Aviation Investigation Report A98H0003
1.19.3 Partial Aircraft Reconstruction
A full-scale metal framework of the front 10 m (33 feet) of the aircraft fuselage was fabricated by the Nova Scotia Department of Transportation and Public Works Mechanical Branch. Identified portions of primary structure, skin panels, and air conditioning ducts were straightened, fracture matched, sewn together with wire, and installed on the reconstruction mock-up. (See Figure 19.) Galleys 1, 2, and 3 were partially reconstructed over separate wire mesh frames and positioned within the reconstructed framework. Pieces of the cockpit seats, cockpit ceiling liner, and CB panels were puzzled together and subsequently fixed into position within the reconstruction mock-up.
Information derived from the physical reconstruction was incorporated into a three-dimensional computer model of the aircraft forward fuselage section. The reconstruction framework and computer model were used to determine the severity and limits of the fire damage, to identify possible fire origin locations, to clarify the spatial relationships between components, and to illustrate how these relationships may have affected the progression of the fire. These tools were also used to help assess the flammability of materials and to identify other safety deficiencies.
- 220.127.116.11 - Tabletop Reconstruction of Cockpit and Forward Cabin Ceiling Areas
- 18.104.22.168 - Air Conditioning Ducts
The reconstructed air conditioning ducts, electrical wiring, and identified components within the forward cabin and cockpit ceiling areas were assembled into a large tabletop mock-up in an attempt to get a top view of the damage patterns and better understand the relative spatial orientation of the items. (See Figure 27.) A wooden frame and clear plexiglass materials were successfully used to rebuild areas that would otherwise become hidden from view once installed in the main reconstruction mock-up. The tabletop mock-up was used to help assess the heat damage pattern.
All of the recovered air conditioning ducts were severely damaged and deformed. Many of the ducts from the front attic area had been heat-damaged; therefore, it was important to reconstruct them to develop an understanding of where the fire started and how it spread. The hundreds of heat-damaged pieces were straightened, fracture matched and sewn together with wire. As only short segments of duct could be rebuilt, it was necessary to consult aircraft manufacturing drawings and expert technicians from the operator and manufacturer to position the rebuilt sections of ducts into the reconstruction mock-up.
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