# Standard Interpretations
1 - 1926.551 - Hooking and Unhooking Loads with a Helicopter During Work on Electric Transmission Systems
2 - 1926.551 - Line maintenance on a de-energized transmission line.
# Regulations
1 - 1926.551 - Helicopters.
# Federal Register
1 - 1926.551 - 37:24880 - Helicopters