AD 78-19-03 ACTIVE

78-19-03 MESSERSCHMITT-BOLKOW-BLOHM GmbH: Amendment 39-3302. Applies to all Model BO-105 helicopters, all serial numbers, equipped with Autoflug safety belts types BAGU FAG-5 and FAG-7 with type GL-2 buckles and a date of manufacture prior to October 1, 1974.

Compliance required as indicated unless already accomplished.

To reduce the possibility of the safety belt release mechanism either jamming or requiring release forces beyond a specified range, while the belt is stressed under a load condition, accomplish the following:

(a) Within the next 30 hours time in service after the effective date of this AD, inspect the safety belts and if the date of manufacture stamped on the belt's name tag is prior to October 1, 1974, before further use, except that the aircraft may be flown in accordance with FAR 21.197 and 21.199 to a place where repairs or replacement can be made -

(1) Replace the safety belt assembly with a serviceable safety belt assembly of the same partnumber; or

(2) Repair the GL-2 buckle assembly in accordance with Augoflug Technical Instruction No. 3/77, or an FAA-approved equivalent, and test the buckle and release mechanism for proper operation in accordance with paragraphs (a)(2)(i) through (iv) of this AD, or an FAA-approved equivalent

(i) Checking the Locking and Release Action of the Buckle.

Set the opening lever of the buckle to position "RELEASE" and press the lever against the stop. Check that the lever flange of the body is at least level with the upper edge of the cover and that it is slightly higher on the side opposite the fixed lug. Release the operating handle and check that it will automatically return to position "DON".

Lift the operating lever position "RELEASE" and press it at right angles to its longitudinal axis to place the body in an inclined position. Check that the body tumbles freely in the cover.

(ii) Checking the Arresting Mechanism of the Operation Lever.
In position "LOCKED" the release force of the arresting mechanism of the operating lever - measured at the strap handle and at right angles to the lever - must be 4.4 + 1.4 lbs.

(iii) Checking the Locking Mechanism of the Multiple-Point Buckle.

Insert the belt lugs into the multiple-point buckle and subject each lug to a load of approximately 20 lbs. with the load applied at right angles to the buckle plane. Perform this test once with the cover of the buckle pointing upwards and once downwards, ensuring that the operating lever and body are unobstructed. The buckle must not open and must keep the belt lugs securely locked.

(iv) Checking the Force to Release.

With the safety belt fastened and positioned to simulate an inverted aircraft/seat position and while applying 250 lbs. load uniformly distributed across the buckle and belt webbing, measure the force necessary on the operating lever to actuate belt release. The measured force to actuate belt release must not be greater than 45 lbs.

(b) Mark the safety belts repaired and tested to comply with paragraph (a)(2) of this AD with permanent legible marking either on the manufacturer's name tag or on the belt webbing near the name tag with the number of this AD and the date repaired.

(c) If the safety belt is tested prior to repair in accordance with paragraph (a)(2) and complies with the limits specified in paragraphs (a)(2)(i) through (iv) of this AD, the compliance time to effect repairs is extended to 150 hours time in service after the effective date of this AD, at which time the GL-2 buckle assembly must be replaced or repaired and retested in accordance with paragraph (a) of this airworthiness directive.

(d) Equivalent means of compliance with the AD must be approved by the Chief, Aircraft Certification Staff, Europe, Africa, and Middle East Region.

This amendment becomes effective October 18, 1978.