Summary of capacity performance
Bulgaria experienced an increase in traffic from 974k flights in 2023 with 55k minutes of en route ATFM delay, to 1 050k flights in 2024 with 102k minutes of en route ATFM delay. There were an additional 88k minutes of ATFM delay, originating in Bulgaria, that were re-attributed to DFS (30k) and HungaroControl (58k) via the NM post operations delay attribution process, according to the NMB agreement for eNM/S24 measures, to ameliorate capacity shortfalls in both Budapest and Karlsruhe ACCs.
NSA’s assessment of capacity performance
During 2024 the number of serviced aircraft increased, surpassing for the first time the level of 1 million flights. The reciprocal bans imposed on the use of EU airspace by Russian aircraft and on the use of Russian Federation airspace by European aircraft still stand. These actions lead to a significant extension of the flight time for some destinations (mainly from/to the Far East and the aggregate flow from/to Other ICAO regions in Asia) and to the shift of non-traditional traffic to the Bulgarian airspace. BULATSA carried out the necessary preparations in a timely manner and successfully dealt with the increased air traffic over Bulgaria by developing sector configurations to handle the traffic and providing the necessary number of air traffic controllers. The number of flights in Sofia FIR is1,050 thousand according to EUROCONTROL data, which is an increase of 8% compared to the previous year, where IFR flights account for 974 thousand.
The reported delay figure for Bulgaria in 2024 is 0.10 (0.0963 min/flight) due to weather (101,192 min) and other (war between Russia and Ukraine 1,091 min). The capacity target for 2024 is not met by 0.0163 min/flight but falls within deadband. Reasons for that were the ongoing increase of traffic significantly above planned levels (+15%) combined with increased level of complexity of operations in Sofia FIR due to traffic flows structure and growing volume of operations at all Istanbul airports given the increasing adverse weather impact.
Monitoring process for capacity performance
The monitoring of capacity performance is effected through regular monitoring of the minutes of delay generated, based on the information provided by NM. Monitoring is done on a monthly basis.
Capacity planning
Capacity planning is done on a network level as part of the capacity planning processes established by NM. Additionally, BULATSA has established internal capacity planning which is takes into account traffic forecast produced by STATFOR/NM, but is also based on the internally produced traffic forecasts, which take into account local specifics and updates where necessary.
The capacity planning process includes:
• HR availability and rostering, both in long term (new ATCO hiring and training), but also in the medium (seasonal) and short term (monthly). HR requirements are assessed and measures are taken to re-prioritize available resources during the busy periods.
• Medium and long term planning of capacity availability based on technological improvements, introduction of SESAR innovations, system upgrades.
• Airspace changes, sectorization and development of interfaces with adjacent FIRs.The issues and plans are regularly reviewed and reassessed in relation to current operational environment and forecasts, as well as to meet capacity profiles and sector configurations as per those in the NOP.
A Capacity Management Board is established internally that convenes once a month in order to discuss the latest information and trends. The Capacity Board includes a broad range of experts (technical, operational, financial and legal) in order to ensure that multidisciplinary approach to capacity is undertaken.
Application of Corrective Measures for Capacity (if applicable)
It is evident from the NM data that the difference between the target as per the PP and the actual values of the En-route ATFM delay per flight in 2024 is only due to weather delay (delay code W as per the ATFCM manual). The Bulgarian airspace is among the most complex airspace volumes in Europe.
Since the outbreak of the war netween Ukraine and Russia, significant traffic flows have shifted to the South-West to avoid the closed airspace volumes. Bulgaria also handled an increasing number of traffic to and from the busiest airport in Europe – the New Istanbul Airport.
As a result for the summer period of 2024 when the weather delays have been accumulated the traffic has increased more than 11% vs 2023 and around 20% vs 2019. The combined effect of the adverse weather conditions during the period April - September, the lack of capacity in the neighbouring FIRs and the constant GNSS jamming and spoofing in the region has enormously increased the complexity for the air traffic controllers and the pilots.
Some of the measures in the neighboring FIRs related to weather and capacity have caused diversion of additional traffic to Sofia FIR. This imposed the need for additional measures to ensure the safety of the operations and 0.10 minutes weather delay per flight was generated.
BG CAA noted also that the NM operated a strategic traffic-re-orientation programme (eNM/S24) during summer 2024, Therefore NMB agreed to protect ACCs affected by extra traffic and reassign ATFM delay to ANSPs causing the initial capacity problem.
NM with the approval of the NMB reassigned 87,686 minutes of the BULATSA ATFM weather delay to the originator ANSPs (DFS and Hungarocontrol) as the combined effect of the local adverse weather and the capacity issues of the mentioned airspace volumes have not provided for the safety of the operations.
BULATSA delivers its commitments in the NOP. The ANSP deals with the increasing complexity and the high traffic levels using flexible sectorization and sector saturation avoidance procedures, optimized and flexible human resources management in terms of existing ATCOs and recruitment of the new ones, and strict ATFM adverse weather procedure.
ATC is provided in a safe and efficient manner and with 0 delay due to ATC reasons. BULATSA has delivered what has been committed in the NOP. Adverse weather conditions and lack of capacity in other airspace volumes that affect the traffic flows are out of the ANSP’s control.
En route Capacity Incentive Scheme
BULATSA: The 2024 actual value for en route capacity (0.1 minutes/ flight) falls within the deadband:- therefore neither bonus nor malus is applicable.
****