Since the last report we have been concentrating on the area of the centre wing aft of the rear spar. Here there is substantial damage particularly to the trailing edge (TE) where all the rib extensions outboard of the inner rib have been bent and or broken downwards in varying amounts (photo 1).
The outer end of each inner TE rib adjacent to the fuselage had also been broken off (photo 2).
Also the outer corner of the starboard TE had been completely wrecked and the damaged remains have been cut off (photo 3) and some of the remnants are shown in photo 4.
This meant that we had no remaining reference as to the exact location of the centre wing TE in the vertical sense. We had no original geometry drawings of the wing so we took a reference from the inboard ends of the outer wings (one of which was undamaged at this point) to define the matching shape of the ribs at the joint between the centre wing and the outer wing, and for the ribs adjacent to the fuselage we were able to extend them to the correct length and hence we had the line to repair and re-align the ribs correctly.
￼We de-riveted much of the TE top skin panels and rolled them back to facilitate access for repair of the TE ribs, some of which are shown re-aligned in photo 1. This is now almost complete and straightening of the bent stringers and also removal of as much as possible of the various dents in ￼￼￼￼￼￼the TE skin panels is continuing. We made various wooden former tools such as the example in photo 5 which was to make new stiffeners to be attached to each TE rib across the cracked/broken parts and also a complete new rib end with its integral stiffener to replace the scrap rib at the wrecked starboard corner (photo 6).
The broken rib stiffener in photo 5 shows part of it completely missing and the new replacement above it.
In photo 6 the repaired rib is positioned with skin pins with the new stiffener from photo 5 in place.
By the middle of 2013 we are hoping to complete all the internal repairs to the centre wing areas aft of the rear spar. We are also intending to start work on the two flap surfaces which fit to a spanwise structure which is located in the rectangular spaces in the ribs (at the right of photo 6).
One of the 2 flap surfaces is in very poor condition at its outboard end where whatever damaged the wing structure shown in photo 3 had already severely damaged the outboard end of the flap in photo 7 below.
The spar has been snapped through and the local skin and flap end structure will all have to be remade. Fortunately the almost completely undamaged port flap will give us all the dimensional information we need to remake the replacement structure.
In addition work is continuing on the repair of the small bomb bay doors aft of the rear spar in the centre wing. As with the main fuselage bomb bay doors these are made with wooden spars and ribs and with light alloy skins. All 4 of these doors were badly dented and on dismantling it was discovered that much of the interior woodwork was too badly broken up to be repaired.
One of our Bristol Aero Collection members has a woodworking business and he kindly acquired some aircraft quality spruce for us and machined the various tapered sections to match the cross- sections of the damaged parts. Photo 8 below shows the first re-assembly of one of the wooden frameworks done by one of our Bolingbroke volunteers in his home workshop.
The darker pieces of wood are the remaining re-usable original pieces with the lighter parts being those newly made. The parts which look like bridges will eventually fit around the 3 hinges shown in the foreground on the tubular hinge structure.
In the last report it was mentioned that another volunteer was about to take on the manufacture of the pilot’s seat, missing from 9048, a complex beaded edge structure.
Photo 9 below shows that the seat is now substantially complete.
Appendix: A Review of Achievements to Date
The restoration has been underway for several years and suitable workshop facilities have only been available quite recently. But much restoration work has been done by volunteers in their home workshops and also by a number of companies who have supported the restoration programme.
For the future the closure of Filton airfield to flying at the end of 2012 has led to a proposal to use the old World War 1 hangars on the north side of the airfield to become the future home of the entire Bristol Aero Collection.
This proposal has been agreed in principal by the airfield owners BAE Systems and the local planning authorities.
An application has been made to the Heritage Lottery Fund for partial funding for the restoration of these buildings and dependent on this we should know later in 2013 what the future holds for us.
From the point of view of the restoration of Bolingbroke 9048 the plan includes one of the WW1 buildings as the restoration centre which, when implemented, would give us much more space than we have had to date and where we will eventually be able to assemble the entire aircraft.
The photographs below show the various levels of restoration work that has been undertaken to date.
Initial restoration work was begun on the rear fuselage in a very large local workshop facility where some space was allocated to us. While not ideal this enabled us to do some limited work on the largest section of 9048, the rear fuselage.
The interior was still full of all the mountings for all the equipment that would have been in use during its maritime patrol use over the Atlantic and the Pacific during 1941 and 1942. Some of these mountings can be seen below.
The labelling shown on some of them was progressively applied to all mountings prior to them being digitally photographed to record their location prior to eventual return after restoration.
The forward part of the fuselage is only the top half as it fits over the centre wing which goes right through the fuselage. As a result it is rather flimsy without the centre wing in place and very susceptible to damage as shown below.
This damage which extended internally, with broken frames and stringers, back as far the rectangular slot you can see in the photo below has been repaired.
Subsequent to its initial use as a maritime patrol use 9048 was relegated to training use and repainted yellow overall. By careful use of paint remover we able to progressively remove layers of the remaining paint from the fuselage and thereby discovered some of the original wartime markings underneath as shown below.
This revealed the original serial number as shown below. Traces of the original camouflage paint were also found and enable us to confirm that the aircraft was originally painted with the standard RAF standard ‘A’ camouflage scheme
The nose fuselage as acquired with the starboard cockpit structure completely missing. The front of the nose was also crushed in and all the tubular frames were bent out of shape before finally breaking.
The nose fuselage with new cockpit structure and the front of the nose restored to the correct shape and with a new skin section in place.
The main landing gear as delivered still mounted in the centre wing (above left). The main landing gear and the tailwheel as beautifully restored by the apprentices at Messier- Services (above right).
Some of the many nose fuselage glazings made for us by GKN Transparencies from moulds loaned to us by the Aircraft Restoration Company at Duxford. These particular ones will cover the forward part of the nose fuselage over the bomb aimers working area.
The Triplex front cockpit glazings supplied by GKN Glazings. These were also used to ensure that the new starboard cockpit structure had the correct geometry.
We still have to decide on the format of the Triplex glazings that fit at the bottom front of the fuselage where the bomb aimer uses the bomb sight to co-ordinate his bomb drops. 9048 is the earliest complete Bolingbroke in existence and what is left of the glazing structure for these panels is different from all other later Bolingbrokes we have looked at.
This is the bomb aiming equipment which will eventually be mounted in the nose of 9048. It has many interlinked complex movements and at present we do not know how it was used.
It came to us in its original Royal Canadian Air Force box complete with a tray of alternate bomb load calibration strips which can be exchanged on the equipment to match whatever bomb load or type of mission is underway.
As a result of the aircraft having been separated into its many sections (probably in the 1970s) the keel which sits under the centre wing and connects to the nose fuselage and also the rear fuselage and for good measure serves as the mounting for half of the main bomb bay doors, was missing. We were advised that even if we could acquire another one from somewhere it would not fit as they were fitted individually to the aircraft and therefore not interchangeable. The structure is some 8 to 9 feet long and in 3 sections. The 2 forward sections are similar in design and assembly and one of our volunteers has made all the parts for these. They will eventually be assembled directly into the aircraft.
Another of our volunteers has taken on the restoration of the whole of the framework which carries the pilots seat and the control column (both of which were missing) and also the complex pulley system which carries all the cables to the flying controls. We didn’t have much to start with - see upper left photo below. Photographs and basic measurements were taken from the Bolingbroke in the Imperial War Museum at Duxford to enable a fully working replica control column to be made. The nearly completed pilots seat which sits on the frame in the bottom left photo is shown in photo 9 above.