AircraftDirectives
Airworthiness Directive

AD 97-23-04 62 FR 59993

Federal Aviation Administration · 14 CFR part 39

FR document
97-29236
Amendment
39-10192
Published
1997-11-06
Models covered
1
Last live check
2026-08-17

Opens your browser's print dialog. Choose “Save as PDF” to export a file. Keyboard: Ctrl+P or Cmd+P.

AD

97-23-04

FR doc 97-29236 · 62 FR 59993

AD 97-23-04Published 1997-11-06Effective 1997-12-01

Superseded by 98-11-01

Supersedence is read from the Federal Register text of the newer AD — the FAA publishes no structured field for it — and names only ADs held in our index.

Requires replacing the fuel tank vent valves with modified fuel tank vent valves.

Full official abstract

This amendment adopts a new airworthiness directive (AD) that applies to Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC-12/45 airplanes. This AD requires replacing the fuel tank vent valves with modified fuel tank vent valves. This AD is the result of mandatory continued airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. The actions specified by this AD are intended to prevent the fuel tank inward vent valve from freezing, which, if followed by a cold soak at altitude, could result in wing airfoil distortion and structural damage with consequent degradation of the airplane's handling qualities.

View on Federal Register (opens in a new tab) Search DRS manually for AD 97-23-04 (opens in a new tab)

Applies to 1 model in our index