AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/PHZL/74 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Propellers - Variable Pitch - Hartzell

AD/PHZL/74

Amdt 1

Two Blade ‘Y” Shank Aluminium Hub 10/2002

Applicability: 1. () HC- () 2Y()- () propellers (also known as Y-shank propellers) that have a hub serial number with “A”, “E”, or no suffix, and installed on or previously installed on:

1. Piper PA-32 series aircraft with Textron Lycoming 540 series engines that are rated at 300HP or higher; or

b.         Pilatus Britten Norman or Britten Norman BN-2 series aircraft (also known as Islander or Trislander) with Textron Lycoming 540 series engines; or

c.         Any aircraft certified in the aerobatic category; or

d.         Any aircraft routinely exposed to aerobatic manoeuvres; or

e.         Any aircraft that has been used for agricultural operations whilst the applicable propeller was installed.

Note 1: This AD does not apply to propellers with the suffix letter “B” at the end of the hub serial number.

Note 2: Incorporation of a “B” suffix hub will provide terminating action for this Directive.

2.        () HC- () 2Y()- () propellers S/N’s listed in Table 1:

Table 1. () HC- () 2Y()- () propellers with the following S/N’s

Propellers - Variable Pitch - Hartzell AD/PHZL/74 Amdt 1 (continued) Requirement: 1. Eddy Current Inspection:

1. No Suffix: For propeller hubs without any serial number suffix carry out an Eddy Current Inspection (ECI) of the propeller hub fillet radius for cracks in accordance with Hartzell SB HC-SB-61-227 Revision 2.

b.         If no cracks are found then permanently mark the end of the hub serial number with the suffix “E” in accordance with Hartzell SB HC-SB-61-227 Revision 2.

c.         E Suffix: For propeller hubs with serial number suffix “E” carry out repetitive Eddy Current Inspections (ECI) of the propeller hub fillet radius for cracks in accordance with Hartzell SB HC-SB-61-227 Revision 2.

d.         Table 1: For propeller hubs with a serial number hub listed in Table 1 carry out initial and repetitive ECI as per Hartzell SB HC-SB-61-227 Revision 2.

e.         Propeller hubs that are cracked are to be replaced prior to further flight.

2.        Hub Replacement:

1. A Suffix: “A” suffix hubs not listed by serial number in Table 1 shall be removed from service in accordance with Hartzell SB HC-SB-61-227 Revision 2.
2. Table 1: All hubs listed by serial number in Table 1 shall be removed from service in accordance with Hartzell SB HC-SB-61-227 Revision 2.

Propeller hubs removed from service as a result of this Directive shall have the hub serial number and type certificate number permanently removed.

Note 3: FAA AD 2001-23-08 Amdt 39-12505 refers.

Compliance: 1. Eddy Current Inspection:

1. No Suffix: Unless previously carried out; within 50 propeller hours Time In Service (TIS) from the effective date of this Directive.
2. E Suffix: At intervals not to exceed 150 propeller hours TIS from the last ECI.
3. Table 1: Unless previously carried out within 50 propeller hours TIS, and thereafter at intervals not to exceed 150 hrs from the last ECI.

2.        Hub Replacement:

1. A Suffix: Propellers with the suffix “A” at the end of the hub serial number excluding those S/N’s listed in Table 1 of applicability, are to be replaced as follows:

1. PA32 and BN-2 series aircraft; at next propeller overhaul but no later than 2000 hours propeller TIS or 31 December 2005, whichever comes first.
2. Aircraft certified in the aerobatic category or aircraft routinely exposed to aerobatic manoeuvres; at next propeller overhaul but not to exceed 1000 propeller hours TIS or 31 December 2005, whichever comes first. For propeller hubs exceeding 1000 hours time in service as of the effective date of this Directive, remove from service within 15 propeller hours TIS.

iii.     Agricultural aircraft; at next propeller overhaul, but not to exceed 2000 hours propeller TIS or 31 December 2005, whichever comes first.

b.         Table 1: At next propeller overhaul but not to exceed 1,000 hours propeller TIS or 31 December 2005, whichever comes first. For propeller hubs exceeding 1000 hrs TIS as of the effective date of this Directive, remove from service within 15 hours propeller TIS.

Note 4: Installation of the “B” serial number suffix hub will require spinner bulkhead modification per Hartzell Manual 113B or Hartzell Manual 117D dependant on propeller type.

This Amendment becomes effective on 3 October 2002.

Background: There have been incidents of hub cracks in Hartzell two blade "compact" aluminum hub propellers. Existing methods using visual inspection has proven to be unsuccessful in detecting cracks. There have now been cases of blade separation. ECI is now considered the only reliable method for detecting cracks. Cracks typically initiate at the same point on the hub. The cracks originate in the hub at a point adjacent to the blade called the "fillet radius". As the cracks propagate toward the centre of the hub, their progression accelerates and results in failure of one hub half, which can then potentially, progress to blade separation.

This amendment introduces a change to include aircraft that can be routinely exposed to aerobatic maneuvers.

The original issue of this Airworthiness Directive became effective on 16 May 2002.

James Coyne

Delegate of the Civil Aviation Safety Authority 23 August 2002

The above AD is notified in the Commonwealth of Australia Gazette on 11 September 2002.