Waypoints

Over the years I've taken a couple of dozen friends, relatives, and, in some cases, virtual strangers up for their first airplane rides. It's always a rewarding and often enlightening experience.

One of my most recent guests was a bright, young attorney from the U.S. Department of Transportation. He was visiting AOPA and expressed an interest in both GPS and air traffic control issues. I took him for a ride in our Better Than New 172 to show him a GPS approach and to explain the air traffic procedures around Frederick, Maryland, home base for AOPA. I let him fly for a few minutes, including right down final. He did a fabulous job, especially considering it was his first flight in a light airplane and first time ever at the controls.

As is typical of other busy air traffic areas, the Washington metroplex is peppered with ATC and military radars. The radars, along with all the airliners carrying TCAS II these days, kept N172B's transponder reply light aglow, which prompted questions from the attorney. Despite the radar activity, I assured him that it would be unlikely that we would even see another airplane in the sky, except maybe back in the pattern at Frederick. Just about then he pointed out an airplane scooting along below us. (Blush.) I estimated the King Air at a mile and heading away from us, not exactly a threat. At its altitude, the King Air would not have been visible on radar.

Frederick is one of more than 300 airports located between 25 and 30 nautical miles from the primary airport of a Class B area that receives special disposition from transponder requirements. Regulatory changes effective in 1989 required that all aircraft operating from the surface to 10,000 feet msl within 30 nm of the primary Class B airport carry Mode C equipment; the area became known as the Mode C veil. Tens of thousands of letters from aircraft owners and pilots — and pointed comments from AOPA and other associations — convinced the FAA that some relief was needed at outlying airports, which often don't have radar coverage at low altitude anyway.

The agency's answer was Special Federal Aviation Regulation 62. The SFAR allowed nontransponder operations at airports between 25 and 30 miles from the primary airport in areas without low-altitude radar coverage. The FAA made SFAR 62 a temporary regulation that was to expire on December 31, 1993. As the deadline neared, everyone assumed the agency would extend the rule, but the date came and went and nothing happened. For more than a year, there has technically been no SFAR 62. Thus, everyone without a transponder who has flown into or out of any of the 300 formerly exempt airports has technically violated the law, though the FAA has not been enforcing it.

For most of 1994, a notice of proposed rulemaking to extend the regulation was held hostage by DOT, which apparently didn't know what to do with it — so, typical of bureaucracy, the simplest way out was to do nothing.

Finally, late in 1994, the NPRM was issued. Among AOPA's comments was a request that the FAA test a plan to allow aircraft without transponders to fly below the Class B areas to within 20 miles of the primary airport and ultimately within 15 miles of it. The outer Class B rings at those distances typically have floors of 1,500 to 2,000 feet agl. Terrain and radar equipment limitations often mean that low-altitude radar coverage isn't available at those distances anyway. When was the last time you saw an airliner flying at 2,000 feet agl 20 miles from the primary airport?

Concerns about general aviation pilots straying into Class B areas are less valid than ever before, thanks to the introduction of some 120,000 loran units and more than 6,000 GPS receivers into GA cockpits (not including thousands more handheld GPSs).

As the comments noted, there has never been a safety problem between air carrier and general aviation aircraft beneath the floor of any Class B airspace and there is no international requirement for a veil encompassing Class B airspace. All of the airspace reclassification of the last couple of years was to bring the United States into compliance with international standards, yet the rest of the world has no Mode C veil around Class B areas.

According to the latest FAA data, about 151,600 general aviation aircraft carry Mode C transponders; about 38,350 do not have any transponders.

Owners of aircraft without the equipment apparently have no desire to transit the Class B airspace or they would have bought transponders. But the veil prohibits them from flying to the nearly 1,200 airports (24 percent of the public-use airports) that will be encompassed once all 32 planned Class B areas are in effect. There are 29 Class B areas now.

Meanwhile, aircraft without electrical equipment are exempt from the veil requirements altogether. They continue to freely come and go to airports under the Class B areas right up to the center core, where Mode C is required down to the surface. Apparently they aren't considered a threat. Likewise, there is no veil requirement around Class C areas. All aircraft are free to fly under the Class C rings right up to the inner circle.

It really makes you wonder why the Mode C veil exists at all and just what the policy makers at FAA and DOT headquarters think they are accomplishing by having it in place.

Of course, this sort of transponder discussion may be a bit more than you need for your neophyte passenger, unless he happens to be a DOT attorney.