Helicopters Magazine

Features Procedures Safety & Training
Establishing More Control

July 30, 2013  By Walter Heneghan

The judicious use of a control hierarchy may be an ideal solution to create a sound hazard and risk management plan at any organization.

The judicious use of a control hierarchy may be an ideal solution to create a sound hazard and risk management plan at any organization.

Risk management principles talk about a variety of means for addressing hazards in order to minimize the risk to our employees or customers.

The control hierarchy is straightforward; it consists of elimination, substitution, isolation, engineering controls, administrative controls and personal protective equipment (PPE). This list is ordered in terms of effectiveness; the most effective means of controlling the risks associated with any hazard is to eliminate it completely. In the simplest terms, if flying in thunderstorms presents a risk to an aircraft of being subjected to severe turbulence, then avoiding the thunderstorm – elimination – removes the risk from the hazard.

In our business, however, not all risks can be eliminated. While I hear it virtually every day – “…well, we may as well stop flying if we don’t want to be exposed to that hazard . . .” – I suggest that it is still imperative to look at eliminating the hazard if we can. Blade strikes during confined area operations is one such example. Sure, we can eliminate blades strikes easily if we stop landing at unprepared landing sites, but is that a practical solution? I hardly think so. But it doesn’t remove responsibility for considering how to eliminate that hazard. The solution may simply be having the pilot choose a different landing spot.


The next control is substitution. Perhaps landing somewhere else puts this control mechanism into play. For example, pick a different spot to land; believe me, the client would rather have to walk an extra 200 metres through the bush than lose the use of the helicopter for the day. Or maybe substitution means using a different helicopter with a smaller rotor disk for the job at hand, although this may not be very effective since there is very little practical difference in rotor diameters among most of the bush aircraft in use today.

Isolation means we separate the hazard from our people by isolating it. Granted, this would be tough to do in this example but not in many others – when refueling in the bush, for example, where are your passengers? Are they in the helicopter, standing nearby or segregated from the refueling operation at a safe distance? These are all things
to consider.

Engineered controls are next in line. As you can see as we progress through the hierarchy, each subsequent step is a bit less effective than its predecessor. So what types of engineered controls are available to avoid blade strikes? Back in the “good old days,” when aircraft had HF radios with the long whip antennae, some of these antennae protruded just beyond the rotor disk, so that served as a telltale sign (although that still puts the obstacle pretty darn close to the rotor.) What about adding some type of radar system or back-up type camera?  As you can see, developing effective controls becomes tougher and undoubtedly, more expensive.

So, next we move on to what are used by virtually every operator – administrative controls. Company memos, training manuals, standard operating procedures (SOPs), best practices, and tribal knowledge are standard procedures. You name it, and there is a procedure for it, but using these procedures requires discipline on the part of the operator and especially by the pilots. We can stipulate half rotor diameter clearance, but how effective is that? It relies completely on the pilot, his customers, and the circumstances of the flight, and changes every day. Administrative controls have a place but it is important to know that they have limited effectiveness.

The final step in the hierarchy of controls is the PPE – the least effective control. This is often useful in mitigating the consequences of the hazard being released. In our circumstances, the consequences of a blade strike could be a rollover accident. Flight suits and helmets would certainly be useful in minimizing personal injury. Ensuring seatbelts and whether or not harnesses should be used is also important. PPE remains an important control and should not be automatically dismissed.

The hierarchy of controls is an important construct that can help us both in completing pre-job risk assessments and in performing daily risk evaluations while on the job. Try to bring this list into your thought processes, eliminate hazards when you can, and you will continue to have safe, successful and profitable flight operations.

Walter Heneghan is the VP of Safety and Quality at Canadian Helicopters. A passionate advocate for aviation safety and sound risk management, the veteran pilot presents his regular column for Helicopters magazine.


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