Boeing 787 makes swift progress towards first flight - at last
By Jon Ostrower
The Boeing 787 is finally making swift progress towards its maiden sortie with several key milestones being passed that clear the way for it to fly by the end of June.
Boeing's prototype 787 (ZA001) saw the light of day on 3 May, when the aircraft was officially moved to the Everett flightline's fuel dock for fuel quantity system verification, ahead of the first starts of its Hamilton Sundstrand APS 5000 auxiliary power unit and Rolls-Royce Trent 1000 engines.
This appearance marked the end of almost two years of factory seclusion for the prototype after the ceremonial roll-out on 8 July 2007 that preceded the programme's rash of part shortages, production problems and design changes.
In recent weeks ZA001 has completed a closed-loop simulation of the first flight with chief project pilot Mike Carriker at the controls. The 20 April "factory gauntlet" was completed faster than planned, as the aircraft moved into final gear swing tests.
© Boeing
In these trials, Boeing experienced a glitch on 25 April when switching power sources from ground to internal mid-swing, causing the aircraft systems to shut down. Boeing quickly restored power and returned the gear to the down position.
The airframer has opted to carry out the final testing while on the flightline to ensure this condition of functionality is satisfied ahead of first flight. The second aircraft, ZA002, completed ground vibration testing on 1 May, another key prerequisite for the first flight.
The aircraft, having completed early validation of the flutter stability of the wing, will now remain in the paint hangar until mid-month before returning to the factory for final preparations before joining ZA001 on the flightline.
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Sabtu, Mei 16, 2009
EASA Cautions Boeing 737 operators of radio altimeter errors
EASA cautions 737 operators of radio altimeter errors
By John Croft
EASA has published a safety information bulletin alerting Boeing 737 operators of an "erroneous low range radio altimeter (LRRA) indication" that has been linked to the fatal crash of a Turkish Airlines Boeing 737-800 at Amsterdam Schiphol on 25 February. The accident killed nine of the 134 on board, including three pilots in the cockpit.
Central to the investigation is a radio-altimeter fault that caused the aircraft's autothrottle to enter retard mode at too high an altitude, reducing thrust to idle speed before the aircraft was in position for its final flare above the runway.
Pilots lost control of the aircraft after speeds decreased to 110kt (204km/h) at approximately 500ft (152m) above the ground due in part to the fault. The system is designed to automatically reduce thrust to idle when the aircraft enters its landing flare approximately 27ft (8m) above the ground.
Dutch investigators revealed on 29 April that several radio altimeter failures had occurred on the accident aircraft in its previous eight flights. EASA notes that "there are reports of further incidents attributed to the same cause".
In its 30 April alert, which references a flight operations technical bulletin published by Boeing, EASA says if one of an aircraft's two LRRAs provides erroneous altitude readings, the associated "flight deck effects" may typically include "inappropriate flight mode annunciation indication of autothrottle retard mode during approach phase with the airplane above 27ft above-ground-level."
The agency is recommending that flight crews, whether operating in automated or manual flight modes, "carefully monitor" primary flight instruments including airspeed and attitude, for aircraft performance and the flight mode annunciation for autoflight modes.
"When the autothrottle mode is selected during critical phases of flight, the pilot flying may consider to keep a hands-on position on the engine throttles to guard against and correct any abnormal behaviour," EASA continues, adding that, "Early intervention prevents unsatisfactory airplane performance or a degraded flight path.
http://www.aviationspace.blogspot.com
By John Croft
EASA has published a safety information bulletin alerting Boeing 737 operators of an "erroneous low range radio altimeter (LRRA) indication" that has been linked to the fatal crash of a Turkish Airlines Boeing 737-800 at Amsterdam Schiphol on 25 February. The accident killed nine of the 134 on board, including three pilots in the cockpit.
Central to the investigation is a radio-altimeter fault that caused the aircraft's autothrottle to enter retard mode at too high an altitude, reducing thrust to idle speed before the aircraft was in position for its final flare above the runway.
Pilots lost control of the aircraft after speeds decreased to 110kt (204km/h) at approximately 500ft (152m) above the ground due in part to the fault. The system is designed to automatically reduce thrust to idle when the aircraft enters its landing flare approximately 27ft (8m) above the ground.
Dutch investigators revealed on 29 April that several radio altimeter failures had occurred on the accident aircraft in its previous eight flights. EASA notes that "there are reports of further incidents attributed to the same cause".
In its 30 April alert, which references a flight operations technical bulletin published by Boeing, EASA says if one of an aircraft's two LRRAs provides erroneous altitude readings, the associated "flight deck effects" may typically include "inappropriate flight mode annunciation indication of autothrottle retard mode during approach phase with the airplane above 27ft above-ground-level."
The agency is recommending that flight crews, whether operating in automated or manual flight modes, "carefully monitor" primary flight instruments including airspeed and attitude, for aircraft performance and the flight mode annunciation for autoflight modes.
"When the autothrottle mode is selected during critical phases of flight, the pilot flying may consider to keep a hands-on position on the engine throttles to guard against and correct any abnormal behaviour," EASA continues, adding that, "Early intervention prevents unsatisfactory airplane performance or a degraded flight path.
http://www.aviationspace.blogspot.com
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