Pilot Counsel:

What is a 'congested area'?

April 1, 2008

John S. Yodice pilots his Cessna 310 in the Washington, D.C., area.

FAR 91.119 tells pilots the minimum altitudes at which they may legally operate their aircraft. We reviewed this regulation in this column in December 1997 (and on AOPA Online) as part of our continuing review of the FARs for pilots and aircraft owners. What brings it up now is a decision of the National Transportation Safety Board (NTSB) interpreting and applying the term congested area. This is a legal term that has bedeviled pilots because it is not defined in the regulations, and in practice, is subject to varying interpretations and applied to varying geographical areas. Its meaning has to be gleaned from FAA enforcement cases as interpreted by NTSB.

To put the interpretation in context, we need to look at the structure of the regulation. The main body of the regulation prescribes minimum altitudes depending on the nature of the geographical area over which an aircraft is operated, one of which is a “congested area.” However, regardless of the geographical area, there is an overriding minimum that applies “anywhere,” and, there is an exception that applies to takeoffs and landings. Let’s review these two before we get to the main body of the regulation. The “anywhere” minimum is not a numerical altitude. Rather, this minimum requires a pilot to fly high enough so that “if a power unit fails” the pilot would be able to make an emergency landing without creating an “undue hazard” to any person or any property on the surface. The exception says that the minimum safe altitudes of the regulation do not apply “when necessary for takeoff or landing.”

The geographical areas where minimum altitudes are specified are: congested areas, populated areas (my term), and open water and sparsely populated areas. The regulation says that “over any congested area of a city, town, or settlement, or over an open air assembly of persons, [a pilot must operate the aircraft at least] 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft.” The regulation specifies minimum altitudes for “other than congested areas.” Over a populated area that is not congested, a pilot must fly at least at “an altitude of 500 feet above the surface.” This minimum is measured vertically, as distinguished from the next minimum we will talk about, which can be measured on the slant. Over a sparsely populated area, or over open water, an aircraft may be operated down to the surface, so long as it is not operated any “closer than 500 feet to any person, vessel, vehicle, or structure.”

Now, to our case. This NTSB decision involved a Gulfstream II multiengine jet operating in the vicinity of a beach and an airfield in Hawaii. The Gulfstream made two low passes off the shore of the beach, and one low pass down the runway of the airfield. These passes were part of pre-arranged filming for the marketing purposes of a production company. Two witnesses described the passes near the beach to be at an altitude they estimated to be at or below 100 feet above the water surface, and within several hundred feet laterally of surfers in the water and people on the beach. A retired FAA air traffic controller who was on duty in the airfield tower said that the Gulfstream approached the runway with gear and flaps retracted, leveled off at approximately 100 feet above the runway surface, and proceeded to make a low pass. The pilot’s explanations were not accepted. He explained that he was 1,000 feet above the water and saw no persons or objects in the water. With respect to the low passes over the airfield runway, he said that he had contacted the airport manager, and the person who answered the number listed under “Restrictions” in his AC-U-KWIK reference guide; that person expressed no objections to his intended pass down the runway.

Our concern here is not with the merits of the case and the dispute about the altitudes that were flown (the pilot wound up with a 150-day suspension of his ATP), but with two FAA and NTSB interpretations gleaned from the case.

Is a beach a congested area? Buried in its wordy decision, the board perfunctorily held that the persons on the beach made it a congested area as an “open air assembly of persons.” It did so without providing any guidance as to how many persons and how closely assembled the persons need to be to constitute a congested area. But clearly the board and the FAA gave notice that a pass below a thousand feet over open water near a beach is problematic.

Is an airport a congested area? The board, perhaps without thinking much about it, did so hold—assuming there are persons in the vicinity. Based on the testimony of an FAA inspector, the board found that the pass down the runway endangered the “individuals in the vicinity of the airport” and therefore implicitly held that the airfield was a congested area. The board seemed to accept that a pass down the runway would be excused if it were “necessary for takeoff or landing,” but the board cited one of its earlier decisions holding that the “landing exceptions do not apply where no landing is intended or possible due to the aircraft configuration.” The board also seemed to suggest that such a pass would be excused if it were with the permission of the FAA. The permission of airport authorities apparently is not enough.

John S. Yodice