Regulatory Brief -- FAA issues direct final AD on Hartzell aluminum propeller hubs

Regulatory Brief

FAA issues direct final AD on Hartzell aluminum propeller hubs

The issue:

On January 8, 2003, the FAA issued a direct final rule airworthiness directive (AD) mandating replacement of certain Hartzell aluminum propeller hub assemblies. The AD affects more than 200 propellers, and applies to many of the most popular general aviation airplanes.

The importance to our members:

The AD requires replacement of defective aluminum propeller hub assemblies with 50 or 100 hours time-in-service (TIS) depending upon aircraft model. Hartzell has agreed to extend full parts and labor warranty coverage for the AD mandated hub replacements, and reports that they have an ample supply of replacement parts in stock.

Significant provisions:

The actions mandated by AD 2003-01-03 are intended to prevent in-flight propeller blade separation that may subsequently result in airframe and engine damage and possible loss of the airplane.
The AD affects the following airplanes:
- American Champion 8GCBC, 8KCAB
- Aermacchi S.p.A. S.208, S.208A
- Bellanca 14-19-3, 14-19-3A
- Cessna 170 series, 172 series, 175 series, 177, A188A,T188C, 310 series
- Diamond DA-40
- Lake (REVO) LA-4, LA-4-200
- Maule M(T)-7-235, M-5-235C, M-6-235, M(X)-7-235
- Mooney M-20 series
- Britten-Norman BN-2 series, MKIII, MKIII-2, MKIII-3
- Piper PA-23, PA-23-160, PA-24, PA-24-260, PA-25-260, PA-28-140, PA-32-300, PA-32S-300, PA-34-200, PA-44-180T
- Socata MS200, MS894A, MS894E, TB-20, TB-21
- Husky A-1, S-1T, S-2A, S-2S
- Univair (Stinson) 108
- Vulcanair P68
AD 2003-01-03 affects Hartzell model ()HC-()2Y-() propellers with Part number D-6522-1, D-6522-2, D-6529-1, and D-6559-3 two-bladed aluminum propeller hubs installed as listed by serial number in AD 2003-01-03 and Hartzell Alert Service Bulletin HC-ASB-61-259.
Hartzell Alert Service Bulletin HC-ASB-61-259 lists 123 total affected propeller hub assemblies by serial number, AD 2003-01-03 lists an additional 78 affected propeller hub assemblies by serial number. 201 total propeller hub assemblies are listed in the Hartzell Alert Service Bulletin and the AD.
The AD requires replacement of propeller hub assemblies within 50 hours TIS or 1 year (whichever comes first) for Piper PA-32 series airplanes with Lycoming 540 series engines rated at 300 horsepower or higher, Britten Norman BN-2 airplanes with Lycoming 540 series engines, and aerobatic, military, and agricultural use airplanes.
The AD requires replacement of propeller hub assemblies within 100 hours TIS or 1 year (whichever comes first) for all other affected airplanes.
Hartzell indicates that, as of AD publication, more than 75% of affected propeller hubs had been replaced
The manufacturer reports that they have ample supply of replacement parts, and that full parts and labor warranty coverage will be extended to affected owners.

AOPA position:

AOPA agrees, that in this particular situation, the possibility for development of fatigue cracks, and possible subsequent in-flight propeller blade separation warrants airworthiness action. AOPA is please that Hartzell has taken care to fully identify the affected population of defective parts to minimize the number of aircraft affected by the AD, has produced and stocked an adequate supply of replacement parts to minimize aircraft downtime for affected owners, and has extended full parts and labor warranty coverage for the AD mandated replacements.

Status:

On January 8, 2003, FAA published direct final rule AD 2003-01-03