Airworthiness Directive 06-6472
one-timeAirworthiness Directives; Eurocopter France Model AS-365N2, AS 365 N3, EC 155B, EC155B1, SA-365N, N1, and SA-366G1 Helicopters
What this AD requires
This amendment revises an existing airworthiness directive (AD) for Eurocopter France (Eurocopter) Model AS-365N2, AS 365 N3, EC 155B, EC155B1, SA-365N, N1, and SA-366G1 helicopters that currently requires inspecting the main gearbox (MGB) base plate for a crack and replacing the MGB if a crack is found. This amendment increases the time intervals for inspecting the MGB base plate and includes minor editorial changes throughout the AD. This amendment is prompted by crack growth tests that indicate that the inspection intervals can be increased without affecting safety. The actions specified by this AD are intended to detect a crack in an MGB base plate and prevent failure of one of the MGB attachment points to the frame, which could result in severe vibration and subsequent loss of control of the helicopter.
Which aircraft AD 06-6472 applies to
Applies only when a main gearbox (MGB) base plate P/N 366A32-1062-03 or P/N 366A32-1062-06 is installed.
Whether AD 06-6472 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.
How AD compliance is recorded
A valid compliance record (14 CFR 43.9) states:
Tailplate reads a tail number’s logbooks and matches every applicable AD — including this one — to its compliance evidence, with recurring next-due dates computed.
Look up a tail number →Read the full directive (Federal Register)Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination. Compliance is established only from an aircraft’s actual records.