Caribbean B738 at Georgetown on Jul 30th 2011, overran runway

Last Update: April 8, 2019 / 14:46:10 GMT/Zulu time

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Incident Facts

Date of incident
Jul 30, 2011

Classification
Accident

Airline
Caribbean Airlines

Flight number
BW-523

Departure
Port of Spain, Trinidad and Tobago

Destination
Georgetown, Guyana

Aircraft Registration
9Y-PBM

Aircraft Type
Boeing 737-800

ICAO Type Designator
B738

Airport
Cheddi Jagan International Airport, Georgetown

Airport ICAO Code
SYCJ

A Caribbean Airlines Boeing 737-800, registration 9Y-PBM performing flight BW-523 from Port of Spain (Trinidad and Tobago) to Georgetown (Guyana) with 157 passengers and 6 crew, overran Georgetown's runway 06 by about 100 meters at 01:32L (05:32Z), broke through the perimeter fence, fell onto a perimeter road and broke up, the front section separating just ahead of the wing root. 52 people were taken to hospitals for assessments, three of them remained in hospital care (one leg fracture).

The airport was closed until about 10:00L (14:00Z).

Gyuana Authorities reported, that 52 people were taken to two hospitals in Georgetown for assessment, all of them but three were released after initial treatment. Three remained in hospital care, one of them with a leg fracture. Guyana's Civil Aviation Authority are investigating the accident.

Georgetown Airport's fire commander told the investigators that firefighters observed the aircraft as it approached but touched down only about half way down the runway abeam the terminal building with about 3000 feet of runway remaining. They needed to douse engine #2 (right hand engine) which was emitting smoke after the aircraft came to a stop.

Aviation sources said, the aircraft touched down with flaps fully extended (40 degrees).

On Aug 10th 2011 it became known to The Aviation Herald, that the flight data recorder showed the flaps at position 30 degrees on final approach, touchdown and rollout, the flaps indicator still showed the flaps at position 30 degrees after the accident.

On Sep 20th 2013 Guyana's presidential advisor stated in a press conference, that the investigation has been completed. The final report states as cause of the accident, that the aircraft landed far beyond the touch down zone due to the captain maintaining excess power during the flare. This resulted in the aircraft not using the full deceleration capabilities and ended in the runway overrun. The final report has not yet been published.

Added on Apr 8th 2019: At some unknown time Guyana's Civil Aviation Authority (GyCAA) released their final report (16MB) concluding the probable causes of the accident were:

The probable cause of the accident was that the aircraft touched down approximately 4700 feet beyond the runway threshold, some 2700 feet from the end of the runway, as a result of the Captain maintaining excess power during the flare, and upon touching down, failure to utilize the aircraft’s full deceleration capability, resulted in the aircraft overrunning the remaining runway and fracturing the fuselage.

Contributory Factors

The Flight Crew’s indecision as to the execution of a go-around, failure to execute a go-around after the aircraft floated some distance down the runway and their diminished situational awareness contributed to the accident.

The GyCAA wrote about the sequence of events:

The pilot reported that after visual contact was made and after crossing the Final Approach Fix (FAF), he disengaged the auto pilot and configured the aircraft for landing. The Flight Data Recorder (FDR) indicated that the flight was normal until the aircraft was approaching the runway. Even before the aircraft was over the threshold, the captain commented that he was not landing here.

As the flight continued over the runway, comments on the Cockpit Voice Recorder (CVR), revealed that the captain indicated to the First Officer (FO) that the aircraft was not touching down. A go-around call was made by the Captain and acknowledged by the First Officer, however three seconds elapsed and the aircraft subsequently touched down approximately 4700ft from the threshold of RWY06, leaving just over 2700 feet of runway surface remaining.

Upon touchdown, brake pressure was gradually increased and maximum brake pressure of 3000psi was not achieved until the aircraft was 250ft from the end of the runway or 450ft from the end of the paved area. The ground spoilers were extended on touchdown. The thrust reversers were partially deployed after touchdown. The aircraft did not stop and overran the runway. It then assumed a downward trajectory followed by a loud impact.

The GyCAA reported the accident resulted in one serious injury, a passenger broke his leg which ultimately resulted in amputation. A number of minor injuries occurred as result of impact as well as evacuation.

The captain (52, ATPL, 9600 hours total, 5000 hours on type) was pilot flying, the first officer (23, CPL, 1400 hours total 350 hours on type) was pilot monitoring.

The GyCAA analysed:

It was noted from the CVR that after passing 11,000ft at 05:19:15.1 there was a considerable amount of light chatter in the cockpit, most of it unrelated to flying the aircraft. The F-COM VOL. 3 states that casual conversation reduces crew efficiency and alertness and should be avoided below 10.000ft15. Further, during the landing phase, the recordings suggest that there was a temporary loss of situational awareness as it seems that neither of the flight crew was aware of the aircraft’s location in relation to the remaining runway. There is also some doubt as to whether the flight crew was certain that the aircraft had actually floated down the runway, which might have been as a result of the high power setting of 59%N1 carried by the captain.

During his interview, the First Officer indicated that he was aware that the aircraft was floating, and he recalled that the Captain had voiced concerns about this. But there is no indication from the CVR that the First officer initiated any action that would have helped to alleviate the accident results. As explained in the F-COM, phase of flight duties are divided between the Pilot Flying (PF) and the Pilot Monitoring (PM). The FO was the PM and was required to make callouts based on instrument indications or observations of appropriate conditions. He is also expected to make callouts of significant deviations from command airspeed. Additionally the Caribbean Airlines Operations Manual Part A – General requires the Co-Pilot to volunteer advice, information and assistance to the Captain that will contribute to the safe conduct of the flight; and to maintain adequate look out during arrival. Thus there was no concerted attempt or decision to take effective action to compensate for the occurrence by either flight crew.

The CVR indicated that three seconds before touchdown the Captain called that he was going around and at the same time he advanced the throttles. The First Officer acknowledged the go around call, but that decision was not carried through. The Caribbean Airlines Operations Manual Part A-General states that once a decision to “Go-Around” has been made, it must never be revoked. The aircraft touched down approximately 4700ft down the runway, which is 3700ft from the beginning of the touchdown zone. Thus the need for a go around was recognized but the same was not executed. The fact that the aircraft touched down three seconds after the pilot made the call suggests that there was a serious lack of situational awareness on the part of the flight crew. The lack of coordination and the absence of joint control and effective decision making further served to exacerbate the situation.

The deployment of the thrust reversers three seconds after touch down in any event would have negated the aircraft’s ability to execute a go around after touch down. The performance study of the FDR indicated that the aircraft thrust reversers were deployed approximately three seconds after touchdown and at approximately 2000ft from the end of the runway. Boeing guidance states that a go-around should never be attempted after reverse thrust has been deployed.

The GyCAA analysed with respect to the runway:

RWY06 at Cheddi Jagan International Airport meets the ICAO specified criteria for safe aircraft operations. The runway does not have any potholes or other physical deficiencies. Although the runway surface was wet at the time of the accident, the lateral grooves along its entire length allows for enhanced drainage so there was no standing water on the runway. The grooves also served their primary purpose of providing increased frictional forces between the aircraft’s tires and the runway surface. Analysis of the friction test data shows that there was no noticeable friction loss along the runway or in the turn area of the high speed exit off the runway.

The runway is 7448ft. long and there is no Runway End Safety Area, but beyond both ends of the runway there is an additional 200ft of usable paved surface. The RESA is a Standard required by ICAO Annex 14. The availability of RESA at the end of RWY06 may have reduced the severity of the accident.

...

The runway is equipped with PAPIs. The beam projection of the PAPIs was 2.39º and was not coincident with the approach slope of the RNAV–GPS RWY06 approach, which is 3°. This slope has since been adjusted to coincide with the RNAV-GPS approach (February 2012).

The shallow approach slope could have exacerbated the previously mentioned visual illusion presented by the lack of approach lighting and the wet runway. This may have accounted for the excessive power inputs by the Captain, which contributed to the aircraft floating down the runway.

With respect to weather the GyCAA analysed: "There were no significant winds at the station; however readings from the FDR indicated that there was an abrupt 180° directional change while the aircraft was on short final. However, at the time of the shift in wind direction, the wind magnitude was less than 5kts and had minimal effect on the aircraft."

The GyCAA analysed the FDR readings:

The analysis of the FDR shows that while on short final the aircraft was sinking below the desired glide-path and the crew increased power. The airplane regained the glide-path, but the pilot did not reduce power as the airplane entered the flare. The excess power resulted in the aeroplane floating beyond the intended touchdown point. Power was not reduced until the airplane was approximately 4000ft down the runway, about 6 seconds before touchdown. 3 seconds later the pilot called a go-around and advanced power, which contributed slightly to the float. However 3 seconds later the wheels touched down.

BW523 had approximately 2900ft of pavement to stop on when it touched down, 4700ft down the runway. Boeing’s landing distance estimates using a calculated aircraft braking coefficient as a function of groundspeed indicate that it was possible to stop the aircraft on the runway using either Detent 2 or maximum reverse thrust. However the ground spoilers were armed and as a result deployed at about the time of touchdown at 05:32:12 and the thrust reversers deployed (less than Détente 2 was commanded by the crew) 2 seconds later at 5:32:14 when the aeroplane was 2000ft from the end of the runway. Further the crew applied gradual brake pressure starting at touch down, maximum brake pressure of 3000psi was not achieved until the aircraft was 250ft from the end of the runway.
Because the aircraft touched down so far down the runway and the crew did not use all of the available deceleration devices, it was not stopped on the paved surface and exited the prepared surface of the runway and impacted a berm resulting in substantial damage to the airframe.

The flight had originated in New York JFK,NY via Port of Spain.

Georgetown's runway 06/24 is 2270 meters/7450 feet long, an ILS is about to be introduced however was not yet active at the time of the accident.

The aerial view along the runway towards the accident site taken about 8 hours after the accident shows the runway covered with a thin layer of water, the accident aircraft's four main wheel tracks visible through different light reflection near the end of the runway and along the runway end safety area, while the aerial view in opposite direction seems to suggest no tyre tracks at all on the runway surface covered with water.

Metars:
SYCJ 300700Z 00000KT 9000 BKN015 24/24 Q1008 NOSIG
SYCJ 300600Z 00000KT 9000 BKN015 24/24 Q1008 NOSIG
SYCJ 300500Z 00000KT 9000 -SHRA FEW014CB BKN015 25/24 Q1009 CB-NE-ENE NOSIG
SYCJ 300423Z 00000KT 9999 TS FEW015CB SCT016 CB-NE-ENE NOSIG
SYCJ 300400Z 00000KT 9999 FEW016 24/24 Q1009 NOSIG
SYCJ 300300Z 00000KT 9999 FEW016 25/24 Q1010 NOSIG
SYCJ 300200Z 00000KT 9999 FEW017 SCT300 25/24 Q1010 NOSIG
SYCJ 300100Z 00000KT 9999 FEW017 SCT300 25/24 Q1010 NOSIG