The unanticipated loss of pressurization at high altitude literally can absorb the air out of one's lung The Oct 26 1999 crash of the Lear 25 carrying golf professional Payne Stewart provided a vivid reminder of the danger that lurchs even though high-altitude flight has become a matter of quotidian routine.

The unanticipated loss of pressurization at high altitude literally can absorb the air out of one's lung The Oct 26 1999 crash of the Lear 25 carrying golf professional Payne Stewart provided a vivid reminder of the danger that lurchs even though high-altitude flight has become a matter of quotidian routine. Indeed, the Lear 25 checklist illustrates the importance of assuring the oxygen take the place of in flight. On the "before starting engines" checklist, oxygen combination of parts to form a whole checks are item number four, right after unlocking the commands buckling up and checking the flight curbs The National Transportation Safety Board (NTSB) room for expectations to complete its investigation of that high-profile crash this year. individual of the factors likely to be examined is the design of the valve for the crisis oxygen bottle. It is rotated outboard to the "on" position and inboard to "off" As single in kind source said, it is "not intuitively obvious" when the result of oxygen is open. When cabin pressurization was dissipated the pilots may have institute themselves without positive-pressure emergency oxygen A little thing may have l to a big problem

It is not oftentimes that larger jetliners experience unlooked for depressurization, but these events do happen for a variety of reasons. Consider pair recent events: the fuselage skin ruptur render free of access Jan. 9th on a Korean Air Lines B747-200 cargo airplane, which was promptly acresed by local authorities when it landed at Penang, Malaysia. And, onward Jan. 14th, the little golden cups deployed when an America West B737-300 en way from Seattle to Phoenix missed pressurization, forcing an unscheduled landing in Boise, Idaho.

Below, a sampling of marked occurrences involving Part 121/135 flights from one side of to the other the last 10 years. plucked from the NTSB database, they illustrate the various ways pressurization los can come to one's mind If there is an overall message to these stories, it present the appearances to be a simple in addition hard truth: avoid taking the easy way, eschew short cuts

May 12 1996; Indianapolis, Ind.; B727-290; American Trans Air; no aircraft damage; 11 minor injuries:

on the subject of reaching cruise altitude at 33000 ft the cabin altitude warning horn haleed The captain noticed the right air conditioning pack was distant from and he, along with the flight engineer, attempted to reinstate the pack without using a checklist. The cabin altitude continued to climb to 14000 feet at which time the warning lights illuminated and the oxygen masks opened in the cabin. While attempting to correct the cabin altitude, the flight engineer inadvertently expanded the outflow valve, resulting in a rapid los of cabin constraining force The captain, the flight engineer, and the lead flight attendant all became unconscious suitable to hypoxia. The captain had delayed donning his oxygen mask. The flight engineer became unconscious after reviving the flight attendant. The first officer, who had barely 10 hours of flight time in the airplane, had donned his oxygen mask when the warning horn first healthyed maintained consciousness and was able to initiate an juncture descent. During the emergency declivity the captain, flight engineer, and the attendant regained consciousness and an urgency landing was made. The airplane was inspected and flight standarded the next day; its pressurization classification functioned with no anomalies.

April 4 1994; Ontario, Calif.; Fairchild SA-227AC; Skywest Airlines; minor damage; 1 minor injury:

Passing in consequence of 19,800 ft. to a cruising altitude of 21000 ft a turbulent "bang" was heard and the captain was partially draw into the mouthed through the broken left side window. After about 4 secondarys he was able to twitch himself back into the aircraft unassisted. He declared an strait and landed without incident. Maintenance records revealed that an airworthiness directive requiring an inspection of the windows was complied with within the past 143 hours. The technical representative for Fairchild stated that maintenance personnel who deportment ed the AD inspection may have failed to discover the crack, due to the tricky inspection procedures employed. The approved inspection transaction allowed for two methods: 1) removal of the external frame retainer for direct viewing of the raise extortionately holes and 2) using a 90-degree prism seated in mineral oil for an indirect view of the raise extortionately holes. The airline was using the inferior method.

Nov. 13 1991; Toledo, Ohio; DC-8-63; Flagship Express; minor damage; no injuries:

The main cargo door render free of accessed in flight and the airplane get backed for a normal landing. Of the couple circuit breakers required to be ventureed prior to takeoff, one was set up still engaged. Inspection of the cargo door revealed several areas of nonconformity, including door fastenings of less than required strength...and damaged wires in a put into bundles The wires were part of the door closing and door locking indicating hypothesis The investigation revealed it was possible for the door to be not completely clos and have the door warning light go on foot out, indicating it was entirely locked.

Oct. 28 1991; Las Vegas, Nev; DC-10-10; United Airlines; minor damage; no injuries: