Air Traffic Control From The Back Of A Truck

Is it possible to have a controlled airport operating in uncontrolled airspace? Is it possible to have a controlled airport operating in uncontrolled airspace? Yes! …And it can confuse pilots into making mistakes.

Most airports that have a control tower also have controlled airspace at the surface. It is so common to have both — controlled airport and controlled airspace together — that we often think of them as one thing. But they are not the same. Most of the time when you have a controlled airport you also have controlled airspace… but not all the time.

Several years ago, on December 17, I flew to Kitty Hawk for the annual celebration at the Wright Brothers memorial. The National Park Service has a small uncontrolled airport at Kitty Hawk named First Flight (figure 1). Most every day of the year pilots can fly to First Flight airport just like any other uncontrolled airport in the country — but on the anniversary of flight, December 17, it’s a different story.

A control tower does not have to be located in a tall building.So many pilots want to fly into First Flight on December 17th that the FAA operates a ‘temporary‘ control tower there for the event. Temporary control towers are not all that unusual. When special events attract large numbers of aircraft to an airport that is otherwise uncontrolled, the FAA supplies a controller to help handle the traffic.

A ‘tower‘ exists anytime a NOTAM is issued, a controller is on duty, and a frequency is available to communicate with it. At First Flight on December 17th the ‘tower‘ was on the back of a truck. Having a temporary tower in operation changes the airport rules — all taxi, takeoff, and landing at the airport can only take place with the permission of the controller. That does not necessarily mean that the airspace rules change. On December 17, every year, First Flight becomes a controlled airport in uncontrolled airspace.

I was inbound from the west toward First Flight flying over the Albermarle Sound, and I knew about the temporary tower. I tuned in the frequency that had been included in the NOTAM and listened in. There was another airplane calling in when I first got on the frequency. The other plane was closer to First Flight than I was and said to the temporary tower, ‘First Flight Tower, this is N1234A, five miles west, inbound for landing at First Flight.’ The controller responded immediately, ‘N1234A the weather at First Flight is 2 miles visibility due to fog, enter and report a left downwind to runway 2.’ The ceremony on December 17th is early in the morning and the coastline fog was creeping over the island.

When the pilot heard the weather report, ‘2 miles visibility‘ he must have thought that this meant IFR conditions existed at the First Flight airport. He figured that the only way he could land with only 2 miles visibility would be to get a Special VFR Clearance, so he asked, ‘First Flight Tower, N1234A is requesting a Special VFR.’ What the controller said next confused the pilot. The controller said, ‘Unable Special VFR, enter and report left downwind for runway 2.’ The pilot thought he was being told he could not land (‘unable special VFR‘) and at the same time was being told he could land (‘enter and report downwind‘). Not knowing what to do the pilot turned around and flew away!

Did the pilot do the correct thing? Remember I overheard this conversation on the radio and was following the confused pilot… so what was the correct thing for me to do? The answer to the puzzle requires the pilot to understand the difference between airspace rules and airport rules. Look back at figure 1 and you will see that the First Flight airport is in uncontrolled airspace. There is a magenta shaded ring around the Manteo Airport that just includes the First Flight Airport. That means that Class G, uncontrolled airspace, is at the surface at First Flight and extends up to 700 feet above the surface.

Now look at figure 2 — it’s a side view of the airspace, complete with the ‘control tower truck‘ and antenna. This airspace structure was unchanged even though there was an operating ‘tower‘ at First Flight Airport.

Unfortunately, the pilot did not understand the rules in effect at the time — and missed a once-in-a-year opportunity because of it
.The reason the controller said ‘Unable Special VFR‘ is because a Special VFR was not needed. The airspace above First Flight was Class G and Class G at that point only requires 1-mile visibility. The weather report said that 2 miles visibility was present, therefore the weather at First Flight was VFR. Special VFR can only be granted where controlled airspace touches the surface — controlled airspace never touches the surface at First Flight; it never comes closer 700 feet over First Flight. The controller was telling the pilot exactly what he needed.

I came in right behind. I called into the tower, ‘First Flight tower, this is N4321B, five miles west, inbound for landing at First Flight.’ The controller, broadcasting from the truck said, ‘4321N, visibility is 2 miles with fog, enter and report left downwind for runway 2.’ I knew that in order to legally fly VFR into First Flight with the visibility at just 2 miles, I would have to only fly in airspace where 2 miles is legal for VFR — Class G airspace. Soon, I could see the barrier island at Kitty Hawk and the First Flight airport with fog wisping across the runway. I descended to 600 feet MSL, which in this case (over the water) was equivalent to 600 AGL. (The sound is at sea level.)

Traffic patterns can be flown between 600 and 1000 feet AGL, but I chose 600 feet this time so that I would remain in Class G airspace when I flew my downwind leg. I chose the altitude because the boundary between Class G and Class E was 700 feet AGL. I made my downwind at 600 feet AGL in class G airspace where 2 miles visibility is legal VFR. At that altitude, I had a 100-foot buffer between myself and the Class E (controlled airspace) where 2 miles visibility is not legal VFR. I reported entering the downwind just as the controller had asked, and he responded with, ‘cleared to land runway 2.’ I landed and took the last parking spot remaining on the tiny ramp. I don’t know where I would have parked if that pilot had not become confused and flown home.

The celebration that year was great. General Chuck Yeager was inducted into the Hall of Fame and I was really sorry the other pilot missed it.