Category A Takeoff: Background
Avoid imitations
Nick did not win the Barnes Wallis Award because of his mere good looks and charm...(sounds of coughing heard)!
there must be some known cases of this proceedure working? Shirley?
Do you do your Air Tests at 95% of MAUW per the charts.....or do you do the Check in a nearly empty aircraft?
A few Rotorheads have been in touch asking for a copy of the old 212 Cat A Supplement. I've scanned it in three parts to keep the file size down, you can download them from here:
Part One
Part Two
Part Three
Please note, this is a scan of an old supplement which may have been superseded and may even be discontinued.
Not for operational use!
Each file is about 6mb, and there is a blue 'Download document' above the file reference.
Part One
Part Two
Part Three
Please note, this is a scan of an old supplement which may have been superseded and may even be discontinued.
Not for operational use!
Each file is about 6mb, and there is a blue 'Download document' above the file reference.
To the best of my recollection the 212 was never re certified using the 3b engines. Does anyone know if it ever was. Performance would be much better I think.
I no longer fly the 212. Just curious.
I no longer fly the 212. Just curious.
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Well I think these Cat A type departures are not as safe as they could be. There is too much reliance on the tail rotor. They have two engines and only one tail rotor, so should base the technique on risking the engines more than the tail rotor by climbing forwards and into translation lift sooner, instead of loading the tail rotor more and for longer than necessary by climbing backwards...
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If you climb forward you enter the avoid curve so if you lose one of the two engines you will crash. So it’s Catch 22.
CAT A procedures are designed to keep you out of the avoid curve. If you are in it then you can’t guarantee a safe landing.
Tail rotors are statistically reliable too!
Tail rotors are statistically reliable too!
Well I think these Cat A type departures are not as safe as they could be. There is too much reliance on the tail rotor. They have two engines and only one tail rotor, so should base the technique on risking the engines more than the tail rotor by climbing forwards and into translation lift sooner, instead of loading the tail rotor more and for longer than necessary by climbing backwards...
That sort of post is what gets traction with media researching this thread for shock/horror headlines without either understanding nor follow up research.
Floater .... I don’t understand how slowly reversing can be less in the avoid curve than pulling vertically and transitioning to SE climb away ASAP ? Surely every knot of forwards speed you get takes you closer to getting out of the avoid ?? ( and in the same logic reversing would make the normal avoid larger , ie higher than a normal hover as it will take valuable seconds and feet to arrest the backwards speed before initiating a nose down attitude to pick up speed ??) I am not saying you are wrong, but to my mind I would feel happier getting to the speed I could at least maintain altitude as soon as possible . I also think that logically the time it would take to drop the nose and pick up some speed would double if you were going backwards with nose up rather than a flat hover ?
I think I must be misunderstanding something ....maybe the powers that be consider the downside of reversing ( which there really must be ) are worth taking for the upside (??) of being able to see your take off spot during the climb .... ??
Old Fat One ..I think some people on here think that for you to post a theory of what you think may have happened...you should have at the very least a proper understanding and almost certainly be an experienced, probably professional, pilot . I tend to agree . My comments are a genuine question regarding the effectiveness of Cat A type take offs and are probably therefore thread drift . Apologies .
I think I must be misunderstanding something ....maybe the powers that be consider the downside of reversing ( which there really must be ) are worth taking for the upside (??) of being able to see your take off spot during the climb .... ??
Old Fat One ..I think some people on here think that for you to post a theory of what you think may have happened...you should have at the very least a proper understanding and almost certainly be an experienced, probably professional, pilot . I tend to agree . My comments are a genuine question regarding the effectiveness of Cat A type take offs and are probably therefore thread drift . Apologies .
Floater .... I don’t understand how slowly reversing can be less in the avoid curve than pulling vertically and transitioning to SE climb away ASAP ? Surely every knot of forwards speed you get takes you closer to getting out of the avoid ?? ( and in the same logic reversing would make the normal avoid larger , ie higher than a normal hover as it will take valuable seconds and feet to arrest the backwards speed before initiating a nose down attitude to pick up speed ??) I am not saying you are wrong, but to my mind I would feel happier getting to the speed I could at least maintain altitude as soon as possible . I also think that logically the time it would take to drop the nose and pick up some speed would double if you were going backwards with nose up rather than a flat hover ?
I think I must be misunderstanding something ....maybe the powers that be consider the downside of reversing ( which there really must be ) are worth taking for the upside (??) of being able to see your take off spot during the climb .... ??
I think I must be misunderstanding something ....maybe the powers that be consider the downside of reversing ( which there really must be ) are worth taking for the upside (??) of being able to see your take off spot during the climb .... ??
the profile flown gives you a safe landing area before oei before tdp, you drift down to where you started, oei after tdp you have sifficient height to transition and clear the roof
Floater .... I don’t understand how slowly reversing can be less in the avoid curve than pulling vertically and transitioning to SE climb away ASAP ? Surely every knot of forwards speed you get takes you closer to getting out of the avoid ?? ( and in the same logic reversing would make the normal avoid larger , ie higher than a normal hover as it will take valuable seconds and feet to arrest the backwards speed before initiating a nose down attitude to pick up speed ??) I am not saying you are wrong, but to my mind I would feel happier getting to the speed I could at least maintain altitude as soon as possible . I also think that logically the time it would take to drop the nose and pick up some speed would double if you were going backwards with nose up rather than a flat hover ?
I think I must be misunderstanding something ....maybe the powers that be consider the downside of reversing ( which there really must be ) are worth taking for the upside (??) of being able to see your take off spot during the climb .... ??
Old Fat One ..I think some people on here think that for you to post a theory of what you think may have happened...you should have at the very least a proper understanding and almost certainly be an experienced, probably professional, pilot . I tend to agree . My comments are a genuine question regarding the effectiveness of Cat A type take offs and are probably therefore thread drift . Apologies .
I think I must be misunderstanding something ....maybe the powers that be consider the downside of reversing ( which there really must be ) are worth taking for the upside (??) of being able to see your take off spot during the climb .... ??
Old Fat One ..I think some people on here think that for you to post a theory of what you think may have happened...you should have at the very least a proper understanding and almost certainly be an experienced, probably professional, pilot . I tend to agree . My comments are a genuine question regarding the effectiveness of Cat A type take offs and are probably therefore thread drift . Apologies .
So if you have gained , as in this case , a maximum of 20-30m by reversing ... you are at say 30-40m height . How much airspeed will you have available to settle back to the same spot ? Enough to be in transition ? I wouid say no . Enough to eliminate possible vortex again no . So what really are you gaining ? You could eliminate all the risks we have discussed in exchange for having to come down admittedly more vertically?
maybe not a point but in the 109 I would rather do vertical because when near transition speed she shakes and rattles like hell !
212 .. just seen your message . Fair enough !!
maybe not a point but in the 109 I would rather do vertical because when near transition speed she shakes and rattles like hell !
212 .. just seen your message . Fair enough !!
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helicrazi
And this takes more than twice as long, exposing the aircraft to a kind of "tail rotor avoid curve". I cringe every time I see this type of departure thinking "I hope that tail rotor doesn't let go, why is it taking so long"...
the profile flown gives you a safe landing area before oei before tdp, you drift down to where you started, oei after tdp you have sifficient height to transition and clear the roof
So if you have gained , as in this case , a maximum of 20-30m by reversing ... you are at say 30-40m height . How much airspeed will you have available to settle back to the same spot ? Enough to be in transition ? I wouid say no . Enough to eliminate possible vortex again no . So what really are you gaining ? You could eliminate all the risks we have discussed in exchange for having to come down admittedly more vertically?
maybe not a point but in the 109 I would rather do vertical because when near transition speed she shakes and rattles like hell !
212 .. just seen your message . Fair enough !!
maybe not a point but in the 109 I would rather do vertical because when near transition speed she shakes and rattles like hell !
212 .. just seen your message . Fair enough !!
I flew the AS33L2. It had a backing-up Cat A helipad procedure. I also flew the EC225, it had a vertical Cat A helipad procedure. Both procedures were entirely valid. The backing-up one gives better view of the reject area but you are backing up into unseen territory and overdoing the backing up results in too much rearwards speed. The vertical one is easier provided you can keep the landing area in view. As a TRE/TRI I did more OEI rejects from just before TDP than I care to remember. What a surprise - none of them had any hint of vortex ring!