w:Cecil Margo

“ Examination of two 1/8" diameter elevator control cables installed in the crown of the main deck cargo compartment revealed that they had been heated to a temperature in the region of 700°C at their fracture points. From tensile tests it was apparent that a cable heated to 700°C will break if a tensile load of between 56 and 100 lbs is applied to it. The minimum breaking strength of a sound cable is 2000 lbs. ”

“ Circuit-breakers installed at various locations, many of which are in the cockpit, provide protection for all wiring by opening in the event of short-circuits, thereby isolating the affected system. In the event of an intense fire in the main deck cargo compartment it is possible that all or many of the wire bundles in raceways G and H would be damaged causing short-circuits. ”

“ The CVR was powered directly from the essential 115v AC bus and was wired to record from the audio selector panels of the pilot, co-pilot, flight engineer and from the cockpit area microphone. The CVR was not wired for "hot mic" recording but all verbal communications from the above mentioned crew members via oxygen masks, hand held and boom microphones would have been recorded.
"Hot mic" recording means that the microphones are connected to a recorder in a manner that ensures the recording of all cockpit sounds within the range of the microphones regardless of audio control panel selections. ”

“ Some 9 hours out and some 46 minutes before the estimated time of arrival at Plaisance the flight deck informed the approach control at Plaisance that there was a smoke problem in the aeroplane and that an emergency descent to flight level (FL) 140 had been initiated. The last radio communication was at 00:04 on November 28th 1987. At about 00:07 the aeroplane crashed into the sea. The wreckage, consisting of thousands of fragments, sank to the ocean bottom at depths of the order of 15 000 feet (about 4,5 kilometers) , although many of the lighter materials floated away on the currents. ”

“ To prevent the formation of air bubbles on the tape and hence a deposit of sea water chemicals, the transfer from the lifting tackle to the transport container was performed under the water. Once on board the ship the sea water was replaced with de-ionised water whilst ensuring non-entry of air into the recorder unit. Ice made from de-ionised water was progressively added to maintain the temperature within the range of 4 to 12°C. The CVR, in the transport container, was then flown to the Operator's suitably equipped laboratory for removal of the tape. ”

“ The investigator-in-charge provided the factual report to the representatives of the participating parties for information and comments.
The State conducting the investigation (RSA) appointed an Accident Inquiry Board in terms of section 12 (1) of the Aviation Act 74 of 1962. The Board comprised one member from each of the States of Japan, the Republic of China, Mauritius, the UK and the USA, and three members, including the Chairman, from the RSA. The members from Japan, the Republic of China and Mauritius, were appointed by their respective governments. ”

“ As the electrical wiring, pitot pressure and pitot static pipe lines to the pitch and yaw control units had probably been damaged by the fire, the manufacturer of the aeroplane was requested to advise what the effects of such damage could have been on the flight characteristics of the aeroplane. ”

“ A search craft has dropped an emergency locator beacon to mark the accident site. The search will continue at first light (01:12) on November 29th. French C160, United States of America (USA) P3 Orion and Air Mauritius Aircraft will continue search for survivors as from dawn on 29th. Sea search is being carried out by a Mauritian navy vessel and other fishing vessels operating in the region".
On November 29th at 02:56 the wreckage pieces were relocated by the crew of a Transall aeroplane and the ships started with retrieval of bodies and floating wreckage. ”

“ Nevertheless the rate at which smoke would rise would depend on the conditions in the cargo compartment at the time.
Access to various pallets is made between the pallets and the fuselage which is very restrictive. Under the most ideal conditions fire fighting with the equipment provided would be difficult. During the search for the fire the fire fighter has both hands occupied, one hand carrying the 16 lb extinguisher and the other holding the 10ft wand. ”

“ The information given was that the aeroplane had taken off from Taipei at 14:23, was flying at FL 310 and that the arrival time at Mauritius was estimated as 00:35. The ZUR radio operator informed flight SA 295 that the selective calling system (SELCAL) was unserviceable and requested that the next call be at 18:00. SELCAL is a coded system whereby a radio station can call an individual aircraft. The flight crew's attention is drawn to a call by audio and visual means. ”

“ Due to adverse weather and the late arrival of a connecting flight the departure time was delayed and the aeroplane took off at 14:23 with 149 000 kg of fuel, 43 225 kg of baggage and cargo, 140 passengers and a crew comprising 5 flight crew members (including an extra co-pilot and an extra flight engineer) and 14 cabin crew members. The calculated flight time was 10 hours 14 minutes. According to the tape recording of the radio communication with Taipei Approach Control the take-off was normal in all respects. ”

“ The team recommended that no new main deck class B compartment designs be approved to the existing class B criteria and that main deck cargo compartments provide a level of safety equal to class C compartments or that cargo be carried in fire resistant containers meeting class C requirements including smoke detection and fire suppression capability. ”

“ Components associated with the left wing and body gears, the right wing gear and the nose gear, were examined and it was established that the landing gear was retracted at the time of impact.
(2) Power plants.
The power plants were extensively damaged by impact forces and only three of the four were found. The nature of damage sustained by the power plants indicated low power, or rotation at the time of impact. (See the report of the power plant manufacturer, App C Volume 2 pp 12–15.)
(3) Large section of left aft fuselage structure incorporating the main deck cargo door. ”

“ The structure fractured at body stations 1640 and 1960 and at strangers 4R and 17R. Extensive heat damage occurred to frames and stringers between body stations 1760 and 1880 and between stringers 4R and 11R. Smoke deposits and heat discolouration of the paint were evident on the skin surfaces behind some frames and stringers which had become detached from the skin. Eight 9G barrier net straps burned off at their fuselage attachment fittings. ”

“ Six consignments of electronic equipment contained small lithium battery cells fitted to circuit boards. These cells were considered non-dangerous as Special Provisions A45 of Doc 9284 - AN/905 had apparently been met. A small quantity, 300 g, granulated activated carbon was carried in the lower cargo hold. According to Special Provision A51 of Doc 9284 - AN/905 granular activated carbon is considered non-dangerous if cooled for more that 8 days since manufacture. The manufacturer stated that the activated carbon in the consignment had been cooled for longer than 180 days after production. ”

“ Taiwan's Commissioner for Customs had conducted random sampling of the cargo consignments from Taiwan before they were loaded on the aeroplane. A computer selected 10 house waybills and one master waybill out of 111 bills. It was found that the items in the consignments agreed with the respective documents. The Chief of the South African Defence Force confirmed that no weapons or explosive devices were carried in the aeroplane for the SA Defence Force. The Executive General Manager of Armscor confirmed that there was no consignment of cargo to or from Armscor on the aeroplane. ”

“ The cable tension regulator can take up 5,05 inches of cable slack.
1.16.7 The manufacturer of the aeroplane analysed the structural capability of the cargo compartment crown section where the most heat damage was observed i.e. between body stations 1640 and 1960. The material allowables used are the properties at room temperature. The results can be summarised as follows:
(1) During level flight (1g) and manoeuvres within the operational spectrum (1g plus/minus 0,3g) the fuselage monocoque structure (skin and stringers) above the main deck floor is subjected to tensile loads. ”

“ The compartment ls divided into two smoke detection zones, each of which is equipped with a dual smoke detection system providing a warning to the flight crew. There is no evidence that the flight crew were aware of any indications of fire prior to the sounding in the cockpit of the main deck cargo warning alarm bell. ”

“ All these fire extinguishers were checked and recertified during 1987.
1.14.5 Supplemental oxygen is provided by separate fixed systems for the flight crew and passengers, and portable oxygen bottles are positioned throughout the cabln and cockpit for use if needed. Individual oxygen masks are automatically released from the passenger service units when the cabin altitude is at or above 14 000 feet. The B-747 Operations Manual warns that passenger oxygen use should be discontinued "below 14 000 feet when smoke or an abnormal heat source is present. ”

“ The debris in both areas had drifted while sinking. The dispersion of items was influenced by their individual sinking characteristics and the effect of the ocean current. High density items were found in the South-eastern area with a progressive spread of items with low sink rates in a downstream (North-westerly) direction.
After location of the wreckage a contractor was selected to provide the technology and equipment necessary to photograph pieces of significance and to retrieve selected pieces. ”

“ The structure failed at body stations 1720 and 1860 and at stringers 12R and 25R. Heat damage to frames and skin was evident between body stations 1780 and 1840 and stringers 12R and 17R. Heat discolouration of paint occurred on the outer skin surface between body stations 1800 and 1840 and above stringer 16R. Heat damage was apparent on the two lower horizontal straps of the 9G barrier net forward of pallet position PR. The remainder of the horizontal straps above the cabin window level were burned off either at a position forward of pallet PR or at the fuselage attachment points. ”

“ The use of passenger oxygen will not prevent passengers from inhaling smoke at any altitude".
1.14.6 Numerous articles of cargo carried in the main deck cargo compartment and also compartment structure, fittings, and components were damaged by fire. Many of the cargo articles and all the packing materials used were flammable. The cargo was largely comprised of electrical components and parts (mainly computers) , hardware, paper articles, textiles and sports equipment. ”

“ All vertical straps at body station 1750 and forward of pallet position PR were burned off at approximately 1,3 meters above the maln deck floor level.
(7) Upper section of galley 4B at body station 1700. (Target 204: see App C Volume 2 p 7.)
There was evidence of heat exposure and smoke deposits on the left and right rear top panels and upper surfaces of the galley unit, particularly in the centre and on the right hand side. The unit was relatively intact with some lateral distortion evident on the left. The right side oven doors showed evidence of severe water impact damage. ”

“ It is intended to provide a restriction that aids In air flow directional control wlthin the aeroplane. Air is introduced into the compartments just below the ceiling levels, passes through the compartments and exits through sidewall grilles at floor level to move downward towards the rear to the two outflow valves located aft of the lower cargo hold. At the same time some air flows into the overhead space above the main deck passenger compartment and moves aft. ”

“ The approved maintenance schedule prescribes that the orifices in the smoke detection sampling manifolds be inspected for obstructions at every tenth Phase A Inspection, i.e. at 4 300 hour intervals. Such an inspection was carried out on February 2nd 1987 at 24 394 total hours i.e. ”