9 degree approach for the 76

[Bladestrike]

The powers that be came up with the following profile for us....500ft at 1/2 mile at Vtoss, maintaining that profile (gives you over 800 per with no wind) with the 50 knots till 100 feet, flare to pull through 55% Q over the pad. (with less than 10 degrees below 30 feet of course). Being fairly new to the 76, I find maintaining 50 knots down to 100 feet followed by a big flare a tad hairy, especially into black holes lit only by reflective cones. You'll make the pad if you lose a stove but...what do the more experienced of you think?

[212man]

The CAA FM Group A profile reuires an LDP at 100 ft and 50 kts with up to 750 ft/min, maintain the 50 kts to 50 ft then flare up to 20 degrees, before levelling to the hover. Sort of an engine assisted auto in the event of an engine failure after LDP.

I seem to recall that at night we tended to be a little more practical about the thing and flew the Group B profile, a lot less exciting for the pax too.

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Another day in paradise

[tech]

Dear Bladestrike.
I don't think that the company wants you to be at 50 kts and 100 feet going into a black, poorly lit cone site.

With no illumination other than reflective cones that would be a hairy ride at the bottom.

I think the idea is to start slowing down to translational lift at about .3 back and 250 feet and sort of walk-it-in from there.

The profile you mentioned works great in the day-time or at well lit helipad with some peripheral lighting for reference.

[Bladestrike]

I do rather like the approach...I just have a heck of a time hitting the correct numbers! There's alot of 76 drivers out there and I was looking for some other views. "Tech", planning any more tours in "Red Neck" country? We miss you.

[HOGE]

I find Group B a much more relaxed affair, but for all landings whether onshore, or more importantly offshore, making it to the pad is the trick! Better to be steep and slow with power on (which gives you an early clue that the landing may not be as gossamer as one would like), rather than too low, too fast, and running out of options/prayers/future employment.

[offshoreigor]

Bladestrike:

I think you will find that with time the 76 will seem less and less slippery. I can see the logic behind your company wanting to maintain 50 KIAS. If you are flying an 'A' model then it is pretty close to VTOSS (52 Kts) a bit of a trade off for simplicity.

I've found over the years that the hardest thing people find about the 76 is getting it to stop. Most pilots who get they're endorsement on the 76 have come off a Bell system (under-slung, semi-rigid head) that reacts much better to a cyclic flare for deceleration.

With a Sikorsky product like the 76 (fully articulated) plus add the forward mast tilt (requiring a nose-high attitude for hover) the problem is a little different.

You will find that by shooting your approach with the head loaded up (ie. 40-45% Q) and 45-50 KIAS, all you require at the bottom is a small flare of 9-10 degrees and an increase in power to about 70% Q to stop the A/C.

Just think of the collective as a big speed brake! BTW, on the 'A++' we use 45 KIAS through 200' with not more than 600 fpm ROD, down to 50' and about 8 degrees of flare at the bottom. This is the primary RFM CAT 'A' approach profile. On the Rig we use 1/2 mile back, 500', 40% Q and 45 KIAS crossing the deck edge at 35 KIAS and 55% Q. Works quite nice actually.

To HOGE:

I agree CAT 'B' is a kinder, gentler approach but I don't think you'll find an offshore operation in the world where CAT 'B' is approved for the 76. It's all CAT 'A' or Class 1.

Cheers, OffshoreIgor http://www.pprune.org/ubb/NonCGI/eek.gif



[This message has been edited by offshoreigor (edited 18 January 2001).]

[Bladestrike]

Thanks guys! Yes, many thousands of hours with ma Bell and Sikorsky does make a slippery beast. I appreciate the info.

[HOGE]

To Offshoreigor:

Never said I used a Group B profile for offshore!

[offshoreigor]

To HOGE:

You're absolutly correct, I misread your post, didn't see the 'but'

My apologies.

Cheers, OffshoreIgor http://www.pprune.org/ubb/NonCGI/eek.gif

[polehog]

Bladestrike The profile you discribe works great. Wheather it is to a cone site or a dark very small offshore pad (Its amazing how small they get at night) The profile allows you to delay the LDP call to much later in the landing profile (or should at least) I have found that many pilots call CDP to early on rig approaches. I have always felt (right or wrong) that many times the call is made by less expearianced pilots"just to get it out of the way". And if you could get inside their head at the critical time you might find that if one mule went quiet they might try for what they preceved as the "relitive safety" of the deck. If they are slow and flat then chances are they are most likely going to scratch the paint part way down the legs. The same is true in cone sites espically in the winter when that big snow storm arrives just at touch down. If the profile is done well and the nose comes up to 8 to 10* and a collective pull to check the rate of decent, then the aircraft tends to want to stop and a nice no hover landing can be made just as the nose starts to drop. If its done correctly in the snow you can touch down just before the snow hits (a slight head wind sure helps)On an offshore platform this procedure really seperates the good from the not so good if its done well its a true art if its done poorly its frightfull.

peace man