A Mechanic’s Guide to Fall Protection Systems  

Fall protection may not be the first thought when climbing atop an aircraft to perform a minor repair. If a task will only take five minutes, the risk of falling may be seen as a lesser evil than the additional time it would take to set up a fall protection system. This is a dangerous risk. With more than 100,000 reported incidents per year, falls from heights often result in serious injury.

Depending on the application, OSHA mandates fall protection when working on surfaces elevated by more than four to six feet. Within the aviation industry, there are multiple methods to control fall hazards, but selection of any given method is dependent on a variety of considerations.

Regardless of the type of aircraft a mechanic is working on — private jet, narrow- or wide-bodied plane — fall hazards are magnified by the fact that the work surfaces are slippery and sloped. This makes the potential for a fall much greater than in other industries. Unfortunately, no single system for controlling falls will work on all aircraft or in every situation. Variables such as location of the airplane, location of the maintenance task on the plane, type of task, fall clearance beneath the work surface and turnaround time all dictate the type of system selected.

Location of the airplane is one of the most important considerations when selecting a system. Unless an aircraft is parked directly under a permanent system in a hangar, a portable system or powered lift outfitted with fall protection is required. Even when parked in a hangar, access to a permanent overhead system may not be feasible. The system may be in use or the hangar, particularly at leased facilities, may not have a system installed. Unless the task can wait, a mobile fall protection system is needed.

Where the work is performed will also help determine which system to specify. If the task is close to the edge of a wing or near a window, for example, an aerial lift such as a scissor lift or cherry picker device could be used. If, however, the work is on the middle of a wing or the crown of the aircraft, a lift may be impractical.

The type of work the mechanic is performing will dictate the amount of mobility required and in turn will determine the most practical fall protection system. If a mechanic is performing stationary work such as an antenna change or damage repair, he or she does not require a great deal of horizontal mobility on the work surface. If, on the other hand, the work involves inspections, cleaning or painting, a great deal of mobility will be required along the wings and fuselage.

In terms of fall clearance, smaller aircraft often don’t have the clearance for a mechanic to use a fall protection anchor at foot level, which can mean a 12-foot free-fall in the event of a fall. He or she will need to tie off to an overhead anchorage point. On larger aircraft, with enough clearance between the work surface and the ground, tie-off at foot level is allowable, and in some cases, far more convenient than connecting to an overhead anchorage. When tied off at foot level, a shock-absorbing lanyard capable of keeping fall arrest forces below the OSHA limit of 1,800 pounds must be used.

In the competitive field of commercial aviation, time is of the essence. For quick, unscheduled repairs, a portable system that a mechanic can easily carry to the plane’s site can greatly reduce headaches. When it’s not feasible to wait for an overhead fall protection system to become available, a portable system as a backup is a necessity.

Aerial Lifts

Aerial lifts such as cherry pickers and scissor lifts are an option when performing stationary work, readily accessible on the side or edge of the aircraft. However, lifts can damage the aircraft if they come into contact with the fuselage or wing. Additionally, awkward positioning in the bucket or cage of a lift device can quickly cause mechanics to become uncomfortable. The freedom of movement that each of the following systems offer are much better suited for aircraft maintenance.

Permanent Systems

Tying off to an overhead permanent engineered system is the best solution for all kinds of aircraft maintenance work. An overhead anchorage point is preferable as it limits free-fall distance in the event of a fall, and therefore reduces the forces that will be exerted on the falling worker. These systems are convenient for stationary work as well as situations in which mobility along the fuselage or wing is needed. Most systems allow the user to bypass the brackets hands-free, so the mechanic never has to disconnect from the line. Some systems available can support up to five users at once. The disadvantage of these systems is that they cannot be moved. An airplane must be located directly underneath it for a mechanic to utilize the system.

There are two basic types of overhead permanent engineered systems: a cable system and a horizontal rail system. A cable system is strung horizontally across hangar roof beams and supported by intermediate brackets spaced evenly to help distribute the forces of a fall. The shuttle, the element that moves along the line, can navigate angles allowing the system to be engineered in a limitless array of configurations. A cable system can be limited to large aircraft. In the event of a fall, the cable, which is not rigid, will dip slightly where the weight of the user is deflected on the line, requiring increased fall clearance.

Horizontal rail systems are ideal for large and small aircraft. These rigid systems are also fixed to overhead support structures. Instead of a cable, however, a partially sealed steel beam with a trolley that moves within it serves as the anchor. Like the cable system, the rail system can span any length.

Free-Standing Systems

Free-standing systems are an ideal alternative to permanent engineered systems. Free-standing systems provide an overhead anchorage point that limits the free-fall distance. The free-standing system has one major advantage over permanent systems: it is mobile. Most systems, which are height adjustable for work on small or large aircraft, can be maneuvered into place by hand, forklift or maintenance vehicle. The drawback to a free-standing system is that mobility is limited to a safe working range, which varies based on the system. There are two types of free-standing systems commonly used in the aviation industry: ladder access systems and horizontal rail systems.

A ladder access system combines easy access to an elevated work area with fall protection from the ground up for the duration of the work being performed, meaning that at no point would a worker be unprotected from a fall. At the top of the ladder is a semi-enclosed platform from which a mechanic can access the wing or fuselage or perform a quick task on the edge or side of the aircraft. One or two fall arrest anchorages are also located at the top of the platform for attachment of a personal fall arrest system. Ladder access systems are ideal for reaching extreme heights, such as the tail of a large commercial jet.

Free-standing horizontal rail systems are essentially the same as the permanent engineered version, with the exception that they are mobile and height-adjustable, but limited to a certain length. They provide anchorages for one or two mechanics either on the same or separate rails. A rail system can be a better option than the ladder access system as it avoids contact with the aircraft, but the vertical reach is more limited and does not provide for fall protection from the ground up.

Vacuum Anchors

A vacuum anchor is a relatively new technology. These systems attach directly to the wing or crown of an aircraft without penetrating or damaging the surface. An optionally included compressed air bottle or connection to an independent air supply provides the vacuum power that holds the anchor to the surface. A fall arrest or restraint lanyard, depending on what the anchor is rated for, can be attached to the anchor and connected to the mechanic’s full body harness. Two anchors can also be set up with a horizontal lifeline running between them for increased mobility along the fuselage or wing. This configuration allows one or two mechanics to tie off to the system.

The vacuum anchor is ideal for quick maintenance tasks such as light or antenna replacements. With some systems weighing in at less than 20 pounds, portability is a major advantage. Additionally, it is quick to set up and is not limited by a specific "safe working area" as freestanding systems are. Due to the fall clearance required when tying off at foot level, the system should only be used on larger aircraft.

When climbing atop an aircraft, there’s no excuse for lack of fall protection, especially when technological advances have made connecting to a pre-engineered system quick and efficient. Saving a minute or two is not worth the risk of serious injury or worse.