AD/PHOF/1 - Blade Pitch Change Fork - Replacement
1AD/PHOF/1 - Blade Pitch Change Fork - Replacement
Start here
Get a plain-English read of 1
Turn the raw legal text into a practical explanation grounded in AD/PHOF/1 - Blade Pitch Change Fork - Replacement.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Image unavailable in extracted text
Propellers - Variable Pitch - Hoffman
AD/PHOF/1 Blade Pitch Change Fork - Replacement 5/83
Applicability: All Hoffman variable pitch Model HO-V123 series propellers fitted to Lycoming Model 0-540 and IO-540 series engines.
Requirement: Required action:
(a) The forks and the pitch change blocks are to be exchanged in accordance with instructions given in overhaul manual E 105 by an appropriately approved organisation.
| Part | Old P/No. | New P/No. |
|---|---|---|
| Pitch change fork | VP 20-747 | VP 20-909 |
| Pitch change block, symetric alternatively | VP 20-554 | VP 20-912 |
| Pitch change block, unsymmetrical | VP-20-550 | VP 20-908 |
(b) Mark modified propellers with 4 mm high letters "SB 3" above the manufacturing year.
Note: German A.D. Luftfahrt-Bundesamt 63-303-61-83-29 refers.
Compliance: Part 1: All models fitted to aerobatic certificated aircraft, by 31st July, 1983.
Part 2: All other models by the next reconditioning inspection or 30th November, 1983 whichever is the sooner.
Background: The manufacturer advises that reports have been received of cracked pitch change forks particularly on aerobatic certificated aircraft, consequently a stronger designed pitch change fork has been introduced.