Critical Consumer Pat Sidley
EVER wondered why you get off a long-haul flight feeling tired, clogged up or — worse still — carrying the start of your fellow passenger’s cold? The likely answer is not to be found in the mysteries of jet lag and circadian rhythm, but in the air you have been breathing on the aeroplane.
The United States consumer organisation, Consumer’s Union, has conducted an extensive investigation on several flights of varying distances, in various makes of aeroplanes and on different airlines. It found that complaints of stale, stuffy air have some foundation.
The US standards for air in the cabins of airliners, set by the Federal Aviation Administration (FAA), are accepted by most airliners throughout the world as the industry minima.
Complaints about the air on flights usually come from two quarters: passengers and crew. Regulators, according to Consumer Reports, seldom find fault.
One of the factors affecting the quality of the air in flight is the age of the aircraft, according to the journal. The older planes use unrecycled air through the air conditioning system. Planes designed and built during the 1980s, however, recycle about half their air to cut down soaring fuel costs.
Fresh air is diverted from the stream of compressed air that creates the engines’ forward thrust. The diverted air is then mixed with cabin air before being sent into the cabin. Some of the old air is sent outside and the rest is filtered to remove dust and germs.
Air inside a cabin is, at its best, probably as dry and as thin as that of Johannesburg. After filtering, there are few traces of dust or disease-carrying bugs but, according to Consumer Reports, odours and gases remain. If recently built, certain aircraft (including some used by South African Airways) filter gases and odours better than others.
In all airliners the pilot can adjust the flow of air to passengers and regulations insist that the air supply to the cabin is entirely separate from that of the cockpit.
According to Consumer Reports, staff unions’ complaints included respiratory trouble, allergies and, in one well-documented case, a flight attendent infected several of his workers with tuberculosis before he was diagnosed and treated.
The regulatory authority, the FAA, doesn’t have minimum ventilation standards; it only requires that cabins be “ventilated”.
Consumer Reports colated information from 158 flights which were tested by volunteers. The temperatures and dryness were more or less normal; the volunteers used as their standard, minima set by heating and air- conditioning experts. However, the carbon dioxide readings explained why consumers complained that the air was stuffy.
Consumer Reports draws attention to the fact that carbon dioxide is not poisonous, but when levels are too high it can interfere with normal breathing and physiological processes. The survey recorded that the highest levels of carbon dioxide occurred during take-offs and landings. The longer the flights at cruising levels, the less carbon dioxide was recorded.
It also found that this did not vary with the airline but with the type of plane. Boeing 757s, not used by SAA but by several airlines servicing South Africa, consistently recorded higher levels of carbon dioxide.
In addition, the 757 recirculates nearly half its air and crams its passengers into less space than most other aircraft. The design of the 757 makes it hard, according to the survey, for pilots to bring in extra fresh air.
Boeing 747-400s tended to do best: there were consistently lower levels of carbon dioxide and passengers have more cubic meterage per person on these planes than most others.
This will explain why many people believe the air is fresher in first class. It’s a simple matter of how many people are crammed into a finite space breathing the same amount of air. It stands to reason that those with more space will get more air. Some airliners, such as CR, allot no more than 10 cubic feet to each passenger which is half the level recommended for public buildings.
Do consumers really catch bugs through the airconditioning systems of airliners? Probably not — but they catch them on aircraft, for a variety of other factors:
* Their proximity to people with infectious diseases.
* The dryness in the air; if mucous membranes are dry, this tends to stop the body adequately fighting off germs.
Consumer Reports illustrates its point that the air in aircrafts is better filtered than that in buildings: it cites the case of a jet “with an inoperative ventilation system grounded in Homer, Alaska, for more than four hours with 53 people aboard. Within a week of the trip, 72 percent of the passengers went down with influenza, all of the cases traceable to a single passenger who developed `flu symptoms during the delay.”
This Critical Consumer has certainly sat in an aeroplane on the tarmac for longer than expected and with no airconditioning. It is worth reminding cabin crew that they should turn it on when this happens.
Other hazards in the air are for people who may have allergies to perfumes, hair sprays, certain cleaning chemicals or upholstery finishes. And a greater hazard for South Africans is the use of insecticides which are marked with a warning urging consumers not to breathe in the spray. Yet it is sprayed all over passengers anyhow.
Airline staff unions have accused airline operators of not using the ventilation in the aircraft to the full capacity and, according to Consumer Reports, there is evidence that saving on fresher air is done to cut costs. The savings are minimal.
Here are some tips on how to survive a flight based on Consumer Reports’ article:
* Avoid 757s and try to find out how full the flight is — the emptier, the better. Try to catch a 747-400 instead.
* Don’t be afraid to complain to cabin crew if the air is stuffy: chances are they are feeling it too and it can, at times, be adjusted.
* Avoid alcohol, decongestants (unless you have an ear infection) or other medication (unless necessary) which causes dehydration. Drink plenty of fluids.
* In the dry atmosphere of the cabin wear spectacles instead of contact lenses.
* If you have `flu, use tissues or hankies instead of coughing and sneezing directly on to fellow passengers and crew.
* Ask the airline if they know where and when your flight will be sprayed with an insecticide. Some airlines may be prepared to make other arrangements for customers with allergies.