Hard Core Category A?
Joined: Mar 2010
Posts: 109
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From: North America
CB,
For the S-76A there are two TDP’s called TDP1 (40 ft) and TDP2 (120 ft). If an engine fails on takeoff before passing TDP1, the landback is vertical. If an engine fails after passing TDP1 and before reaching TDP2, the pilot must rotate nose-down and landback with forward speed. TDP2 is the “real” TDP, as fly-away must not be attempted if an engine fails before passing TDP2.
I think you are remembering an S-76C++ procedure where TDP1 is 70 ft and TDP2 can be as high as 170 ft.
HT
For the S-76A there are two TDP’s called TDP1 (40 ft) and TDP2 (120 ft). If an engine fails on takeoff before passing TDP1, the landback is vertical. If an engine fails after passing TDP1 and before reaching TDP2, the pilot must rotate nose-down and landback with forward speed. TDP2 is the “real” TDP, as fly-away must not be attempted if an engine fails before passing TDP2.
I think you are remembering an S-76C++ procedure where TDP1 is 70 ft and TDP2 can be as high as 170 ft.
HT
Joined: Feb 2012
Posts: 4
Likes: 0
From: Europe
My question referred basicly to the AS355F2's performance: probably there is a maximum (decreased) weight limit to the helicopter to be able to fly in CAT A Class 1 (appropriate for take off/en-route/landing - according OPS)
Joined: Nov 2000
Posts: 4,330
Likes: 74
From: White Waltham, Prestwick & Calgary
Yes, but for quick reference 2100 kg in a country like UK is about right, although you should really use the chart in Suppl 11.1. The max weight is normally 2540 kg so that would make sense.
His question is not very clear, though. Cat A Class 1?
phil
His question is not very clear, though. Cat A Class 1?
phil
Joined: May 2003
Posts: 921
Likes: 30
From: Europe
Paco,
You're quite correct that the question was not framed in a way that an answer could easily be provided.
After exchanging a series of PMs with 'rvl', it would appear that her question was about operating from a 'congested hostile environment' and therefore related to the 'helipad' procedure.
As I always point out, on a runway, the clear area CAT A procedure provides little that PC2 could not provide - PC1 has to be achieved by 200ft in either case and the take-off mass is almost always related to the second segment climb (which starts at that level).
Jim
You're quite correct that the question was not framed in a way that an answer could easily be provided.
After exchanging a series of PMs with 'rvl', it would appear that her question was about operating from a 'congested hostile environment' and therefore related to the 'helipad' procedure.
As I always point out, on a runway, the clear area CAT A procedure provides little that PC2 could not provide - PC1 has to be achieved by 200ft in either case and the take-off mass is almost always related to the second segment climb (which starts at that level).
Jim
Joined: Jan 2005
Posts: 90
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From: Always on the back of the drag curve.
AS355F1 Cat A Clear Area 2400kg Cat A Helipad 2200kg
AS355F2 Cat A Clear Area 2400kg Cat A Helipad 2200kg
The Max T/O Mass of 2540 for F2 is unscheduled for Cat A i.e the extra 140kgs - but on a particular day you may be able to take off Class 2 at 2540kg and maintain CAT en route performance
I think!! UG
AS355F2 Cat A Clear Area 2400kg Cat A Helipad 2200kg
The Max T/O Mass of 2540 for F2 is unscheduled for Cat A i.e the extra 140kgs - but on a particular day you may be able to take off Class 2 at 2540kg and maintain CAT en route performance
I think!! UG
Joined: Aug 2012
Posts: 12
Likes: 0
From: Nepal
Helicopter Performance Class
Hi! Could you please tell me how can we distinguish between Helicopter Performance Classes 1, 2 and 3? Is this classification based on types of helicopters or the number of passengers they can carry? Or any other thing? Any suggestions will be appreciable!! 
Joined: Aug 2004
Posts: 2,105
Likes: 50
From: Aberdeen
For a twin engined helicopter, it is determined by how the operator chooses to operate it. Of course there may be some operational regulations requiring operation in one of those classes, depending on the rules applicable in the locale. See for example JAR-OPS 3. The rules are a bit too complex to briefly explain in a post.
A single engine heli can only operate in PC 3.
In simplistic terms, with PC1, in the event of an engine failure you can maintain safe flight or land on the helipad/ runway. PC 2 is the same except that there is a brief period during takeoff and landing when you may have to make a forced landing off the helipad / runway if an engine fails
PC3 you may have to make a forced landing any time an engine fails.
A single engine heli can only operate in PC 3.
In simplistic terms, with PC1, in the event of an engine failure you can maintain safe flight or land on the helipad/ runway. PC 2 is the same except that there is a brief period during takeoff and landing when you may have to make a forced landing off the helipad / runway if an engine fails
PC3 you may have to make a forced landing any time an engine fails.
Last edited by HeliComparator; 24th November 2012 at 07:50.
