George Tonking - HELI OPS

GIVE THAT MAN A BELL

I know it’s clichéd, but where has the year gone? December, the busiest month in our profession, is upon us. And it’s busy, not only because the security industry is on high alert, but because many pilots, like normal people, go on holiday with their families, leaving a gap for extra charter work.

I RECENTLY COMPLAINED to a colleague about how tired I was before the silly season had even started. He was having none of it and clearly told me to wind my neck in and to remember how privileged I was to have the job I do. Too often, in our short-sightedness, we don’t recognise what’s obvious to others. In my case, this includes the fact that I get to fly diverse machines, compared to many of my peers in the helicopter industry worldwide who tend to fly one specific type, basing their careers on it. In the helicopter world, unlike aeroplanes, we don’t have many series-type aircraft. Every helicopter is a different type on which to be rated. And once rated, you need to stay “current” on each type, lest you lose your rating. Fortunately, as my good friend and colleague pointed out, my line of work allows me to stay relatively fresh on a high number of the types on which I’m rated. A closer look at my logbook revealed just that, with fluctuating numbers during different seasons. At the time of writing this column, I am current on

Every 6 of the 13 types I hold a rating for. That’s something. It helicopter is doesn’t mean that I’m superskilled, just that the variety of a different jobs I’m called to do regularly requires choppers with type distinct personalities. One of those, which I first learned to fly many years ago, is the beautiful, sleek Bell 407. In helicopter development, one of the costliest outlays is the testing process and type certification. It is, therefore, far more cost effective to develop on a proven design platform than to start a clean-sheet design. The Bell

407 had its origins in the Bell 206 Jet Ranger – retaining many of the hard-fought typecertifications of both the Jet Ranger and the Long Ranger (itself a derivative of the “Jetty”). But the 407 is no Jet Ranger, if that’s what you’re thinking. For one, the 407’s fuselage is wider, its windows bigger, and its cabin roomier – allowing for two crew and five passengers.

The biggest difference, however, lies in the design of the dynamic components or rotor system. All previous civilian Bell designs used a teetering or see-saw type of semi-rigid twobladed rotor with traditional metal greased bearings. In 1993, when development began, Bell took the main rotor design of the military OH-58D (model 406) helicopter – which was also a descendant of the 206 – and adapted it for the new 407.

1995 saw the first flights of the Bell 407 prototypes and production model, with a 4-bladed “Soft-in-Plane” main rotor assembly. The basic layout of the main rotor and mast attachment uses a composite hub assembly damped by elastomeric cushions, similar to the Airbus H125 design from the early ’70s. The efforts proved successful, not only in increasing aircraft speed and improving performance but also in decreasing vibration, leading to an exceptionally smooth-flying helicopter.

True to form, Bell didn’t leave it there – they also approached Allison Engines to produce a powerful Model 250 turbine engine to bring the 407 to life – the Allison (now Rolls Royce) 250-C47B. At 813 shaft horsepower, if you can close the doors, you can fly. Its ease of use is enhanced with dual-channel FADEC redundancy, which includes a one-button start sequence. Bell also debuted the 407 with a full digital engine-monitoring instrument panel – a first for helicopters.

The 407 has come a long way in its almost three decades of evolution, with one of the

An IMC capable Bell 407 G1000 safely through the weather.