Flying CAT "A" profile over weight

[blade root]

I have seen and have flown with a few pilots who insist on flying the CAT "A" VTOL profile when well above the weight restrictions imposed by the Flight Manual.

Why? any benefits in doing so ?

just putting it out there for comment.

[Wizzard]

I suppose the main benefit would be that if an engine stops you'll have a fair idea of what the crash site looks like

[Fortyodd2]

Perhaps they don't like their passengers or love their wife & kids very much

[TunaSandwich]

Excactly wizzard, surely better to bend the skids/colapse the seats/ whatever back on the pad than cartwheeling down a back alley?

blade root, I assume you're talking about over CAT A weight limits as opposed to airframe weight limits?

I've been surprised myself by being with pilots in the reverse situation, skimming accross rooftops in order to gain airspeed rather than gaining altitude over the spot when over Cat A weight limits.

Depends on the individual situation of course and if the takeoff area is not too congested then would probably go for airspeed, but congested areas, particularly if there are other human beings around, would definitely go for a CAT A profile to crash me back on the pad.

[Flying Bull]

Hi blade root, it´s kind of a policy - until they tried to recover an engine failure in such a situation i.e. in a simulator. There after they might change to the "exposure time" method - keeping the time, where an engine failure kills you - as short as possible. Going through the accident statistics engines fail quite often, when on high power settings. So keeping the time with high power as short as possible makes sense. At 35 to 40 KIAS you´re normally capable to fly away with only one donk running - and you reach that speed in a few seconds - compared to a CAT A profile when overweight...... When you start to talk to one of them - take the books and go on the CAT-A pages - its written down, when CAT A is recommended and allowed. When you are out of the parameters - its the pilots decision how to depart - and I stick to the exposure time method - giving only a few seconds of thrill... Would not fly with a pilot, if he insists on departing with a CAT A profile when overweight. Greetings Flying Bull

[SASless]

Firstly, I would suggest if one is "over-weight" then the Cat A profile does not apply....period.

Secondly, I would suggest unless the takeoff area allows for a use of any other approved profile and....operative word "and"....the proposed takeoff path allows for a safe rejected landing prior to achieving Vtoss or the profile CDP....one is back to flying helicopters using old fashioned commonsense.

Thirdly, at some point in yer life , you are going to have to operate outside nice cozy airports and fall back into what helicopters are built to do. When that happens, one should forget the regimentation and etched in stone rituals one learned flogging off to the rigs as it is apples and oranges.

[blade root]

Tuna Sandwich (and others),

When I refer to over weight, I mean the (generally restricted) Cat A weight not the MTOW.

[Epiphany]

Pilots who do this are simply showing their ignorance of CAT A performance. I remember watching some idiot in a Jetranger flying a helipad profile when taking off from Battersea heliport. Gawd only knows what he thought he was doing.

[skadi]

Pilots who do this are simply showing their ignorance of CAT A performance. I remember watching some idiot in a Jetranger flying a helipad profile when taking off from Battersea heliport. Gawd only knows what he thought he was doing.

Jetranger and CAT A ?????????

[paco]

Just being picky as it's a slow afternoon - it's Category A and Performance Class 1 (or whatever) - not Category A Performance!

I too have seen people in singles doing the backwards takeoff bit. Gosh.

Phil

[Epiphany]

Thank you Phil but it will still have a detrimental effect on the performance of the helicopter whatever you call it. I didn't want to complicate the issue when most folk still refer to it as CAT A. For those who don't understand or have to fly CAT A (PC1) - If you are flying a CAT A profile at weights above the max allowable for that procedure (particularly a helipad) then you are very likely exposing yourself to more risk than just doing a normal helicopter departure. If you have not been taught it properly then don't do it.

[mickjoebill]

backwards single

I too have seen people in singles doing the backwards takeoff bit. Gosh.

Phil

Is the backward take off bit in a single appropriate when there is a built-up area lets say for 1/4 mile immediately around the takeoff point ?

Mickjoebill

[Hilico]

Is the backward takeoff appropriate in a single ever?

[C of G]

Is this concept not the basis for Performance Class 2? Fly the CAT A profile without the weight restriction? Pardon my ignorance on the subject as we don't have a Performance Class 2 counterpart on the FAA side. I was told it was keeping the exposure time to a minimum. My only time playing wth the profiles in in an EC135P2+ and it does well at sealevel with OEI at all stages. Thanks...

[paco]

C of G - Perf 2 is a cross between Perf 3 and Perf 1. You start off as 3 until you reach the point at which you can maintain Perf 1 conditions. The difference between the two is the exposure time which statistically figured to be OK in terms of engine failure. It was created to allow older helicopters such as the 212 to operate until the new stuff comes in.

If you could fly the profile in the first place you wouldn't need it!

Phil

[Non-PC Plod]

Have done a bit of experimentation with this. We have some customers operating regularly at 7000' pressure altitude at plus 35 deg C, at fairly high AUM who have to depart from helipads with a fence round them. During recurrent training in the simulator, they wanted to see what was the best plan for a departure with possible engine failure i mind, given that they were over the WAT limits for Cat A.
Whatever profile they flew, they were going to crash, but we managed to find a profile which was a cross betwen the helipad and the short field concept that genrally allowed a more controlled and survivable crash than any of the documented procedures.
It took a bit of playing with - you cant necessarily assume any technique is going to work until you try it with a real failure! Generally, something close to a Cat A profile seems to give you minimum hurt if you have the failure early in the departure, but you have the option of weighing this up against reducing your exposure time, and hoping the failure will come later if it happens.
I reckon the best plan is to get in a simulator and do some experimentation at your typical weights and DA.

[Phoinix]

Can you describe in more detail a typical, more survivable crossover between Cat A and short field departure?

[Non-PC Plod]

Sorry, I'm not going to stick my neck above the parapet and suggest alternative ways to conduct your departures. If you have to operate in marginal conditions, your best bet is to get in a simulator and simulate your particular conditions and find out what sort of crash feels best. For example, you may find that clearing the fence around your helipad and crashing into the clear ground beyond gives you a reduced impact if the engine failure happens above a particular height, whereas you are better falling vertically than crashing into the fence if the engine failure occurs below that height.

[tecpilot]

Having seen some Cat A flight tests with bended skids by testpilots and since them i believe Cat A is only a paper to find an alibi for JAA. If we are light enough to fly Cat A elevated heliport, we can fly in the OEI limits mostly. For BK117 OEI limit 140% for 12 sec.

And Cat A seems to run out in some countries because most twins are allways to heavy for Cat A charts on the usual operation weight. The new wizard is therefore "exposure time". For BK117 15sec. Leave the spot as quick as possible and don't stay endless in backward high hover.

Amusing!