Backgrounders

TRANSPORTATION SAFETY BOARD OF CANADA
AVIATION SAFETY RECOMMENDATIONS

DATE ISSUED: 27 March 2008

FORWARDED TO:

The Honourable Lawrence Cannon, P.C., B.A., M.B.A.
Minister of Transport, Infrastructure and Communities

SUBJECT: Emergency Fuel Shut-Off

Background

On 11 August 2007 at about 0908 central daylight time,1 a FireFly 12B hot air balloon, C-FNVM, attempted a landing in a field adjacent to Birds Hill Provincial Park near the northern outskirts of Winnipeg, Manitoba. The balloon was operated by Sundance Balloons International under Special Flight Operations Certificate (SFOC) 5812-10-36 issued by Transport Canada (TC). One pilot and 11 passengers were on board for a local sightseeing flight of about one hour's duration, originating in the southeast of Winnipeg and terminating in the northeast of Winnipeg.

The flight had been extended beyond Winnipeg as the pilot searched for a suitable landing area. The winds in the landing area chosen were much stronger than anticipated. The balloon touched down and skipped several times. The basket was dragged on its side for about 700 feet and at one point tipped far enough for the burners to strike the ground. When the balloon stopped, the pilot ordered the passengers to evacuate the basket. A propane fuel leak occurred and an intense uncontrolled fire ensued before the evacuation was completed. The pilot and two passengers suffered serious injuries in the intense fire. Four other passengers suffered minor injuries, some with burns. Two of the propane tanks and a fire extinguisher canister exploded, and the basket of the balloon was destroyed by fire. The investigation (A07C0151) is ongoing.

A balloon is an aircraft as defined in the Aeronautics Act. Some balloon operators use this type of aircraft for hire and reward and are thus a commercial air service and air carrier as defined in the Act. However, although the FireFly 12B and other large balloons can carry up to 12 fare-paying passengers, they are not regulated at a level comparable to other commercial operators.

Fuel System

The fuel system consisted of six 10-gallon propane tanks divided into two groups, yellow and blue. Each group had one master tank (MT) and two slave tanks (ST). All six propane tanks were secured to the centre compartment walls of the basket using nylon straps. The blue group fed one burner and the yellow group, the other

 
Photo 1 - Fuel system

Photo 1. 

Fuel system

burner. Each MT had a main fuel source and an alternate/No. 2 fuel source, and each source was turned on and shut off by a screw-type valve similar to a BBQ propane tank valve. Each MT also had a pilot light shut-off valve, a relief valve, and a quantity indicator. Each ST had a similar screw-type valve, a relief valve, and a quantity indicator. The fuel system was not equipped with an emergency shut-off valve.

Propane Hoses and Fittings

Each group of tanks was connected by braided hoses with crimped sleeve fittings to a fuel cross-over valve and pressure gauge cluster. Each burner was fed by three low-pressure, non-braided hoses with crimped sleeve fittings.

On the accident flight, the balloon had a seventh propane tank on board. The seventh tank was used as an inflater tank. It was not determined how the tank was secured in the basket. The envelope of the balloon was heated/inflated on the ground using the inflater tank (to avoid using the operating fuel in the other six tanks). The inflater tank with its remaining fuel was connected to the refuelling port of the second ST using the low-pressure, quick-disconnect hose and was used as extra fuel in flight.

Historical Data

The number of balloons currently registered in Canada is 482. Whether used to carry fare-paying passengers or not, the balloons are registered privately. Since 01 January 1997, there have been 15 reported accidents involving balloons in Canada. Of these, 12 involved fatalities and/or serious injuries, for a total over the period of 3 fatalities and 26 serious injuries. Three of those 15 accident flights, authorized by an SFOC, involved 31 fare-paying passengers of which there were 2 fatalities and 15 serious injuries. Two of these accidents are currently under investigation as Class 3 occurrences: A07C0151 and A07P0295. Another fatal accident, A01O0200, was investigated as a Class 3 occurrence, but did not involve an SFOC or fare-paying passengers.

Unsafe Conditions and Underlying Factors

The FireFly 12B balloon flight manual recommends that fuel be shut off during hard landings. In addition, fuel should be shut off during certain emergency situations. The balloon design does not incorporate a single-lever or emergency fuel shut-off, nor do the airworthiness standards require such equipment. With the current equipment configuration, in order to shut off fuel, the pilot must first determine which tanks are in use, and then screw the valve/valves closed. For the basket used, the pilot normally stands in one of the centre compartments, and it may be difficult for him or her to reach the tanks in the other centre compartment. In an emergency situation, this process would be awkward and time-consuming. Although a balloon is considered an aircraft in the Aeronautics Act, unlike most aircraft, it is not equipped with emergency fuel shut off valves.

During the dragged landing, the pilot was unable to reach across the centre compartment divider to turn off the fuel at the tanks, and he had no emergency means of doing so. As the basket dragged and bounced across the field, the burner support structure lost its integrity and the basket tipped over. These events allowed the burners of the balloon to strike the ground. The propane hoses were pulled out of the burners and liquid propane vented in the vicinity of the pilot lights and ignited, causing the intense fire and subsequent explosion.

Recommendation

While some commercial balloon operators in Canada have fare-paying passenger loads in the range of those of commuter and air taxi operators, their passengers are not assured of the same level of safety and oversight by regulations and standards. The inability to quickly shut off the fuel supply during landing or in an emergency increases the risk of a fire and/or explosion, compromising balloon passenger safety. Therefore, the Board recommends that:

The Department of Transport ensure that balloons carrying fare-paying passengers have an emergency fuel shut-off. A08-02

Assessment Rating: Satisfactory Intent

As the investigation continues, the Board may make further safety recommendations should additional safety deficiencies be identified.



Wendy A. Tadros
Chair
on behalf of the Board


1.   All times are central daylight time (Coordinated Universal Time minus five hours).