AD 64-21-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Maryland Air Industries, Inc. | F-27 | Airworthiness Directives; FAIRCHILD Model F-27 Aircraft |
| aircraft | Maryland Air Industries, Inc. | F-27A | Airworthiness Directives; FAIRCHILD Model F-27 Aircraft |
| aircraft | Maryland Air Industries, Inc. | F-27B | Airworthiness Directives; FAIRCHILD Model F-27 Aircraft |
| aircraft | Maryland Air Industries, Inc. | F-27F | Airworthiness Directives; FAIRCHILD Model F-27 Aircraft |
| aircraft | Maryland Air Industries, Inc. | F-27G | Airworthiness Directives; FAIRCHILD Model F-27 Aircraft |
| aircraft | Maryland Air Industries, Inc. | F-27J | Airworthiness Directives; FAIRCHILD Model F-27 Aircraft |
| aircraft | Maryland Air Industries, Inc. | F-27M | Airworthiness Directives; FAIRCHILD Model F-27 Aircraft |
Unsafe Condition
Cracks have been found in the rib caps and stringers in the vertical stabilizer where the rib at water line 201.575 attaches to the hat and zee section stringers.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect for cracks in the skin, rib, and stringers on both sides of the vertical stabilizer along and directly adjacent to water line 201.575 using X-ray, dye penetrant with at least a 10-power glass, or FAA-approved equivalent. Repair or replace cracked parts with FAA-approved repair or same part number before further flight, except ferry flight under CAR 1.76. Adjust inspection intervals per Fairchild Service Bulletin 55-4 or FAA approval.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Compliance required as indicated. For aircraft with less than 1,000 hours' time in service on the effective date, comply prior to 1,050 hours' time in service (if not within last 200 hours) and thereafter every 200 hours. For aircraft with 1,000+ hours, comply within 50 hours after effective date (if not within last 150 hours) and thereafter every 200 hours.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Maryland Air Industries, Inc. Model F-27 Aircraft, Serial Numbers 1 through 97, and 99.
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
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.