$_{Figure 7-7.}$  Contour flying. (c) Over other than congested areas. An altitude of 500  feet above the surface, except over open water or  sparsely populated areas. In those cases, the aircraft  may not be operated closer than 500 feet to any  person, vessel, vehicle, or structure.” 14 CFR part 91, section 91.119(a) requires a pilot to fly  at an altitude that allows for a power unit failure and/or  an emergency landing without undo hazards to persons or  property. All aircraft should be operated so as to be safe, even  in worst-case conditions. Every good pilot is always thinking  “what if...,” and should operate accordingly. This portion of  the regulation can be applied in the following way. When  climbing over an obstacle, a pilot can make the balloon just  clear the obstacle, fly over it with room to spare, or give the  obstacle sufficient clearance to account for a problem or  miscalculation. An obstacle can be overflown while climbing,  descending, or in level flight. Descending over an obstacle  gives the greatest opportunity to misjudge clearance over an  obstacle. In level flight, the danger is reduced. Hazards are  minimized by climbing. Most instructors teach minimizing  the hazard by climbing when approaching an obstacle, thus  giving room to coast over the obstacle in case of a burner  malfunction. 14 CFR part 91, section 91.119(b) concerns flying over  congested areas, such as settlements, towns, cities, and  gatherings of people. There is no standard definition of  “congested area” or “open air assembly of persons” but case  law has indicated that a subdivision or homes, constitute a  congested area, as does a small rural town.  A balloon pilot must stay 1,000 feet above the highest  obstacle within a 2,000-foot radius of the balloon. This is  a straightforward regulation and easy to understand. Note  that the highest obstacle is probably an antenna, tower, or  some other tall object, not the rooftops. Two thousand feet is  almost one-half mile. This portion of the regulation is often  forgotten or ignored.  [Figure 7-8] A conscientious pilot includes livestock of any form—dairy  cows, horses, poultry—in the 1,000-feet above rule. Domestic  animals, while not specifically mentioned in the regulations,  are considered to be property; and experienced pilots know  that almost all poultry, exotic birds, swine, horses, and cows  may be spooked by the overflight of a balloon. Livestock in  large fields seem to be less bothered by balloons; however,  it is always a good idea to stay at least 1,000 feet away from  domestic animals. This is discussed in detail on page 7-16. 7-9