What it does
This Airworthiness Directive (AD/B717/31) requires inspections and, where applicable, modification of the aft elevator standby loop drive assembly on McDonnell Douglas Model 717-200 aeroplanes identified in Boeing Alert Service Bulletin (ASB) 717-27A0039 dated 6 December 2007. Two discrete mandatory actions are set out in the instrument. First, all affected aeroplanes must receive a general visual inspection of the drive assembly of the aft elevator standby loop for three specific conditions: interference between the clevis and bolt of the bellcrank assembly; correct orientation of the pull‑pull cable clevis bolt; and excessive freeplay of the bellcrank assembly bearing. The AD instructs that any applicable corrective actions discovered by that inspection must be completed before further flight. Second, aeroplanes identified as Group 1, Configuration 1 in the Boeing ASB must have the pull‑pull cable clevis in the drive assembly of the aft elevator standby loop modified, in accordance with the Boeing ASB (Requirements 1 and 2 of the AD as quoted in the instrument).
The AD binds operators to follow Boeing ASB 717-27A0039 dated 6 December 2007 to accomplish the required actions. The instrument also expressly accepts later revisions of that ASB only where those revisions have been approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2008-18-05; such FAA‑approved revisions are deemed acceptable for compliance with the equivalent requirements of this AD. The AD sets two different compliance timing rules: Requirement 1 must be done within 3,000 flight hours or 27 months after the AD’s effective date, whichever is later; Requirement 2 must be done at the time specified in paragraph 1.E, "Compliance", of the Boeing service bulletin, with a specific caveat where the service bulletin specifies a compliance time after its own date, in which case the AD shifts that countdown to run from the AD’s effective date. The AD becomes effective on 20 November 2008. The AD records its safety rationale as a report of an aborted takeoff due to a control column disconnect, and states the intended safety outcome as prevention of bolt binding that could cause slow rotation, control column disconnect on takeoff, and a runway excursion if an aborted takeoff were required.