Airworthiness Directive · Amendment 39-11930 · Bell Helicopter Textron Canada Model 407 Helicopters
Bell Helicopter Textron Canada Model 407 Helicopters
Superseded. A later AD replaced this one: AD 2002-22-10. Comply with the one in force.
Model 407 helicopters, serial numbers 53000 through 53347, certificated in any category.
Note 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
This amendment adopts a new airworthiness directive (AD) for Bell Helicopter Textron Canada (BHTC) Model 407 helicopters. This AD requires inspecting the brackets that attach each horizontal stabilizer slat (slat) to the stabilizer for a crack and replacing the slat assembly if a crack is found. Installing airworthy segmented slat assemblies would be required prior to flight after December 31, 2000 and would constitute terminating action for the requirements of this AD. This amendment is prompted by an incident in which a slat separated from a helicopter. The actions specified by this AD are intended to prevent a slat from separating, impact with a main or tail rotor blade, and subsequent loss of control of the helicopter.
To prevent a horizontal stabilizer slat (slat) from separating, impact with a main or tail rotor blade, and subsequent loss of control of the helicopter, accomplish the following:
(a) Within 50 hours time-in-service (TIS) and thereafter at intervals not to exceed 100 hours TIS, visually inspect the brackets, part number (P/N) 206-023-119-109 or -110 or P/N 407-023-801-127 or -128, that attach the slats, P/N 407-023-002-117, to the horizontal stabilizer for a crack.
(1) If any crack is found, replace the slat assembly, P/N 407-023-002-117, with an airworthy segmented slat assembly, P/N 407-023-001-101, before further flight. Replace the slat assembly in accordance with Part II of the Accomplishment Instructions in Bell Helicopter Textron Alert Service Bulletin No. ASB 407-99-32, dated December 7, 1999.
(2) If no crack is found, replace each slat assembly, P/N 407-023-002-117, with an airworthy segmented slat assembly, P/N 407-023-001-101, prior to flight after December 31, 2000.
(b) Installing airworthy segmented slat assemblies, P/N 407-023-001-101, constitutes terminating action for the requirements of this AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
