What the HEC?! – Human External Cargo

What the HEC?! – Human External Cargo

Winching (or hoisting), used for Search & Rescue (SAR) or for personnel transfer to and from otherwise difficult to access locations, is the most widely known form of what is known as Human External Cargo.  Some operators however transfer personnel by harnesses on long-lines.

Here Southern California Edison (SCE), a subsidiary of Edison International, a public utility based in Rosemead, California, use a twin engine Airbus Helicopters EC135 (H135) to transfer power transmission linesman to pylons in remote locations.


The company say that:

… linemen recently attached GoPro cameras to their helmets and took flight to replace aging insulators on a transmission line near Corona, California. The towers traverse the Santa Ana Mountains and help carry electricity from Menifee to Anaheim.

Before taking flight, the entire crew and helicopter pilots met for a tailboard, or safety discussion, to go over specifics of the day’s work. They discuss potential hazards, the weather forecast and the nearest hospital in case of an emergency. After the tailboard, each crew member checks their own harness to make sure it’s ready for flight. They then do a buddy check on another lineman to be extra safe.

Eight linemen were assigned to the job and paired up for the two-minute flight. The crew was flown up to the tower, followed by their equipment and new insulators.

HEC (Credit: SCE)

Linesmen ‘Land’ on a Tower (Credit: SCE)

SCE took delivery of the EC135 in 2008 and has a fleet of six helicopters of various types based at the utility’s Chino Airport location.  An article published in 2012 describes the history of the HEC operation, the equipment and training.

They have recently added their first medium helicopter, a Bell 205 for under slung cargo work.  The company also construct pylons with chartered helicopters using under slung load techniques similar to ones Aerossurance has discussed recently.  They also contract for wire slinging operations.

Also see our articles:

UPDATE 9 December 2015: Aerossurance’s friends in South Africa have shared with us this video, which we suspect is from the 1990s, of power line work for ESKOM in SA.

UPDATE 5 February 2017: Our new article Fatal Low Altitude Hover Power Loss: Power Line Maintenance Project looks at how an engine compressor failure while installing power line markers resulted in an unsurvivable impact and fire.

See our article The Tender Trap on procuring aviation services

UPDATE 22 March 2017: RTE-STH, the helicopter division of French public utility company RTE, has commissioned Airbus Helicopters’ UK to deliver a power line maintenance customisation kit for its H135s.

The EASA-certified kit, comprising aircraft modifications and the development of seven baskets and bespoke attachment devices, will allow RTE engineers direct access to carry out essential maintenance work on live power line cables.

RTE-STH has ordered HEC Baskets for its H135s (Credit: Airbus Helicopters)

RTE-STH has ordered HEC Baskets for its H135s (Credit: Airbus Helicopters)

Initial flight testing is now under way and delivery is expected in 2018.

UPDATE 27 December 2019: Fatal Powerline Human External Cargo Flight

Aerossurance has extensive helicopter operations, safety, regulation and contracting experience.  For practical aviation advice you can trust, contact us at: enquiries@aerossurance.com