Flight Inspection

BULATSA performs strict, periodic airworthiness control of the serviceability of the Communication, Navigation and Surveillance (CNS) systems. Such specialized inspections have been conducted for more than 50 years since the introduction of the first radio navigation equipment used on the territory of the Republic of Bulgaria.

The signals emitted by the radio aids are checked from the air, using a specialized laboratory equipped with an automated flight inspection system. The system consists of on-board equipment, a positioning ground station and a telemetry data transmission unit.

The periodic flight inspections are carried out according to an annual schedule approved by CAA. In addition, BULATSA carries out specialized flight inspections to check the operational suitability of aids and CNS systems after modernization, commissioning, repair, or after operational reports which require an inspection. The following systems and facilities are subject to Flight Inspections (FI):

• Instrument Landing System (ILS) – (CAT I, II & III);
• ILS markers (MKR);
• VHF Omni Directional Radio Range (VOR)-CVOR/DVOR;
• Tactical Air Navigation (TACAN);
• Distance Measuring Equipment (DME);
• Non-Directional Beacon (NDB);
• VHF, UHF Communication;
• VHF Direction Finding (VDF);
• UHF Direction Finding (UDF);
• Primary and Secondary Surveillance Radar (PSR & SSR MODE A/C/S);
• Precision Approach Radar (PAR);
• Visual Approach Position Indicator (PAPI, VASI);
• Area Navigation (RNAV, RNP) based on GNSS and RNS;
• Flying standard instrument flight procedures (SID and STAR).

The periodic (annual) schedule includes the implementation of a flight inspection at the following locations: