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-   -   Super Puma quandary. (https://www.pprune.org/rotorheads/19936-super-puma-quandary.html)

CTD 30th Oct 2001 15:49

430??

Nick sed: Note the performance charts for the 212 and 412 that mysteriously limit you to "wind within 45 degrees of the nose" while hovering.

CTD answered with reference to the 212 and 412 charts, which have no such statement. Ahhmmm.......you get the wine? I like deep reds.

I'll be offline for a while as I sort out my new career path.....see you guys soon.

Nick Lappos 31st Oct 2001 01:57

CTD still doubts, and has certainly put himself up to the bet with his wine reference, so here goes:

All those who want a copy of the Bell 212 or Bell 412 or Bell 430 charts where tail rotor authority is traded for gross weight, please email me at my pprune listed email address.

As an example that is pertinent to the original thread, the Bell 412 gains 1,000 pounds of increased gross weight when it loses the ability to hover in a crosswind, according to the "fantasy" chart I am holding.

I like them medium rare, CTD, usually a Rib-eye, but almost any kind will do! :D :D

bintanglagi 31st Oct 2001 02:35

Looks as though someone who has been involved in helicopter certification says that their is a very good reason for limiting crosswinds. The whole point of raising this topic.
For most Super Puma operators, they won't be limited to one runway in a very windy place in the middle of nowhere. Normally there's a choice of departure directions or it's very warm and quiet.
Obviously QM had a problem in his place, and Arcticfox says that two incidents (one not really a problem in his terms) have occurred where he's operating.
If a company wants to work out of a remote area that is prone to rather large winds across the runway, then the last thing you want is commercial pressure and then to explore the "outside of the envelope" if something went wrong. Nobody is going to help you then if the wheels break off, or if you're on your side.
Stick to what the Flight Manual is trying to say (even in the French translation)!

QM 31st Oct 2001 11:18

Absolutely bintanglagi, look after number one as no one else will!

Pat Gerard 31st Oct 2001 13:27

Bintanglagi

Hang on here. I am getting in touch with Eurocopters test pilots. I know a couple of them and I shall try to convince them to reply direct to this thread.
Enjoy your time off.

Pat

nicknorman 2nd Nov 2001 03:33

A Eurocopter flight test engineer I once spoke to was happy to admit that the reason for the reduction in xwind limit above 18410 was simply that they didn't want to spend the time (and money) re-certifying all those limits and so made do with the minimum permitted xwind limit which is apparently 17 kts. However the fact that there is no scientific reason for the limit does not detract from its legal standing. In practice the real limit before crashing on a reject would probably be between 17 and 35 but I wouldn't like to be the one to find out what it is :eek: Someone correctly said that as you land from the reject with the rotors drooping you will lose tail rotor effectiveness. Once the aircraft starts to swing with full pedal you've had it. As a trainer I would not consider practicing rejects at that sort of weight with a 90deg 35 knot crosswind at 18960 and I know I would rightly be sacked if I did. And that would be when my candidate was all primed up for an engine failure. When it happens for real on a dark sleepy morning you will spend the first 5 seconds going "Oh **** !" and by then it will all be over. You need a fair safety margin, not a manoeuvre that you can just get away with when you're at your very best.

With a strong wind from the North, can't you take off into wind down the taxiway? With a 4 second CDT (+1 deg colective pitch) you need only 100m or so. Once past CDT you can turn left a touch to avoid upsetting the neighbours. If there is too much clutter of parked aircraft, get them to move!!

Nick Lappos 2nd Nov 2001 15:19

NN reported:
A Eurocopter flight test engineer I once spoke to was happy to admit that the reason for the reduction in xwind limit above 18410 was simply that they didn't want to spend the time (and money) re-certifying all those limits and so made do with the minimum permitted xwind limit which is apparently 17 kts.

Nick sez:
That sounds a bit fishy, NN, because the team had to test at the higher weight at 17 knots sideward flight to certify (increase in weight or altitude is never a gimmie), and to go to 35 knots takes a few more data points, and about 15 minutes more test time, literally. They are already set up and in position, and have taken the 17 knot point, so there is no increase in bother. I'll ask my TP friends at Eurocopter to find out, as well.


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