Risk Rises When Airline Mechanics Strike Happens

08/15/2005

Paul Munnis

As if there isn’t enough to worry about when traveling these days we add flight physics problems to the subject matter.

According to the NASA Standard Model for Pressure, Temperature and Altitude, there are three major risks in flight should explosive decompression occur. Note that an aircraft cabin is pressurized to produce a feeling of comfort, it is also heated, it also has oxygen fed into it.

If the air temperature at sea level is 59 degrees fahrenheit, then the temperature of the air outside of an aircraft at 35,000 feet is minus 68.72 degrees fahrenheit.

If the sea level air pressure is 29.92 inches of mercury and an aircraft cabin is pressurized to 4,000 feet, then that pressure is 25.84 inches of mercury. Yet outside of the aircraft cruising at 35,000 feet the air pressure is 7.08 inches of mercury. The difference is 18.8 inches of mercury.

When the stewardess switches on her PA system to read you the flight safety instructions she tells you that should there be a sudden loss of cabin air pressure an oxygen mask will drop down and you should put it on and take care of any others having breathing problems. The flow of oxygen is started in the mask by pulling gently on the hose.

Here is what she doesn’t tell you.

A sudden loss of cabin air pressure is a major flight disaster. Let’s say it occurs because of a puncture in the skin of the aircraft fuselage.

Then the pressure will seek to equalize meaning that the higher pressure cabin air will rush to the hole in the side of the aircraft. It will suck with the force of a tornado anything and everything in its path. That includes people. Those masks that dropped from the ceiling will likely be sucked out too. In the meantime, due to a lack of oxygen you will turn blue. Due to the sudden cold you will also likely freeze to death. If you were unbelted then you could be sucked out of the hole. Even if you are belted to your seat then the airline seat could be yanked from the seat tracks, with you in it, and then sucked out of the hole.

Should the loss of cabin pressure be caused by a failure of the cabin pressurization system only then the masks will still be there and there is a possibility that you might actually get oxygen from them. However, you will still rapidly freeze to death as the temperature will suddenly drop. The very act of putting on a mask may be a heroic effort rewarded by death from freezing.

This is the situation that apparently happened when the Greek airliner lost cabin pressure yesterday and 121 people died as a result. They never had a chance.

There is still plenty of risk when you fly and there are Physics forces at work over which you have no control.

Flight is essentially a contest between man and the physics of the air. When man triumphs it is because his artificial life support systems succeeded.

Sometimes these fail and it is a likelihood that deferred maintenance and inspection increases the risk of failure.

As we look to imminent airline strikes and the resultant deferred maintenance upon aircraft then we need to understand that the risk to life increases with each such flight. Eventually, critical sub-systems fail and people could die as a result. The airline will hide behind the FAA inspectors and the FAA will hide behind inspector shortages and the industry will seek to issue reassurances to the public yet the risks will have gone up for the traveler. Hopefully, at some point the pilots will refuse to fly the aircraft thus grounding aircraft and canceling flights until the fleet can be properly maintained. Pilots are also passengers. During the period right after a strike, until the fleet has its deferred maintenance caught up, then risk to travelers is also heightened.

Passengers may want to weigh these risks against necessity when traveling on an airline that is in the midst of a mechanics strike.