Aircraft information passenger configuration

3

Aircraft information

3.6.1 Airframe
Owner and operator
Turk Hava YoBari A.0. (Turkish Airlines Inc)

Constructor
McDonnel Douglas Corporation

Type: DC-10-10
Maker’s Serial No: 46,704

Date of first flight: 27. 2.?2

Delivery date: 10. 12. 72.

Registration: TC-JAY

Certificate of Airworthiness and Certificate of Registration (combined in Turkey in the same document): No 342 dated 20. 12. 72 and valid (Certificate of Airworthiness) until 3. 12. 74.

Last inspection at Istanbul: 21. 1. 74 (Inspection Sc-4) Total flying time: since manufacture: 2,955 hours 52 minutes (in the aircraft log book); since the last periodic check: ‘C’ Check: 81 hours 34 minutes ‘D’ Check: 487 hours, 17 minutes.

Previous accidents: none.

3.6.2 Engines
Manufacture: General Electric Company
Type and power: CF6-6D
Maxim' take-off thrust: ll8,144 kg

Airframe position
(From left to right)

Maker serial number 451 - 215 Total operating time 2,358 hours

3.6.4 Weight distribution and centre of gravity

THY aircraft at Orly use Paris Airport services for what are known as the ‘Traffic’ operations which include the preparation of the load and trim sheets and the passenger manifests.

Weight

The initial Load Sheet was supplemented at the very last minute by the addition of 20 passengers. The part of the Load Sheet at the bottom left-hand side of the printed form was not changed accordingly. This shows a total passenger weight of 23,170 kg and a take-off weight of 16.1,628.kg;

The ‘Passengers’ item on the Load Sheet shows an entry of 306 adult passengers (male: 56 + 193; female: 57;) 6 children and l infant. The corresponding load of 23,170 kg was calculated as follows:

306 adult passengers x 75 kg = 22,950
06 children x 35 = 210
01 infant x 10 = 010
Total = 23,170

The“Last' Minute Changes’ item shows 20 additional passengers and a corresponding weight of 1',480 kg, ie s total of 333 passengers (326 adult passengers, 6 children and 1 infant) and a corresponding load of 24,650 kg. The distribution of these last minute 20 passengers among the passenger compartments was not shown on the Balance Sheet.

In view of the item ‘Last Minute Changes’, the crew could have calculated the actual take-off weight to be 163:,108 kg, as a result of the addition of the 20 extra passengers (1,480 kg).

The fact that the relevant take-off speeds used by the pilot were higher than those corres-pounding to the weight initially calculated, gives reason to suppose that the increase in the load was evaluated by the crew of TC-JAY.

Limitations applicable to DC-10-10 TC-JAY:

Maximum take-off weight:.195,000 kg
Maximum landing weight: 164,890 kg
Maximum zero fuel weight: 151,950 kg.

On the day of the Fight, the maximum take-off weight permitted under the limitations (landing limitation) was 172,600 kg (164,890 kg + estimated fuel consumption of 7,710 kg = 172,600 kg). The actual take-off weight of 163,178 kg was within the required limitation for the flight in question. In considering whether the centre of gravity-position of TC-JA'V for flight TK 981 was within the appropriate limits, a judgment can be formed on the beds of: the Flight Manual, section 1, page 4-1 (approved by the F.A.A.)", the TtlY Balance Sheet used by traffic staff. for the planned and the actual zero fuel weights of 135,318 kg and 136,798 kg respectively, the Manual prescribes a forward limit of 8% M.A.C.

The centre of gravity envelope is established in the Manual on the assumption of complete and accurate knowledge of the loads as regards both weight and location in the aircraft. The centre of gravity diagram established on the basis of a calculation for possible errors is more stringent and fixed the forward limit at 10.2% M.A&. The 11.3% position calculated for TC-JAV was therefore within the limits referred to above.

In the same way, the centre of gravity position for the take-off weight was 16.7%; it was therefore within the limit of 12.6% fixed by the Flight Manual

Freight and baggage In order to distribute the load among the three cargo compartments of the DC-IO-1O, the traffic officers had to take into account the following considerations:
The forward cargo compartment had been loaded at Istanbul with 2,S96 kg of freight and baggage destined for London.

The four containers loaded with 1,525 kg of baggage at Orly could be placed only in the central or forward compartments as the aft cargo compartment was kept for bulk cargo. There was no freight of this type for flight TK 981 on departure from Orly on 3 March. The four containers with 1,525 kg of baggage ware placed in the central compartment. During the short stop at Orly, there was no reason connected with the centre of gravity position to transfer to the central compartment the containers loaded into the forward compartment at Istanbul.

Passengers

The planned distribution of passengers among the three cabin compartments at the time of completion of the Load and Trim Sheet was as follows: compartment 1 (forward) compartment 2 compartment 3 (rear) (capacity: 86 passengers): 76 (capacity: 108 passengers): 98 (capacity: 151 passengers): 140 ie a total of 314 passengers as shown on the diagram on the right-hand side of the form used.

Hypotheses regrading the variation in the calculated position of the centre of' gravity, as a function of: the presence of the last minute passengers; the fuel consumption between the time of takeoff and the time when failure of the airframe occurred; the loss of persons and parts of the aircraft during flight, Number of passengers on,hoed: 332 adults and children+ l infant. Passengers regarded as a causal factor in a possible chancre in the centre of gravity position: 18 (excluding 1 infant).

Recapitulation

Forward centre of gravity limit for zero fuel weight. Forward centre of gravity limit for weight with fuel on board

FAA Approved Airplane Flight Manual'. 8% M.A.C. – Centre of gravity diagram: 10% M.A.C. FAA Approved Airplane Flight Manual: 12% M.A.C;

First possibility (less favourable): The 38 passengers were. distributed between compartments 1 and 2:

Compartment 1: Compartment 2: Compartment 3;
86 passengers (+ 10)
166 passengers-(+ 8)
140 passengers (no change).

Fuel consumption estimated at 2,060 kg, corresponding to about 24,000 kg of fuel on board at the time of depressurization.

Centre of gravity position for zero fuel: Centre of gravity position (on depressurization):
9% M.WC. 15% M.A.C. Centre of gravity position after the loss in flight of passengers and aircraft structure (about 500 kg) 14% M.A.C.

For the zero fuel weight: centre of gravity position within the forward limit according to the Flight Manual centre of.gravity position outside the forward limit by 1%, according to the diagram. For the weight with fuel: centre of gravity position always within the forward limit.

Second possibility: The 18 Passengers were distributed among compartments 2 and 3:

Compartment 1: Compartment 2: Compartment 3:
76 passengers (no change)
105 passengers(+ 7)
151 passengers (+ 11).

Centre of gravity position for zero fuel: Centre of gravity position on depressurization: 11.6% M.A.C. 16.8% M.A.C. Centre of gravity position after the loss of weight from the rear of the aircraft: 16.0% M.A.C.

Conclusions
In both cases the centre of gravity position remains within the normal limits.The possibility of movement of passengers forward as a result of panic on the collapse of the floor cannot be regarded as a possible hazard for the centre of gravity position. In the less favorable of the above two hypotheses, at least 50 passengers would have had to move in order to bring the centre of gravity position to its forward limit with fuel.

Although the distribution:of the 332 persons over the 34S cabin seats is not known, centre of gravity problems cannot be regarded as factors aggravating the situation which occurred as a result of the ejection of the aft cargo door.