AD 72-21-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Aerotek II, Inc. | B-1 | Airworthiness Directives; Aero Commander Models B-1 and B-1A Series Airplanes |
| aircraft | Aerotek II, Inc. | B-1A | Airworthiness Directives; Aero Commander Models B-1 and B-1A Series Airplanes |
Unsafe Condition
Failures of the landing gear shock struts, specifically P/N 18004-1 and P/N 18004-2, which could lead to loss of structural integrity.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove and discard main landing gear shock struts P/N 18004-1/-2 along with all hardware except wire cutters P/N 18026. Install replacement struts P/N 18045-1/-2 with specified hardware including NAS 1306 bolts, AN 960 washers, and AN 365 nuts. Replace wire cutters with AN 3-6A bolts, AN 960-10 washers, and AN 365-1032 nuts on both struts.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within the next 100 hours' time in service after the effective date of this AD
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Aerotek II, Inc. Models B-1 and B-1A series airplanes, serial numbers 10,000 through 10,035
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
Landing Gear Shock Struts
Applicability Source Text
Show captured applicability text from the source AD
AD Final Rules - DRS_72-21-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 72-21-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Aero Commander Models B-1 and B-1A Series Airplanes Subject: Landing Gear Shock Struts Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 10/06/1972 Make: Aerotek II, Inc. Model: B-1 | B-1A Product Type: Aircraft Product Subtype: Small Airplane Affected AD: Superseded AD: Affected By: Superseded By: Service/Office: Office of Primary Responsibility: CFR Part Reference: Part 39 Comments: AIRWORTHINESS DIRECTIVES FINAL RULES: 72-21-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1527 AD NUMBER: 72-21-01 SUBJECT HEADING: Airworthiness Directives; Aero Commander Models B-1 and B-1A Series Airplanes ACTION: SUMMARY: DATES: Effective October 6, 1972. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 72-21-01 AERO COMMANDER DIVISION, NORTH AMERICAN ROCKWELL CORPORATION: Amdt. 39-1527. Applies to all Aero Commander (Intermountain) (CallAir) Models B-1 and B-1A series airplanes, S/N's 10,000 through 10,035. Compliance required within the next 100 hours' time in service after the effective date of this AD, unless already accomplished. To prevent failures of the landing gear shock struts, accomplish the following: (a) Remove main landing gear shock struts, P/N 18004-1 (left hand) and P/N 18004- 2 (right hand) and discard struts and all hardware except the wire cutters, P/N 18026. (b) Install replacement shock struts. P/N 18045-1 (left hand) and P/N 18045-2 (right hand). Attach these struts with the following hardware: (1) Upper strut attachment (2 required per strut): NAS 1306-26 Bolt AN 960-616 Washer AN 365-624 Nut (2) Lower strut attachment (1 required per strut): NAS 1306-38 Bolt AN 960-616 Washer AN 365-624 Nut (c) Replace the wire cutter, P/N 18026, on the new landing gear shock strut with two AN 3-6A bolts, two AN 960-10 washers, and two AN 365-1032 nuts. Repeat for the opposite strut. Aero Commander Service Bulletin A-23 pertains to this same subject. This amendment becomes effective October 6, 1972. FOOTER:
Document Text
Show stored source text (verify against official source)
AD Final Rules - DRS_72-21-01.html Copy URL Print/Save as PDF Document Versions Feedback Details AD Number: 72-21-01 Document Type: AD Final Rules Docket Number: Unknown Subject Heading: Airworthiness Directives; Aero Commander Models B-1 and B-1A Series Airplanes Subject: Landing Gear Shock Struts Status: Current Citation: This information is not available. Citation Publish Date: Effective Date: 10/06/1972 Make: Aerotek II, Inc. Model: B-1 | B-1A 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: 72-21-01 CITATION: This information is not available. PAGE NUMBER: DOCKET NUMBER: Unknown AMENDMENT: 39-1527 AD NUMBER: 72-21-01 SUBJECT HEADING: Airworthiness Directives; Aero Commander Models B-1 and B-1A Series Airplanes ACTION: SUMMARY: DATES: Effective October 6, 1972. ADDRESSES: FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: REGULATORY TEXT: 72-21-01 AERO COMMANDER DIVISION, NORTH AMERICAN ROCKWELL CORPORATION: Amdt. 39-1527. Applies to all Aero Commander (Intermountain) (CallAir) Models B-1 and B-1A series airplanes, S/N's 10,000 through 10,035. Compliance required within the next 100 hours' time in service after the effective date of this AD, unless already accomplished. To prevent failures of the landing gear shock struts, accomplish the following: (a) Remove main landing gear shock struts, P/N 18004-1 (left hand) and P/N 18004- 2 (right hand) and discard struts and all hardware except the wire cutters, P/N 18026. (b) Install replacement shock struts. P/N 18045-1 (left hand) and P/N 18045-2 (right hand). Attach these struts with the following hardware: (1) Upper strut attachment (2 required per strut): NAS 1306-26 Bolt AN 960-616 Washer AN 365-624 Nut (2) Lower strut attachment (1 required per strut): NAS 1306-38 Bolt AN 960-616 Washer AN 365-624 Nut (c) Replace the wire cutter, P/N 18026, on the new landing gear shock strut with two AN 3-6A bolts, two AN 960-10 washers, and two AN 365-1032 nuts. Repeat for the opposite strut. Aero Commander Service Bulletin A-23 pertains to this same subject. This amendment becomes effective October 6, 1972. FOOTER:
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.
Related Airworthiness Directives
79-16-04
final ruleAirworthiness Directives; SL Industries Models B-1 and B-1A Airplanes
Unsafe Condition: Failure of the wing rear spar at the wing-fuselage attachment fitting (P/N 160049) due to cracking.
74-02-02
final ruleAirworthiness Directives; SL Industries, Inc Models B-1 and B-1A Airplanes
Unsafe Condition: Failure of the front wing spar due to cracks, elongated fastener holes, or corrosion in the spar web area of the P/N 16045-1 and -2 fittings.