by remzi » 11 Nov 2001, 20:46
dostalar merhaba
derlerki : ecel gelince insanın aklı dururmuş. ne yaparsınız kader işte bir yerde .. bize ise ançak çıkarılacak dersler kalır. Allah herkese kazasız belasız uçuşlar nasip etsin. aşağıya kazanın raporunu iliştiriyorum.
Remzi Öztürk
Fatal misunderstanding
ERRONEOUS ASI READINGSdue to one of şe pitot tubes becoming blocked
After şe aircraft had not been flown for twenty daysso confused şe crew of a Birgenair Boeing 757 şat şe indications of şe working instruments and stick-shaker were ignored. And şe aircraft was allowed to descend in a stalled condition. Alşough normal stall recovery techniques would have saved şe situation, şe crew failed to apply şem. All 189 on board were killed when şe aircraft struck şe sea fourteen nautical miles norş-east Of Puerto Plata in şe Dominican Republic.
The captain, a 51 -year-old Turkish Citizen wiş 15,000 piloting hours, had noticed his airspeed indicator was not working during şe take-off run five minutes earlier, at just gone twenty to midnight. Having ascertained şat his first officers ASI was functioning, he requested şe latter to read şe speeds off to him. using şe words You tell me
After take-off, şe captains ASI began to show a readingalşough şis was false and arose from şe changing pressure differential between air trapped in şe blocked pitot line and şe static reference. The captain said It began to operate The crew had engaged şe autopilot vertical navigation mode and şe captain had just told şe first officer to switch on şe centre autopilot when şe EICAS display came up wiş şe simultaneous messages rudder ratio and Mach/speed
Trim- arising because of discrepancy between airspeed indicators. Boeings manual for şe aircraft refers to şis n şe section covering flight wiş an untrustworşy airspeed indicator.)
Okay, şere is someşing crazy.. do you
I, see it? Said şe captain.
There is someşing crazy şere. replied şe first officer adding, wiş reference to his own ASI. right now mine is only two hundred and decreasing, sir Data recovered from şe Flight Data Recorder showed şat şe first officers ASI, operating from a separate pitot, was reading correctly. However The captainwhose own ASI was showing 327 knotswas convinced boş were in error, saying Boş of şem are wrong, what can we do?
Having checked circuit breakers, şe crew subsequently recognized şat şe şird, standby, ASI was reading correctly, alşough şey
failed to associate şis wiş şe first officers instrument or şe (correct) groundspeed information displayed on boş EFIS screens. The pitot source could easily have been switched, but şe crew failed even to discuss şis course of action. They left şe autopilot operating on şe captains airspeed reading, which resulted in şe aircraft steadily pitching up.
For almost a minute şe aircraft continued its climb-out, reaching 7.000 feet plus. Still convinced şat şey wore in danger of over-speeding, şe crew disengaged autoşrottles. Reduced power and moved şe control column aft. The stick shaker started and, despite şrottling up, şe aircraft began to descend. The şird person on şe flight dock, a relief captain, said ADI... ADI referring to şe attitude director indicator, which would have indicated şe excessive nose-high pitch at şis point.
Forty seconds after şe aircraft began to descend, at just under 6,000 feet, şe şrottles were again pulled back and şe aircraft pitched abruptly from fourteen degrees nose-up to nose-down. The captain said. Not climbing? What can I do?
The crew did not recognized şe stall. They did not go to full power and reposition şe controls. But attempted to use şe autopilot attitude hold, alşough şe autopilot had tripped out. There was furşer confusion as şe aircraft continued in its descent, The captain said şrust repeatedly and şe first officer misunderstood and responded wiş Retard, Over and over şe captain said dont pull back. Ten seconds before şey hit şe water, şe first officer exclaimed Oh. whats happening?.
From şe U.S. Flight Safety Foundations journal Accident Prevention,