AD 49-23-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing Airplane Company, Wichita Division | 75 (Army PT-13) | Airworthiness Directives; BOEING Model 75 Series Airplanes |
| aircraft | Boeing Airplane Company, Wichita Division | A75 (Army PT-13A, -13B, -13C) | Airworthiness Directives; BOEING Model 75 Series Airplanes |
| aircraft | Boeing Airplane Company, Wichita Division | A75J1 (Army PT-18) | Airworthiness Directives; BOEING Model 75 Series Airplanes |
| aircraft | Boeing Airplane Company, Wichita Division | A75L3 | Airworthiness Directives; BOEING Model 75 Series Airplanes |
| aircraft | Boeing Airplane Company, Wichita Division | A75L300 | Airworthiness Directives; BOEING Model 75 Series Airplanes |
| aircraft | Boeing Airplane Company, Wichita Division | A75N1 (Army PT-17, -17A, Navy N2S-1, -4) | Airworthiness Directives; BOEING Model 75 Series Airplanes |
| aircraft | Boeing Airplane Company, Wichita Division | B75 (Navy N2S-5) | Airworthiness Directives; BOEING Model 75 Series Airplanes |
| aircraft | Boeing Airplane Company, Wichita Division | B75N1 (Navy N2S-3) | Airworthiness Directives; BOEING Model 75 Series Airplanes |
| aircraft | Boeing Airplane Company, Wichita Division | D75N1 (Army PT-27) | Airworthiness Directives; BOEING Model 75 Series Airplanes |
| aircraft | Boeing Airplane Company, Wichita Division | E75 (Army PT-13D, Navy N2S-5, PT-13D/N2S-5) | Airworthiness Directives; BOEING Model 75 Series Airplanes |
| aircraft | Boeing Airplane Company, Wichita Division | E75N1 (Army PT-13D, Navy N2S-5, PT-13D/N2S-5) | Airworthiness Directives; BOEING Model 75 Series Airplanes |
| aircraft | Boeing Airplane Company, Wichita Division | IB75A | Airworthiness Directives; BOEING Model 75 Series Airplanes |
Unsafe Condition
Altered fuselage bottom truss installations for crop dusting or seeding hoppers may lack equivalent structural strength, leading to potential failure of the truss members.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect fuselage bottom truss for alterations related to hopper installations. Ensure equivalent structural strength is provided for any removed or revised truss members. Verify open bays in the truss meet specified dimensions and gusset requirements.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
prior to next periodic inspection
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Model 75 Series airplanes with crop dusting or seeding hopper installations
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Fuselage Truss
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_49-23-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 49-23-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; BOEING Model 75 Series Airplanes Subject: Fuselage Truss Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Boeing Airplane Company, Wichita Division Model: 75 (Army PT-13) | A75 (Army PT-13A, -13B, -13C) | A75J1 (Army PT-18) | A75L3 | A75L300 | A75N1 (Army...Show more Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 49-23-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 49-23-01 SUBJECT HEADING: Airworthiness Directives; BOEING Model 75 Series Airplanes ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 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. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_49-23-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 49-23-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; BOEING Model 75 Series Airplanes Subject: Fuselage Truss Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: Make: Boeing Airplane Company, Wichita Division Model: 75 (Army PT-13) | A75 (Army PT-13A, -13B, -13C) | A75J1 (Army PT-18) | A75L3 | A75L300 | A75N1 (Army...Show more Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 49-23-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: AD NUMBER: 49-23-01 SUBJECT HEADING: Airworthiness Directives; BOEING Model 75 Series Airplanes ACTION: SUMMARY: DATES: ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 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. FOOTER:
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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