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.

January 27, 1975

Mr. Bruce Michael Cross
1900 Washington Building
Seattle, Washington 98101

Dear Mr. Cross:

Assistant Secretary John Stender has asked me to reply to your letter of January 3, 1975, which requested an interpretation of Section 29 CFR 1926.551(l), "Ground Lines."

A review of 29 CFR 1926.551(l) does not preclude the use of a helicopter to set in place a two-legged electrical transmission tower and to secure it to the point of attachment. 29 CFR 1926.551(l) relates to any attempt to maintain support, such as guy lines to fixed structures, while the load is being secured to the base. It is permissible for the purpose of securing the tower to the base that some bolts can be secured in the base to provide sufficient pre-support until the helicopter is free and the structure is finally secured.

The interest of 29 CFR 1926.551(l) is to prevent placing the safety of the helicopter and ground crews in jeopardy.


Barry J. White
Associate Assistant Secretary for
Regional Programs