Airworthiness Directive · Amendment 39-11548 · Twin Commander Aircraft Corporation 600 Series Airplanes
Twin Commander Aircraft Corporation 600 Series Airplanes
The following Model 600 series airplanes, all serial numbers, that are:
(1) Equipped with pneumatic deicing boots; and
(2) Certificated in any category.
680, 680E, 680F, 680FL, 680FL(P), 680T, 680V, 680W, 681, 690, 685, 690A, 690B, 690C, 690D, 695, 695A, and 695B
This document adopts a new airworthiness directive (AD) that applies to all Twin Commander Aircraft Corporation (Twin Commander) 600 series airplanes. This AD requires you to revise the Airplane Flight Manual (AFM) to include requirements for activating the airframe pneumatic deicing boots. This AD is the result of reports of in-flight incidents and an accident that occurred in icing conditions where the airframe pneumatic deicing boots were not activated. The actions specified by this AD are intended to assure that flightcrews have the information necessary to activate the pneumatic wing and tail deicing boots at the first signs of ice accumulation. Without this information, flightcrews could experience reduced controllability of the aircraft due to adverse aerodynamic effects of ice adhering to the airplane prior to the first deicing cycle.
To address this problem, you must revise the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) to include the following requirements for activation of the ice protection systems. You must accomplish this action within the next 10 calendar days after the effective date of this AD, unless already accomplished. You may insert a copy of this AD in the AFM to accomplish this action:
”• Except for certain phases of flight where the AFM specifies that deicing boots should not be used (e.g., take-off, final approach, and landing), compliance with the following is required.
• Wing and Tail Leading Edge Pneumatic Deicing Boot System, if installed, must be activated:
—At the first sign of ice formation anywhere on the aircraft, or upon annunciation from an ice detector system, whichever occurs first; and
—The system must either be continued to be operated in the automatic cycling mode, if available; or the system must be manually cycled as needed to minimize the ice accretions on the airframe.
• The wing and tail leading edge pneumatic deicing boot system may be deactivated only after leaving icing conditions and after the airplane is determined to be clear of ice.”
Yes. Anyone who holds at least a private pilot certificate, as authorized by section 43.7 of the Federal Aviation Regulations (14 CFR 43.7), may incorporate the AFM revisions required by this AD. You must make an entry into the aircraft records that shows compliance with this AD, in accordance with section 43.9 of the Federal Aviation Regulations (14 CFR 43.9).
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
