Tethered vs. Moored Balloons

by Joseph C. White


What is in a name? Words are meaningful descriptions-usually. Consider the term "tethered balloon" as distinguished from "moored balloon." What exactly is the difference, or is there any? Webster speaks of a tether as a restraint placed upon an animal or other living creature, whereas a mooring line is what holds a vessel or similar object firmly in place. This is apparently not of much help toward understanding the pertinent FAA regulations, as evidenced by the misunderstandings and occasional misadventures which have occurred with improperly restrained balloons.

For example, in Georgia, a hot air balloon was used during a ceremony dedicating a pavilion to a well-known balloonist and public-spirited citizen. The balloon's airworthiness certificate had expired, so instead of being free flown it was tethered to a truck and towed over the crowd while two men in the gondola sprayed the onlookers with champagne. Suddenly the balloon began to rise, and the two occupants realized that the tether had broken. Eventually a descent was initiated and one of the men, who had taken some student pilot training, threw out a drag line to slow down the movement over the ground. The lines caught in some trees with an abrupt arresting force that snapped the support cables and allowed the gondola to plummet 200 feet to the earth. Both men suffered serious injuries.

The National Transportation Safety Board investigation listed as a probable cause, "unqualified person operated the balloon." However, from FAA's point of view the entire operation was illegal and hazardous from start to finish, because the balloon was in a non airworthy condition and should not have been flown, much less by an uncertificated crew. Would it have been less illegal if this balloon had been securely "moored" while the champagne spraying took place? Not necessarily; a balloon that is a registered aircraft should normally not be moored, because the design standards are for the loads imposed for maneuvering in free flight, rather than a moored operation.

FAA regards any balloon which is designed for carrying persons as an aircraft, and as such it must be certificated and operated in accordance with the applicable rules for aircraft. Such a passenger carrying balloon is considered tethered when it is inflated and held to the ground, in whatever manner. A moored balloon (for which there are no prescribed airworthiness standards because passenger carrying was not intended) is essentially any lighter-than-air object operated under 14 CFR Part 101. Such a balloon must be restrained with mooring lines to hold it stationary in the intended location, and the balloon must comply with the provisions of 14 CFR Part 101.

To be operated as an aircraft, a tethered balloon must be registered with FAA. It must also be constructed, certificated, maintained, and operated in accordance with various FARs (Parts 43, 61, and 91). Only a certificated and properly rated pilot may operate such aircraft, and said pilot must always be on board when passengers are carried-even when on a tether. If the passengers are carried for pay, the pilot must have a commercial certificate. The pilot is responsible at all times for the safety of persons on board, as well as for the safety of other aircraft and persons on the ground below.

Incidentally, flight experience may be logged in a tethered balloon, by a pilot or student, for the actual time that the movements of the balloon are not fully influenced by the tether-i.e., when the pilot is controlling ascent, descent, and neutral buoyancy by means of hot air input, venting, off-weighting, etc.

Any balloon not designated to carry people is not regarded by FAA as an aircraft and is regulated under 14 CFR Part 101 only insofar as it might become a hazard or obstruction to flight. It must be more than six feet in diameter or have a gas capacity of more than 115 cubic feet, must be flown no higher than 500 feet above the ground and no less than 500 feet below the base of any cloud, must be flown no closer than five miles from the boundary of any airport, and must not be flown when the visibility is less than three miles. When operated between sunrise and sunset the balloon and its mooring lines must have colored pennants or streamers attached at 50 foot intervals beginning at 150 feet AGL and visible for at least one mile. When operated between sunset and sunrise the balloon and its mooring lines must be lighted to give a visual warning regardless of its altitude. To prevent runaway accidents, an automatic rapid deflation device must be attached so that it will activate if the mooring lines fail. This device must function independently from any crew or other human input.

The accompanying illustrations and tabular comparisons should help prevent future misunderstandings about restrained balloon operations. If you still have any doubts, consult your local FAA Flight Standards District Office before setting out your lines.

You might have a bear by the tail.

Mr. White is a specialist in the Air Traffic Rules Branch in FAA Headquarters. This article originally appeared in FAA Aviation News, October 1994.


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