Airworthiness Directive · Amendment 39-15852 · Propellers/propulsors
Fokker Model F.27 Mark 050 Airplanes
This AD applies to Fokker Model F.27 Mark 050 airplanes, certificated in any category, as identified in Fokker Service Bulletin SBF50-61-025, dated July 4, 2007, unless engines that are installed have previously been modified in accordance with Fokker Service Bulletin SBF50-61-024.
The FAA is superseding an existing airworthiness directive (AD) that applies to certain Fokker Model F.27 Mark 050 airplanes. The existing AD currently requires repetitive visual checks for oil leaks of both engines between the spinner and the engine cowling, and directly behind the heated intake lip of the engine; repetitive inspections for oil leaks at the feathering pump on both engines; and corrective actions if necessary. This new AD retains the requirements of the existing AD. This AD also requires replacing the outlet port (high-pressure) bobbin with a new, improved outlet port (high-pressure) bobbin, which terminates the repetitive visual checks and inspections. This AD results from reports of oil leakage at the engine feathering pump. We are issuing this AD to prevent oil loss from the feathering pump, which could cause the engine to shut down in flight.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Before the next flight after October 21, 2005 (the effective date of AD 2005-20-21): Do a visual check for oil leaks between the spinner and the engine cowling, and from directly behind the heated intake lip, of both engines, in accordance with Fokker All Operator Message (AOM) AOF50.037 (Ref TS04.57535), dated November 2, 2004. Repeat the visual check thereafter before each flight, until the terminating action required by paragraph (m) of this AD is done. If any leak is found, before further flight, do the action in paragraph (h) of this AD, except as required by paragraph (j) of this AD.
Except as required by paragraph (g) of this AD, at the applicable time in paragraph (h)(1) or (h)(2) of this AD: Do a detailed inspection for oil leaks at the feathering pump on both engines and do any applicable corrective action before further flight, except as required by paragraph (j) of this AD. Do all actions in accordance with the Accomplishment Instructions of Fokker Service Bulletin SBF50-61-023, dated November 3, 2004. Repeat the detailed inspection thereafter at the applicable interval in paragraph (h)(1) or (h)(2) of this AD, until the terminating action required by paragraph (m) of this AD is done.
(1) For airplanes identified in paragraph 1.A. “Effectivity,” sub-paragraph (1) of Fokker Service Bulletin SBF50-61-023, dated November 3, 2004: Do the first inspection before the next flight after October 21, 2005, and repeat the inspection thereafter before each flight.
(2) For airplanes identified in paragraph 1.A. “Effectivity,” sub-paragraph (2) of Fokker Service Bulletin SBF50-61-023, dated November 3, 2004: Do the first inspection within 32 flight hours after October 21, 2005, and repeat the inspection thereafter at intervals not to exceed 32 flight hours.
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.”
(i) Although Fokker AOM AOF50.037 (Ref TS04.57535), dated November 2, 2004, specifies that operators should report cases of oil leakage and send failed O-rings to Fokker Services B.V., this AD does not include that requirement.
As of the effective date of this AD: If during any inspection required by paragraph (g) or (h) of this AD, oil leakage is found at the feathering pump mounting pad of an engine, before further flight, replace bobbin part number (P/N) 638005614 with bobbin P/N 638005637 and install a gasket on the feathering pump of that engine, in accordance with the Accomplishment Instructions of Fokker Service Bulletin SBF50-61-025, dated July 4, 2007.
(k) After accomplishing the actions in paragraph (j), no person may replace an engine with one that has not been modified according to Fokker Service Bulletin SBF50-61-025, dated July 4, 2007.
(l) As of 24 months after the effective date of this AD, no person may install an engine on any airplane, unless it has been modified according to Fokker Service Bulletin SBF50-61-025, dated July 4, 2007.
Within 24 months after the effective date of this AD: Replace the outlet port (high-pressure) bobbin P/N 638005614 with a new, improved outlet port (high-pressure) bobbin P/N 638005637 and install a gasket on the feathering pump of that engine, in accordance with the Accomplishment Instructions of Fokker Service Bulletin SBF50-61-025, dated July 4, 2007. Doing the replacement required by this paragraph on both engines terminates the requirements of this AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
