Helicopter Height-Velocity (H-V) limitations
I feel I have now done as much as I can in providing the background and information to this debate. Unless there are comments put onto the thread, I will bring it up front at the end of October and before the EASA 27 November comment deadline.
Most of what has been posted on this thread has been gathered into a single document "Comment to EASA NPA 2014l-19" which can be found here:
https://www.dropbox.com/s/8nms9apezz...14-19.pdf?dl=0
If you intend to comment on the NPA, feel free to use the text in the document as you wish (without needing attribution).
At the end of the document (after the conclusions) you will find two Appendices: Appendix A - Equivalent Safety Finding on CS 29.1587(b)(6); and Appendix B - Appropriate Standards for Passenger Carriage.
Jim
Most of what has been posted on this thread has been gathered into a single document "Comment to EASA NPA 2014l-19" which can be found here:
https://www.dropbox.com/s/8nms9apezz...14-19.pdf?dl=0
If you intend to comment on the NPA, feel free to use the text in the document as you wish (without needing attribution).
At the end of the document (after the conclusions) you will find two Appendices: Appendix A - Equivalent Safety Finding on CS 29.1587(b)(6); and Appendix B - Appropriate Standards for Passenger Carriage.
Jim
I see that the CAA has just issued an Official Record Series 4 exemption to permit momentary flight within within the H-V avoid curve for operations with exposure. It also states in the preamble to the exemption that this will be mirrored by other States in Europe.
ORS4 No.1042: Helicopter Height Velocity Envelope - Requirement under Regulation (EC) No. 216/2008 that an Aircraft Must be Operated in Accordance with its Airworthiness Documentation | Publications | About the CAA
Jim
ORS4 No.1042: Helicopter Height Velocity Envelope - Requirement under Regulation (EC) No. 216/2008 that an Aircraft Must be Operated in Accordance with its Airworthiness Documentation | Publications | About the CAA
Jim
As was indicated would be done, this is a reminder that the closing period for comments on NPA 2014-10 is within a couple of weeks:
look for NPA 2014-19 and comment in the usual way.
As indicated before, all points contained in this thread have been gathered into a single document which can be found here:
https://www.dropbox.com/s/8nms9apezz...14-19.pdf?dl=0
Any of the text from this document can be used in your comment without attribution.
Jim
Dear CRT User,
please note that NPA-2014-19 "Helicopter Height-Velocity (H-V) limitations" is now open for consultation on the EASA website.
To place comments, please use the automated Comment-Response Tool (CRT) available at:
http://hub.easa.europa.eu/crt/
The deadline for submission of comments is 27 Oct 2014.
Thank you for your interest in and contribution to the European Aviation Safety Agency's rulemaking activities.
Kind regards,
The EASA consultation team
please note that NPA-2014-19 "Helicopter Height-Velocity (H-V) limitations" is now open for consultation on the EASA website.
To place comments, please use the automated Comment-Response Tool (CRT) available at:
http://hub.easa.europa.eu/crt/
The deadline for submission of comments is 27 Oct 2014.
Thank you for your interest in and contribution to the European Aviation Safety Agency's rulemaking activities.
Kind regards,
The EASA consultation team
As indicated before, all points contained in this thread have been gathered into a single document which can be found here:
https://www.dropbox.com/s/8nms9apezz...14-19.pdf?dl=0
Any of the text from this document can be used in your comment without attribution.
Jim
Join Date: May 2002
Location: tomorrowland
Posts: 41
Likes: 0
Received 0 Likes
on
0 Posts
NPA 2014-19 CRD
One year has expired since the closing period for comments on "NPA 2014-19
Helicopters H-V limitations"
Has a CRD been issued?
If not does anybody know the reason?
Helicopters H-V limitations"
Has a CRD been issued?
If not does anybody know the reason?
Last edited by gmrwiz; 9th Nov 2015 at 16:51. Reason: Looking for an answer.
Join Date: May 2002
Location: tomorrowland
Posts: 41
Likes: 0
Received 0 Likes
on
0 Posts
I have asked EASA about the CRD to NPA 2014-19 and this is the answer:
Thank you for your email and your interest in the European Aviation Safety Agency’s rulemaking activities.
Further to your enquiry, please note that the CRD to NPA 2014-19 shall be issued in 2016/Q1 together with the related Executive Director Decision.
Thank you for your email and your interest in the European Aviation Safety Agency’s rulemaking activities.
Further to your enquiry, please note that the CRD to NPA 2014-19 shall be issued in 2016/Q1 together with the related Executive Director Decision.
EASA clearly understood the comments that were reported on this thread; a proposal is contained in the amended Basic Regulation that is now going through due process.
Article 4 of Annex V 'AIRCRAFT PERFORMANCE AND OPERATING LIMITATIONS' mirrors the approach taken by the FAA in FAR 91.9(a) and (d). Thus it restores the status quo ante contained in JAR-OPS 3.005(b) and its associated Appendix - i.e. to permit momentary excursions through the limiting height velocity envelope (to an adequate level of safety).
Jim
Article 4 of Annex V 'AIRCRAFT PERFORMANCE AND OPERATING LIMITATIONS' mirrors the approach taken by the FAA in FAR 91.9(a) and (d). Thus it restores the status quo ante contained in JAR-OPS 3.005(b) and its associated Appendix - i.e. to permit momentary excursions through the limiting height velocity envelope (to an adequate level of safety).
Jim
Join Date: May 2002
Location: tomorrowland
Posts: 41
Likes: 0
Received 0 Likes
on
0 Posts
It seems at least strange that the Basic Regulation can be modified to accept the momentary penetration inside the H-V.
NPA 2014-19 was created to find a way to allow the penetration without violating the regulation itself. The NPA clearly states that:
“Even if it is possible to include a paragraph in the Basic Regulation allowing dispensation or alleviation from the AFM limitations, the Agency has decided not to because respecting the airworthiness limitations is an accepted general principle which should be maintained”.
In addition para 2.1.3. Assessing the regulatory domains of NPA says:
“Operational Regulations cannot alleviate against airworthiness limitations, and neither operational regulations nor airworthiness limitations can alleviate against the Basic Regulation”.
I am very curious to see the way in which EASA has solved this problem.
NPA 2014-19 was created to find a way to allow the penetration without violating the regulation itself. The NPA clearly states that:
“Even if it is possible to include a paragraph in the Basic Regulation allowing dispensation or alleviation from the AFM limitations, the Agency has decided not to because respecting the airworthiness limitations is an accepted general principle which should be maintained”.
In addition para 2.1.3. Assessing the regulatory domains of NPA says:
“Operational Regulations cannot alleviate against airworthiness limitations, and neither operational regulations nor airworthiness limitations can alleviate against the Basic Regulation”.
I am very curious to see the way in which EASA has solved this problem.
The essential issue that had (has) to be addressed is that regulating (limiting) operations from within certification regulations results in unforeseen consequences.
The method suggested in NPA 2014-19 sought to change the basic premise of PART 29.1 - i.e. that all helicopters with more than 9 passenger seats should be operated for 'passenger transportation'; either through the utilisation of Category A procedures (29.1(c) - PC1), or by applying the HV Diagram as a Limitation and limiting the mass with the second segment climb performance (29.1(e) - PC2). Neither of these foresees the complexity of offshore operations or addresses, where permitted, Exposure.
States have, for some time, lived with this 'feature' of Part 29.1 in a similar way; when providing a regulation which requires compliance with the operating procedures and limitation of the Flight Manual, they provide the appropriate alleviation to the HV Limitation in its immediate vicinity.
Hence:
Jim
The method suggested in NPA 2014-19 sought to change the basic premise of PART 29.1 - i.e. that all helicopters with more than 9 passenger seats should be operated for 'passenger transportation'; either through the utilisation of Category A procedures (29.1(c) - PC1), or by applying the HV Diagram as a Limitation and limiting the mass with the second segment climb performance (29.1(e) - PC2). Neither of these foresees the complexity of offshore operations or addresses, where permitted, Exposure.
States have, for some time, lived with this 'feature' of Part 29.1 in a similar way; when providing a regulation which requires compliance with the operating procedures and limitation of the Flight Manual, they provide the appropriate alleviation to the HV Limitation in its immediate vicinity.
Hence:
FAR 91.9(a) and FAR 91.9(d);
JAR-OPS 3.005(b) and Appendix 1 to JAR-OPS 3.005(b).
(Proposed) EASA Essential Requirements: Annex V Article 4.1 and 4.2:JAR-OPS 3.005(b) and Appendix 1 to JAR-OPS 3.005(b).
4.1. An aircraft must be operated in accordance with its airworthiness documentation and all related operating procedures and limitations as expressed in its approved flight manual or equivalent documentation, as the case may be. The flight manual or equivalent documentation must be available to the crew and kept up to date for each aircraft.
4.2. Notwithstanding 4.1., for operations with helicopters a momentary flight through the limiting height velocity envelope may be permitted, provided that an adequate level of safety is ensured.
This returns the Essential Requirements to the status quo ante and achieves operational flexibility with the least disruption. It requires no amendment of EASA OPS which were drafted in the understanding that such a clause would be provided.4.2. Notwithstanding 4.1., for operations with helicopters a momentary flight through the limiting height velocity envelope may be permitted, provided that an adequate level of safety is ensured.
Jim
The EASA Comment Response Document (CRD) and opinion is now available:
https://easa.europa.eu/document-libr...nt/npa-2014-19
It is extremely gratifying to see EASA accepting informed opinion. What a pity then that nugatory work could not have been avoided - saving time and money.
Jim
https://easa.europa.eu/document-libr...nt/npa-2014-19
It is extremely gratifying to see EASA accepting informed opinion. What a pity then that nugatory work could not have been avoided - saving time and money.
Jim
Join Date: May 2002
Location: tomorrowland
Posts: 41
Likes: 0
Received 0 Likes
on
0 Posts
The real pity is the NPA 2014 -19 itself.
The reason why it was written is clearly stated in Chapter 2 at 2.1.1 of the NPA:
“ Some aircraft flight manuals present HV envelope with variables for altitude and temperature included, allowing the pilots to insert the experienced values and thereby knowing whether or not operations will be performed inside the HV envelope. Other AFMs present conservative HV envelopes based on worst case scenarios. These are not allowing pilot calculations and are very limiting to operations”.
And the consequence of this poor HV definition (see page 10-24 of the NPA) is:
“ Avoiding the HV envelope requires reduction of landing or take-off masses for some helicopters types whilst others are prevented from operating.”
Therefore, to protect the operability of these helicopters, EASA decided to propose a change to Annex IV to regulation (EC) No 216/2008. The allowance to penetrate the HV envelope during take-off and landing from/to helideck is, in fact, included in the proposal of the European Commission for revision of Regulation No 216/2008 (see the EASA “Executive Director Decision 2016/005/R of 23 February 2016) .
This allowance, if introduced in the revised regulation No 216/2008, is:
a)unsafe because, when the HV really exists, an engine failure inside the HV envelope will be catastrophic
b)unfair with respect to those manufacturers who spent money and executed very dangerous test for defining a detailed HV envelope.
The right decision should have been to impose, to the manufacturers whose HFM did not provide a detailed HV charts, to define them and introduce in the Limitations section of the HFM.
In the USA FAR 91.9 d) gives similar alleviation but only when “ a safe ditching can be accomplished” and for specific helicopter’s configurations.
§91.9 Civil aircraft flight manual, marking, and placard requirements.
c)Any person taking off or landing a helicopter certificated under part 29 of this chapter at a heliport constructed over water may make such momentary flight as is necessary for takeoff or landing through the prohibited range of the limiting height-speed envelope established for the helicopter if that flight through the prohibited range takes place over water on which a safe ditching can be accomplished and if the helicopter is amphibious or is equipped with floats or other emergency flotation gear adequate to accomplish a safe emergency ditching on open water.
Unfortunately this is not the case for the operations in the North Sea that is considered “hostile environment” and, therefore, a safe ditching cannot be accomplished.
In addition to this HV topic, I think that time has arrived for imposing that helicopters operating from/to helideck in CAT operations must:
a)be Category A certified
b)fly the Category A procedures (PC1) for Take-off and Landing from/to helideck
c)be (these procedures) in the Normal and Emergency Procedures sections of the HFM approved by EASA
This because people, regularly flying from/to the oil rigs, are passengers at all the effects and, as such, must be protected with the highest safety standards offered by technology and airworthiness regulations.
The usual justification that the helideck environment is so peculiar that PC1 procedures cannot be executed is inconsistent. In fact the procedures can be, to some extent, adapted to the specific helideck. But the important element concerning the safety is that helicopter is to be operated at the mass derived from the HFM at the Weight, Altitude, Temperature (WAT) curves applicable to the procedure that the pilot wants to fly. And, sometimes, the mass allowed is lower than the MCTOM
It has to be noted that similar obligations already exists in the Air Ops regulation 965 /2012. Annex IV Section 2.
CAT.POL.H.310 (c)(2) for Take-Off and CAT.POL.H.325(c)(2) for landing, require to fly PC2 enhanced procedures for operations from/to helideck for any helicopter operated in hostile environment.
And these procedures, that should not be invented by the operators but EASA approved, correspond to PC1 because allow to survive an engine failure either in take-off or landing from/to a helideck, without ditching.
I am wondering if the National Aviation Authorities (NAA) are imposing them or are granting an exemption.
I say that because when these procedures were introduced by JAR-OPS 3, Amend 5, in July 2007, some NAA’s granted exemptions to the operators with the usual justification that the adoption of these procedures imposed, to some helicopter models, to operate at mass below the MCTOM.
I hope that the European Institutions are sensible to safety and reject the EASA’s request for penetrating the HV envelope.
Sometimes safety should prevail on business.
The reason why it was written is clearly stated in Chapter 2 at 2.1.1 of the NPA:
“ Some aircraft flight manuals present HV envelope with variables for altitude and temperature included, allowing the pilots to insert the experienced values and thereby knowing whether or not operations will be performed inside the HV envelope. Other AFMs present conservative HV envelopes based on worst case scenarios. These are not allowing pilot calculations and are very limiting to operations”.
And the consequence of this poor HV definition (see page 10-24 of the NPA) is:
“ Avoiding the HV envelope requires reduction of landing or take-off masses for some helicopters types whilst others are prevented from operating.”
Therefore, to protect the operability of these helicopters, EASA decided to propose a change to Annex IV to regulation (EC) No 216/2008. The allowance to penetrate the HV envelope during take-off and landing from/to helideck is, in fact, included in the proposal of the European Commission for revision of Regulation No 216/2008 (see the EASA “Executive Director Decision 2016/005/R of 23 February 2016) .
This allowance, if introduced in the revised regulation No 216/2008, is:
a)unsafe because, when the HV really exists, an engine failure inside the HV envelope will be catastrophic
b)unfair with respect to those manufacturers who spent money and executed very dangerous test for defining a detailed HV envelope.
The right decision should have been to impose, to the manufacturers whose HFM did not provide a detailed HV charts, to define them and introduce in the Limitations section of the HFM.
In the USA FAR 91.9 d) gives similar alleviation but only when “ a safe ditching can be accomplished” and for specific helicopter’s configurations.
§91.9 Civil aircraft flight manual, marking, and placard requirements.
c)Any person taking off or landing a helicopter certificated under part 29 of this chapter at a heliport constructed over water may make such momentary flight as is necessary for takeoff or landing through the prohibited range of the limiting height-speed envelope established for the helicopter if that flight through the prohibited range takes place over water on which a safe ditching can be accomplished and if the helicopter is amphibious or is equipped with floats or other emergency flotation gear adequate to accomplish a safe emergency ditching on open water.
Unfortunately this is not the case for the operations in the North Sea that is considered “hostile environment” and, therefore, a safe ditching cannot be accomplished.
In addition to this HV topic, I think that time has arrived for imposing that helicopters operating from/to helideck in CAT operations must:
a)be Category A certified
b)fly the Category A procedures (PC1) for Take-off and Landing from/to helideck
c)be (these procedures) in the Normal and Emergency Procedures sections of the HFM approved by EASA
This because people, regularly flying from/to the oil rigs, are passengers at all the effects and, as such, must be protected with the highest safety standards offered by technology and airworthiness regulations.
The usual justification that the helideck environment is so peculiar that PC1 procedures cannot be executed is inconsistent. In fact the procedures can be, to some extent, adapted to the specific helideck. But the important element concerning the safety is that helicopter is to be operated at the mass derived from the HFM at the Weight, Altitude, Temperature (WAT) curves applicable to the procedure that the pilot wants to fly. And, sometimes, the mass allowed is lower than the MCTOM
It has to be noted that similar obligations already exists in the Air Ops regulation 965 /2012. Annex IV Section 2.
CAT.POL.H.310 (c)(2) for Take-Off and CAT.POL.H.325(c)(2) for landing, require to fly PC2 enhanced procedures for operations from/to helideck for any helicopter operated in hostile environment.
And these procedures, that should not be invented by the operators but EASA approved, correspond to PC1 because allow to survive an engine failure either in take-off or landing from/to a helideck, without ditching.
I am wondering if the National Aviation Authorities (NAA) are imposing them or are granting an exemption.
I say that because when these procedures were introduced by JAR-OPS 3, Amend 5, in July 2007, some NAA’s granted exemptions to the operators with the usual justification that the adoption of these procedures imposed, to some helicopter models, to operate at mass below the MCTOM.
I hope that the European Institutions are sensible to safety and reject the EASA’s request for penetrating the HV envelope.
Sometimes safety should prevail on business.
Join Date: Dec 2008
Location: N/A
Posts: 845
Likes: 0
Received 0 Likes
on
0 Posts
"I hope that the European Institutions are sensible to safety and reject the EASA’s request for penetrating the HV envelope.
Sometimes safety should prevail on business"
Sounds to me like you are the one interested in the business case rather than safety.
Safety abuse, playing on regulator's paranoia, for business purposes is insincere and cynical.
Where's the safety evidence for PC1? You are an AW salesman I guess? Or someone trying to pitch for a bigger budget?
Sometimes safety should prevail on business"
Sounds to me like you are the one interested in the business case rather than safety.
Safety abuse, playing on regulator's paranoia, for business purposes is insincere and cynical.
Where's the safety evidence for PC1? You are an AW salesman I guess? Or someone trying to pitch for a bigger budget?
Join Date: Jan 2003
Location: Citizen of the globe
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
This is an obsession with yesterdays problems. The reliability of modern engines in a twin installation is such, that the risk during momentary exposure is practically negligible.There are plenty of other safety matters we should be worrying about. In regards to modern twins, this obsession with HV envelopes given the very specific conditions from which they are derived and are relevant, is beyond me.
Join Date: Aug 2001
Location: Cornwall
Age: 75
Posts: 1,307
Likes: 0
Received 0 Likes
on
0 Posts
Obsessions.......
.... yes some people seem to make mountains out of mole hills but there is a reason for that. If the regulations reflected the reality of our world then all would be fine but we, or at least some, have found out the hard way that when there is a disconnect between what we accept as the norm and what the rules have to say about it then it can result in the unjust prosecution of the pilot despite all above him giving tacit support to the institutional ignoring of what the rule book says.
A few months ago I pointed out that it is impossible for a night departure from an offshore platform to comply with the rules governing Vmini - but we all do it and will no doubt continue to do it. One day a pilot may end up in the dock because he broke that rule. We all know that night ops offshore would be crippled without the ability to launch off into the inky gloom so it is convenient for all to ignore it.
There is enough documentation supporting the concept off exposure and this should be enough to allow the pilot to escape censure in the event of a crash due to an engine failure at the critical moment - probably!
G
A few months ago I pointed out that it is impossible for a night departure from an offshore platform to comply with the rules governing Vmini - but we all do it and will no doubt continue to do it. One day a pilot may end up in the dock because he broke that rule. We all know that night ops offshore would be crippled without the ability to launch off into the inky gloom so it is convenient for all to ignore it.
There is enough documentation supporting the concept off exposure and this should be enough to allow the pilot to escape censure in the event of a crash due to an engine failure at the critical moment - probably!
G
Join Date: Jan 2003
Location: Citizen of the globe
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
Geoffers.... my point alluded more to the matter of safety in response to this nonsense.
"I hope that the European Institutions are sensible to safety and reject the EASA’s request for penetrating the HV envelope"
Momentary exposure in a modern twin should be allowed... its sensible and the risk is negligible, particularly given the HV curve provides absolutely nothing in the way of absolutes.
Your point regarding a&%e covering is well noted
"I hope that the European Institutions are sensible to safety and reject the EASA’s request for penetrating the HV envelope"
Momentary exposure in a modern twin should be allowed... its sensible and the risk is negligible, particularly given the HV curve provides absolutely nothing in the way of absolutes.
Your point regarding a&%e covering is well noted
Join Date: Dec 2008
Location: N/A
Posts: 845
Likes: 0
Received 0 Likes
on
0 Posts
I am sorry I don't mean to be rude to you, and I would be fascinated to known how a rational person being sincere can reach the conclusions you have. Normally it requires an abscence of any rational technical understanding (hence salesman). Also there is one manufacturer that has invested in extremely powerful machines capable of PC1 at MAUW. AW has a strong vested interest in this unfortunately illogical concept.
Join Date: Jan 2011
Location: Univers
Posts: 34
Likes: 0
Received 0 Likes
on
0 Posts
Examples of illogical in a sentence
It is illogical to think that things will change on their own.
<the illogical claim that playing basketball makes people taller because one sees so many tall players>
AnFI
Do you have any idea of what you are talking about?
It is illogical to think that things will change on their own.
<the illogical claim that playing basketball makes people taller because one sees so many tall players>
AnFI
Do you have any idea of what you are talking about?
Join Date: Dec 2008
Location: N/A
Posts: 845
Likes: 0
Received 0 Likes
on
0 Posts
I do
and I am in good company as Nick Lappos has often patiently explained
it's ok for someone that is not particularly technical to believe intuitively that the vast power reserve enabling no exposure at all sounds like a good idea but it really is a badge of ignorance
as far as i have been able to gather there once was a case of an engine failing during this critical phase, really not worth the lost payload potential etc etc
this is a discussion about the subtlties of the stichwork on the Emporer's clothes
and I am in good company as Nick Lappos has often patiently explained
it's ok for someone that is not particularly technical to believe intuitively that the vast power reserve enabling no exposure at all sounds like a good idea but it really is a badge of ignorance
as far as i have been able to gather there once was a case of an engine failing during this critical phase, really not worth the lost payload potential etc etc
this is a discussion about the subtlties of the stichwork on the Emporer's clothes
Do you have any idea of what you are talking about?
I do
No you don't.
And quasi-enlisting Nick Lappós to back up your bogus argumentation will not make YOUR false conclusions any more reasonable and convincing.
Power does matter. It isn't the only important factor, but it matters.
Anyone who has had to take off from a helideck with barely enough power AEO to do so, and done the same in an aircraft that flies like an elevator will know that.
There are other risks and some of them may be greater in terms of frequency (CFIT for example), but that isn't an argument for focusing on the other risk/s at the expense of one that can be improved/managed.
TT
