David Learmount / London

The best helicopter companies rival airlines for safety standards despite the complexity of their tasks. How do they do it?

Helicopter safety rates vary enormously according to the aircraft's capabilities and equipment, who is flying it, and what it is being used for. But the biggest single factor seems to be the operator's cultural and procedural approach to safety.

Helicopters receive a lot of bad publicity that many rotary-wing operating companies do not deserve, so it is worth considering how the best in the industry achieve their high levels of safety.

At one end of the spectrum, as in the fixed-wing sector, is the piston-single machine, owned or flown by a helicopter private pilot licence holder. At the other extreme is the commercial transport operation. This is flown in a sophisticated, multi-engined, instrument meteorological conditions (IMC)-equipped helicopter by two pilots, both with instrument ratings (IR). The captain and possibly the co-pilot will also hold air transport pilot licences.

Between these extremes, civil helicopter pilots carry out professional work of a staggering variety, from agricultural and air ambulance flying, to police work and search and rescue. Some of this activity is inherently dangerous - yet even operators that carry out high-risk tasks have a consistently good safety record. Transport tasks include air taxi, corporate work and offshore oil support in different flying environments, ranging from the relatively benign Gulf of Mexico to the perilous North Sea. Finally, there are a few regular helicopter link services run by scheduled airlines.

Where industry works closely with - or even sets the pace for - the regulatory authorities, lessons learned have reduced accident rates dramatically. The oft-cited North Sea arena is an example of this, according to Capt Brian Hodge, chief of flight operations (helicopters) at the UK Civil Aviation Authority's Safety Regulation Group. "Some 15 years ago, we used to have a ditching every two to three years on average. Now, it hardly ever happens." Many of the improvements made to equipment and operational techniques have been industry-driven. Hodge says they include:

fitting of health and usage operating systems; industry-driven introduction of twin crewing - even where it is not compulsory; introduction of cockpit resource management training for pilots in multi-crew aircraft, rather than merely adding a second pilot; use of operational data from flight data recorders to enable analysis of flight operations practices, and improving procedures and individual training.

This shows that North Sea operators wanted safety to improve and were prepared to invest to do it. All helicopters used in the area are twin-engined, twin-piloted, and with both pilots possessing a full IR.

Hodge says that there are many ways in which offshore operations can improve, and there is a regulatory anomaly that - theoretically at least - robs helicopter pilots of the opportunity to make full official use of global navigation satellite systems such as GPS. These are technically not permitted for use as the sole means of navigation for aviation. But with the departure of Decca from the market, the North Sea is a navigation systems "no-man's land", says Hodge, adding that there is nothing else there for navigation, and even a few radio communications "black holes" in the operating area.

Platform approach

He is clearly hinting that, especially with the European Geostationary Navigation Overlay System coming on line next year as a back-up for GPS, platform approach procedures using a judicious combination of onboard radar and GPS should be officially researched and sanctioned. They may not be perfect, but they are the best - and in this case the only - system available. Visual approach cues should not be ignored either, says Hodge. A study into improving helideck lighting is also under way.

Hodge would like to think airline systems such as enhanced ground proximity warning could be made available in helicopters, but at around £70,000 ($120,000) per aircraft, it is uneconomic.

On dry land - in most of the world - even professionally employed helicopter pilots normally operate without an instrument rating, and it is only a minority of helicopters that are even instrumented to permit real IMC flight. Single-engined helicopters are "never" IMC-equipped, according to Hodge, although they could be. This makes them more primitive than many club single-engined, fixed-wing light aircraft, which are often IMC-capable, even if the capability is rarely used because of the lack of crew qualification.

In the UK, helicopters used for classifiable public transport roles have to be twin engined, IMC-capable aircraft, and either crewed with two pilots, each with their own full flight instrument panel, or equipped with an autopilot. But for some demanding roles like air ambulance operation or for police work, often neither the pilot nor aircraft are IMC-capable. It seems helicopter operators, in most cases, accept that they will normally operate only in visual meteorological conditions (VMC). Helicopters are permitted to fly at night, providing there is good visibility and the aircraft is flying within sight of the ground. Perhaps it is not surprising, then, that an even higher proportion of helicopter fatal accidents than those involving fixed-wing aircraft are caused by pilots being caught in unexpected IMC, according to both the UK and US authorities. And in these circumstances, because the helicopters are unequipped and the pilots unqualified to fly in cloud or poor visibility, they press on trying to remain below the unexpected lowering cloudbase until they collide with the ground or an obstacle. Often, at night, VMC pilots suddenly find themselves in cloud that they could not have seen, and some become disorientated and lose control.

Despite this evidence, Hodge does not see it as his job to tell pilots they should be instrument rated if their job does not warrant it - even if it might give an extra layer of safety. The problem is that training for an IR is expensive, as is maintaining its currency, and so is equipping the cockpit of a relatively simple helicopter to be fully IFR capable.

Importance of IR

Bristow Helicopters, one of the world's largest international operators, especially in offshore work, sees pilot IR and fully IMC-capable helicopters as fundamentals whatever the flying environment.

Derek Whatling, Bristow group safety officer, is a helicopter pilot with a military background. He insists that all pilots in both seats of Bristow aircraft are fully instrument rated. Bristow UK had a bad year last year, losing two aircraft - one of them with all the crew and passengers - in as many days after enjoying years of safe operation in varied environments all over the world. In the first event, on 15 July 2002, a Sikorsky S-61N on search-and-rescue duties over Poole Harbour, UK, got a fire warning for No 2 engine as the transmission oil pressure and master caution lights came on. The fire drill failed to extinguish the fire. Then the No 1 engine fire warning came on; but by that time the co-pilot had identified a landing field and pointed it out to the captain, who set the helicopter down. The crew evacuated safely but the aircraft burned out. The time from the first warning to touchdown was 1min 20s, which showed the benefits of high-quality training.

The fault, according to investigation so far, was a turbine bearing failure that is still being studied.

The next day a Bristow Sikorsky S-76A suffered a catastrophic failure over the North Sea, with the loss of its crew and nine passengers. According to the UK Air Accident Investigation Branch, a main rotor-blade structural failure separated the entire rotor head from the aircraft. The inquiry showed that the blade had suffered a lightning strike in 1999, after which it had been sent to the manufacturer for examination and declared safe. The CAA has now issued an airworthiness directive saying that any rotor blade suffering a lightning strike should be discarded even if there is no apparent damage.

Safety, for Whatling, is multi-faceted. He believes in industry-wide sharing of experience. Bristow is a member of the worldwide British Airways Safety Information System organisation, a network of individual company safety and operational databases that enables companies to track their own safety performance and share their information in a controlled manner if they wish. Safety, says Whatling, is also "thinking about the job. Asking: Ôshould I be doing this?' You don't go rushing into it."

Training credence

He would like to see the best helicopter full-flight simulators given some training credence by regulators, because he believes that - in the multi-crew environment at least - as with their fixed-wing counterparts, helicopter full-flight simulators should be allowed to be used as a substitute for some of the type rating or instrument rating training hours that pilots need to do, even if they must still take their final IR handling examination in the air. He says that while Bristow pilots all earn their initial IR in a full hands-on airborne course, they carry out their renewals in a simulator.

Whatling's office, with the help of the CAA's world accident database, has worked out that the total accident rate for fully equipped twin-engined helicopters above 2,500kg (5,500lb) in the transport role is around 1.5 per 100,000 flying hours (see graph), and the fatal accident rate is about 0.02 per 100,000 flying hours - which is as good as airline operations with twin turboprops.

Source: Flight International