- Models
- 75 (Army PT-13), A75 (Army PT-13A, -13B, -13C), A75J1 (Army PT-18), A75L3, A75L300, A75N1 (Army PT-17, -17A, Navy N2S-1, -4) and 6 more
- Data sheet
- TCDSA-743
- Registered aircraft
- 1,654 matched by model
- Product
- Aircraft · Small airplane
Unofficial copy of the text in the FAA’s Dynamic Regulatory System. The FAA’s own copy is the authoritative one. DRS record last changed May 30, 2024.
Copies of the files this page was built from, with their SHA-256. Retrieved October 18, 2026.
| File | Size | SHA-256 | Original |
|---|---|---|---|
| FAA DRS HTML | 21 KB | 499e0289…5bac89d | FAA DRS (API key needed) |
On this page
The airworthiness directive
49-23-01 BOEING: Applies to All Model 75 Series Airplanes With Crop Dusting or Seeding Hopper Installations.
Compliance required prior to next periodic inspection.
Inspect to determine whether fuselage bottom truss was altered for installation of hopper throat. All alterations involving the removal or revision of the truss members require that equivalent structural strength be provided. One open bay in the bottom truss either immediately forward or immediately aft of the cross member (streamline tube) at Station 2L is permissible provided that it is limited to a rectangle bounded by the longerons, the above-mentioned cross member and a 7/8 x 0.035, or larger, x4130 tube parallel to the streamline tube and not more than 8 inches forward or aft thereof. The inside corners of this open rectangle should have 0.065-inch x 4130 gussets, or equivalent, extending along the longerons at least 2 inches.
(Boeing Report No. WD-10645 covers this same subject and includes an alternate alteration recommended as preferable to the above. Copies of the report are obtainable from the Boeing Airplane Co., Wichita Division, Wichita 1, Kansas.)
This supersedes AD 46-31-03.
Affected TCDS · 1
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 1,654
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.
| 1936 | 2 |
|---|---|
| 1937 | 11 |
| 1938 | 5 |
| 1939 | 2 |
| 1940 | 74 |
| 1941 | 290 |
| 1942 | 351 |
| 1943 | 344 |
| 1944 | 39 |
| 1945 | 27 |
| 1946 | 8 |
| 1947 | 4 |
| 1948 | 2 |
| 1949 | 10 |
| 1950 | 5 |
| 1951 | 1 |
| 1952 | 1 |
| 1954 | 1 |
| 1955 | 2 |
| 1957 | 3 |
| 1958 | 3 |
| 1959 | 1 |
| 1960 | 1 |
| 1967 | 1 |
| 1970 | 1 |
| 1971 | 1 |
| 1972 | 2 |
| 1976 | 1 |
| 1984 | 1 |
| 1996 | 1 |
459 with no year recorded