# AD 46-24-01: Wing Drain Holes - Type: Airworthiness directive - Status: Current - Products: Boeing Airplane Company, Wichita Division 75 (Army PT-13), A75 (Army PT-13A, -13B, -13C), A75J1 (Army PT-18), A75L3, A75N1 (Army PT-17, -17A, Navy N2S-1, -4), B75 (Navy N2S-5), B75N1 (Navy N2S-3), D75N1 (Army PT-27) and E75 (Army PT-13D, Navy N2S-5, PT-13D/N2S-5) - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Small airplane - Registered aircraft: 1,530 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/844493E3C3EE55C486256A34005BA75A.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/46-24-01 ## The airworthiness directive 46-24-01 BOEING: (Was Mandatory Note 4 of AD-743-3.) Applies to A75L3, 75, A75, B75, E75, A75J1, A75N1, B75N1, D75N1 Series Aircraft. Compliance required at next periodic inspection. The lower wings lack adequate drainage just forward of the ailerons with the result that water is entrapped by the dural angle forming the lower rear edge of the wing at the aileron gap. Since this will cause eventual deterioration of the rib ends a No. 30 hole should be drilled through the fabric and the dural angle just outboard of the rib at the inboard end of the aileron cutout and each of the 12 ribs outboard of this station. The holes should be drilled aft of the rear spar and just forward of the 120 degrees bend in the dural angle. Care should be exercised to avoid damage to the rear spar while effecting this work. As a safety measure, a stop should be used on the drill to prevent penetration in excess of 1/2 inch. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A-743](https://openairdocs.org/tcds/A-743): The Boeing Company; names 9 of 12 models: B75N1 (Navy N2S-3), 75 (Army PT-13), A75J1 (Army PT-18), E75 (Army PT-13D; Navy N2S-5; PT-13D/N2S-5), A75L3, A75 (Army PT-13A; -13B; -13C), A75N1 (Army PT-17; -17A; Navy N2S-1; -4), D75N1 (Army PT-27)… ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 1,530 (1,530 by airframe model, 0 by engine model) - Makers: Boeing 1,518, Boeing Stearman/Huff 1, Boeing/Cains Richard G 1, Boeing/Dekker 1, Boeing/Hawk 1, Boeing/Humm Stanley 1, Boeing/Johnson 1, Boeing/Mays 1, Boeing/Mehrer 1, Boeing/Mountain View Air Rep 1 Models with the most aircraft: - [Boeing A75N1(PT17)](https://openairdocs.org/model/boeing-a75n1-pt17): 759 aircraft (airframe model) - [Boeing E75](https://openairdocs.org/model/boeing-e75): 261 aircraft (airframe model) - [Boeing B75N1](https://openairdocs.org/model/boeing-b75n1): 241 aircraft (airframe model) - [Boeing A75](https://openairdocs.org/model/boeing-a75): 93 aircraft (airframe model) - [Boeing A75N1](https://openairdocs.org/model/boeing-a75n1): 59 aircraft (airframe model) - [Boeing D75N1](https://openairdocs.org/model/boeing-d75n1): 35 aircraft (airframe model) - [Boeing A75L3](https://openairdocs.org/model/boeing-a75l3): 32 aircraft (airframe model) - [Boeing 75](https://openairdocs.org/model/boeing-75): 18 aircraft (airframe model) - [Boeing B75](https://openairdocs.org/model/boeing-b75): 15 aircraft (airframe model) - [Boeing E75(N2S-5)](https://openairdocs.org/model/boeing-e75-n2s-5): 2 aircraft (airframe model) - [Boeing A75J1](https://openairdocs.org/model/boeing-a75j1): 2 aircraft (airframe model) - [Boeing/Smith A75N1](https://openairdocs.org/model/boeing-smith-a75n1): 1 aircraft (airframe model) - [Boeing/Dekker A75N1](https://openairdocs.org/model/boeing-dekker-a75n1): 1 aircraft (airframe model) - [Boeing Stearman/Huff A75-N1](https://openairdocs.org/model/boeing-stearman-huff-a75-n1): 1 aircraft (airframe model) - [Boeing/Mays A75N1](https://openairdocs.org/model/boeing-mays-a75n1): 1 aircraft (airframe model) - [Boeing/Hawk E-75](https://openairdocs.org/model/boeing-hawk-e-75): 1 aircraft (airframe model) - [Boeing/Porter/Epperson B-75N1](https://openairdocs.org/model/boeing-porter-epperson-b-75n1): 1 aircraft (airframe model) - [Boeing/Mountain View Air Rep A75N1](https://openairdocs.org/model/boeing-mountain-view-air-rep-a75n1): 1 aircraft (airframe model) - [Boeing/Mehrer A75N1](https://openairdocs.org/model/boeing-mehrer-a75n1): 1 aircraft (airframe model) - [Boeing/Cains Richard G A75N1](https://openairdocs.org/model/boeing-cains-richard-g-a75n1): 1 aircraft (airframe model) All 24 models: https://openairdocs.org/ad/46-24-01/models.md Every aircraft: https://openairdocs.org/ad/46-24-01/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.