|Date||26 September 1997|
|Summary||Controlled flight into terrain due to pilot error, ATC error, and GPWS malfunction|
|Site||Near Pancur Batu, Deli Serdang, North Sumatra, Indonesia |
|Aircraft type||Airbus A300B4-220|
|IATA flight No.||GA152|
|ICAO flight No.||GIA152|
|Call sign||Indonesia 152|
|Flight origin||Soekarno-Hatta Int'l Airport, Jakarta, Indonesia|
|Destination||Polonia Int'l Airport,|
Garuda Indonesia Flight 152 was a scheduled domestic Indonesian passenger flight from Soekarno-Hatta International Airport in Jakarta to Polonia International Airport in Medan, North Sumatra, operated by Garuda Indonesia using an Airbus A300B4 registered PK-GAI.
On 26 September 1997, during instrument approach to Polonia International Airport, flight 152 descended below its cleared altitude and crashed into mountainous woodlands 30 miles (48 km) from Medan. All 222 passengers and 12 crew were killed. The crash site was in a ravine near the village of Buah Nabar in the Sibolangit district south of Medan. With 234 fatalities, it is the deadliest aviation disaster in Indonesia's history.
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.
At 1:13 pm (local time), air traffic controllers in Medan cleared Flight 152 for an ILS approach into runway 05 from its 316 degree heading.(p3) 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,(p6) and First Officer Tata Zuwaldi (also 41), a former flight engineer who recently upgraded to pilot, was instructed to turn left heading 240 degrees to intercept the ILS localizer. 120 seconds prior to impact, the crew was asked to turn left further, to 215 degrees. At 1:30 pm, Medan instructed the crew to descend to 2000 feet, and to turn right heading 046 degrees to line up for arrival into runway 05,(p3-4) 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.[clarification needed] 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, 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.(p4) 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 over 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 ft, probably due to the captain inputting the wrong altitude.(p45) The pilots did not notice this while they were focused on turning to the correct heading.(p36) 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(p16) 27km from the runway 05 threshold, (p1) 18 km to the south of the center line.[failed verification] The aircraft hit the ground at 1:32 p.m.,(p4) right wing low, turning towards the airport in the process at a heading of 230-240 degrees(p17) and an altitude of 1,550 ft MSL.(p45) All 234 people on board died.(p4)
The passengers were mostly Indonesian, with six Japanese, four German, three Taiwanese, two American, two British, two Canadian, one Australian, one Belgian, one Dutch, one French, one Italian, one Malaysian, and one Swedish national.
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.
One of the passengers killed in the crash was businessman Yanto Tanoto, the president director of pulp and rayon company PT Inti Indorayon Utama Polar, and the younger brother of Sukanto Tanoto.
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.
The first lawsuit was filed by Nolan Law Group in Chicago, Illinois 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 Airlines, 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.
It is uncertain if any lawsuits made reference to the air traffic controller giving instructions and information to the wrong airplane, then leaving out some of that information when he finally repeated it to the crew of the accident plane.
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".
Garuda Indonesia now uses the flight number GA186 on this route, while GA152 is now used on the Jakarta - Batam route. The airline uses Boeing 737-800 aircraft for both routes.