Flight Inspection is responsible for monitoring the proper operation of ground-based navigation aids from the air, in accordance with recommendations of the ICAO and regulations issued by the Polish authorities (appropriate Ministry and Polish Civil Aviation Office) and for monitoring conventional and RNAV flight procedures.
Carrying out land-based surveillance of the ground based equipment operation does not guarantee, that radio or light signals received by equipment onboard aircraft and by crew are correct and fall within the requested tolerances. Therefore, it is necessary to check the signals in the air space where they are used.
Flight Inspection has existed since 1963, being successively with the LOT Polish Airlines, Air Traffic and Airdromes Directorate and “Polish Airports” State Enterprise. Today Flight Inspection operates within Polish Air Navigation Services Agency.
About 80 % of Inspection tasks is checking the radio and light navigation aids from the air. In vast majority radio navigation aids are owned by PANSA. Light systems are owned by airports. About 150 light and radio navigation devices operate currently in Poland. Inspection carries out commissioning, periodic and special checks, and categorizing checks for ILS systems. Within the framework of these controls, the following equipment is checked:Instrument Landing System(ILS). Non-directional Beacon (NDB), Omni-directional Radio Range (VOR and DVOR), Distance Measuring Equipment (DME), light navigation aids (approach lights systems and runways light systems), Precision Approach Path Indicators (PAPI) and radars used in air traffic control. Flight procedures are also checked - newly designed and existing – conventional and area navigation (RNAV) based on DME-DME sensors and satellite navigation systems (GNSS). In the near future procedures for flight inspection of radio frequencies that are used in aviation communication will be implemented.
In order to fulfill above missions, Polish Flight Inspection flies two L-410 UVP-E 15 Turbolet aircraft (SP-TPA and SP-TPB) equipped with sophisticated measuring devices. The airplanes are well known in Polish aviation community as "Papuga" - "The Parrot". This nickname dates from tail painted in characteristic color strips. Formerly, bright colors of flight inspection aircraft, facilitated their observation by the theodolite operator, which was in recent years the base of reference. Currently, the core of the reference system are satellite systems, supported by ground reference stations (PDGPS) used during the inspection of the ILS systems for Category II and III. With the currently used systems, the accuracy of determining the position of the flight inspection plane is determined with an accuracy of 1 meter, and using ground reference stations, even the accuracy of a few centimeters.
Both aircraft are equipped with flight inspection systems manufactured and installed by the German company Aerdodata, a world leader in the design and manufacture of this kind of equipment. Systems allow to conduct a comprehensive analysis of the operation of navigation equipment or correctness of airline procedures. Measuring devices equipped with specialized software allows collecting and recording of complex navigation signals on board of the aircraft, in real time. These navigation signals are selected on a number of components and subjected to a thorough analysis in relation to the actual position determined by the reference system. In radio navigation devices mainly the accuracy of equipment is checked, as well as related derivatives and range of operation. If any false readings or deviations from the nominal parameters beyond acceptable tolerances are found, flight inspectors, by radio, subcontract ground operating services to make some adjustments on inspected devices. When adjustments are not able to compensate for abnormal signal parameters, operating range of the device is being limited (eg. by designating the sectors in which the signal is useless for navigational purposes) or ground-based device is excluded from the operational work. Following the adjustment or repair and measurements carried out on the ground, Flight Inspection shall inspect again from the air. If all parameters are normal, device is restored to operational work, and a protocol with the inspection results is issued as a confirmation.
The records of all inspected parameters of the inspected facilities, charts and the analysis of the results are then stored. It allows to make a comparison of the parameters during the further controls over time, taking into account the impact of even such factors as the location of new natural obstacles or the process of wearing of antenna systems exposed to adverse weather conditions.
All types of approach lights (constant or flashing lights) and runway lights (threshold, edges, touchdown zone, the central line and the end of the runway) are also subject to the air monitoring. Any irregularity of light signal, such as improper angular adjustment in horizontal and vertical planes, lack of a light filter, damaged housing or an inoperative light source, is observed by the flight inspector, recorded photographically and stored as a supplement to the written findings. The control of intensity of the different groups of lights is also checked. The correctness of informing the flight crew about their position relative to the runway is the most important parameter of visual navigation systems, that are monitored from the air.