Airworthiness Directive · Amendment 39-11745 · Boeing Model 737 Series Airplanes
Boeing Model 737 Series Airplanes
Superseded. A later AD replaced this one: AD 2004-04-03. Comply with the one in force.
Model 737-300, -400, and -500 series airplanes equipped with
IPECO flightcrew seats; as listed in Boeing Alert Service Bulletin 737-25A1363, dated November 5, 1998; certificated in any category.
Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes 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 (b) 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) that is applicable to certain Boeing Model 737 series airplanes. This action requires a one-time general visual inspection of the seat locks and seat tracks of the flightcrew seats to ensure that the seats lock in position and to verify that lock nuts and bolts of adequate length are installed on the rear tracklock bracket, and corrective action, if necessary. This action is necessary to prevent uncommanded movement of the flightcrew seats during acceleration and take-off of the airplane, which could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.
To prevent uncommanded movement of the flightcrew seats during acceleration and take-off of the airplane, accomplish the following:
(a) Within 90 days after the effective date of this AD, perform a one-time general visual inspection of the seat locks and seat tracks of the flightcrew seats to ensure that the seats lock in position and to verify that lock nuts and bolts of adequate length are installed on the rear tracklock bracket, in accordance with Boeing Alert Service Bulletin 737-25A1363, dated November 5, 1998.
(1) If the seat lock pin fully engages in all lock positions of the seat track, and the rear tracklock bracket is correctly installed, no further action is required by this AD.
Note 2: For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”
(2) If the seat lock pin does not fully engage in all positions of the seat track, and lock nuts and bolts of adequate length are not installed on the rear tracklock bracket, prior to further flight, install lock nuts and bolts of adequate length on the tracklock bracket and re-align the seat tracks, in accordance with the alert service bulletin.
