As the conclusion of the technical investigation the IC issues the following safety recommendations:

BA2010-004-4P-1: As based on the ATS Manual the TPC may have permitted the runway crossing without the ADC switching on the runway occupancy indicator. After the serious incident, on 30 January 2010 HungaroControl Zrt. took the measures listed in paragraph BAÜ2010-004-4P-1. The IC has acknowledged these measures. Besides,

the IC recommends HungaroControl Zrt. to incorporate the bulletin issued on 30 January 2010 into the work procedures of the air traffic controllers.

The IC expects as a consequence of the measure that air traffic control will apply the runway occupancy indicator appropriately, and the occurrences similar to the one investigated will be avoidable. Further, the measures taken by HungaroControl Zrt. will become a documented part of the ATC work procedures.

BA2010-004-4P-2: The ADC permitted the snow clearing convoy indirectly, through the TPC, to cross the runway, thus ADC lost the possibility of direct control.

The IC recommends HungaroControl Zrt. to modify the ADC work procedures in such a way that the crossbar lights at the runway holding position be operated by the ADC when vehicles carry out work on the runway.

The IC expects as a consequence of the measure that from now on the ADC will dispose of a direct tool for granting clearance to the ground traffic relating to the runway which might prevent the unjustified usage of the runway in case of communication failure between the ADC and the TPC.

BA2010-004-4P-3: The concerned vehicles were clearly discernible on the ground radar during the time of the occurrence, but the use of the ground radar was not obligatory.

The IC recommends HungaroControl Zrt. to determine an objective visibility value in the work procedures below which the ADC shall use primarily the ground radar to check runway occupancy.

The IC expects as a consequence of the measure that in case of reduced visibility the controllers will use the ground radar without subjective judgement, in a standard and efficient way.

BA2010-004-4P-4: During the occurrence the term “crossing the runway” was not interpreted unanimously by the air traffic services and the personnel of the ground vehicles.

The IC recommends Budapest Airport Zrt. and HungaroControl Zrt. to apply a standard radio communication procedure according to which all vehicles that cross the runway in a straight line and at the shortest possible path shall request “crossing the runway” and all other vehicles shall request and be granted permission to “use the runway”.

The IC expects as a consequence of the measure that the clearances relative to the use of the runway and their execution will become unambiguous and clear to follow.

BA2010-004-4P-5: The 3D tower simulator of HungaroControl displays data differing from the real life data regarding the movement of the snow clearing convoy and it does not represent the effect of the pillars obstructing the view, thus it depicts a false image.

The IC recommends HungaroControl Zrt. to have the tower simulator simulate the movement of the snow clearing convoy and the pillars belonging to the structure of the control tower true to life. If this is not possible the control personnel shall be informed about the difference.

The IC expects as a consequence of the measure that during the training and renew training the air traffic controllers will acquire working methods more in line with reality.

BA2010-004-4P-6: During the technical investigation of the occurrence it was not possible to analyze the communication between ADC and TPC and between ADC and SV because they were conducted via unrecorded channels.

The IC recommends HungaroControl Zrt. to install in the tower an equipment capable of recording the voice communication in the tower.
The IC expects as a consequence of the measure that the communication between the workstations of the tower becomes analyzable, which may contribute to the development of safer work procedures.

BA2010-004-4P-7: During the technical investigation it was revealed that the lack of harmonization regarding the subprojects in connection with the instalment of the ground radar and the relevant different equipment, like the secondary surveillance radar transponders in the vehicles, led to numerous misunderstandings and the reduction of efficiency.

The IC recommends HungaroControl Zrt. and Budapest Airport Zrt. to coordinate the projects relevant to the ground radar and to the connecting equipment and to inform its personnel carrying out the operative tasks about the actual conditions.

The IC expects as a consequence of the measure that harmonization throughout the works related to installing the equipment seriously influencing flight safety will accelerate the process of instalment and proper information exchange will contribute to efficient and safe operation.

BA2010-004-4P-8: The notification system applied by HungaroControl Zrt. in connection with the case was not functioning well, hence TSB was only informed about the serious incident later by the inquiry of the Swiss investigative body who had been sent a report by the cockpit crew.

The IC recommends HungaroControl Zrt. and NTA AD to review and, if necessary, to modify the notification system and its efficiency with special attention to assuring that the occurrences which are obligatory to be reported shall be forwarded without delay to the organizations concerned.

The IC expects as a consequence of the measure that in line with the legislative background all occurrences which are obligatory to be reported will be reported and recorded promptly in the future.