Flight International 09Mar2020

AIR TRANSPORT

flightglobal.com 3-9 March 2020 | Flight International | 17

A changing

environment

in retirement

News Focus P

I

nvestigators in Kenya have

disclosed that the crew of a

Fokker 50 continued a take-off

roll, despite multiple alerts warn-

ing of a serious engine problem,

before the aircraft crashed some

50s after becoming airborne.

The inquiry into the 2014

accident, involving a Skyward

International Aviation turboprop

departing Nairobi’s main inter-

national airport, found that 27

high-level “triple-chime” alerts

had sounded as the aircraft rolled

along runway 06.

Aural alerts had commenced

as early as 8s after the take-off

was initiated but, while the air-

craft was well below the V1 deci-

sion speed, the crew did not act

to abort the take-off roll.

Flight-data recorder informa-

tion indicates that the left-hand

Pratt & Whitney Canada PW

engine was exhibiting problems,

with increasing torque but

declining propeller speed com-

pared with the right-hand engine.

INQUIRY DAVID KAMINSKI-MORROW LONDON

Fokker 50 crew ignored multiple alerts

Skyward turboprop sounded 27 high-level ‘triple-chime’ warnings during take-off roll before 2014 fatal crash at Nairobi

K

azakhstan’s government has

released an animation detail-

ing the take-off sequence of the

Bek Air Fokker 100 involved in a

fatal accident at Almaty.

The sequence shows the diffi-

culties the crew had in controlling

the aircraft as it rotated from run-

way 05R while departing for Nur-

Sultan airport on 27 December.

It oscillated on lift-off but failed

to gain altitude, striking the run-

way several times before overrun-

ning and veering into a building.

Icing remains the suspected

cause of the aircraft failing to be-

come airborne.

Bek Air was grounded after

the  accident and has repeatedly

appealed to authorities to allow it

to restart operations. The airline

recently issued, extraordinarily,

Carrier was grounded immediately after the fatal accident last year

Vladimir Zaikin/EPA-EFE/Shutterstock

was the captain’s decision,

because it could not be checked

from the ground.

The first officer also says that

the aircraft was able to track the

runway centreline during the

departure but had passed the V

decision speed when problems

emerged, and the crew therefore

purported audio conversations

between accident investigators

and the first officer of the flight,

who initially survived the acci-

dent but passed away on 28 Janu-

ary, shortly after the discussion.

Bek Air says the recordings

were captured by airline employ-

ees who were present.

The transcript of the discus-

sion includes a question on how

the crew checked the surface of

the wings for ice.

The first officer apparently

replies that he made a tactile

check in three places, saying that

he was able to check the front of

the wing – which was “clean and

dry” – more easily because he

was taller than the captain.

He says the de-icing of the sta-

biliser – and only the stabiliser –

INVESTIGATION DAVID KAMINSKI-MORROW LONDON

Animation shows Bek Air Almaty crash sequence

did not consider aborting the

take-off roll.

Control difficulties began, he

says, after the nose-wheel lifted.

He retracted the landing-gear, but

only on the second attempt – and

after a second call from the

captain – because the aircraft was

rolling sharply. ■

“On [its] ground roll for take-

off, the aircraft seemed to take

[more] runway than anticipated

before attaining the take-off

speed,” the Kenyan air accident

investigation department states,

indicating that the roll lasted

more than 90s.

The aircraft lifted off from the

high-elevation airport at about

100kt (185km/h) but was “barely

climbing”, the inquiry says,

reaching no more than 50ft above

ground after about 20s while con-

tinually deviating to the left of

the extended centreline.

It subsequently collided with a

building 2,100m (6,890ft) north-

northeast of the runway end.

None of the four occupants – two

pilots, an engineer and a load-

master – survived.

The aircraft had been conduct-

ing a cargo service to Mogadishu,

in darkness, on 2 July 2014.

Investigators found discrepan-

cies in the loadsheet for the aircraft

and analysis of the cargo, including

a shipment of the mild narcotic

qat, indicated that the aircraft was

500-1,500kg (1,100-3,300lb) above

its maximum certificated gross

weight at take-off.

The captain, who had been

flying, had logged more than

6,800h in command of Fokker

50s, although the inquiry says

it  was “unable to determine”

whether either pilot had demon-

strated an ability to fly the turbo-

prop with one engine inoperable.

Analysis of recordings from

the previous positioning flight by

the aircraft (5Y-CET) showed a

“three-chime” alert had occurred,

and that the crew had spent time

trying to diagnose the problem.

Despite the evidence from the

cockpit-voice recorder, the moni-

toring pilot for the flight “denied

knowledge” of any anomalies,

says the inquiry.

Investigators could not obtain

any evidence that any problem

was recorded in the technical

log, nor that any maintenance

was conducted in relation to the

apparent anomaly. At least one

of the crew members – possibly

the captain – from the position-

ing flight was among those

fatally injured during the subse-

quent accident.

While the “three-chime” alert

sounded repeatedly during the

ill-fated flight’s take-off roll, the

inquiry says “it is not clear” why

the crew continued to proceed

with the flight.

Cirium fleets data shows the

aircraft was originally delivered

to Lufthansa CityLine in 1992

and served with Air Nostrum and

Avianca Brazil before being trans-

ferred to Skyward from Dutch

operator Denim in May 2014.

It had been operated in Kenya for

just 92h before the crash.

Although the accident oc-

curred in 2014, the inquiry was

signed off only at the end of

November last year and pub-

lished by the transport ministry

in January. ■