Inex-Adria Aviopromet Flight 1308

Inex-Adria Aviopromet Flight 1308 was a charter flight, operated with a McDonnell Douglas MD-82, which brought Yugoslavian tourists to Corsica. On 1 December 1981, on its final approach, the plane crashed into Mont San Petru; all of the 180 passengers and crew died. The crash is the first, and the deadliest, major aviation accident involving an MD-80 model aircraft.

Background

Kompas, a travel agency based in Ljubljana, chartered a tourist flight to Ajaccio through Inex-Adria Aviopromet. On 22 October 1981, a request was sent by Inex-Adria to the General Directorate of Civil Aviation to authorize a charter flight, from Ljubljana to Ajaccio and back, on 1 December. On 16 November, the request was approved, with the flight being numbered JP-1308. Though Inex-Adria stated its intention to use a McDonnell Douglas DC-9, they instead flew an MD-82, as it was a newer and larger aircraft. Additionally, 43 more passengers were boarded than applied for, including Inex-Adria employees, Kompas tourists, and/or their families. There were seven crew members, meaning that there were 180 people on the flight.

Accident

Flight JP 1308 took off from Ljubljana Airport (then Brnik Airport) at 06:41, on a chartered flight from Slovenia (at the time Yugoslavia) to Corsica's capital city of Ajaccio with 173 Slovenian passengers and 7 crew members. At 07:08, with the aircraft in Italian airspace, the controller in Padua contacted a colleague in Ajaccio, and requested an actual weather report. A moderate wind 10 knots was blowing from the southwest (240°), and the sky was covered with separate clouds. When the flight crew learned of this, they decided to land on runway 03, while Kunović clarified that if the wind increased, they would fly around for inspection. At 07:28, the plane entered the zone of the control center in Rome, and the flight was cleared to descend to flight level FL 270 (27,000 ft. The flight crew asked whether or not they were cleared to descend. The controller told the crew that they were not cleared, and the crew acknowledged the transmission, thanking the controller.

At 07:31, the controller again cleared flight 1308 to descend to FL270, which the crew acknowledged, reporting that they were leaving FL330 (33,000 ft) and beginning to descend. The controller also clarified that the flight would be cleared to descend to FL190 (19,000 ft) after passing Elbe. The Cockpit Voice Recorder (CVR) recorded a sound similar to the activation of the "Fasten seat belt" sign; Kunović instructed Terglav to calculate the landing parameters. A flight attendant entered the cockpit and asked to reduce the temperature in the cabin, which the first officer did. At 07:33, the controller cleared Flight 1308 to descend to FL 190 at Bastia. After reviewing the calculations, the flight crew determined the approach speeds as 221. At some point, Terglav let his son enter the cockpit, as a child's voice was heard asking when the aircraft would descend.

At 07:35, the aircraft entered the air traffic control space in Marseille. At 07:35:50, the flight crew contacted control to report their descent to flight level (FL) 210, and that they planned to descend to FL 190 in the direction of Ajaccio. Permission was requested for a further reduction. In response, the flight crew was instructed to maintain FL 190 (19,000 ft) to Bastia, bypassing closed airspace, and to "squawk" 5200 on the aircraft's transponder. At 07:40:35, the flight crew reported that they were 50 mi from Ajaccio, and remained at FL 190. They again requested permission to descend, being cleared to descend to FL 110 (11,000 ft). Non-standard terminology—"cleared down 110"—was used, prompting discussion amongst the crew.

The flight crew reviewed the approach procedure for the Instrument Landing System (ILS) on runway 03. In this process, Terglav's son was heard twice, speaking about observing a mountain similar to Servin; according to the investigation, it was of the Monte Cinto array. Focusing on the elevation of the airport, 52 ft, the crew set the decision height to 643 ft.

At 07:43:57, Kunović reported being 28 mi on VOR Ajaccio, and being at FL 110. At 07:47:10, he contacted the Ajaccio approach controller for the first time, saying, "Bonjour, Ajaccio, Adria JP 1308. We're level 110, approaching Ajaccio VOR, and further descent." The approach controller told the flight crew they would be landing on runway 21, instructed them to keep on the VOR Ajaccio, and informed them of the weather: atmospheric pressure (QNH) 1009, airfield pressure (QFE) 1008, wind 280° at 20 knots.

At 07:49:31, the flight crew told the approach controller, "Just now, Ajaccio VOR, level is 110, in holding pattern." At 07:49:36, the approach controller responded, "Report leaving Alpha Juliet Oscar on radial 247 for final approach". At 07:49:04, Kunović said, "Okay, sir. We're just over Ajaccio VOR, and we're requesting further descent." The approach controller appeared to believe that the flight crew would skip the holding pattern and proceed to a direct approach on radial 247 from AJO VOR, as done by many pilots making the same approach, while Kunović, who had never flown to Ajaccio, entered a holding pattern over AJO VOR. The Jeppesen map showed a holding pattern with an airspeed of 150 kn, while the aircraft's IAS was around 230 - 250 kn, which dramatically increased the radius of the holding pattern.

Believing that the aircraft was flying on radial 247 outbound from AJO VOR, at 07:49:52, the approach controller approved a descent to 3,000 ft, QNH 1009, on the radial 247. QNH 1009 was a redundant piece of information which increased the mental load of the crew. A more critical issue was that the aircraft was not on radial 247 out from AJO VOR, as the approach controller believed, but in AJO VOR holding pattern with minimum holding altitude (MHA) of 6,800 ft. By approving a descent to 3,000 ft the approach controller precipitated the crash. The flight crew contributed by failing to understand that they were to on AJO VOR radial 247, not remain in a holding pattern, and that their holding pattern's MHA was 6,800 ft.

At 07:50:05, Kunović responded, "Roger, will do, and we're leaving 11 for 3000, radial 247 out of one one zero QNH, repeat again, one zero zero nine." This created further confusion, as he used the vague term radial 247, reinforcing the approach controller's belief that the flight crew were skipping the holding pattern, and gave the wrong QNH. At 07:50:19, he told the approach controller, "We're in holding over Ajaccio. Call you inbound on radial 247." At 07:50:28, the approach controller responded with a simple, "Roger," not realizing that the flight crew weren't following instructions. At 07:52:15, Kunović radioed, "We're rolling inbound, out of 6000." and the approach controller responded with, "Roger, 1308. Report turning inbound." Kunović meant that the plane was turning left in the holding pattern towards AJO VOR, but the approach controller thought he meant that the aircraft was turning towards the airport over the sea.

The last transmission from JP 1308 was received at 07:52:25, when Kunović reported, "Turning inbound to Ajaccio because at the moment, we're in cloud." At 07:52:30, the approach controller, still believing that JP 1308 was turning inbound to Ajaccio Airport and entering its final approach, responded "Roger 1308, report Charlie Tango on final, surface wind 280°/20kts." From 07:52:43, turbulent flows were recorded on the FDR, as the aircraft was flying above mountain peaks of 1,000 - 2,500 ft. The flight crew were surprised by the mention of CT NDB by the approach controller.

At 07:53:08, an alarm was triggered by the aircraft's ground proximity warning system. Surprised, the flight crew did not execute evasive manoeuvres until 07:53:17. At 07:53:20, the left wing struck a barren surface near the top of Mont San-Pietro, shearing off 8.5 m. Transmitting four seconds of whistling to the approach controller, the aircraft rolled upside down, entered an uncontrolled dive, and crashed into the gorge on the other side of the mountain, killing everyone aboard. The time of the accident was 7:53 a.m. (07:53 UTC).