Airworthiness Directive · Amendment 39-17554 · Main landing gear strut/axle/truck
Agusta S.p.A. and Bell Helicopter Textron Helicopters
This AD applies to Agusta S.p.A. Model AB412 and AB412 EP helicopters and Bell Helicopter Textron Model 412, 412CF, and 412EP helicopters with a DART Aerospace Ltd. high gear aft crosstube (crosstube), part-number (P/N) D412-664-203 installed under Supplemental Type Certificate (STC) No. SR01298NY, certificated in any category.
We are adopting a new airworthiness directive (AD) for Agusta S.p.A. (Agusta) Model AB412 and AB412 EP, and Bell Helicopter Textron (Bell) Model 412, 412CF, and 412EP helicopters with certain DART Aerospace Ltd. (Dart) high gear aft crosstubes (crosstube) installed. This AD requires adding a life limit of 10,000 landings to the crosstube and removing from service any crosstubes with more than 10,000 accumulated landings. This AD is prompted by five separate reports of crosstube failures. The actions in this AD are intended to prevent failure of the crosstube and subsequent collapse of the landing gear.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
Within 30 days:
(1) Create a component history card or equivalent record for each crosstube. Determine the number of landings on each crosstube and enter it on the component history card or equivalent record. If the number of landings is unknown, calculate 10 landings per flight hour.
(2) Revise the Airworthiness Limitations section of the maintenance manual to reflect that crosstube, P/N D412-664-203, has a retirement life of 10,000 landings.
(3) Remove from service any crosstube with a number of landings equal to or greater than 10,000.
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.
