockton as I wanted to get on the ground ASAP. So I pulled the CB for the Instrument Panel/Nav Lights and the smoke cleared away. I didn't go with the POH which says Master switch off & Alternator switch off as I didn't want to be without the governer while not able to see the tachs in such gusty weather.

 

The scariest part was coming in on short final, when I was + or - 30 degrees of my desired heading at any 1 time! Getting to a parking spot was a bitch also as I had to hover taxi backwards down a taxiway while facing into the wind. Needless to say I stayed the night in Byron, and called the school in the morning about electrics problem!!

 

I learned a valuable lesson that night, about how local terrain can affect the weather. I've since spent countless hours studying that sort of stuff. I've flown in winds a little weaker but close to that strength over here on the east coast since, but with my students on board, and the extra weight makes a big difference. The chopper is a lot more skitish when you're solo.

[AngelFire_91]

I've personally been out in 28g38, and we regularly go out in 25 - 30kts in a 300. As long as you stay on top of the Helicopter it's not a huge deal. Just don't let it get away from you, always be thinking ahead and dancing. The 300's POH says something like "Controllability has been verified in winds up to 17kts." But there is no limitation per se. And if we have to shut down in anything over about 25kts we do a "High wind shut down" where you set it down with a right quartering tailwind to help reduce the chances of chopping the tail.

[slick1537]

You may not manipulate the controls of an r22 if you have less than 200 hr RW or less than 50 hours in an R22 if the surface winds are higher than 25 kts, or gusting more than 15 kts. If you are a Robbie pilot you should know this, it is there for your safety. Since most Robbie students have less than 200 hours before they become an instructor this disqualifies most from flying when the metars report winds over 25 kts. The DPE for my private checkride made sure he asked me about that limitation.

 

http://rgl.faa.gov/Regulatory_and_Guidance...9D?OpenDocument

Edited July 23, 2008 by slick1537

[mountainchopper]

what is the theory behind a right quartering shutdown? so the blade theoretically flaps up after cyclic control is diminished? Just one more interesting concept I've never really thought about it before.

 

The worst I've been in was in an unforecasted 38 gusting 52 in a 22 before, you didn't so much hover as just try and keep it between some self determined skid height criteria. Anymore in the 44 I won't go out in anything greater than 25 with a student or 30 by myself. and once it gets up around 35 or 40 I start looking for an airport. The wind doesn't bother me so much as the mechanical turbulence created by the mountains. At this MSL they can control your AGL much more than the collective can.

[Gomer Pylot]

When the blade is turning slowly, there isn't enough inertia (or gyroscopic force) to keep it level if the wind gusts. When it's not turning, the droop stops keep it from flapping too much, but in the range where it's turning too slowly to control but the droop stops are out, the blades can flap so low that they can chop the taiboom. The blade tends to rise when it's advancing into the wind, and fall when it's retreating, but gyroscopic precession makes it actually happen later. How much later depends on the speed of rotation and the force of the lift. Many tailbooms on helicopter with teetering rotor systems have been surgically removed by the blades flapping on startup or shutdown.

[AngelFire_91]

what is the theory behind a right quartering shutdown? so the blade theoretically flaps up after cyclic control is diminished? Just one more interesting concept I've never really thought about it before.

Yeah, the theory is that the blade will up flap and miss the tail during shutdown. It does work quite well most times, and you can see it really will down flap infront of the cabin, so just make sure no one is walking in front of the chopper.

 

EDIT... Dang! Gomer you beat me to it. We must have been typing at the same time.

[helonorth]

I work offshore and we are not allowed to fly in over 40 kt. winds. And no, you would not make

a precautionary landing in the water. Bell defines "land as soon as possible" as "land without

delay at the nearest suitable area at which a safe approach and landing is reasonably

assured". The water in the GOM is not one of those places. Of course, if you have the

engine quit, you don't have much choice. And yes, the waves do look scary. You are

almost always in sight of at least one platform, though, so normally you would have a 5-10

minute flight, at most, if a "land as soon as possible" situation came up. I had some

guys that really wanted to get offshore on a really windy day. As soon as they were

reporting less than 40kts., we went. After practically crawling across the helidecks and

scared they were going to get blown off the platforms, they said "back to the beach!" The

flying is no problem, but a ditching in those conditions would be a real struggle for

survival.

[Wally]

what is the theory behind a right quartering shutdown? so the blade theoretically flaps up after cyclic control is diminished? Just one more interesting concept I've never really thought about it before.

 

The worst I've been in was in an unforecasted 38 gusting 52 in a 22 before, you didn't so much hover as just try and keep it between some self determined skid height criteria. Anymore in the 44 I won't go out in anything greater than 25 with a student or 30 by myself. and once it gets up around 35 or 40 I start looking for an airport. The wind doesn't bother me so much as the mechanical turbulence created by the mountains. At this MSL they can control your AGL much more than the collective can.

 

It doesn't make any difference to the aircraft whether the relative wind's wind over the ground or due to you flying.

 

You can most certainly get into LTE in high winds, or any wind condition at all. It'll just look different, you might not even know you're hovering.

 

The turbulence the wind generates, whether due to mountains, buildings, whatever- is much more dangerous than good clean wind.

 

I have ABSOLUTELY NO confidence in putting the wind anywhere but on the nose for starts and shutdowns- especially if there's any turbulent flow. Without sufficient RPM to stiffen the blade, it bounces as it will. I've seen blades bounce and then flex to a negative angle of attack, increasing the downward deflection, and that's very a very bad thing with a tail boom underneath it.

Don't imagine you have any 'control' of where the blades go until there's sufficient centrifugal force to stiffen them and enough RPM to put control inputs in phase- gyroscopic precession requires enough RPM to make the disk a gyro. Until those things happen, the most you can do is be in the right place and encourage the blades not to do anything. Put the wind on the nose, add a little forward cyclic (not so much as to get it bouncing, see previous) and try hold the tip path plane about where it is in normal flight. Caveat- never tried this without droop stops.

Edited July 23, 2008 by Wally

[rotormandan]

I think my highest was around 30. In the spring time it gets pretty windy so it's pretty regular with gusts up in the 20s. I've pretty much stayed out of anything reported above 30 and luckly haven't been caught in any thing by suprise. Demo flights with 22 kt winds are pretty scary.

 

For the off shore flying, that'd be a pretty crazy sight seeing those waves underneath. Good to know about the platform distances.

 

You may not manipulate the controls of an r22 if you have less than 200 hr RW or less than 50 hours in an R22 if the surface winds are higher than 25 kts, or gusting more than 15 kts.

 

That limit is only for pilots under 200 TT helicopters and/or with less that 50 RHC hours. I guess if you have that time the only limits are your personal ones and VNE. Seems like a ship that small would have some wind limit, not so much for LTE but just for getting blown over while hovering.

[Goldy]

or gusting more than 15 kts.

 

 

Might be important to note that what this means is a wind gust differential of 15 knots. So if the wind is reported at 5, gusting to 21...you can't fly if you dont have the required time.

 

Highest in an R22 for me was 25, gusting to 32. Turning crosswind to downwind is always fun in a 22 in those kind of winds.

 

Like another poster stated, its really not the wind, its the gusts and turbulence that gets you....which is what we usually get at low altitudes.

 

Goldy