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Cabin Fumes from Non-Fire Sources
From SKYbrary Wiki
Non Combustion-related Fumes
| Article Information | ||
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| Category: | Fire Smoke and Fumes | 
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| Content source: | SKYbrary | 
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| Content control: | EUROCONTROL | 
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Contents |
Description
Fumes from various non-fire related sources are often experienced within the cabin of passenger aircraft.
Sources
Most modern passenger aircraft are equipped with pressurised, climate controlled, cabins. In spite of the aircraft designers’ intentions, unwanted fumes frequently permeate the interior of the aircraft. Open doors and hatches as well as certain on-board sources can introduce fumes to the cabin environment. However the usual path of entry for fumes is via the aircraft pressurisation and climate control systems.
The majority of passenger aircraft utilise bleed air from the engine compressor or from the APU to pressurize and heat or cool the aircraft cabin. As a consequence, any contaminants introduced into the compressor at the point from which the bleed air is extracted may result in fumes in the cabin.
Effects
The effects of fumes in the cabin range from mildly annoying to potentially life threatening. Numerous sources cite the health risks associated with exposure to a contaminated cabin environment.
Typical Scenarios
- Passenger catering items are being boarded via the right rear cabin door. At the same time, luggage is being loaded in the aft hold using a belt loader. A quartering wind blows the exhaust from the poorly maintained belt loader engine into the cabin through the open door. Several passengers and one cabin crew member become nauseous due to the fumes.
- A flight attendant is using one of the galley ovens to heat her lunch. She is distracted by a minor medical issue with one of the passengers and the item is left in the oven for a protracted period. Smoke from the overcooked lunch fills the galley and permeates into the forward cabin. The meal is removed from the oven and dowsed with water. The smoke quickly dissipates.
- While waiting in the departure queue, engine exhaust from the preceding aircraft enters the engines. In the engine compressor, some of the air is bled off to supply the air conditioning system introducing fumes into the cabin.
- The aircraft is de-iced with type I fluid and anti-iced with type IV due to falling snow. During the takeoff roll, residual de-icing fluid migrates into the engine intake. In the compressor, some of the fluid enters the bleed air system and fumes are introduced into the cabin via the air conditioning system. The condition is short lived as the bulk of the residual de-icing fluid shears off of the airframe prior to rotation speed.
- A leaking seal within the compressor of the engine allows small amounts of engine oil to enter the bleed air system. The cabin is quickly filled with heavy oil fumes. Emergency oxygen masks are deployed and the aircraft diverted to a nearby aerodrome.
Defences
Sound maintenance practices for both the aircraft and for the ground support equipment, a comprehensive understanding of how fumes can be introduced to the cabin, and robust situational awareness are the key defences for minimizing fumes within the aircraft.
Solutions
- Ground support equipment should be well maintained to minimize the exhaust emissions. Support equipment, to the extent possible, should be positioned in such a way that the likelihood of fumes entering the aircraft is minimized.
- During ground operations, air conditioning systems should be turned off when the aircraft is exposed to the exhaust from other aircraft or from ground support equipment and fumes are noticeable within the cabin.
- After de-icing, a “packs off” (air conditioning system off) configuration for takeoff will ensure that residual de-icing fluid does not enter the air conditioning system during the takeoff roll. The bulk of the fluid will shear off of the airframe and engines by the time the aircraft is airborne. When the packs are turned back on at thrust reduction altitude, there will be very little fluid left to cause fumes.
Related Articles
Further Reading
- "Call For Public Inquiry - Air Travel Toxic Fumes Air Passengers And Crew At Risk From Contaminated Air" - National Health Federation (UK), 2008.
- "Beware frequent fliers: Aircraft cabin air can be toxic" - article in Economic Times (India), 2010.