SIMPLEFLYING VIDEO OF THE DAY
The plane gave the impression to be too heavy for the set takeoff configuration. The freighter did not grow to be airborne in time to clear the airport embankment, simply meters from the top of the runway. The tail part broke off because it got here involved with the berm, bringing the airplane down and killing all seven members of the crew.
Background
The flight crew was comprised of a captain, a primary officer, a flight engineer, a floor engineer, and a load grasp. A set of reduction pilots have been additionally onboard because of the nature of the four-sector journey between Europe and North America. MK Airways required its flight crew to work a 24-hour work shift with as much as 18 hours within the air, which was almost twice as a lot because the aviation trade norm.
The load grasp was chargeable for overseeing onboard cargo load, and offering load sheets to the pilots for takeoff configuration. On the time, MK Airways had just lately transitioned from a handbook configuration course of to a computerized Boeing-fitted software referred to as the Boeing Laptop computer Software (BLT).
The BLT required pilots to enter deliberate plane configuration from the load sheet and calculate takeoff parameters. The applying would return engine strain ratio (EPR) and V-speed calculations required for takeoff. The applying additionally allowed pilots to print BLT-generated information playing cards for the takeoff process.
Unfolding of occasions
The primary leg of the journey between Bradley and Halifax had commenced at a a lot lighter takeoff weight of 530,000 lb (240,000 kg). As a consequence of having a partial cargo load and simply sufficient gas for a 1-hour hop to Halifax, pilots had calculated a de-rated (lowered thrust) takeoff configuration within the BLT.
Throughout the stopover, 116,600 lb (53,000 kg) of seafood was loaded onto the plane. Accounting for the extra gas load, the plane weighed a complete of 776,600 lb (353,000 kg). Ideally, the pilots would enter the up to date plane configuration from the load sheet into the BLT to calculate new takeoff parameters for the transatlantic leg. The desk beneath exhibits plane configuration for 2 completely different thrust circumstances.
|
De-rated Thrust |
Most Thrust |
| Flight leg |
Bradley (BDL) – Halifax (YHZ) |
Halifax (YHZ) – Zaragoza (ZAZ) |
| Takeoff weight |
240 metric tonnes |
353 metric tonnes |
| Engine Strain Ratio (EPR) |
1.31 |
1.60 |
| Rotation velocity (VR) |
129 knots (148 mph/239 kph) |
162 knots (186 mph/300 kph) |
| Secure climb-out velocity (V2) |
137 knots (158 mph/253 kph) |
168 knots (193mph/311 kph) |
Whereas the load sheet had been up to date by the load grasp, the brand new (most thrust) configuration by no means made it into the BLT. Furthermore, MK Airways’ procedures prevented using BLT-generated takeoff playing cards, however as an alternative required pilots to manually write takeoff parameters from the BLT display screen to the handwritten playing cards.
Findings
Investigation revealed that because the BLT was by no means up to date with the brand new configuration, the de-rated takeoff parameters from the earlier flight have been copied into the handwritten takeoff playing cards. Investigators additionally famous that the inaccurate parameters may have been caught by checking plane weights on the BLT-generated playing cards.
The tail of the Boeing 747-200F scrapped the grass on the finish of the runway earlier than putting the airport berm. Photograph: TSB Canada
Because of MK Airways’ work shift insurance policies, the pilots had been on responsibility for over 19 hours on the time of the accident. Furthermore, the bottom engineer and the load grasp had been working for over 45 hours straight.
Crew fatigue, mixed with low visibility takeoff circumstances, prevented the pilots from recognizing insufficient takeoff efficiency. All in all, company recklessness made the accident inevitable, and a hefty value was paid by the seven crew members on board.
