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Last updated: 18 September 2019
Status:Final
Date:Monday 9 April 2018
Time:21:33
Type:Silhouette image of generic B739 model; specific model in this crash may look slightly different
Boeing 737-9B5
Operator:Korean Air
Registration: HL7725
C/n / msn: 29999/1512
First flight: 2004-05-18 (13 years 11 months)
Total airframe hrs:30740
Engines: 2 CFMI CFM56-7B24
Crew:Fatalities: 0 / Occupants: 8
Passengers:Fatalities: 0 / Occupants: 91
Total:Fatalities: 0 / Occupants: 99
Aircraft damage: Substantial
Aircraft fate: Repaired
Location:Osaka-Kansai International Airport (KIX) (   Japan)
Phase: Landing (LDG)
Nature:International Scheduled Passenger
Departure airport:Jeju (Cheju) International Airport (CJU/RKPC), South Korea
Destination airport:Osaka-Kansai International Airport (KIX/RJBB), Japan
Flightnumber:KE733
Narrative:
Korean Air Lines' flight 733, a Boeing 737-9B5, suffered a tail strike accident on runway 06L at Osaka-Kansai Airport, Japan, when the flight crew were commencing a go-around due to bouncing. The plane landed safely at the second approach 15 minutes later. No personal injuries were reported.
The aircraft departed Jeju, South Korea at 20:24 hours with the captain as Pilot Flying on the leg to Osaka-Kansai. The landing briefing commenced at around 20:59 prior to the descent did not include information regarding a tailwind at the time of the landing.
As the aircraft had commenced the ILS approach to runway 06L, the controller reported wind from 030° at 3 kt. Both the autopilot and the auto-throttle of the aircraft were disengaged at around a radio altitude of 1,200 ft. In addition, the aircraft continued a stabilized approach. The captain, who was assuming that a landing would be made with a tailwind component, planned to put the thrust levers to their idle position earlier than usual when performing a flare in order to prevent that a touchdown would be long down on the runway.
At around 21:32:54, the captain moved the thrust levers to their idle position along with initiating the flare at 2° pitch angle at a radio altitude of about 30 ft. Although the captain tried to continue raising the nose and to reduce the rate of descent, the timing of such maneuvers was slightly delayed. Reducing the rate of descent was infeasible because the thrust levers had already been set to their idle position. The captain tried to reduce the rate of descent of the aircraft by pulling the control column further.
The first officer, who felt the rate of descent was large, pulled the control column to reduce the rate of descent without making any call-out. Having noticed the operation of the FO, the captain kept the control column so as to follow the FO's operation.
At around 21:32:57, the right main landing gear of the aircraft touched down at pitch angle of about 3.5°, and all spoilers began to deploy when the auto speed brake was activated.
Subsequently, after the left main landing gear had touched down, the aircraft bounced. The maximum vertical acceleration recorded in the FDR during this period was 1.87 G.
The captain, who was unable to predict the degree of the bounce and assumed that the impact accompanied by the touchdown after the bounce would be hard, executed a go-around maneuver. The pitch angle of the aircraft immediately before executing the go-around was about 5°. The aircraft started climbing positively at about 10° pitch angle after its both main landing gears touched down again approximately one second after it had executed the go-around.
The aircraft landed on runway 06L conducting the ILS approach again after flying in accordance with the missed approach procedure.
Both the flight crew members did not recognize that the aircraft had struck the runway until the scratch marks were found on the lower aft fuselage by mechanics after the aircraft arrived at the allotted parking spot. The scrape mark on the runway was 15 meters long.

Probable Cause:

PROBABLE CAUSES
In this accident, it is highly probable that the lower aft fuselage of the aircraft was damaged with contacting the runway because its pitch angle became too high during the go-around following the bounce at the time of the landing.
Regarding the pitch angle became too high, it is somewhat likely that because the Captain, who thought the impact after the bounce would become hard and tried to avoid the second touchdown, performed large nose up maneuver.

Accident investigation:
cover
Investigating agency: JTSB
Status: Investigation completed
Duration: 1 year and 3 months
Accident number: AA2019-5
Download report: Final report

Classification:
Tailstrike
Runway mishap

Sources:
» https://headlines.yahoo.co.jp/hl?a=20180410-00000039-jij-soci
» https://headlines.yahoo.co.jp/hl?a=20180410-00050070-yom-soci
» Flightradar24

METAR Weather report:
12:30 UTC / 21:33 local time:
RJBB 091230Z 01003KT 9999 FEW030 BKN045 13/08 Q1020 NOSIG=


Photos

photo of Boeing-737-9B5-HL7725
accident date: 09-04-2018
type: Boeing 737-9B5
registration: HL7725
photo of Boeing-737-9B5-HL7725
photo of Boeing-737-9B5-HL7725
 

Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not display the exact flight path.
Distance from Jeju (Cheju) International Airport to Osaka-Kansai International Airport as the crow flies is 808 km (505 miles).

This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.
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