OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

November 20, 1974

Subject: Interpretation of 1926.551(i), "Hooking and Unhooking Loads from Hovering Helicopters"

This memorandum is being written at your request to clarify what is apparently a misunderstanding concerning the interpretation of the above standard.

Accordingly, our interpretation is as follows:

Implicit in the phrasing in the adverb clause beginning the first sentence of the standard 1926.551(i), i.e., "When employees are required to perform work under hovering craft..." it is contemplated that employees will, in fact, be required under certain circumstances to perform work under hovering aircraft. Illustrative of these circumstances are situations involving guiding the load and securing the load prior to disengaging the lifting mechanism (slings, hooks, etc.) from the craft.

The last sentence of the aforementioned standard is interpreted to mean that securing the load is necessity prior to unhooking the load carried by the aircraft.

Please advise Mr. Jim Whitt, Deputy Commissioner of Labor and Industry (907/586, 3005), Mr. Larry Hanna, attorney for the Helicopter Association of America (206/682, 8770), and any other interested parties that workplace situations (as described to the National Office by Mr. Granchi of your office, Mr. Bailey of your office, Mr. Whitt and Mr. Hanna) do not indicate that the above referenced standard was violated.

The facts as related by the above four sources to the Office of Compliance Programming and the Office of Standards were that a helicopter lift was being effected to transport to the worksite and to lower and install power distribution towers. This required that a ground crew position and secure the tower onto its base while the tower is suspended form a hovering helicopter prior to disengagement of the sling and hook.

This interpretation has been concurred in by Don Shay and Bud Joyce, Office of Compliance Programming, Mr. Frank Memmott, Office of Standards, and Baruch Fellner, Office of the Associate Solicitor for Occupational Safety and Health.

Barry J. White
Associate Assistant Secretary for