RESEARCH OF THE A380 AIRCRAFT VORTEX WAKE IMPACT ON MS-21 CLASS AIRCRAFT

Abstract

The paper is devoted to the problem of safe flight in vortex hazard conditions. A vortex wake is always produced behind flying aircraft. This vortex wake is invisible to other aircraft following it. Therefore, getting into a vortex wake from a preceding aircraft often becomes unexpected and quite often leads to flight incidents. This is confirmed by the statistics of flight accidents. With the introduction of aircraft weighing more than 500 tons, the problem of vortex safety has only sharpened. The fact is that the old standards that define safe intervals between flying aircraft are still active. These standards are given in this paper. It is also shown that even if these standards are observed, the flight of a medium-class aircraft at the same level as a heavy-class aircraft is unsafe. To study the effect of the vortex wake from the preceding aircraft, a special computational software complex based on the discrete vortex method was developed. This complex has passed the necessary testing and state registration. A number of measures were carried out to validate and verify the developed complex, confirming the operability of the programs included in it and the reliability of the results obtained. On the basis of this computational and software complex studies on the effect of the  A380 aircraft vortex wake on MS-21 class aircraft were performed. The studies were undertaken for various altitudes and speeds of the A380 aircraft and for its various flight configurations. As a criterion for the MS-21 aircraft safe flight, the roll moment that occurs due to falling into the vortex wave, in particular, its coefficient was chosen. If the coefficient of the MS-21 aircraft roll moment when it hits the vortex wake exceeds that from the ailerons, such a flight is considered dangerous. The distances behind the A380 that are unsafe for the MS-21 aircraft flight are given.