Airworthiness Directive · Amendment 39-14858 · Bombardier Model DHC-8-400 Series Airplanes
Bombardier Model DHC-8-400 Series Airplanes
This AD applies Bombardier Model DHC-8-400, DHC-8-401, and DHC-8-402 airplanes, certificated in any category; serial numbers 4001 and 4003 and subsequent.
The FAA is adopting a new airworthiness directive (AD) for certain Bombardier Model DHC-8-400 series airplanes. This AD requires repetitive cleaning/inspecting of the drain hole of each pitot static probe and repetitive cleaning of the pitot lines in the pitot static system. This AD results from reports of incidents of airspeed mismatch between the pilot, co-pilot, and standby airspeed indications caused by contamination in the pitot static system. We are issuing this AD to prevent erroneous/misleading altitude and airspeed information from a contaminated pitot static system to the flightcrew, which could reduce the ability of the flightcrew to maintain the safe flight and landing of the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 30 days after the effective date of this AD, do paragraphs (f)(1) and (f)(2) of this AD. Thereafter, repeat the actions in paragraphs (f)(1) and (f)(2) of this AD at intervals not to exceed 70 flight hours.
(1) Clean the drain holes of all the pitot static probes in accordance with a method approved by the Manager, New York Aircraft Certification Office (ACO), FAA. Paragraph 4.B., Procedure 2, subparagraphs (1) through (3) of Bombardier Task 20-00-40-170-801 in the Bombardier Dash 8 Q400 Aircraft Maintenance Manual (AMM), PSM 1-84-2, Part 2, is one approved method for accomplishing the requirements of this paragraph.
(2) Before further flight after cleaning the drain holes of the pitot static probes, as specified in paragraph (f)(1) of this AD, do a general visual inspection of the drain holes of all the pitot static probes for blockages, in accordance with a method approved by the Manager, New York ACO. Paragraph 4.A., Procedure 1, of Bombardier Task 20-00-40-170-801 in the Bombardier Dash 8 Q400 AMM, PSM 1-84-2, Part 2, is one approved method for accomplishing the requirements of this paragraph.
Note 1: For the purposes of this AD, a general visual inspection is: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”
(g) If any blockage is found in the drain hole of any pitot static probe during the inspection required in paragraph (f)(2) of this AD, before further flight, repeat the cleaning and inspection specified in paragraphs (f)(1) and (f)(2) of this AD on the affected pitot static probe.
Within 30 days after the effective date of this AD, clean the pitot lines of the pitot static system in accordance with a method approved by the Manager, New York ACO. Bombardier Task 34-11-00-170-801 in the Bombardier Dash 8 Q400 AMM, PSM 1-84-2, Part 2, is one approved method for accomplishing the actions required by this paragraph. Thereafter, repeat the cleaning of the pitot lines at intervals not to exceed 600 flight hours.
