Safe Working in Aircraft Fuel Tanks: An Australian Experience

Abstract

An audit of an aircraft fuel tank entry program was conducted for a major commercial airline for all its maintenance facilities across Australia in the winter of 1995. Entry into aircraft fuel tanks as a special form of confined space is a unique and difficult form of work. The possible health and safety hazards include toxic effects of fuel vapors, oxygen deficiency, flammability, and explosion. Entry into and movement within fuel tanks are restricted, and conventional rescue techniques may not be practicable in the event of a mishap. In some ad hoc maintenance operations where short turnaround time is required to avoid aircraft delay, wet tank entry with inadequate atmospheric purging could be encountered. This problem could become exacerbated in summer months when high ambient temperatures would significantly enhance the vaporization of jet fuel inside the tanks. In this audit, the program documentation and procedure manuals for fuel tank maintenance were reviewed, facilities and plant were inspected, and generic assessments and tests were conducted to evaluate the actual safety procedures used for work in different types of commercial aircraft. Subsequently, new systems and plant for more efficient work in fuel tanks were identified, and training and emergency response programs were developed. This audit also included an evaluation of the current work practices, systems, and plant used in major local and overseas airlines and manufacturers. A comprehensive program was developed, which included a permit-to-enter system, an integral system of respiratory protection and communications, new atmospheric purging facilities to eliminate the need for wet tank entry, and appropriate fuel tank worker accreditation, emergency response, and training programs.