Cat eh!

[Steve76]

How about a definition of CAT A performance and how it applies to your operation.. .Do you base a go/nogo decision on your OEI performance? . .What ROC does OEI max continuous and OEI 30 min afford you on your helo type?. .cheers <img src="wink.gif" border="0">

[Steve76]

I concur! ha! :)

[Kalif]

That must be some sort of Cat A profile you're using, or there again am I using the wrong one. Maybe I need to read the S76 AFM again.. .The only profile that gives my passengers a thrill is the A109 Power helipad; very quick, very yahoo!

[Bladestrike]

As you no doubt know, Cat A performance guarantees 100 fpm at Vtoss to 100 feet, then 150 fpm at Vbroc to 1000 feet, achieving Vbroc prior to exceeding your 2.5 minute power duration. It's right in the Sikorky FM. And we use our Cat A weights, as well as being able to maintain a 50 fpm climb at our MOCA, in determining go/no-go.

[ 22 February 2002: Message edited by: Bladestrike ]</p>

[Bladestrike]

..and if you do the profile properly, you'll give the passengers a thrill on take-off, and yourself one on final. I don't know about the "C" but 50 knots at 100 feet on the "A" was fun, the 61 is 150 feet at 35 knots, quite pleasant in comparison!

[IHL]

As a side bar to Bladestrike: A category "B" take-off at maximum Cat "B" weights guarantees . .a 0 rate of climb using 21/2 minute OEI power.

[Steve76]

Thats what I was after IHL.. .I got interested as I went looking the other day and couldn't find it. I understand it to be 100ft ROC, OEI at max cont. I wanted to confirm that as the aussie ATPL refers to it heavily and I wanted to ensure I wasn't getting the actuals mixed up with the theories.. .Back to the books..... . <img src="smile.gif" border="0">

[Bladestrike]

According to the FAA, "The maximum take-off gross weight for Category "B" is based on the helicopter's ability to hover, in ground effect, at all altitudes and temperatures within the approved limitations."

[Nick Lappos]

IHL,. .That is the "modified Cat B" rule made for the North Sea a while back (30 years) The CAA recognized the safety of simple zero rate of climb, and allowed a special profile that carried more payload than Cat A enroute

True Cat B is purely the ability to hover, twin engine IGE and to make a safe landing along the route if an engine fails. Singles are operated Cat B.

Part 29 of FAR/JAR allows Cat B if the aircraft carries 9 passengers or less.

There are other watered down paragraphs for "Cat B, 9 passengers or less", such as tail rotor controllability. No demonstrated crosswind controllability is required 9 pax or less in a Part 29 helo, if the manufacturer applies for it. Thus the screwy Bell hover charts about wind from the nose vs wind from any direction, where extra payload is added at the expense of tail rotor authority. This is true for the 430 and the 412.

The logic of limiting the exposure for a less safe configuration is interesting!

[ 24 February 2002: Message edited by: Nick Lappos ]</p>

[IHL]

As a side-bar to the above side bar ( I like that terminology today) on the 76A if you look up the Max Cat B take-off weight , where the take-off weight is less than 10,500 lbs due to the effects of altitude and temperature and plot that weight,temperature,and altitude against the 52knot , 21/2 minute OEI , forward climb performance chart, you will find invariably that the rate of climb is zero , "0" FPM .

[Nick Lappos]

IHL,. .that is interesting! It is a coincidence, but nonetheless quite intriguing.