May 24, 2012
Modern aircraft are so complex that using the word “mechanics” to describe the people who service them no longer seems to fit; they work surrounded by computers, electronics, and tools that bear no resemblance to the ball-peen hammers of yore. Still, the Aircraft Maintenance Technicians (AMT) Association has established May 24 as a day for national recognition of their profession, and in so doing, pay honor to the man who is considered the very first American AMT.
When the Wright brothers needed help around their bicycle shop, they hired one Charles E. Taylor, a mechanic and machinist. Charley, as they called him, was the kind of man who might have been described in those days as “good with his hands.” Born in 1868, shortly after the end of the U.S. Civil War, he became a trusted employee around the Wrights’ bike shop in the first years of the 20th century, where he repaired bicycles and even ran the place when the brothers were gone.
Although Orville and Wilbur began flying in gliders, their goal was always to fly a powered aircraft that could stay aloft as long as its fuel lasted. To do that, they needed an engine–but not just any engine. When they sought bids from established manufacturers, they stipulated that the engine had to be light but powerful. It also had to run smoothly enough that the vibration didn’t tear their airplanes apart. It was hardly surprising that no one in industry was interested in such a tall order–especially when they were buying just two units. They got no replies.
The Wrights may not have known a lot about engines, but they knew Charley. Could he produce a 200-cubic-inch engine that delivered eight horsepower, the minimum requirement they’d calculated they would need for their Flyer? According to a remark by Taylor quoted in the Smithsonian monograph series Annals of Flight, “We didn’t make any drawings. One of us would sketch out the part we were talking about on a piece of scrap paper.” Taylor’s capable hands began to turn out the parts: He made the complicated crankshaft entirely by hand from a single “solid block of steel about 32 inches long, six inches wide and one and five-eighths inches thick,” as he recalled in a short documentary made by United Aircraft Corporation on the 50th anniversary of the Wrights’ first flight. First he drilled holes through the steel billet to remove metal, then, when he had the part shaped in rough form, he used a metal cutting lathe to create the circular bearing surfaces on each crank throw. The aluminum crankcase was custom cast by a local Ohio foundry.
It took Taylor just six weeks to finish it, and instead of eight horsepower, it produced about 12. Instead of a heavy, complex carburetor, it had a flat induction chamber on top of the engine with a kind of collar mounted on it that dribbled the fuel into the chamber to vaporize. The basic outlines of that original engine survived evolutionary changes that produced more horsepower and greater reliability, but the engine from the first successful powered flight in 1903 no longer exists. It was damaged, put in storage, then lost.
Charley lost his life savings during the Great Depression, and after moving to California, fell on hard times. Correspondence between him and Orville Wright (in the collected papers of the brothers) shows an enduring affection and respect between them.
In 2001, the FAA unveiled the Charles E. Taylor Master Mechanic Award for AMTs with 50 years in maintenance who also had at least 30 of those years as licensed airframe and powerplant mechanics. In 2002, California became the first state to celebrate AMT Day and link it to the memory of Taylor. Currently, 52 U.S. states and territories have embraced May 24 as AMT Day, and the U.S. House of Representatives has passed a similar resolution; a Senate measure is said to be underway.
So mark your calendar and try to find some AMTs to thank. It won’t be easy, due to airport security that Charley and the Wrights could never have imagined. You can always ask a pilot to thank an AMT for you.
May 16, 2012
Yesterday the Defense Department sharply curtailed flying in the Lockheed Martin F-22 Raptor due to pilot reports of disorientation similar to the symptoms of oxygen deficiency. Although the DoD has been aware of the situation for a while, recent TV broadcasts may have given the issue a new focus while a supplemental oxygen system is being readied as backup.
The Raptor isn’t engaged in combat anywhere, but it will proceed with a deployment to the Mideast for joint maneuvers. Training flights are to be restricted to a distance allowing for immediate landing. Other types of aircraft will handle long-range patrol missions in Alaska.
The decision may not accurately be described as “grounding” the airplane, but it comes very close.
May 11, 2012
Early May was not a good time to be a public affairs officer for the F-22 Raptor. Both ABC and CBS investigated the airplane’s troubles with a system that provides enriched oxygen to the pilot at high altitude. A CBS “60 Minutes” segment extensively interviewed two Air Force pilots who went public with their decisions to refuse to fly any more missions in the F-22, which is not currently engaged in combat.
The pilots say they have experienced symptoms that appear to indicate hypoxia, or a lack of oxygen that occurs at high altitude. One told the CBS interviewer that he recognized the early onset of hypoxia but became so hampered by his lack of ability to focus that he was unable to recall where the control was to activate the emergency oxygen supply.
Older aircraft supply oxygen to the crew from pressurized tanks, which are heavy and can explode if struck by a projectile. With newer aircraft like the F-22, the Air Force has been moving to systems based on a molecular sieve principle, in which nitrogen can be separated from ambient air by forcing it under pressure to adsorb onto a substance to which the nitrogen adheres, thereby providing air that is higher in oxygen content. So far, it’s not clear whether the system employed by the F-22 has a fundamental design problem, or if the airflow from the system is being contaminated somehow.
Air Force flight surgeons suggested that pilots wear sensors that clip onto one fingertip and read body oxygenation levels; the devices are familiar to hospital patients whose vital signs are monitored continually by automatic machines. But if contamination rather than an actual lack of oxygen is causing the symptoms of hypoxia, such sensors would not help. Charcoal filters were installed to cleanse the pilots’ airflow of any possible contaminants, but the filters only added to the problem when pilots began inhaling black dust from the charcoal.
So far, one pilot’s death in a Raptor crash is being blamed on the suspect oxygen system. Pilots are especially wary because hypoxia has bewildering symptoms, among which is a sudden feeling of elation. Its onset may reduce a pilot to a conscious but dysfunctional state within one or two minutes, and all military air crew members are trained in chambers that simulate oxygen deprivation at high altitude by pumping the air out while trainees try to write words or recognize pictures of common objects.
As a result of the controversy, the utility of the F-22 itself is being questioned, mostly due to its sophistication and cost. Reports say that one flight hour in one of the fighters costs the Air Force north of $40,000. And critics say the Raptor was designed to fight a foe that doesn’t exist. Interestingly, the two pilots interviewed by CBS both praise the airplane and love to fly it. But it’s hard to love anything when you’re starting to pass out.
You can watch the “60 Minutes” segment below: