With 50,000 square miles of service territory, electricity provider Southern California Edison (SCE) has long had a vested interest in creating more efficient ways to inspect its transmission towers and powerline structures. One particular work-method program it recently developed is called human external cargo (HEC), and involves using a Eurocopter EC135 P2+ to transport up to two line workers from ground level to the top of transmission towers using a type of long-line system.

Line workers regularly need to journey to the tops of these towers and structures for required inspections and repairs, but due to the remote locations of some towers, these journeys can be difficult and time-consuming. The use of helicopters and the HEC work-method, though, has led to dramatic improvements in time and efficiency. 

Overall, the HEC program appears to be a solid win-win: it not only results in more efficient inspections, it also decreases the environmental impact associated with accessing the towers by road. Compared to our traditional method of line workers climbing the towers, HEC operations have proven to be very efficient and cost-effective, said SCE aircraft operations chief pilot Torbjorn Corell (known to most simply as TC). 

To better understand and learn more about the development and future of this unique program one that has prioritized safety while achieving greater efficiencies Vertical accepted SCEs invitation to visit its HEC operations. 

Operating helicopters is nothing new to SCE: it has been using them since the 1950s for powerline patrol and support of ground operations (and has also contracted larger helicopters in the past to help with powerline construction). Currently, SCEs aircraft fleet consists of four Eurocopter AS350 B3s and two EC135 P2+s, along with one MD 500.

While the fleet is involved in more than just HEC, this unique program is what we had come to the companys helicopter base at the Chino Airport (some 20 miles northeast of Anaheim, Calif.) to learn about. Appropriately, Corell began our tour with an overview of how SCE adopted this short-haul concept. 

As far as the program history, there was an initial feasibility study compiled in 1998 to give a clear understanding of what SCE wanted to do, he recalled. We began by researching and benchmarking other utilities and rescue helicopter programs to understand and learn about how they operated. For the operational study, SCE flew MD 500 helicopters, in conjunction with a man-rated basket. In 2008, SCEs management authorized the program to move forward and obtain the specific aircraft and equipment required for the HEC mission.

The Eurocopter EC135 P2+ ended up being the helicopter of choice, for a number of reasons, including its twin engines and acceptable one-engine-inoperative performance; small physical footprint; comfort for pilots during external-load operations; and quiet Fenestron tail rotor system. Also, the company already operated a fleet of AS350 B3s, so SCE saw additional efficiencies in staying with a Eurocopter product.

To date, the selection of the P2+ appears to have been a good one. Said Corell: The EC135 P2+ is working well for us and has not had any field issues. So far, the aircraft has been a good choice for the mission, although we would prefer increased engine power, since we operate in hot weather and high altitudes.

Crew-wise, explained Corell: SCE utilizes two pilots when flying HEC missions. All doors and most of the seats are removed from the aircraft. The EC135 P2+ is not presently [U.S. Federal Aviation Administration] certified for left-seat pilot-in-command, so SCE uses a [second] pilot in the right seat. He is responsible for the remote-control grip with the dual-hook release mechanism, in case the load needs to be jettisoned. He also observes engine parameters while the flight captain is flying.

Special equipment for the HEC mission includes a belly-mounted dual-hook, dual-release system that was certified in the United States by Eurocopter. The Siren Inc. designed [dual] hook beam system, said Corell, is mounted under the EC135 P2+ in tandem, between the front and aft skid tubes. Hook 1 is the primary hook and is mounted almost directly below the transmission, while Hook 2 is the secondary hook. During HEC operations, the dual hook is critically important for lineman safety. SCE has gone beyond the industry standard in safety with employing the twin-hook system, coupled with the extensive training for pilots and linemen to mitigate the risks associated with HEC operations.  

Corell said SCE also designed its own dedicated human cargo rope system: One of our technical specialists and I came up with the concept, and we contacted Barry Cordage in Canada to manufacture the synthetic rope, which is made of Dyneema SK75 material. The rope is marked green to indicate its use for human short-haul only. We have incorporated two snap hooks on two separate lanyards for redundancy, and [they] are attached to two separate D-rings. The lanyards are different lengths and marked with different colors, with the green being the primary lanyard, which attaches to the front, upper D-ring on the linemans Yates 390 RTR harness. The red safety lanyard attaches to the front, lower D-ring of the harness and acts as a back-up system.

He added: The lanyards are connected to the short-haul rope via a rigging plate, which enables us to lift the crews in a single or dual configuration. The rope system is covered in a sheath to protect it from the environment and has proven very durable. With that said, we closely inspect it prior to each use and log its condition. Pilots and ground crew must attend a special rope inspection class in order to sign-off for HEC use. We also keep the ropes extremely clean, as a dirty rope can become conductive and cause it to transfer electricity. We never allow the rope to even touch the ground during the HEC operation. 

On top of the extra safety from the hook and rope systems, line workers are issued special personal protection equipment for the HEC mission, including Petzl hardhats, hearing protection and dust goggles. SCE also decided on the Yates 390 RTR electric-arc/flash-rated professional tower harness system: a full-body harness approved by SCEs transmission department. Said Corell, We made the decision in order to prevent orthostatic intolerance or suspension trauma. To further prevent injuries, line workers are limited to 15 minutes in the harness at a time, but can go for another 15 minutes of travel time by just touching the ground. (The actual HEC process sees the line workers placed on the towers and the helicopter then departs to pick up a different crew. Each crew inspects their tower while climbing down and the helicopter picks them up on the ground next to the tower. On any one team, there are four crews with two line workers in each crew going from tower to tower. Each tower takes about eight to 12 minutes to inspect, depending on what they find.)

The core of virtually any safety initiative is training, and SCEs HEC program is no different: training is essential for everyone here, beginning with the pilots. SCE has three levels of pilot qualifications: Flight Captain 1, Flight Captain 2 and Flight Captain 3 (or chief pilot). HEC qualification is an endorsement available to flight captains 2 and 3.

New SCE pilots   who must be instrument-flight-rules rated, able to demonstrate long-line proficiency and have 3,000 hours of flight time with 800 in the mountains are considered basic flight captains, and must undergo a specific training program to achieve the first level of qualification, Flight Captain 1. During the first six months after being hired, new pilots actually have very little responsibility. First, they must complete 30 hours of ride-along flights with veteran SCE pilots to get an understanding of the company way of doing things. They next have to complete a company indoctrination, which teaches them about the flight department.

After the completion of a number of other tasks, including mandatory factory training in each helicopter type, basic flight captains start powerline patrol training, as SCE wants its pilots to have a complete understanding of the grid system and tower construction. To get this education, new pilots go on a ride-along with a ground-based patroller. SCE has also designed a unique wire-hazard-awareness flight-training program in which a new pilot flies with the companys chief pilot or a unit trainer on a series of practical courses. These courses are designed to teach pilots what they need to know about the wire environment and its hazards. Additionally, new pilots will complete a powerline patrol checkride with the chief pilot or a unit trainer.

A new pilot will reach Flight Captain 1 status after being qualified on SCEs Big Creek operation in the central-eastern part of the state, where several hydroelectric powerplants are operated. At the Flight Captain 1 level, the pilot can now pursue endorsements, (such as precision pole sets and line stringing endorsements) leading up to the Flight Captain 2 qualification, and, beyond that, to the HEC qualification, which involves special training in the short-haul techniques used in the program.

The training program for HEC line workers, meanwhile, begins with two days of ground school, using qualified HEC line workers as instructors (they also teach the practical portion of the training). Since new pilots must also attend this training, the ground school starts to bring the line workers and pilots together as a team, as well as give them an understanding of the HEC pilots thought processes. Ground school also teaches basic helicopter knowledge and emergency procedures, and covers details on the electrical grid system, tower construction and communication procedures between HEC pilots and line workers. Once ground school is complete, the pilots and line workers are tested on what theyve learned.

The practical portion of the training, meanwhile, includes field training with a helicopter around actual towers. Each line worker flies in the harness a minimum of four times (the first two with an instructor), and are taught multiple hand and head signals so HEC operations can be sustained without using radio communication. (New pilots also have to fly in the harness during this training to gain a better perspective of what the line workers face). During training flights, line workers are required to show instructors that they clearly understand all the proper signals and procedures for attaching (insertion) and detaching (extraction) from the tower.

On their third training flight, the line workers fly solo, and are observed by instructors that are strategically placed around and on top of the towers. The instructors will observe any unusual actions from the line workers and will advise them of problems during debriefing. Each line worker then needs to demonstrate a complete understanding of the signals and emergency procedures during his or her fourth flight, the checkride. 

In all, SCE has qualified over 200 line workers for HEC operations, but is planning to train more in the future. 

During all HEC missions, SCE utilizes helicopter operations specialists and helicopter maintenance technicians as ground crews. These positions also require extensive classroom and field training in safety responsibilities, rigging and equipment; landing zone control; and emergency responsibilities. Plus, helicopter operations specialists are also tasked with all operational functions of setting up HEC missions, including the jobsite survey; developing external-load lift plans and U.S. Federal Aviation Administration congested-area plans; and the rigging and fuel-support services. 

While HEC missions are in progress, helicopter operations specialists and helicopter maintenance technicians serve as helicopter operations controllers (HOCs). HOCs are tasked with ensuring the project is conducted within SCE policies and procedures, and in compliance with all U.S. Federal Aviation Regulations. They are also responsible for landing zone control and use the buddy check system to help provide the last checks of the line workers harnesses and equipment.

According to Corell, SCEs transmission department inspects its towers and lines every other year through regulations dictated by the California Public Utilities Commission. It is currently in the midst of an intense operational tower inspection cycle that will last into next year. 

With this current inspection cycle, SCE is flying HEC missions for a two-week period, and then gives everyone a one-week period of rest. The plan is to continue this schedule throughout the year and into 2013, unless the feedback recieved from all departments involved determines a change is required. 

To date, SCE has inspected over 2,000 towers across its service territory using the HEC method. At the same time, we have our HEC line crews do scheduled and unscheduled maintenance and various repair work, noted Corell. We also have them install line marker balls and change spacers between conductors.

Currently, SCE is only in the first phase of its HEC program: using a harness to transfer line workers conducting tower inspections. Said Corell, As we become more comfortable, we will add additional work methods. One thing we are not doing is rushing we are progressing slowly and methodically. We decided early on to create a program with safety being the main priority. . . . Our goal was to obtain as much redundancy as possible with the equipment used by HEC line workers.

Phase 2 of the HEC program will involve mid-span tower work using a sky chair. SCE will use the same Yates 390 RTR harness for this work, but the line workers will sit in the chair suspended via the short-haul rope. This will enable SCE to install marker balls, change out spacers and do similar work more effectively. The SCE aircraft operations division is currently developing procedures for the sky chair, and expects to be operational with it in the third quarter of 2012.

The third phase of the HEC program will involve using the sky chair for mid-span work between towers with energized conductors. SCE expects to undertake Phase 3 in the near future.

Human external cargo missions are one way in which Southern California Edisons aircraft operations division is helping the company meet its objective of delivering electricity safely, reliably and cost-effectively while also protecting the environment. Its a win-win situation, indeed!