Airworthiness Directive · Amendment 39-17175 · Equipment and furnishings
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 747-400 series airplanes, certificated in any category, as identified in Boeing Special Attention Service Bulletin 747-25-3586, dated November 12, 2010.
We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-400 series airplanes. This AD was prompted by reports of water leaking into electrical and electronic equipment in the main equipment center (MEC). This AD requires modifying the floor panels; removing drains; installing floor supports, floor drain trough doublers, drain troughs, and drains; and sealing and taping the floor panels. We are issuing this AD to prevent water from entering the MEC, which could result in an electrical short and potential loss of several functions essential for safe flight.
Within 24 months after the effective date of this AD: Modify the floor panels; remove drains; install floor supports, floor drain trough doublers, drain troughs, and drains; and seal and tape the floor panels; at the applicable locations; in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 747-25-3586, dated November 12, 2010.
