Airworthiness Directive · Amendment 39-15511 · Ice and rain protection
BAE Systems (Operations) Limited Model BAe 146 and Model Avro 146-RJ Airplanes
This AD applies to all BAE Systems (Operations) Limited Model BAe 146-100A, -200A, and -300A series airplanes, certificated in any category; and all Model Avro 146-RJ70A, 146-RJ85A, and 146-RJ100A airplanes, certificated in any category.
We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from service history of incidents and accidents involving transport category turbojet airplanes without leading edge high lift devices. This service history shows that even small amounts of frost, ice, snow, or slush on the wing leading edges or forward upper wing surfaces can cause an adverse change in the stall speeds and stall characteristics, and can negate the protection provided by a stall protection system. While there have been no accidents or incidents related to wing contamination associated with the BAE Systems (Operations) Limited Model BAe 146 and Model Avro 146- RJ airplanes, these airplanes are also transport category turbojet airplanes without leading edge high lift devices, and therefore may be similarly sensitive to small amounts of wing contamination. This AD requires revising the airplane flight manual to include a new cold weather operations limitation. We are issuing this AD to prevent possible loss of control on takeoff resulting from even small amounts of frost, ice, snow, or slush on the wing leading edges or forward upper wing surfaces. We are issuing this AD to require actions to correct the unsafe condition on these products.
Within 14 days after the effective date of this AD, revise the Limitations Section of the Airplane Flight Manual (AFM) to include the following statement. This may be done by inserting a copy of this AD in the AFM.
“1. Takeoff is prohibited with frost, ice, snow, or slush adhering to the wings, control surfaces, engine inlets, or other critical surfaces.
2. A visual and tactile (hand on surface) check of the wing leading edge and the wing upper surface must be performed to ensure the wing is free from frost, ice, snow, or slush when the outside air temperature is less than 42 degrees F (6 degrees C), or if it cannot be ascertained that the wing fuel temperature is above 32 degrees F (0 degrees C); and
a. There is visible moisture (rain, drizzle, sleet, snow, fog, etc.) present; or
b. Water is present on the wing; or
c. The difference between the dew point and the outside air temperature is 5 degrees F (3 degrees C) or less; or
d. The atmospheric conditions have been conducive to frost formation.”
Note 1: When a statement identical to that in paragraph (f) of this AD has been included in the general revisions of the AFM, the general revisions may be inserted into the AFM, and the copy of this AD may be removed from the AFM.
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.
