Exactly 47 years ago today, on October 30, 1975, Inex-Adria Aviopromet Flight 450 crashed while landing in Prague. Of the 120 passengers and crew, 75 people died.

The aircraft involved in the accident was a four-year-old McDonnell Douglas DC-9-32 registered YU-AJO. In charge of the flight was 40-year-old Captain Miodrag Marović, assisted by 49-year-old First Officer Rade Popov.

Czech tourists were returning home after an Adriatic vacation

Inex-Adria Aviopromet Flight 450 was a charter flight carrying home Czech tourists who had been vacationing on the Adriatic Sea. The flight took off in the morning from Tivat Airport (TIV) in Montenegro for the one-hour thirty-minute flight to what is now Václav Havel Airport (PRG), Prague, in the Czech Republic

Image: GCmaps

As they crossed into Czechoslovakia airspace, local Air Traffic Control (ATC) took over the aircraft at 09:01. After identifying itself, the pilots asked for a weather report and were told that visibility in Prague was 5,000 feet. ATC then informed the pilots that the instrument landing system (ILS) for Runway 24 and the precision approach radar (PAR) were inoperative.

The pilot asked – “I understand, but what do we do now?” ATC responded – “You can continue to Prague or divert to another airport.”

“Please wait” – the pilot replied.

After a brief pause, the pilot said: “So the RVR of 1,100 meters and the ILS and approach lights out of service?”

ATC responded, saying: “The ILS is out of order. The approach lights and the runway lights are working. There are also beacons (NDBs) in operation.”

Based on the information, the crew decided to proceed with the landing.

As the plane was approaching the PG NDB (beacon) at an altitude of 5,000 from the southeast, ATC instructed the pilots to continue to the beacon and then make a standard approach for a landing on what is now Runway 24.

The pilots failed to turn when they were supposed to

After being cleared to descend to 1,800 feet, the pilots entered a published landing procedure. However, as the plane passed over the village of Vodochody, they missed making a right turn. Now after making a wider-than-normal turn, the pilots started their final approach for a landing on Runway 24.

Having deviated from the flight path, the plane descended into a gorge above the Vltava River, which was much lower than the height at which the airport was located. Now having to climb, the plane struck some trees 299 feet below the airport’s elevation and crashed into a residential neighborhood killing 75 of the 120 passengers and crew.

Speculation as to why the plane crashed

Because Czechoslovakia was still a communist state at the time of the accident, there are no publicly available investigation reports. What is known about the crash, however, is the following:

• The plane was 0.7 miles to the left of the published glide path
• The airport’s ILS and PAR systems were not working
• The visibility at the time was poor

A theory many people had was that the pilots mistook a lighted railway track and road for the airport. According to Czechoslovakian civil pilot and air accident expert Ladislav Keller, the pilot’s setting of the radio compasses indicated that the crew did not prepare well for landing. They would have stopped the descent if they had been monitoring their instruments correctly.

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