Kulula B738 at Cape Town on Feb 27th 2013, rejected takeoff

Last Update: May 27, 2015 / 17:15:00 GMT/Zulu time

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Incident Facts

Date of incident
Feb 27, 2013

Classification
Incident

Cause
Rejected takeoff

Airline
Kulula

Flight number
MN-104

Departure
Cape Town, South Africa

Destination
Johannesburg, South Africa

Aircraft Registration
ZS-ZWP

Aircraft Type
Boeing 737-800

ICAO Type Designator
B738

A Kulula Boeing 737-800, registration ZS-ZWP performing flight MN-104 from Cape Town to Johannesburg (South Africa) with 181 passengers and 6 crew, rejected takeoff from Cape Town at low speed after the right hand engine (CFM56) emitted a huge bang and ejected debris axially (contained). The aircraft slowed safely and returned to the apron.

The runway was temporarily closed for a runway inspection and sweeping to clean the debris, mainly separated turbine blades.

The airline confirmed the aircraft rejected the takeoff at low speed due to an engine failure, the engine was shut down and the aircraft returned to the apron. Something flew into the engine resulting in the failure.

South Africa's CAA reported in their list of February incidents released on Mar 26th 2013, that the right hand engine failed, the aircraft rejected takeoff and returned to the apron on the left hand engine.

ZS-ZWP resumed service on Mar 3rd 2013.

On May 27th 2015 South Africa's Civil Aviation Authority (SACAA) released their final report concluding the probable cause of the incident was:

Aborted take-off as a result of the No. 2 engine failure due to the failure of the HPT blade.

Contributory factor

Failure of the HPT blade coating resulting on a corrosion and a subsequent failure of the blades

The aircraft was accelerating for takeoff on Cape Town's runway 01 when at about 30 knots a loud bang was heard followed by vibrations, the right hand engine's N1 and N2 instruments rapidly spooled down to zero and the crew rejected takeoff within 50 meters. Tower activated the crash alarm, two fire vehicles responded to the aircraft and found engine debris on a substantial area of the runway surface.

The crew completed the "engine severe damage memory items" checklist and taxied the aircraft to the apron.

A post event examination of the right hand engine revealed "excessive" damage to the engine including deformations of the engine casing, the engine parts had been contained however. There was extensive turbine blade damage visible from the tail pipe. Further examination showed the forward sump scavenge strainer plug was found contaminated with composite material from the high pressure turbine seal. Loose studs with the nuts still attached were found inside the engine at the bottom of the casing.

The flight data recorder had not recorded any anomaly prior to the event.

The engine was shipped for examination by the manufacturer, a boroscopic inspection there identified three high pressure turbine blades had liberated below their platforms. The CAA analysed: "Fracture surface analysis of under-platform separated blades revealed that the primary fatigue crack initiation occurred via multiple origins from the internal surface located within the cavity. The analysis also showed evidence of secondary fatigue crack initiation on the internal surface of the cavity. Heavy oxidation was observed on the crack surface and most of the blade fracture surface showed characteristics of tensile overload as a result of secondary impact damage."