Airworthiness Directive · Amendment 39-10915 · Allison Engine Company 250-B and 250-C Series Turboshaft and Turboprop Engines
Allison Engine Company 250-B and 250-C Series Turboshaft and Turboprop Engines
Allison Engine Company 250-B15, 250-B17, 250- B17F, series turboprop engines and 250-C18, 250-C20, 250-C20R, 250- C28, 250-C30 series turboshaft engines, installed on but not limited to AeroSpace Technologies of Australia Pty Ltd Models N22B, N22S, and N24A; Beech Aircraft Corporation Model 35; Cessna Aircraft Company Model 210; Maule Aerospace Technology Corp. Models MX-7-420 and MXT-7-420; Partenavia Construzioni Aeronauticas S.p.A. Models AP68TP 300 and AP68TP 600; Pilatus Britten-Norman Models BN-2T and BN-2T-4R; SIAI Marchetti S.r.l. Models SF600 and SF600A airplanes; AGUSTA Models A109, A109A, A109AII, A109C; Bell Helicopter Textron Models 47, 206, 206A, 206B, 206L, 206L-1, 206L-4, 230; Enstrom Helicopter Models TH-28 and 480; Eurocopter Canada Model BO 105 LS A-3; Eurocopter Deutschland Models BO-105A, BO-105C, BO-105S and BO- 105LS A-1; Eurocopter France Models AS355E, AS355F, AS355F1 and AS355F2; Hiller Model FH-1100; McDonnell Douglas Helicopter Company Models 369D, 369E, 369F, 369H, 369HM, 369HS, 369HE, 369FF, 500N; Rogerson Hiller Corp. Model UH-12E, Schweizer Model 269D; and Sikorsky Model S-76A rotorcraft; and Lockheed Martin Tactical Defense System Model GZ-22 airship.
This amendment adopts a new airworthiness directive (AD), applicable to certain Allison Engine Company 250-B and 250-C series turboshaft and turboprop engines, that requires replacing existing beryllium copper main fuel control (MFC) bellows assemblies with Inconel 718 stainless steel welded MFC bellows assemblies. This amendment is prompted by reports of leaking MFC bellows assemblies resulting in an uncommanded minimum fuel flow condition, loss of engine fuel flow control and subsequent forced landing. The actions specified by this AD are intended to prevent MFC bellows assembly leakage, which can result in an uncommanded minimum fuel flow condition and subsequent loss of engine fuel flow control.
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.
Engines
