True Cat A Performance
Join Date: Jul 2002
Location: Texas
Posts: 512
Likes: 0
Received 0 Likes
on
0 Posts
Xnr, I don't fly in Canada, don't intend to ever get close to Canada, therefore I'm not worried about legalities of Cat A landings. I don't intend to ever again venture north of the Red River (the one our President patrolled during the Vietnam conflict as a member of the Texas Air National Guard, watching for invaders from the north). It just gets too cold for me. 
That said, I know that the S76A++ & 412 can be landed single engine to a platform. I've practiced it both in the sim & in the aircraft. You're likely to get a little movement at high gross weights, but a few feet is normally acceptable, if you planned the approach correctly. The S76C+ has a 'training mode' that allows restricting the power to single-engine levels for practice.
That said, I know that the S76A++ & 412 can be landed single engine to a platform. I've practiced it both in the sim & in the aircraft. You're likely to get a little movement at high gross weights, but a few feet is normally acceptable, if you planned the approach correctly. The S76C+ has a 'training mode' that allows restricting the power to single-engine levels for practice.
XNR,
AS355 F1 (MTOW 2400 kg) Cat A level helipad is 2090kg at SL/30 degC. The N model will do it at 2400 kg.
I see what you are getting at now though (appologies for the above sucking eggs stuff). The supplement in our F1 states "Though the helicopter is not certified to FAR 29 for Category A operation this supplement deals with the procedures and performance allowing the aircraft to be operated in a similar way." In other words, the aircraft can be operated to Cat A but it is not actually "certified" as such. I think that was your point XNR wasn't it?
AS355 F1 (MTOW 2400 kg) Cat A level helipad is 2090kg at SL/30 degC. The N model will do it at 2400 kg.
I see what you are getting at now though (appologies for the above sucking eggs stuff). The supplement in our F1 states "Though the helicopter is not certified to FAR 29 for Category A operation this supplement deals with the procedures and performance allowing the aircraft to be operated in a similar way." In other words, the aircraft can be operated to Cat A but it is not actually "certified" as such. I think that was your point XNR wasn't it?
Thread Starter
Join Date: Apr 2002
Location: Can
Posts: 172
Likes: 0
Received 0 Likes
on
0 Posts
From what I can read the criteria for landing on a platform allows you to carry more payload than a ground level helipad.
My point in this discussion is that the Cat A ground level helipad performance restictions turns most twins into aircraft that are operating at not much more than their empty weight. They have very limited payload. I agree that the new generation aircraft are better.
Do you have any such restrictions to helipads in the U.S. and if so how is this restriction worded.
IMHO a restriction of this sort basically disqualifies aircraft with proven reliability from landing at that helipad (i.e. S76A )
I agree with most who say it is better to have reliability that full Cat A performance.
Helmet
So if your aircraft is not certified and the helipad is restricted I guess you can't land there either.
My point in this discussion is that the Cat A ground level helipad performance restictions turns most twins into aircraft that are operating at not much more than their empty weight. They have very limited payload. I agree that the new generation aircraft are better.
Do you have any such restrictions to helipads in the U.S. and if so how is this restriction worded.
IMHO a restriction of this sort basically disqualifies aircraft with proven reliability from landing at that helipad (i.e. S76A )
I agree with most who say it is better to have reliability that full Cat A performance.
Helmet
So if your aircraft is not certified and the helipad is restricted I guess you can't land there either.
Last edited by Xnr; 4th Jan 2003 at 23:41.
XNR; Which pads Mate?
Shawn: with regards to the 703. Its my understanding that to hold a 703 approval you must be able to maintain at least MOCA IFR. Thus to maintain MOCA in our op. we should be looking at 30min power at 150ft/min ROC. Thus the same req. as Cat A or Class 1. I have been wrong before thou....
Howdy OffshoreIgor? How are those aussies treating ya?
Kick them where it hurts for me please
Shawn: with regards to the 703. Its my understanding that to hold a 703 approval you must be able to maintain at least MOCA IFR. Thus to maintain MOCA in our op. we should be looking at 30min power at 150ft/min ROC. Thus the same req. as Cat A or Class 1. I have been wrong before thou....
Howdy OffshoreIgor? How are those aussies treating ya?
Kick them where it hurts for me please
Thread Starter
Join Date: Apr 2002
Location: Can
Posts: 172
Likes: 0
Received 0 Likes
on
0 Posts
Check the roof top pad in your area and any other pad that is in the middle of a built up area without a suitable reject site other than the pad itself. (Check the CFS)
Chances are that they have had this restriction placed on them.
A couple of roof tops out east have a restiction that reads something like "the aicraft must be able to maintain 4.5 metres (15') above all obstacles on the approach and departure path OEI."
Thats a pretty tall order.
The problem is that guys don't realize that the pads have been restricted and are continuing to land and take off at near gross weight.
If there is ever an incident the laywers will have a feeding frenzy. Every finger will be pointing at the pilot.
With regards to our op we must be able to maintain the MOCA OEI (no rate of climb) but this is not a Cat A requirement.
Chances are that they have had this restriction placed on them.
A couple of roof tops out east have a restiction that reads something like "the aicraft must be able to maintain 4.5 metres (15') above all obstacles on the approach and departure path OEI."
Thats a pretty tall order.
The problem is that guys don't realize that the pads have been restricted and are continuing to land and take off at near gross weight.
If there is ever an incident the laywers will have a feeding frenzy. Every finger will be pointing at the pilot.
With regards to our op we must be able to maintain the MOCA OEI (no rate of climb) but this is not a Cat A requirement.
Join Date: Oct 2002
Location: scotland
Posts: 79
Likes: 0
Received 0 Likes
on
0 Posts
Cat A Performance
All twins I have flown have have Cat A capability, clearly with restricted weights, some better than others. The AS355F1 is perfectly capable of helipad departures and arrivals, and to be honest the figures given seem quite relaxed ie. it is not too big a deal if an engine does go bang. With newer machines the limits seem to get pushed harder such that if the worst should occur then there is little margin for error. The 355 has very basic graphs giving a fixed profile, the 365 has variable Vtoss and Vy to give more options depending field length. The added complexity increases what we can do legally.
All manufacturers want to get the most out of their machines, which means if they can they will work closer to the limits, so long as we are professional in our approach this is fine, but it does leave a door open to getting caught out if we are not.
Remember Cat A is for the whole flight so guaranteed ground clearance in the cruise is part of it, and during climb out, 3% is 150ft per mile, a 500ft hill 3 miles away gives more than 3% gradient.
All manufacturers want to get the most out of their machines, which means if they can they will work closer to the limits, so long as we are professional in our approach this is fine, but it does leave a door open to getting caught out if we are not.
Remember Cat A is for the whole flight so guaranteed ground clearance in the cruise is part of it, and during climb out, 3% is 150ft per mile, a 500ft hill 3 miles away gives more than 3% gradient.
Join Date: Jul 2002
Location: Texas
Posts: 512
Likes: 0
Received 0 Likes
on
0 Posts
In the US, there is no requirement that I know of to comply with Cat A anywhere, anytime. I know of no pads which require it. Common sense may dictate otherwise, but there is no regulatory requirement. Some local government entities may have their own requirements, but I don't know of any.
Join Date: Dec 2001
Location: Philadelphia PA
Age: 74
Posts: 1,835
Likes: 0
Received 2 Likes
on
2 Posts
Steve76:
I was in the fortunate position to never have to interpret the operational rules (703, etc.). But you can do the MOCA thing in many helicopters that do not have Category A performance. Two completely separate things.
xnr
The wording about demonstrated performance (instead of just Category A) is something I'll take credit for. I suggested that, particulary for the S-76A, there was a supplement for less than 9 passengers (i.e. air ambulance) that had a demonstrated vertical takeoff profile, and that it should be given credit for that. Very long story about that whole thing came about.
Transport Canada uses the same regulatory material as the FAA for certification (i.e. Part 27 and Part 29).
The UK CAA recognized long ago that Part 27 helicopters, specifically the AS-355 series, could demonstrate Category A performance, but may not have had some of the other features needed to get Category A (engine isolations, and other very esoteric, but important things).
This has been a great discussion.
I was in the fortunate position to never have to interpret the operational rules (703, etc.). But you can do the MOCA thing in many helicopters that do not have Category A performance. Two completely separate things.
xnr
The wording about demonstrated performance (instead of just Category A) is something I'll take credit for. I suggested that, particulary for the S-76A, there was a supplement for less than 9 passengers (i.e. air ambulance) that had a demonstrated vertical takeoff profile, and that it should be given credit for that. Very long story about that whole thing came about.
Transport Canada uses the same regulatory material as the FAA for certification (i.e. Part 27 and Part 29).
The UK CAA recognized long ago that Part 27 helicopters, specifically the AS-355 series, could demonstrate Category A performance, but may not have had some of the other features needed to get Category A (engine isolations, and other very esoteric, but important things).
This has been a great discussion.
Far 91.3 allows an offshore operator to momentarily breach the H-V limitations for Part 29 certified helicopters, from an elevated deck if the water is suitable for an intentional landing and the helicopter is equipped with floats. The reg does not address or specifically talk about land based elevated decks......wonder how all that figures in??? What if you have an elevated deck without adequate forced landing areas below....can you still violate the H-V limits as so stated in the 91.3 reg? This would apply to very many of the EMS Hospital pads that some 412's operate out of....and with the Bell method of putting H-V diagrams in the Limitations section of the RFM.......
Care to address this situation Shawn or Nick ?
Care to address this situation Shawn or Nick ?
This subject is going to get a lot more heated when/if the annex 14 regs NPA18, come into force. JAR Ops 3 is looking to allow only true Class 1 (old Cat A) into out of hospital landing sites as of 2004/5/8 depending on who you talk to. Either the operator will have to buy a true Class 1 helo or the hospital will have to re-build its landing site to accept Class II ops.
Class I will become more and more the norm for more commercial ops as the european regs bite.
Class I will become more and more the norm for more commercial ops as the european regs bite.
Went to the roof yesterday champ....
I was thinking of you.... isn't that nice!
I think that TC were only considering the departure performance and never considered the arrival aspect when they placed that paragraph in the CFS.
I was thinking of you.... isn't that nice!
I think that TC were only considering the departure performance and never considered the arrival aspect when they placed that paragraph in the CFS.
Thread Starter
Join Date: Apr 2002
Location: Can
Posts: 172
Likes: 0
Received 0 Likes
on
0 Posts
Shawn
My understanding is that the S76A supplement for Cat B operations for 9 pass or less is just a reprint of the H/V chart in the supplement section.
It does not include a vertical profile procedure.
Some companies have developed vertical procedures and are now allowed to use them Cat B because of this supplement.
It is my understanding that they can now enter the H/V chart because it is no longer a restriction but now an advisory because of the reprint in the supplement section.
It is the first time that I have seen anything in a supplement that is only advisory.
Steve76
I am flattered to hear that you were thinking of me MATE.
My understanding is that the S76A supplement for Cat B operations for 9 pass or less is just a reprint of the H/V chart in the supplement section.
It does not include a vertical profile procedure.
Some companies have developed vertical procedures and are now allowed to use them Cat B because of this supplement.
It is my understanding that they can now enter the H/V chart because it is no longer a restriction but now an advisory because of the reprint in the supplement section.
It is the first time that I have seen anything in a supplement that is only advisory.
Steve76
I am flattered to hear that you were thinking of me MATE.
Join Date: Dec 2001
Location: Philadelphia PA
Age: 74
Posts: 1,835
Likes: 0
Received 2 Likes
on
2 Posts
xnr:
You are not alone in being confused about this. This is what caused the problem in the first place. More than 9 passenger helicopters (all of which would be Part 29 certified) have the HV chart in the limitations section. You are not, repeat not, allowed to operate there.
BK 117, which normally has less than 9 passengers (and the HV chart in the performance section), has a supplement for 10 passenger configuration - the HV chart is moved to the Limitations section in that supplement.
The S-76 is normally configured for more than 10 passengers, so the HV chart is in the Limitations section. The less than 9 passenger supplement allows it to be moved to the performance section.
Because the HV chart is now no longer a limitation, the vertical profile can be used.
If there is a Category A supplement for a helicopter, it will have wording in the supplement to the effect that the HV chart is not a limitation when using the Category A performance charts and profiles.
Supplements have the same authority as the rest of the flight manual, they just supplement it. Normally this is for additional equipment, but for Category A (and less than 9 passengers), this is a normal state of affairs.
All Part 27 helicopters have the HV chart in the performance section - it is not a limitation for those machines.
Look carefully at the wording at the beginning of the limitations section - it will say something to the effect that you must observe these limitations - what many people do not realize is that by exceeding those limitations, or operating outside of them, they have gone outside the area that is certified and in the Type Certificate Data Sheet, and have invalidated their certificate of airworthiness (and therefore their insurance...).
The things I learned at TC about the flight manual that I'm sure most pilots aren't aware of was pretty frightening. You may have seen something in the Aviation Safety Newsletter some time ago about 'what commercial pilots need to know about certification' - I wrote that to try to prevent problems like this. It was considerably cut down from what I wanted to say.
I can send it to you if you contact me off-line.
You are not alone in being confused about this. This is what caused the problem in the first place. More than 9 passenger helicopters (all of which would be Part 29 certified) have the HV chart in the limitations section. You are not, repeat not, allowed to operate there.
BK 117, which normally has less than 9 passengers (and the HV chart in the performance section), has a supplement for 10 passenger configuration - the HV chart is moved to the Limitations section in that supplement.
The S-76 is normally configured for more than 10 passengers, so the HV chart is in the Limitations section. The less than 9 passenger supplement allows it to be moved to the performance section.
Because the HV chart is now no longer a limitation, the vertical profile can be used.
If there is a Category A supplement for a helicopter, it will have wording in the supplement to the effect that the HV chart is not a limitation when using the Category A performance charts and profiles.
Supplements have the same authority as the rest of the flight manual, they just supplement it. Normally this is for additional equipment, but for Category A (and less than 9 passengers), this is a normal state of affairs.
All Part 27 helicopters have the HV chart in the performance section - it is not a limitation for those machines.
Look carefully at the wording at the beginning of the limitations section - it will say something to the effect that you must observe these limitations - what many people do not realize is that by exceeding those limitations, or operating outside of them, they have gone outside the area that is certified and in the Type Certificate Data Sheet, and have invalidated their certificate of airworthiness (and therefore their insurance...).
The things I learned at TC about the flight manual that I'm sure most pilots aren't aware of was pretty frightening. You may have seen something in the Aviation Safety Newsletter some time ago about 'what commercial pilots need to know about certification' - I wrote that to try to prevent problems like this. It was considerably cut down from what I wanted to say.
I can send it to you if you contact me off-line.
Thread Starter
Join Date: Apr 2002
Location: Can
Posts: 172
Likes: 0
Received 0 Likes
on
0 Posts
Shawn
Yes, that is pretty much how I understand it also. But this brings up a very interesting point.
Lets say that you are operating a S76A in the off shore configuaration....you are on the rig and you have more than 9 passengers on board.....your helideck is 100' above the water.....as you aircraft leaves the deck you are now within the H/V chart.
So from what you said in the above post you are not in compliance with your C of A and your insurance is now void.
Yes, that is pretty much how I understand it also. But this brings up a very interesting point.
Lets say that you are operating a S76A in the off shore configuaration....you are on the rig and you have more than 9 passengers on board.....your helideck is 100' above the water.....as you aircraft leaves the deck you are now within the H/V chart.
So from what you said in the above post you are not in compliance with your C of A and your insurance is now void.
Join Date: Dec 2001
Location: Philadelphia PA
Age: 74
Posts: 1,835
Likes: 0
Received 2 Likes
on
2 Posts
Interesting point. But I'm sure there is an answer somewhere. The legal point is that your takeoff performance was (probably) based on the helipad. I'll check with the ops people to see what they say.
Guest
Posts: n/a
To XNR
As I understand it, only Performance Class 1 helicopters are permitted to operate from elevated heliports or helidecks across the pond.
These are helicopters which, for take-off purposes
" shall be able, in the event of a critical power unit failing at or before the take-off decision point, to discontinue the take-off, and stop within the rejected take-off area available, ....or if past the take-off decision point, to continue the take-off, and then climb, clearing all obstacles along the flight path by an adequate margin......" (ICAO Annex 6 Part III)
Narrows it down somewhat, eh?
As I understand it, only Performance Class 1 helicopters are permitted to operate from elevated heliports or helidecks across the pond.
These are helicopters which, for take-off purposes
" shall be able, in the event of a critical power unit failing at or before the take-off decision point, to discontinue the take-off, and stop within the rejected take-off area available, ....or if past the take-off decision point, to continue the take-off, and then climb, clearing all obstacles along the flight path by an adequate margin......" (ICAO Annex 6 Part III)
Narrows it down somewhat, eh?
Thread Starter
Join Date: Apr 2002
Location: Can
Posts: 172
Likes: 0
Received 0 Likes
on
0 Posts
I believe that the rules have been tightened yet another notch, thus the topic of this thread.
In Canada, my understanding is that Class1 (Cat A) performance helicopters may operate in 2 different categories and the regs for each are not the same.
As Shawn says you can operate with less than 9 passengers or more than 9 passengers.
If you operate with less than 9 you may enter the H/V chart for the purpose of your operation.....if you are operating with 9 or more you may not enter the H/V chart for any reason.
Therefore my question was if you are coming off a rig with 9+ passengers on board, as soon as you leave the deck with low airspeed you are now in the curve.
In Canada, my understanding is that Class1 (Cat A) performance helicopters may operate in 2 different categories and the regs for each are not the same.
As Shawn says you can operate with less than 9 passengers or more than 9 passengers.
If you operate with less than 9 you may enter the H/V chart for the purpose of your operation.....if you are operating with 9 or more you may not enter the H/V chart for any reason.
Therefore my question was if you are coming off a rig with 9+ passengers on board, as soon as you leave the deck with low airspeed you are now in the curve.
Join Date: Dec 2001
Location: Philadelphia PA
Age: 74
Posts: 1,835
Likes: 0
Received 2 Likes
on
2 Posts
The 9 passenger thing is even more subtle than that. It's not how many passengers you have on board, it's how many you can carry in that configuration.
So, if you're in the 12 passenger configuration, but only have 9 passengers on board, you are still governed by the 12 passenger (i.e. no flight in the HV curve) limitation. If your configuration is for 9 passengers (and for the S-76, this requires a Flight Manual Supplement), then and only then can you use the HV in the performance section.
Conversely if you have a BK117 in the 'normal' (less than 9 passengers) then you can fly into the HV curve because it's in the performance section. Put the high density seating into the machine and the HV curve moves to the limitations section regardless of the number of passengers who actually get into the machine.
Subtle, eh?
So, if you're in the 12 passenger configuration, but only have 9 passengers on board, you are still governed by the 12 passenger (i.e. no flight in the HV curve) limitation. If your configuration is for 9 passengers (and for the S-76, this requires a Flight Manual Supplement), then and only then can you use the HV in the performance section.
Conversely if you have a BK117 in the 'normal' (less than 9 passengers) then you can fly into the HV curve because it's in the performance section. Put the high density seating into the machine and the HV curve moves to the limitations section regardless of the number of passengers who actually get into the machine.
Subtle, eh?
Thread Starter
Join Date: Apr 2002
Location: Can
Posts: 172
Likes: 0
Received 0 Likes
on
0 Posts
Thanx again Shawn
Did you come up with anything on how an aircraft when configured for more than 9 passenger can lift off a rig or elevated helipad legally.
I have been asking around and the only answer I could get is "they can't ...so everyone just does it illegally"
What do you say?
Cheers
Did you come up with anything on how an aircraft when configured for more than 9 passenger can lift off a rig or elevated helipad legally.
I have been asking around and the only answer I could get is "they can't ...so everyone just does it illegally"
What do you say?
Cheers