Iranian investigators believe failure to switch an Iran Air ATR 72-600’s avionics to follow a new approach resulted in the aircraft’s landing on the wrong runway following a service to Tabriz.

The aircraft, arriving from Baku as IR779 on 10 February, had been conducting an approach with clearance for runway 30L.

But the aircraft instead landed on the parallel runway 30R, says the Iranian Civil Aviation Organisation.

The ATR (EP-ITM) had descended to 17,000ft and been told to expect the ILS1 arrival pattern to 30R.

Its crew requested information on the runway condition and, based on the better braking data, sought instead the ILS2 approach to 30L.

But the inquiry states that the crew failed to configure the avionics to follow the switched approach path.

Despite the subsequent air-ground communications confirming the 30L approach, the ATR ultimately landed on 30R. The two runways are separated by less than 190m.

The inquiry says that the 30R runway lights were turned off at the time, to assist the crew, although cockpit-voice recorder information confirms the crew observed precision-approach path indicator lamps. The lamps are located between the two runways.

While the first officer sought to go around, owing to the runway lights being off, the aircraft proceeded to land. “Lack of effective communication between the two pilots is evident,” the inquiry states.