Airworthiness Directive · Amendment 39-14730 · Fokker Model F27 Mark 050 Airplanes
Fokker Model F27 Mark 050 Airplanes
This AD applies to all Fokker Model F27 Mark 050 airplanes, certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for all Fokker Model F27 Mark 050 airplanes. This AD requires doing an initial inspection of the leading edge sections of the elevators to detect loose leading edges and to ensure that there is no gap between the sections and the front spar, and corrective actions if necessary. This AD also requires determining the type of leading edge installed on the elevators. For certain airplanes, this AD requires repetitive inspections until the modification of the leading edge sections of the elevators and the application of sealant, which would end the repetitive inspections. This AD results from reports that the leading edges of the elevators were found loose, although the fasteners were still in place; in one case a stud was broken. In addition, the fastener attachment holes were elongated and worn out, and fretting damage was found on the elevator front spar and balance weights. Investigation revealed that vibration, induced by the propeller slipstream, was the cause of these discrepancies; the stud failure was due to improper installation of the fasteners. We are issuing this AD to prevent jamming, restricting, or binding of the elevators due to loose or missing fasteners, which could make the movement of the elevator difficult and decrease aerodynamic control of the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
For all airplanes: Within 6 months after the effective date of this AD, do the actions required by paragraphs (f)(1) and (f)(2) of this AD, in accordance with the Accomplishment Instructions of Fokker Service Bulletin SBF50-55-012, dated October 11, 2004.
(1) Do a detailed inspection of the leading edge sections of the elevators to detect loose leading edges and to ensure that there is no gap between the sections and the front spar, including all applicable corrective actions. All applicable corrective actions must be done before further flight.
(2) Determine the type of leading edges installed on the elevators: If the leading edges are single-type, no further action is required by this AD. If the leading edges are divided-type, repeat the inspection required by paragraph (f)(1) of this AD thereafter at intervals not to exceed 6 months, until the actions specified in paragraph (g) of this AD have been done.
Note 1: For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”
For airplanes equipped with the “divided type” elevators: Within 24 months after the effective date of this AD, modify the leading edge sections of the elevators and apply sealant (including doing the inspection of the gap and all applicable corrective actions), in accordance with the Accomplishment Instructions of Fokker Service Bulletin SBF50-55-013, dated October 11, 2004. All applicable corrective actions must be done before further flight. Accomplishing the actions in this paragraph ends the repetitive inspections required by paragraph (f)(2) of this AD.
Note 2: Fokker Service Bulletin SBF50-55-013 refers to Fokker Component Service Bulletins F3203-010-55-01 and F3203-011-55-02, both dated October 11, 2004, as additional sources of service information for modifying the leading edge sections of the elevators and applying sealant.
