29 Aralık 2007 Cumartesi


This summer flights to Istanbul and Antalya had delays of around one hour. My sister's airplane had to wait one hour at London Heathrow airport the motors working. Luckily, EUROCONTROL's air traffic flow management center at Brussels keeps airplanes on the ground till there is a window of safe opportunity in the traffic.

What went wrong and why does the Turkish air traffic system can not handle heavy traffic loads? Is it safe to fly to Turkey during the heavy season, namely the June, July, August and the new year, Christmas season?
Is it safe?

The answers to these questions may be found in the EUROCONTROL Experimental Center's Report No: 396. "In 2003 the Turkish ANS Service Provider DHMI (Devlet Hava Meydanlari Isletmesi) requested assistance from EUROCONTROL for a series of simulations to analyse the current ATC sectorisation and routeing schemes within the Turkish airspace against forecast traffic growth until 2015 and propose a new sectorisation plan suitable to existing and planned route network". "The simulation study has to provide a “survival plan” for the existing system until SMART becomes operational, and to provide a revised
sectorisation plan for the new system up to the year 2015". SMART is DHMI's new project which is supposed to replace the current ATC system left from 1980's.

The SMART project bidding was won by the INDRA company last year. But the project was cancelled on the ground that although THOMSON had offered some 30 million Euros more they had also offered a more sophisticated technical system. DHMI cancelled the bidding and made an other this year, around
January... This time only two companies entered the bidding process. The bidding was cancelled once more when one of these companies withdrew... No reason was given...

It is impossible to tell every detail of EEC Report 396 here... You can find it on both EUROCONTROL and DHMI sites or you may request it from me.

The pith of the issue is, EEC report 396 states clearly that the Turkish ATC system, specially Istanbul and Antalya may not be able to respond healtily to the Air Traffic beginning with 2005 - 2010... You can see
careful and restrained warnings, such as "Additional sectorisation capability should be made as dynamic as possible to relieve temporary overload".

During this simulation there has been conflicts between the Turkish side and possibly members of the EUROCONTROL simulation theme because:

". Despite the fact that members of the working group have accepted restrictions only with a certain degree of hesitation it must be said that their application lead to the fact that no High or Upp sector is faced with serious problems. Contrary to this are the Ist-Mid-West and the Ank-South-Low sectors which show the highest loadings for this exercise. In Europe, strategic restriction of flight operation is in general use. The safe and orderly handling of the high number of flights could not be possible otherwise. Turkey has a tradition of offering, as far as possible, an unrestricted flight path to the operators. In the future however, in order to cope with the increased traffic demand and to provide a safe service, it will be necessary to consider restrictions with regard to flight levels, routes and times more regularly".

"As traffic grows yearly, solutions will be found gradually and constraints applied if and when necessary. The working group is convinced that useful and intelligent solutions will be tested and applied to assure the safe
and efficient control of the increasing traffic and refrain from making specific suggestions in this area".

". saturation of the Istanbul sectors depend to a large extent on the traffic in and outbound Istanbul. Since no restrictions apply, a flight entering at high level will penetrate all existing sectors during its descent. Departing flights climbing to a high level will also penetrate all sectors. With strategic restrictions the number of flights per sector and hour can be reduced".

The reporter TEWES declares the simulation target as impossible to achieve by:
"Despite that all these results are theoretical ones, they gave good indications and hints to the working group where to start to search for improvements, especially having in mind the traffic forecast for the year
2015. It was evident that the sector plan developed for the 2005 scenario was not able to cope with the traffic demand forecast for 2010."

There certainly are more to say about the report but I will suffice by making a few comparisons with a similar report of a simulation done for Bulgaria...

1-Bulgarians used both military and civil data in their simulations.
2-Bulgarians used only August data where as Turkish data is dispersed two different times of the year.
3-Bulgarian report indicates the names of the Bulgarian ATC personnel.
The Turkish reports do not indicate any individual who would take conciencious responsibility.
4-Signs by comparison indicate that the DHMI system has discrepencies in Planning Controller and Radar Controller functionalities.
5-Signs by comparison indicate that the DHMI system is a system left from 1980's which does not have automatic strip printing.

By the way, strips are the last resort of air traffic controllers when the radar picture is lost...

Safety is a feeling at the personal level. I fully understand that you choose or not to fly over Istanbul under these conditions at specific times...

But, safety has also a technically established universal definition that is assigned to a meaning. No air traffic controller should claim his skill to be over his vigilance...

Note: Any specific question is wellcome. I have a very detailed analysis of this report and what may have gone wrong there.