Bombardier (Canadair) CL-600 (Challenger) Series Aeroplanes

AD/CL-600/32 Amdt 2 (Continued)

Aircraft that are visually determined to be crack free are to be re-inspected at intervals not to exceed 600 flight cycles; until modified in accordance with Bombardier Service Bulletins 600-0680, 601-0503, or 604-53-006, as applicable.

2. Aircraft that are visually determined to have cracks that do not extend up to the angles as specified in the Requirement, may only be returned to service under the following conditions:

No more than one crack exists at each corner; and,

b. Angles on the aft side of the web are visually confirmed to be crack free; and,

c. No crack extends under the angles; and,

d. Aircraft shall be re- inspected at intervals not exceeding 100 flight cycles; and,
e. The cracked bulkhead is to be repaired before the aircraft accumulates 600 flight cycles or within 12 months, whichever occurs first, after the date of initial detection of the crack.

The compliance times remain unchanged by this issue. This amendment becomes effective on 11 July 2002.

Background: A check of 105 Challenger aircraft has revealed 13 aircraft with fatigue cracks in the pressure bulkhead frame at the forward end of the wing box cutout.