COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Propellers - Variable Pitch - Hartzell AD/PHZL/57 Amdt 2 Blade Tip Stalling 12/88 Applicability: All Hartzell propeller models HC-B4TN-5( ) L/LT 10574(B) or HC-B4TN-5( ) L/LT10574A(B) or HC-B4TN-5( ) L/LT10574AS(B) installed on Dornier DO-228- 100 or 200 with Garrett engine model TPE-331-5-252D. Requirement: Action in accordance with Hartzell Service Bulletin No 140F and Hartzell Service Instruction 167D, as applicable. Note: Dornier Telex AOT/228/87/017 and FAA AD 87-15-05 R1 refer. Compliance: 1. Inspect blades daily in accordance with Hartzell Service Bulletin 140F. Note: Certification of this inspection by pilots is not acceptable unless they hold a Maintenance Authority for this purpose. 2. Within 100 hours time in service after 25 February 1988 or by 25 August 1988 whichever occurs first in accordance with Hartzell SB 140F. Thereafter, reinspect at intervals not exceeding 100 hrs TIS. Background: During the landing run use of the 'Beta' range above 55 KIAS could result in blade tip stalling. If this condition is encountered higher than normal blade stresses will be introduced which may result in cracking of the propeller blades. This amendment raised to incorporate latest edition of manufacturer's data which changes the blade tip inspection area. This Directive is further amended to incorporate manufacturers requirements which delete applicability for some blade models.