AD 70-09-05

70-09-05 SIKORSKY: Amdt. 39-978. Applies to Orlando Helicopters Airways, Inc. Models HRS-1/CH-19, HRS-3/H-19B, H-19D, H-19G helicopters certificated in all categories.

Compliance required within the next 15 hours' time in service after the effective date of this airworthiness directive, unless already accomplished.

To prevent failure of the main rotor shaft due to fatigue cracks originating from surface defects, accomplish the following:

(a) Inspect main rotor shaft P/N S14-35-4308-1, -2, -3, or -4 for cracks and surface defects in accordance with Sikorsky Service Bulletin No. 55B35-3 dated April 3, 1970, or later FAA approved revision or an equivalent inspection procedure approved by the Chief, Engineering and Manufacturing Branch, FAA Southern Region.

(b) Main rotor shafts exhibiting crack indications, or unsalvageable surface defects, shall be retired from service prior to further flight and replaced with a shaft which has been inspected in accordance with paragraph (a).

(c) Main rotor shafts found with salvageable surface defects may be reworked in accordance with Sikorsky Service Bulletin No. 55B35-3 dated April 3, 1970, or later FAA approved revision, or an equivalent rework procedure approved by the Chief, Engineering and Manufacturing Branch, FAA Southern Region. Should the extent of rework necessitate removal of the shaft from the main gear box, then the replacement shaft must be inspected in accordance with paragraph (a).

(d) Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Southern Region may adjust the compliance time specified in this airworthiness directive if the request contains substantiating data to justify the increase for that operator.

This amendment becomes effective April 30, 1970.