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Interagency Aviation Tech Bulletin 26-01: Cargo Hook Operational Checks

· DOI Office of Aviation Services · 2025

Public domain · DOI Office of Aviation ServicesAviation Safety Documents

Overview

The Interagency Aviation Tech Bulletin 26-01: Cargo Hook Operational Checks () is a public-domain DOI Office of Aviation Services aviation safety document, republished here as a free chaptered HTML edition with a linked table of contents and the official PDF.

Publisher
DOI Office of Aviation Services
Document
Year
2025
Pages
2

Key points

  • An uncommanded release of a human external cargo secondary hook occurred during a non-agency operation, prompting an inspection.
  • The inspection revealed a missing cotter pin on a castellated nut, preventing the hook load beam from fully seating.
  • An Emergency Directive was issued requiring inspections of the cargo hooks, leading to a Tactical Pause for short-haul operations.
  • Pre-operational checks for cargo hooks must be completed before external load and longline missions.
  • Some cargo hooks may have a sight window for confirming the hook lock indicator.
Frequently asked questions
What caused the uncommanded release of the cargo hook?

The uncommanded release was caused by a missing internal cotter pin on a castellated nut, which prevented the hook load beam from fully seating.

What actions were taken following the incident?

An Emergency Directive was issued requiring inspections of the hooks, and a Tactical Pause was implemented for all short-haul operations until inspections were completed.

What are the recommended pre-operational checks for cargo hooks?

The recommended checks include activating the primary electrical release, the secondary hydraulic or cable release, and the remote cargo hook electrical release, ensuring all are properly closed.

Who should be contacted for more information regarding the cargo hook checks?

For additional information, contact Josh Ingle at the Forest Service or Joe Rogan at the Department of the Interior.

What feature may some cargo hooks have to assist with checks?

Some cargo hooks may have a sight window that allows users to see a hook lock indicator for additional confirmation of the hook being in the locked position.

Document

Interagency Aviation

TECH BULLETIN

No. IA TB 26-01 October 2, 2025 Page 1 of 2 Subject: Helicopter Cargo Hook Operational Checks Area of Concern: All Helicopter External Load Operations Distribution: All Helicopter Operations Discussion: In recent weeks a single occurrence of an uncommanded release of a human external cargo secondary hook occurred during a non-agency utility operation. The hook involved was sent to the STC holder for disassembly and inspection. This inspection revealed that an internal cotter pin was not installed on a castellated nut which resulted in the hook load beam not getting fully seated into the locked position. The hook associated with this system is an electric and hydraulic actuated system that is like-in-kind to the cargo and remote cargo hooks used in resource and wildland fire helicopter operations. The STC holder issued Emergency Directive ED-B1514-1 requiring an inspection of the hook. As a result, the Forest Service, National Park Service, and Bureau of Land Management issued an immediate Tactical Pause for all short-haul operations pending an inspection of the hook. All inspections were completed, communicated to the proper agency contacts and the pause was rescinded.

This event highlights the importance that all individuals involved in interagency helicopter external load and longline missions must receive training in these operations. Each helicopter equipped with cargo and remote cargo hooks has specific pre-operational use checks that are required to be completed before operations commence.

Recommendations: Work with the Helicopter Manager, Pilot, and Mechanic to become familiar with all safety and operational checks for the equipment installed on your helicopter.

Check, then double-check, that the pre-flight cargo hook checks have been completed prior to engaging in external load and longline missions!

Examples of pre-flight cargo and remote cargo hook checks: Check #1 : Pilot activates the primary electrical release of cargo hook.

Reset/close the load beam.

Check #2 : Pilot activates the secondary hydraulic or cable release of cargo hook.

Capture the bucket, longline, or cargo rings on the load beam and close.

Check #3 : Pilot activates the remote cargo hook electrical release.

Capture the swivel on the load beam and close.

No. IA TB 26-01 October 2, 2025 Page 2 of 2 Some make(s)/model(s) of cargo and remote cargo hooks have a sight window that will allow the user to see a hook lock indicator. If your helicopter has a cargo or remote cargo hook with this feature, an additional confirmation of the hook being in the locked position should be performed.

Figure 1. Some cargo hooks have sight window that will allow the user to see a hook lock indicator For additional information or questions, contact your agency POC: Forest Service : Josh Ingle, National Helicopter Program Manager at, (406) 558-9690 or joshua.ingle@usda.gov Department of the Interior : Joe Rogan, National Helicopter Program Manager at, (208) 387-5446 or jrogan@blm.gov /s/ Walker Craig /s/ Beau Dobberstein Walker Craig Beau Dobberstein Chief Technical Services Rotor Wing Branch Chief DOI, Office of Aviation Services USDA, Forest Service

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Document details

Doc number
Publisher
DOI Office of Aviation Services
Year
2025
Pages
2
File size
331 KB