On November 16, 2006, Far Eastern Air Transport (FEA) Flight EF306, a Boeing 757 type aircraft with registration number B-27015, was on a scheduled passenger flight from Taipei Tao Yuan International Airport to Jeju International Airport, Korea. There were 2 flight crew, 6 cabin crew and 129 passengers on board.

On the way to the destination, during a descent to FL 310 from FL390 following the instruction of the Incheon area control center (Incheon ACC), a Traffic Advisory (TA) warning of Traffic Alert and Collision Avoidance System (TCAS) was issued while passing FL340. At that time, Incheon ACC requested EF 306 the leveling at FL340 traffic, and FL TG659 changed heading to 270. While EF306 passing FL 338, TCAS RA ‘DESCEND’ warning appeared, EF306 flight crew followed the instruction and manipulated the aircraft to descend for an avoidance maneuver. During the avoidance maneuver, the maximum negative g experienced was –1.06g and then reversed to +2.48g before level off at FL310. EF306 requested for an emergency landing, 4 passengers were seriously injured, 10 passengers and 6 cabin crew sustained minor injury, with the interior of the aircraft sustained minor damage. TG659 on board occupants sustained no injury and the aircraft sustained no damage.

During the eight months factual data collection period, the investigation team invited Korea ARAIB together with R.O.C. CAA and operator representatives to attend the organization meeting and factual verification meeting. On 2007/07/02, the investigation team went to Bangkok for Thai Airways flight crew interviewing and TCAS equipment testing.

All factual data had been verified by the investigation team members on 2007/07/11, comments from the U.S. team have also been reviewed .The factual report contains factual information only without analysis or conclusions.

The analysis process will be commenced by the ASC immediately after the release of the factual data report. It is expected that the final report will be finished at the end of this year and reviewed by the board members of Aviation Safety Council before its official publication in the beginning of 2008.

To achieve the common goal of prevention and the purpose of being not to portion blame or liability, the ARAIB & ASC investigation agencies fully cooperated with each other under the ICAO Annex 13 practices, and shared all information in an open manner. It is our belief that this collaborative relationship will also be continued in the future .

The whole factual report can be downloaded at the ASC web site (http://www.asc.gov.tw).

More information can be requested from
Aviation Safety Investigator
Tracy Jen
886-02-89127388-E310
Tracy@asc.gov.tw

Attachment:
Summary of Factual Data Report

• According to the records provided by FEA, the pilots’ physical conditions and training records were normal
• ASC received the SSFDR readout data of the TG659 from Thai Airways. During the activation of TCAS UP Advisory mode, “TCAS Advisory Alt Rate” recording was 1,500 ft/min, and “Vertical Speed” increased from 64 ft/min to 1,648 ft/min. The altitude increased 126 ft (in 11 seconds); vertical acceleration readout between +1.0 g’s and +1.24 g’s.
• According to the EF306 FDR:
  • “TA” activated at 02:06:48, at altitude of 34,052 ft.
  • TCAS “RA – Descend” activated between 02:07:01 ~ 02:07:18; “TCAS Advised Alt Rate” recording was 1,500 ft/min; altitude loss of 2,112 ft (in 18 seconds); airspeed increased 30 knots.
  • Pitch angle readout from nose up of 4.4 to nose down of 17.8 degrees (02:07:01 ~ 02:07:07);
  • The descend rate was increasing from 336 ft/min to 12,096 ft/min (02:07:01~02:07:08);
  • The descend rate decreased from 11,760 ft/min to 2,064 ft/min (02:07:09~02:07:18);
  • The vertical acceleration readout from +1.0 g to -1.06 g’s and then +2.48 g’s (02:07:01~02:07:08)
• At the time of occurrence, two controllers were working at the Incheon South Sector. According to the transcripts of ACC communication, the radar system data, EF306 and TG659 CVR and FDR recorders, SSRC instructed EF306 descend to FL 310 at 02:02:53, with the distance between EF306 and TG659 being about 70 NM. At 02:06:55.9, SSRC instructed EF306 stop immediately and then clear descend. At that time, the distance between the two airplanes was about 13 NM. At 02:06:55.9, SSRC instructed TG659 to turn right heading 270 immediately, while the distance between the two airplanes was about 12 NM. According to the radar system data of Incheon ACC, at 02:07:03 (RA), the distance between two airplanes was about 8.3 NM. At 02:07:40, while the distance between two airplanes was about 1.17 NM, the altitude difference of the two aircrafts was 2,700 feet.
• The TCAS test results of EF306 and TG659 indicated that both complied with the maintenance manual specification.
• According to the cabin crew interview records, several passengers were injured due to unfastening their seat belts.
• During taxiing in after landing, at 02:29:08, the purser told the total number of injured passengers to cockpit crew and recommended more ambulances.
• The airport category of rescue and fire fighting in Jeju Airport was 9 according to Airport Operations Manual Para 3.3. There were 1 ambulance, 9 chemical Fire Fighting Trucks in Jeju Airport; and there were one driver, one nurse and one doctor on every ambulance.