Garuda Indonesia Flight 152

Garuda Indonesia Flight 152 (GA152/GIA152) was a scheduled domestic flight operated by Garuda Indonesia from Soekarno-Hatta International Airport, Tangerang, to Polonia International Airport, Medan, in Indonesia. On 26 September 1997, the aircraft flying the route crashed into mountainous woodlands near the village of Buah Nabar, Sibolangit, killing all 222 passengers and 12 crew members on board. It is the deadliest aviation disaster in Indonesia's history.

Aircraft
The aircraft was an Airbus A300B4 FFCC, or "forward-facing crew concept." The FFCC model is a modified version of the A300B4 in which the flight engineer station is eliminated, and the relevant controls are simplified and relocated to be positioned on the overhead panel between the two pilots. This control arrangement is similar to the Airbus A310 series, the difference being that the FFCC retains most of the analogue flight instrumentation of the original A300. The FFCC would later be developed into the A300-600 series, in which all elements of the flight deck are brought to A310 standards, including the addition of electronic flight instrumentation. The two pilots aboard the accident flight were qualified to fly both the FFCC and the -600 model, however the adequacy of their conversion training between the two would later be called into question.

The aircraft was delivered in 1982 and was powered by two Pratt & Whitney JT9D-59A turbofan engines and had flown over 27,000 hours (over 16,500 take-off and landing cycles) at the time of the accident.

Accident
At 1:13 pm (local time), air traffic controllers in Medan cleared Flight 152 for an ILS approach to Runway 5 from its 316 degree heading. The crew, led by Captain Hance Rachmo Wiyogo (41), a pilot with 19 years of flying experience at Garuda Indonesia and nearly 12,000 flying hours, and First Officer Tata Zuwaldi (also 41), a former flight engineer who recently upgraded to pilot, were instructed to turn left to a heading of 240 degrees so as to intercept the ILS localizer. Two minutes prior to impact, the crew was asked to turn further left, to 215 degrees. At 1:30 pm, Medan instructed the crew to descend to 2,000 ft, and to turn right heading 046 degrees to line up for arrival into runway 05, and asked the crew to report the direction in which the plane was traveling. Air traffic controllers then became confused as to which plane they were talking to, as another flight with the same number (Merpati Nusantara Airlines Flight 152) was also in the area at the time.

Earlier in the day, another Flight 152, Merpati Nusantara Airlines Flight 152, was handled by the same air traffic controller. This led to the controller mistakenly saying "Merpati one five two turn left heading 240 to intercept runway zero five from the right side"; as the wrong call sign was used, the Garuda pilots disregarded these instructions. The controller, on not receiving a response, queried the pilots to get their attention, this time using the correct call sign, "Indonesia 152". The controller then repeated most of his instructions, but specifically failing to repeat that the flight would be making its approach on the south side of the runway, or right side. The pilots believed they were flying the approach on the north side of the airport, which reflected the information on the approach chart the pilots were using. Thus, when the pilots were instructed to turn right to a heading of 046 maintaining 2,000 ft to capture the localizer for the ILS to runway 05, out of habit – or possibly due to the detailed approach chart – the captain initiated a left turn to a heading of 046. The First Officer was distracted during the turn and did not notice for a while that the aircraft was turning left. When he did notice, he told the captain he was turning the wrong way, and the captain questioned the controller over which way they needed to turn, to which the controller confirmed they were to turn right. A confusing conversation took place over which way to turn, with the controller not having a clear picture of what the flight was doing, due to being unaware that he had left out some critical instructions after his "Merpati 152" mistake and due to the Medan radar system having a refresh time of 12 seconds.

Without a constant up-to-date view of the flight's heading, the controller thought the plane was continuing left, when it was actually turning right and over high terrain. During this time the flight descended below 2,000 feet, probably due to the captain inputting the wrong altitude. The pilots did not notice this while they were focused on turning to the correct heading. Five seconds prior to initial impact with the treetops, the First Officer made a comment about the airplane's altitude. The FDR recorded increases in pitch and engine power, likely commanded by the crew in an effort to correct their altitude. Shortly before the recording ended, the cockpit voice recorder registered the sound of the plane striking trees, followed by shouting from the pilots. The aircraft crashed into a ravine 27 km from the runway 05 threshold,  18 km to the south of the center line. The aircraft hit the ground at 1:32 p.m., right wing low, turning towards the airport in the process at a heading of 230-240 degrees  and an altitude of 1,550 ft MSL. All 234 people on board died.

Victims
The passengers were mostly Indonesian, eight Turkish with six Japanese, four German, three Taiwanese, two American, two British, two Canadian, two Ghanaian, one Australian, one Belgian, one Dutch, one French, one Italian, one Malaysian, one Pakistani, one South African and one Swedish national.

Passenger remains
Forty-eight of the bodies recovered from the crash were never identified and were buried in a mass grave in a cemetery outside Medan's Polonia Airport, where 61 victims of the 1979 Garuda Fokker F28 crash were also buried. The remaining 186 bodies were identified and returned to their families for private burial.

Investigation
The causes of the crash, according to the official report of the National Transportation Safety Committee (NTSC), were:

"There was confusion regarding turning direction of left turn instead of right turn at critical position during radar vectoring that reduced the flight crew's vertical awareness while they were concentrating on the aircraft’s lateral changes. These caused the aircraft to continue descending below the assigned altitude of 2000 ft and hit treetops at 1550 ft above mean sea level."

The report also criticized the airline's conversion training for pilots who fly both the A300-600 and A300B4-FF models. The former is equipped with digital navigation displays, while the latter is equipped with analog equipment. Though both are sufficient for conducting instrument approaches, the captain may have been overwhelmed due to his lack of familiarity with the analog instrumentation.

Contributing to the accident was the failure of the Ground Proximity Warning System (GPWS) for undetermined reasons and the inadequate vectoring charts used by the controllers at Medan.

Lawsuits
The first lawsuit was filed on September 24, 1998, on behalf of American passengers Fritz and Djoeminah Baden. Additional lawsuits were filed in state and federal courts in Chicago related to 26 more victims. The sole defendant in the lawsuits was Sundstrand Corporation (later Hamilton Sundstrand), the manufacturer of the GPWS. The plaintiffs alleged that the GPWS was defectively designed, that the manufacturer was aware of its deficiencies in mountainous terrain for over a decade, and had the system worked as designed the accident could have been avoided. Sundstrand disputed these claims and did not accept responsibility. Nearly six years after the crash the lawsuit was settled out of court.

A suit against Garuda Indonesia, brought by Joyce Coyle in Oregon (Coyle v. P.T. Garuda Indonesia) was dismissed on the grounds that the US court had no jurisdiction to hear a case about domestic flights operated by a government-owned airline in another country.

Aftermath
Flights between Jakarta and Medan are now operated by flight numbers 118, 182, 184, 186, 188 and 190 (operating to Kualanamu International Airport as a successor for Polonia airport since 2013). As of January 2023, Garuda Indonesia continued to operate the flight number 152, now serving the route between Jakarta and Batam, using a Boeing 737-800.

Dramatization
The crash of Garuda Indonesia Flight 152 is featured in the fifth episode of the Season 17 of Mayday (Air Crash Investigation). The episode is titled "Lethal Turn".