Mother of invention

November 1, 2005

Editor in Chief Thomas B. Haines has been reporting on the general aviation industry for 20 years.

When Plato wrote, "Necessity, who is the mother of invention," he probably wasn't thinking about the needs of general aviation. Yet as general aviation pilots, we benefit every day from inventions pioneered by bright minds faced with tough challenges in developing and improving the airplanes we fly.

When Raytheon Aircraft needed to leapfrog the competition to maintain a strong foothold in the business jet market, it couldn't just fall into the "same old, same old" method of building a new airplane. Instead, with the help of its vendors, it set about developing a new way to manufacture fuselages. Using a high-tech "Viper" machine, Raytheon spins the fuselages for the Premier IA and the Hawker Horizon out of strands of composite material. The result is an entire fuselage that two workers can pick up. Because of its thinner frame, the interior can be wider than most similarly sized airplanes without increasing exterior dimensions — resulting in a larger cabin without any more drag.

Alan Klapmeier, co-founder of Cirrus Design, survived a midair collision. When he and his brother Dale designed the SR20 and SR22 they wanted to make sure their customers had more options than Alan did, so they tapped Ballistic Recovery Systems' expertise in developing whole-airplane parachutes. The resulting Cirrus Airframe Parachute System (CAPS) has saved several lives already (see " Pilot to Pilot: Cirrus Design's Alan Klapmeier," page 113).

When Columbia Aircraft wanted a reliable, automatic deice system for its Columbia 350 and 400 aircraft, it turned to Northcoast Technologies to invent one. The result, which should be shipping later this year, is a godsend for Columbia owners who operate in areas prone to icing. The ThermaWing system developed by Northcoast uses a powerful, newly designed alternator, which also acts as a backup aircraft power supply and can drive an air conditioner. The alternator provides electricity to warm thermal panels on the leading edges of the wings and tail to melt ice. To prevent the melted ice from running back farther on the wing and refreezing, the system automatically cycles on and off to cool the wing and then quickly heat it, causing the moisture to flash off the surface, preventing runback.

Similarly when aircraft owner Bill Bainbridge wanted a compact backup alternator for his airplane and found that none available met his needs, he invented one himself. Today, B&C Specialty Products alternators are standard equipment as backup alternators on several airplanes.

One hot invention

One of the most interesting, but certainly esoteric, inventions to come out of GA lately is the PhostrEx fire suppression system invented by Eclipse Aviation for its Eclipse 500 very light jet. Those of us who mostly fly piston-powered airplanes don't think much about engine fire-suppression systems, but in the turbine world, they're required gear.

Engine fires in piston or turbine engines are rare, but they can be deadly indeed. As we reported in the November 2004 issue (" Fire in Flight!"), if you suspect an engine fire in your piston airplane, the goal is to get on the ground immediately. Attempting to make it to an airport may be a fatal mistake. That's challenging enough from only 10,000 feet or so, but imagine if you are cruising high into the flight levels in your jet or turboprop and you suspect an engine fire — within spitting distance of thousands of pounds of Jet-A. Even at an emergency descent rate of 5,000 feet per minute, you're still a long time getting down. As a result, most turbine aircraft carry some sort of fire suppression systems.

In the early days of aviation — even before turbine engines — manufacturers tinkered with all sorts of materials, including some that were so toxic that upon deployment they did more harm to the crews than the fire itself might have. In the late 1940s, the Army Corps of Engineers coined the term Halon to describe halogenated hydrocarbons — materials that contain carbon, fluorine, chlorine, bromine, and iodine. Halon, which essentially evacuates oxygen from the environment and thus snuffs a fire, became the material of choice for aircraft manufacturers. Compressed into spherical containers, the material would be discharged as a gas into the engine compartment when the flight crew hit the Fire button on the panel — usually after being alerted to the condition by an annunciator.

By the 1980s, it was obvious that Halon was one agent that was contributing to the depletion of ozone in the upper atmosphere, causing the international community to ban its manufacture by the mid-1990s. Halon use is for the most part banned, except for military and aviation uses. Manufacturing of it has stopped, so existing supplies must be reclaimed whenever possible. Once acceptable alternative materials are developed, even the military and aviation must stop using it.

So this is the environment that Eclipse Aviation stepped into a few years ago when it began developing the 500 — having the requirement for a fire suppression system, but knowing that the only available system would someday be eliminated in favor of something newer. In addition, current systems are rather large and heavy and the cylinders must be tested at frequent intervals — usually about every five years.

With low weight and simplicity as an Eclipse company mantra, the engineering team began to look at alternatives. Contacted by a scientist who had patented a new fire suppression material, the team set out to prove that a new system could be invented that worked better than Halon and without the environmental hazards. After three years of development and testing, the company had its system approved by the FAA and the Environmental Protection Agency. Because PhostrEx, as it is called, can replace Halon it could be that all newly certificated turbine aircraft will be required to use it or some other new system that comes along — potentially providing a new revenue stream for Eclipse, which has patented the concept.

To prove the effectiveness of PhostrEx, Eclipse built an engine-fire test rig complete with a detailed mock-up of the Pratt & Whitney PW610F that powers the 500. The rig allows the Eclipse team to simulate fires almost anywhere inside the mocked-up nacelle. During a visit to Eclipse's Albuquerque, New Mexico, headquarters last spring, I was able to witness one of the more than 200 test fires set in the rig — and quickly extinguished by the PhostrEx system. The PhostrEx container is about the size and weight of a 35mm film canister, whereas a typical Halon cylinder is a sphere about the size of your two fists put together. PhostrEx is much more potent than Halon. According to Eclipse, two teaspoons of the new material are equivalent to 2.5 cups of Halon. The PhostrEx system weight is about 90 percent less than a traditional Halon system. Eclipse expects that the system will need to be changed only every 10 years — half as often as a Halon system.

It is stunning to watch a nacelle fire instantly snuffed out when the tiny cartridge of PhostrEx is discharged — even when the nacelle is in an environment that simulates the airflow at cruise speeds. PhostrEx chemically shuts down a fire in about one-tenth of a second and then quickly combines with the surrounding air to become inert.

Like Viper, CAPS, ThermaWing, and other innovations going on all around us, PhostrEx shows that GA companies are not just plodding along relying on yesterday's research and development. They are investing in products that will make our flying safer and more reliable.

Flying home

The law enforcement world lost two of its finest within a month of each other. Friend and fellow pilot Mike Sullivan, a retired Jefferson County (Wisconsin) chief deputy, died August 13 in a boating accident on Lake Winnebago in Oshkosh. A consummate flight instructor and corporate pilot, Mike shared his immense aviation knowledge and experience in the most casual of conversations. Every flight I make is safer as a result of my time — brief as it may have been — learning from Mike. I will miss his friendship and his teaching.

Three weeks later, on September 6, my father-in-law, Homer Riley, a retired Pennsylvania State Police sergeant, died after a six-month battle with pancreatic cancer. Homer was an occasional passenger in my airplane and an enthusiastic supporter of my flying since the day I soloed at age 16. He was courageous until the very end, worried about those of us around him and not at all worried about his fate. We used our airplane a lot during those long six months to make regular visits to see him. On our way home a few days after the funeral, we made one circle over the cemetery — a final aerial tribute to a man I already miss dearly.

E-mail the author at thomas.haines@aopa.org.

Thomas B. Haines

Thomas B Haines | Editor in Chief, AOPA

AOPA Editor in Chief Tom Haines joined AOPA in 1988. He owns and flies a Beechcraft A36 Bonanza. Since soloing at 16 and earning a private pilot certificate at 17, he has flown more than 100 models of general aviation airplanes.