McCauley Propeller Systems propeller assemblies, models
2D34C53/74E-X; D2A34C58/90AT-X; 3AF32C87/82NC-X; D3AF32C87/82NC-X;
D3A32C88/82NC-X; D3A32C90/82NC-X; and 3AF34C92/ 90LF-X, with
propeller hubs listed by serial number in Table 1 of this AD:
C58, C34, C49, C78, C98
030725, 030726, 030727, 030728,
030729, 030730, 030748, 030749,
030750, 030751, 030752, 030753,
030754, 030755, 030756, 030757,
030758, 030759, 030760, 050403,
050407, 050408, 050410, 050475,
C87 blank index, C72, C93
042239, 042524, 042527,
042528, 042529, 050071,
C92, C74, C86
C87 D index
Note 1: Because a propeller hub can be
interchanged and re-identified as a different model with the
installation of different studs or adapters, any of the affected
hubs could have been re-identified as a different model. Each
propeller hub model listed in Table 1 of this AD is the original
hub configuration when shipped from McCauley. Note 2: A list of
aeroplanes that these hubs can be fitted to can be found in Table 2
of FAA AD 2005-24-09.
1. Remove from service propeller assemblies with affected propeller
hubs, listed in Table 1 of this AD.
2. Propeller assemblies with affected propeller hubs listed in
Table 1 of this AD must be disassembled, inspected, and have the
propeller hub replaced with a serviceable propeller hub.
3. For retention nuts that were removed from an affected
propeller hub, visually inspect the retention nut threads with a
10- power magnifier before assembly into a replacement propeller
hub. Reject the nut for any signs of galling, heavy localized
loading, thread deformation, or chipped threads that may have been
caused by thread interference in the propeller hub.
4. Report the findings of any propeller hub removed during
Requirement 1 of this
New Technologies and Systems Section
Manufacturing, Certification and New Technologies Office
Civil Aviation Safety Authority,
GPO Box 2005, Canberra, ACT 2601
Fax (02) 6217 1903 or (02) 6217 1442
5. Do not install hubs listed in Table 1 of this AD.
Note 3: McCauley Alert Service Bulletin No. ASB251A, dated 28
September, 2005 pertains to this AD.
Note 4: FAA AD 2005-24-09 Amdt 39-14389 refers. Compliance: For
Requirements 1, 2 and 3: Within 10 flight hours or 10 calendar days
after the effective date of this AD whichever occurs first.
For Requirement 4: Within 10 calendar days after the completion of
the inspection detailed in Requirement 2 of this AD.
For Requirement 5: After the effective date of this AD.
This Airworthiness Directive becomes effective on 15 December
Background: In August of 2005, McCauley
Propeller Systems reported to the FAA that a repair facility had
found a single, new, unused propeller hub with improperly machined
socket retention threads. Further investigation revealed that
McCauley Propeller Systems had improperly machined socket retention
threads on 40 propeller hubs, manufactured in 2004 and 2005. Using
a propeller hub with improperly machined socket retention threads
could cause concentrated loading on the threads, resulting in
cracking of the hub and blade separation. This condition, if not
corrected, could result in failure of the propeller hub, blade
separation, and loss of control of the aeroplane.