AD 96-24-08
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Air Tractor, Inc. | AT-250 | Airworthiness Directives; Air Tractor, Inc. Models AT-250, AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-402, AT-501, and AT-502 Airplanes |
| aircraft | Air Tractor, Inc. | AT-300 | Airworthiness Directives; Air Tractor, Inc. Models AT-250, AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-402, AT-501, and AT-502 Airplanes |
| aircraft | Air Tractor, Inc. | AT-301 | Airworthiness Directives; Air Tractor, Inc. Models AT-250, AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-402, AT-501, and AT-502 Airplanes |
| aircraft | Air Tractor, Inc. | AT-302 | Airworthiness Directives; Air Tractor, Inc. Models AT-250, AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-402, AT-501, and AT-502 Airplanes |
| aircraft | Air Tractor, Inc. | AT-400 | Airworthiness Directives; Air Tractor, Inc. Models AT-250, AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-402, AT-501, and AT-502 Airplanes |
| aircraft | Air Tractor, Inc. | AT-400A | Airworthiness Directives; Air Tractor, Inc. Models AT-250, AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-402, AT-501, and AT-502 Airplanes |
| aircraft | Air Tractor, Inc. | AT-401 | Airworthiness Directives; Air Tractor, Inc. Models AT-250, AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-402, AT-501, and AT-502 Airplanes |
| aircraft | Air Tractor, Inc. | AT-402 | Airworthiness Directives; Air Tractor, Inc. Models AT-250, AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-402, AT-501, and AT-502 Airplanes |
| aircraft | Air Tractor, Inc. | AT-501 | Airworthiness Directives; Air Tractor, Inc. Models AT-250, AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-402, AT-501, and AT-502 Airplanes |
| aircraft | Air Tractor, Inc. | AT-502 | Airworthiness Directives; Air Tractor, Inc. Models AT-250, AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-402, AT-501, and AT-502 Airplanes |
Unsafe Condition
The Gerdes part number (P/N) A-850-5 or Cleveland P/N 60-9 parking brake valve may inadvertently slip to the 'PARK' position during flight, causing constant pressure on the brakes which cannot be relieved, leading to airplane overturning upon landing when brakes are applied.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace the Gerdes P/N A-850-5 or Cleveland P/N 60-9 parking brake valve with a Scott P/N 4500A-2 parking brake valve in accordance with Air Tractor Service Letter #76 Instructions. Special flight permits may be issued to operate the airplane to a location where the requirements can be accomplished.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Required within the next 75 hours time-in-service after the effective date of this AD, unless already accomplished.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Air Tractor, Inc. Models AT-250 (serial 250-0491), AT-300 (300-0001 through 300-0708), AT-301 (301-0001 through 301-0708), AT-302 (302-0001 through 302-0708), AT-400 (400-0001 through 400-0708), AT-400A (400A-0001 through 400A-0708), AT-401 (401-0001 through 401-0708), AT-402 (402-0001 through 402-0708), AT-501 (501-0001 through 501-0036), and AT-502 (502-0001 through 502-0036) equipped with the specified parking brake valves.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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