June 15th, 2017

Aviation "News"

Welcome back. In my first post, I stated that I may comment on this or that or put forward an opinion by way of this journal. Here's one for you.
During my career,  I have read some awful news reporting about most things to do with aviation from the MSM. I get that they have to sell papers, that bad/sensational/scandalous news sells, you always hear about the plane crash, never about the successful landings...that never sells papers. As Don Henley famously sang "Give us dirty laundry!" But when "things aviation" reporting gets so sensational (and so wrong) it really annoys me.
Case in point. Just shortly after my first post, there came a breathless news report about some nut bar passenger who had tried to open an aircraft entry door in flight. The report, written by someone who knows nothing about it and probably in all innocence
(or maybe I should say in all ignorance) created vivid readers' "mind's eye" visions of horror as the door would burst open and the bad guy, the struggling flight attendants trying to stop him and the first 4 rows of business class passengers are sucked from their seats to scream and plummet to their deaths into the oceans below. Wow. Pure Hollywood eh?  There are enough nervous flyers to go around thank you. This BS only creates  more.
Some technical background; Airplanes are pressurized using sophisticated controls so that passengers can travel at high altitudes without the need for oxygen masks. We all know this. The actual process is very simple. Oceans of clean "outside" air are pumped into the aircraft cabin using engine power. This air is conditioned, cooled or heated as required using AC units, heat exchangers etc for passenger comfort. What pressurizes the aircraft is the rate that the air is let out. In other words, cabin pressure is maintained at a certain level by outflow valves (some are as big as man hole covers, the B-747-400 had two if I remember.) that slowly open or close as required to keep the pressure to a programmed schedule for maximum passenger comfort. The point is this. Aircraft doors are called "plug type doors" They do open out on the ground, but before they can do that they must open in. And at seven to nine pounds per square inch typical of a pressurized cabin at altitude, the math works out to about 2500 to 3000 pounds of pressure keeping that door in its place. Arnold himself could not budge it. It's pretty easy to pull an old rubber stopper out of a bathtub drain with a foot of water in it. Imagine the drain is 100 feet under water.  Same principle as an airline jet "plug-type" door. Unless the airplane is almost completely depressurized, that door isn't going anywhere without a fight. Relax. Until next time, over n' out.