If the aircraft is subsequently under control and there is no imminent danger to aircraft then the Emergency may be downgraded eg. " AI-424, cancel Mayday, fire under control, maintaining FL 160, request priority landing,"
Treat all cases of fire or smoke, which have subsequently gone out, as serious and proceed accordingly, however do not forget to carry out all procedures so that a safe landing can be made successfully.
ENGINE FAILURE / REJECTED TAKE OFF
In spite of the equipment reliability, every pilot must be prepared to make the correct Go/Stop decision on every take off. The crew must differentiate between situations that are detrimental to a safe take off, and those that are not. As speed approaches V1, the successful completion of a reject T/O, becomes increasingly critical. One common and misleading way to think of 'V1 is to say that V1 is the decision speed'. This is misleading because V1 is not the speed to begin making the operational GO/STOP decision. The decision must have been made and the reject initiated latest by V1. If a reject is initiated at a speed higher than V1 and if the aircraft is at a Field length limit weight , an overrun is inevitable. A reject after passing V1 should only be attempted if a pilot has reason to conclude that the aircraft will be unsafe or unable to fly. The time given for recognizing an engine failure is one second, hence VEF is prior to V1. V1 is therefore, at least one second after the engine failure (VEF). During this period the aircraft continues to accelerate. At heavy weights near V1 the aircraft is typically moving at 200 to 300 feet per second i.e. accelerating at the rate of 3 to 6 Kts. per second. This means a delay of a second or two in initiating the reject would result in an overrun. Full stopping capability must be used till the aircraft comes to a complete STOP.
The Runway surface can affect both the acceleration and the deceleration capability. Applicable Runway corrections, e.g. Wet / Contaminated, etc. must be applied. Avoid take off at high Brake temperatures. T/O performance is adversely affected with an inoperative Anti-skid system. A tire burst may be loud enough to be confused with an engine compressor stall (Engine instruments normal ).
A tire failure may not be felt at all, may cause the aircraft to pull to one side (i.e : Engine instruments normal ) or cause the aircraft to shake and shudder to the extent that the instruments are difficult to read. Leaving the gear down in case of a suspected tire failure with all engines working will( may ) not adversely affect performance.
The chances of an overrun during a reject initiated because of a tire problem are increased due to loss of braking and (the chance that) additional tires may fail during the stop attempt. Hence it is generally better to continue the take off in case of a tire problem and land back, more so, because the entire length of the runway will be available for stopping, instead of just about 40% that would be available in case of a reject. Unless debris from the tyre has caused serious Engine anomalies it is far better to get airborne. Land with full runway length. 中國航空網 m.k6050.com 航空翻譯 www.aviation.cn 本文鏈接地址：Airbus ABNORMAL/EMERGENCY PROCEDURES 空客非正常/緊急程序(4)
