On-Board Inert Gas Generation System (OBIGGS)

Fuel tank explosions are an extremely rare occurrence in civil aviation. Even so, for many years aircraft manufacturers and operators have been looking for effective ways to reduce the potential for explosions originating in the fuel tanks of both civilian and military aircraft.

The goal is to develop technologies to dramatically reduce the possibility lightning, static electricity or, in the case of military aircraft, enemy fire will ignite the volatile fuel-air mixture in an aircraft’s partially full fuel tank, causing an explosion.

For several decades, the military has used various methods to introduce inert gases into aircraft fuel tanks and reduce the chance of explosions. Reticulated foams, liquid nitrogen and halon inerting systems have proven successful, using a combination of stored-gas and gas-generating systems.

Honeywell is working on a new kind of On-Board Inert Gas Generation System (OBIGGS). The OBIGGS is an on-board system that generates a dry nitrogen-enriched air “blanket” to cover the interior of the fuel tank and displace the flammable fuel-air mixture. To accomplish this task, engine bleed air is passed through a hollow-fiber, permeable membrane, or air separation module. There, the oxygen in the bleed air is selectively removed.

The system will consist of either an independent bleed air conditioning system or one that is integrated with the aircraft environmental control system, along with an air separation module and instrumentation to control the operation and distribution of air to the fuel tanks. The OBIGGS system is expected to be lighter and more reliable than current inerting systems.