Original Message

For example, a rotorcraft certified as a Part 27 IFR Category A rotorcraft would not need to meet certain airworthiness standards in Subpart D, Design and Construction, of Part 29, including the following:
• Section 29.631, which relates to bird strikes. There is no comparable provision in Part 27. As a result, it is doubtful that the Bell 429 was designed or tested against bird strike criteria, since there are no such criteria under Part 27. The importance of these criteria is highlighted by the recent scrutiny that the NTSB and FAA have been giving to accidents related to bird strikes.
• Requirements related to doors, emergency exits, and fire extinguishers (FAR §§ 29.783, 29.809, 29.811, 29.812, 29.813, and 29.851).
Another significant example is Subpart E, Powerplant, where Part 29 has a requirement not found in Part 27 for protection against uncontained engine rotor failures (FAR § 29.903(d)(1)), and more stringent requirements in terms of endurance testing of the rotor drive system and control mechanisms (FAR §§ 29.923 and 29.927), and in terms of fire protection (FAR §§ 29.1195(b) and 29.1203).