89-23-11 AIRBUS INDUSTRIE: Amendment 39-6374. Docket No. 89-NM-94-AD.
Applicability: Model A300, A310, and A300-600 series airplanes, certificated in any category.
Compliance: Required as indicated, unless previously accomplished.
To prevent collapse of the nose landing gear, accomplish the following:
A. Perform an ultrasonic inspection of the nose landing gear barrel, in accordance with Airbus Industrie Service Bulletins A300-32-388, Revision 1, dated January 24, 1989 (for Model A300 series airplanes); A310-32-2040, dated July 15, 1988 (for Model A310 series airplanes); or A300-32-6023, dated July 15, 1988 (for Model A300-600 series airplanes); as follows:
1. For airplanes with nose landing gears having less than 11,500 cycles accumulated as of the effective date of this AD, perform the inspection prior to the accumulation of 12,000 cycles.
2. For airplanes with nose landing gears with 11,500 or more cycles accumulated as of the effective date of this AD, perform the inspection within 500 cycles or 3 months after the effective date of this AD, whichever occurs first.
B. If no ultrasonic echo is observed, or the echo amplitude is lower than or equal to ten percent (10 percent) of ultrasonic generator screen height, repeat the inspection required by paragraph A., above, at intervals not to exceed 1,250 cycles.
C. If an echo amplitude higher than ten percent (10 percent) and below eighty percent (80 percent) of ultrasonic generator screen height is observed during the inspection required by paragraphs A. and B., above, prior to further flight, perform a visual inspection to determine if the crack is visible, in accordance with Airbus Industrie Service Bulletin A300-32-388, A310-32- 2040, or A300-32-6023, as appropriate.
NOTE: The above-listed service bulletins reference Messier-Hispano-Bugatti (MHB) Service Bulletin No. 470-32-641 for additional inspection instructions.
1. If no crack is visible from the outside of the barrel, repeat the visual inspection prior to each flight. Replace the nose landing gear barrel within 100 cycles after discovery of first echo, in accordance with Airbus Industrie Service Bulletin A300-32-389 (for Model A300 series airplanes), A310-32-2041 (for Model A310 series airplanes), or A300-32-6024 (for Model A300-600 series airplanes), each dated October 15, 1988, as appropriate. (Reference: MHB Service Bulletin 470-32-642.)
2. If a crack is visible from the outside of the barrel, replace the nose landing gear barrel prior to further flight, in accordance with Airbus Industrie Service Bulletin A300-32- 389, A310-32-2041, or A300-32-6024, as appropriate. (Reference: MHB Service Bulletin 470- 32-642.)
3. After replacement is accomplished, the repetitive inspections required by paragraphs A. and B., above, may be discontinued.
D. If an echo amplitude equal to or higher than eighty percent (80 percent) of ultrasonic generator screen height is observed during the inspections required by paragraphs A. and B., above, prior to further flight, perform a visual inspection to determine if the crack is visible, in accordance with Airbus Industrie Service Bulletin A300-32-388, A300-32-2040, or A310-32- 6023, as appropriate. (Reference: MHB Service Bulletin 470-32-641.)
1. If no crack is visible from the outside of the barrel, one ferry flight for return to the main base is allowed before the barrel must be replaced.
2. If a crack is visible from the outside of the barrel, the barrel must be replaced prior to further flight, in accordance with Airbus Industrie Service Bulletin A300-32-389, A310-32-2041, or A300-32-6024, as appropriate. (Reference: MHB Service Bulletin 470-32- 642.)
3. After replacement is accomplished, the repetitive inspections required by paragraphs A. and B., above, may be discontinued.
E. Within 18 months after the initial inspection for cracks, modify the nose landing gear barrel, in accordance with Airbus Industrie Bulletin A300-32-389, A310-32-2041, or A300- 32-6024, as appropriate. (Reference: MHB Service Bulletin 470-32-642.)
F. The inspections required by paragraphs A. and B., above may be terminated following modification of the nose landing gear barrel, in accordance with Airbus Industrie Bulletin A300-32-389, A310-32-2041, or A300-32-6024, as appropriate. (Reference: MHB Service Bulletin 470-32-642.)
G. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Standardization Branch, ANM-113, FAA, Northwest Mountain Region.
NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who may add any comments and then send it to the Manager, Standardization Branch, FAA, ANM-113.
H. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.
All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Airbus Industrie, Airbus Support Division, Avenue Didier Daurat, 31700 Blagnac, France. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or the Standardization Branch, 9010 East Marginal Way South, Seattle, Washington.
This amendment (39-6374, AD 89-23-11) becomes effective on December 4, 1989.