AD 71-13-03

71-13-03 HAWKER SIDDELEY AVIATION: Amdt. 39-1230 as amended by Amendment 39-1259. Applies to Model DH-114 "Heron" airplanes.

Compliance is required as indicated.

To prevent possible failure of the Dunlop compressed air bottles used in the emergency landing gear extension system and emergency braking system, accomplish the following on or before August 31, 1971.

(a) For all airplanes, inspect the air bottle (P/N AH.7360 or AC.11038) used in either of the emergency landing gear extension system air bottle assemblies (P/N AC.11768) located under the pilot's seat: If the air bottle was manufactured before January 1, 1959, replace the air bottle assembly with a serviceable assembly of the same part number which incorporates an air bottle (P/N AH.7360 or AC.11038) manufactured on or after January 1, 1959. The date of manufacture is etched on the collar of the bottle.

(b) For airplanes which have incorporated Modification 281 (Emergency Braking System), inspect the airbottle (P/N AC.10685 or AC.11038) used in the emergency braking system air bottle assembly (P/N ACM.16784) located on the left forward face of the crew cabin sloping bulkhead. If the air bottle was manufactured before January 1, 1959, replace the air bottle assembly with a serviceable assembly of the same part number which incorporates an air bottle (P/N AC.10685 or AC.11038) manufactured on or after January 1, 1959. The date of manufacture is etched on the collar of the air bottle.

(Hawker Siddeley Technical News Sheet, Series: Heron (114), No. S.6, Issue 2, covers this subject.)

Amendment 39-1230 became effective July 30, 1971. This Amendment 39-1259 becomes effective July 31, 1971.