Sunday, September 10, 2006



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
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
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...

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