Airworthiness Directive · Amendment 39-13963 · Bell Helicopter Textron Canada Model 407 Helicopters
Bell Helicopter Textron Canada Model 407 Helicopters
Superseded. A later AD replaced this one: AD 2022-23-02. Comply with the one in force.
Model 407 helicopters, with landing gear crosstube assemblies, part number (P/N) 407-050-101-101 and -103; P/N 407-050-102-101 and -103; P/N 407-050-201-101 and -103; P/N 407-050-202-101 and -103; P/N 407-704-007-119; P/N 407-722-101; P/N 407-723-104; P/N 407-724-101; or P/N 407-725-104, installed, certificated in any category.
Note 1: This AD applicability includes both Bell crosstube assemblies and Bell's approved production and spare alternate crosstube assemblies from Aeronautical Accessories Incorporated (AAI).
This amendment adopts a new airworthiness directive (AD) for Bell Helicopter Textron Canada (Bell) Model 407 helicopters that requires creating a component history card or equivalent record for each crosstube assembly, converting accumulated run-on landings to an accumulated Retirement Index Number (RIN) count, and establishing a maximum accumulated RIN for certain crosstube assemblies. This amendment is prompted by fatigue testing, analysis, and evaluation by the manufacturer that determined that run-on landings impose a high stress on landing gear or crosstubes and may cause cracking in the area above the skid tube saddle. The actions specified by this AD are intended to prevent fatigue failure in a crosstube assembly due to excessive stress during run-on landings and subsequent loss of control of the helicopter.
To prevent fatigue failure of the crosstube assembly and subsequent loss of control of the helicopter, accomplish the following:
(a) Before further flight, create a component history card or equivalent record for each crosstube assembly.
(b) Before further flight, determine and record the accumulated Retirement Index Number (RIN) for each crosstube assembly as follows:
(1) For each crosstube assembly, record one (1) RIN for every run-on landing.
(2) For any crosstube assembly with an unknown number of run-on landings, assume and record ten (10) RINs for each 100 hours TIS since the crosstube assembly was installed (for example, 5,000 hours of time-in-service equals 500 RIN).
(c) Replace any crosstube assembly on or before reaching 5,000 RIN.
Note 2: Bell Helicopter Textron Alert Service Bulletin No. 407-03-59, dated October 15, 2003, pertains to the subject of this AD.
(d) This AD revises the Airworthiness Limitations section of the maintenance manual by establishing a retirement life of 5,000 RIN for the affected crosstube assemblies.
(e) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Regulations and Policy Group, Rotorcraft Directorate, FAA, for information about previously approved alternative methods of compliance.
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.
