General
In order to understand how NPRM 80-25 effected the certification of Category A and Category B rotorcraft, it is necessary to examine what changed and why. There were two substantial changes: one concerned the applicability of the H-V Diagram as a Limitation; and another the certification and operating criteria with respect to mass and numbers of passengers carried.
In addition the upper limit of 20,000lbs, for permitting the Operating Limitations of Category B, was removed.
Changes that Affected the Requirements for the H-V Diagram
The substantial change to Part 29.1 was made effective in 1983; before that time, although multi-engine rotorcraft could be certificated in Category A and/or Category B, they both had to have the H-V Diagram as a Limitation.
In NPRM 80-25 a number of changes were made to ensure that, whilst Category B no longer required the H-V Diagram as a Limitation, it was still required for the definition of the Category B take-off and landing WAT limit conditions. The necessary changes were made (in this amendment and subsequent ones) to partition the requirements such that all cases were covered .
The following amendments were made:
• 29.1 ‘Applicability’ – to establish when the H-V Diagram, as a limitation, was necessary .
• 29.79 (eventually moved to 29.87 and the title changed from ‘Limiting height-speed envelope’ to ‘Height velocity envelope’) - as a single requirement, the establishment of an H-V Diagram;
• 29.1517 ‘Limiting height-speed envelope’ - to ensure that it contained a requirement only for Category A rotorcraft;
• 29.1587 ‘Performance Information’ – adding clause (b)(6) to require the H-V Diagram as Performance Information for Category B (because of changes to 29.1517);
• 29.1583(f) ‘Operating Limitations’ – remained unchanged because it (only) pointed to 29.1517.
In spite of the intent being made quite clear in NPRM 80-25, there is still confusion, in some certificating authorities*, as to when one or both of the requirements (information and/or limitation) have to be met.
* Evidenced in the ESF awarded to the AW189 by EASA.
It is understood that in all cases, 29.87 has to be complied with – in addition:
• When a rotorcraft is certificated in Category B – compliance has to be shown with 29.1587(b)(6);
• When a rotorcraft is certificated in Category A:
• compliance has to be shown with 29.1517 and 29.1583(f); or
• if the Category A procedures are mandated, 29.1583(f) is deemed to have been satisfied. However the Category A procedures have either to be contained in the Limitations Section or referenced in the Limitations Sections as being mandatory requirements;
• When a rotorcraft is certificated in Category A and B – compliance has to be shown with 29.1517 and 29.1583(f) but 29.1587(b)(6) is optional;
• When a rotorcraft is certificated under 29.1(e) – compliance has to be shown with 29.1517 and 29.1583(f);
• When a rotorcraft is certificated in under 29.1(e) and 29.1(f) – compliance has to be shown with 29.1517 and 29.1583(f) but 29.1587(b)(6) is optional.
The requirement of the H-V Diagram as a Limitation is bound to two imperatives:
1. when a rotorcraft is configured with 10 or more seats; and/or
2. when a rotorcraft is certificated in Category A under CS-29.
Jim