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Friday, August 1, 2008

Hone in on What You Really Want

Ernie Stephens and James T. McKenna

Paul Schaaf has been through several aircraft completions, and has learned some lessons through them. The chief pilot for the Fairfax County, Va. Police Dept’s Helicopter Div was project manager for the recent upgrade of its two Bell Helicopter Model 407s to what is called the Mission Enhanced configuration. He also participated in past completions of the division’s old 206 LongRanger and the 407s.

Formed in 1983, the division has six pilots and 12 flight officer paramedics charged with providing police and emergency medical services to 1.2 million residents spread over 399 sq mi (1,033 sq km). It also supports neighboring jurisdictions in Washington and in Maryland and Virginia.

One major lesson Schaaf has learned is not to be taken in by a completion shop’s desire to please its customers. "If you go to a completions house and tell them what you want, they are always going to nod their heads and say, ‘Yes, we can do that.’ They’re just ready to please," Schaaf said.

With the department’s previous 407 completions, the division’s pilots and tactical flight officers (TFOs) laid out an instrument panel packed with things to please everyone. "We spec’d out this massive instrument panel that stretched from windshield to windshield," he said. The panel had about everything the pilots and TFOs needed, but it didn’t permit very good visibility through forward windshields or chin bubble until the aircraft was right over a target.

He believes a completions shop at times should challenge a customer and ask, "Do you really want to do that?" he said. But an operator shopping a completions or refurbishment job should be aware of the desire to please and challenge himself about the job’s details.

For the Mission Enhanced 407s, the Fairfax pilots, TFOs and mechanics made a mockup of their instrument panel, center consoles and control boxes, then tried out different configurations to see how they might work in routine operations. They went over such mundane but important details as which way crewmembers wanted the mute selector for the Chelton Flight Logic electronic flight instrumentation system or communications frequency selector to switch.

The result is a slender instrument panel and console that offers good visibility while allowing the pilot and TFO to work efficiently without interfering much with each other. "The pilot and TFO are not crossing hands," Schaaf said.

Another lesson he learned, Schaaf said, is to seek out a completions shop that is willing to look beyond standard or traditional solutions to installation questions. That was the case with Mount Pleasant, Pa.-based Paradigm Aerospace, which did the Mission Enhanced 407 work.

Despite the refinements by its crewmembers, the division was still looking at a combination of instrument panel and displays that filled the windshield from left to right. The left edge is occupied by a 12.1-in AeroComputers, night-vision-capable touch-screen monitor. At the right edge is filled with an Avalex moving-map display. Paradigm developed foldable mounts for each, so the pilot and TFO can fold them down when they are making an approach to landing or need greater visibility outside.

Paradigm also came up with an innovative solution for the aircraft’s "medical wall," the aft wall of the 407’s cabin.

Traditionally, it is one solid piece, but behind it are nine different electrical or electronic components, such as the fuel totalizer, emergency locating transmitter, radar altimeter, the Garmin GDL90 transceiver for Automatic Dependent Surveillance-Broadcast services and the air data attitude heading reference system (ADAHRS).

"In the past to get to them, you had to pull the whole wall, including unplugging and breaking the oxygen lines" for the EMS setup, Schaaf said. "Paradigm said, ‘Let’s split the wall in two.’ Now we remove eight screws and get full access to everything behind there. It’s one of our favorite features and it didn’t cost one penny extra."

Schaaf points to another bit of innovation on the belly of the aircraft. Traditionally, he said, cabling for the sensor ball on the nose of the aircraft is run from the aft up through overhead of the cabin, then down through the cockpit. That requires a fair amount of engineering and modification. Paradigm asked Schaaf how the division would feel about running the cable on the exterior along the belly. It’s not as pretty, but permits easier installation, replacement and troubleshooting and a shorter cable run, Schaaf said.

"I don’t think anyone else could have done" the Mission Enhanced upgrade, Schaaf said. "It was pretty bold, some of the things we did."

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