but it also could be used as saying that area is congested. All the examiners I have talked to have said the same as well.
The law isn't that simple, unfortunately. There are a number of legal interpretations on the issue, and they tend to base their decisions off of NTSB cases. Here's one:
OCT. 3, 1979
PETER N. BASKIN, ESQUIRE
Dear Mr. Baskin
In response to your letter dated August 28, 1979, and subsequent telephone conversation, we offer the following answers to your three questions. The facts on which our interpretations are based are as follows:
A fixed wing aircraft operating at an altitude of 600 feet flew directly over a populated subdivision of Prince William County, Virginia. The subdivision consisted of at least 40 residential homes on one acre lots. While operating in this area, the aircraft made a number of steep turns over one of these houses.
1. What is the interpretation of the term "congested area of a city, town or settlement" as that term is used in Section 91.79(b) of the FARs?
The meaning of the term "congested area" is determined on a case-by-case basis. It first appeared in the Air Commerce Regulations of 1926. No abstract regulatory definition has yet been developed. However, the following guidelines indicate the interpretations of the Civil Aeronautics board (now National Transportation Safety Board) in attempting to give meaning to the term.
a. The purpose of the rule is to provide minimum safe altitudes for flight and to provide adequate protection to persons on the ground. Thus, it distinguishes flight over sparsely settled areas as well as large metropolitan areas from low flying aircraft. Thus, size of the area is not controlling, and violations of the rule have been sustained for operation of aircraft: (i) over a small congested area consisting of approximately 10 houses and a school (Allman, 5 C.A.B. 8 (1940)); (ii) over campus of a university (Tobin, 5 C.A.B. 162, 164(1941); (iii) over a beach area along a highway, and (iv) over a boy's camp where there were numerous people on the docks and children at play on shore.
b. The presence of people is important to the determination of whether a particular area is "congested." Thus, no violation was found in the case of a flight over a large shop building and four one-family dwellings because, in the words of the CAB examiner, "it is not known (to the court) whether the dwellings were occupied." In that case, the area surrounding the buildings was open, flat and semiarid.
c. The term has been interpreted to prohibit overflights that cut the corners of large, heavily congested residential areas.
As made clear in FAR 91.79, the congested area must be an area of a city, town, or settlement.
2. What is the interpretation of the term "sparsely populated areas" as contained in Section 91.79(c)?
While this term is not expressly defined, we can conclude that it is something other than a congested area under Section 91.79(a). A subdivision of at least 40 occupied residential homes on adjacent one acre lots in Price William County, VA, would not be considered a sparsely populated area. Such a subdivision would well constitute a "settlement" under the rule.
3. What is the interpretation of the term "intentional maneuver involving an abrupt change in an aircraft's attitude" as contained in Section 91.71? Pursuant to a telephone conversation with Mr. Hamlen on September 7, you stated that your specific question in reference to this term was whether steep turns of 45 deg..- 60 deg.. were acrobatic maneuvers within this definition.
Steep turns of 45 deg...- 60 deg... are not considered to be acrobatic maneuvers so long as they are incident to normal flight; however, climbing steep turns might be. E. E. Basham, Sr., 13 C. A.B. 61, 73.
Please feel free to contact us if we can be of further assistance.
Sincerely,
EDWARD P. FABERMAN
Acting Assistant Chief Counsel
Regulation and Enforcement Division
Office of the Chief Counsel
