Spitfire Restoration Progress Update - April 2016
Despite having had no electricity or water for several months at the air force base due to infrastructure repairs, progress has been made.
The Spitfire Fuselage:
The fuselage is now stripped out except for the cabling and piping systems. Plans are in place to move forward, and one could add that we now have a repair strategy. The current thinking is to design and build a jig that will locate frame 5, frame 19 and the longerons. The idea is to procure these parts due to their importance in loading, interface and the extensive damage suffered during the crash. From there, the serviceable structural components will be transferred from the damaged fuselage into the jig. A lot of thought still needs to go into the process; however, the basic concept seems sound.
The fuselage is an early semi-monocoque structure consisting of a stressed skin, frames, stringers and longerons. The wing’s main spar and the engine bearer’s attachments come together at frame 5. Frame 5 is a crucially important junction. The main spar attaches to a built-up structure at the bottom of frame 5 with a set of 16 close tolerance bolts. The engine bearer attaches to four fittings, two at the top and two at the bottom of frame 5, with tapered bolts. The fittings, in turn, connect to 4 longerons that run from frame 5, all the way back to frame 19 at the empennage.
The empennage is detachable, and the interface at frame 19 is an important attachment point. The wing’s rear spar attaches to frame 10, which is in the cockpit area. The wing is constructed around a single main spar with a continuous D-box ahead of it. The wing has a huge cut-out inboard behind the main spar to accommodate the landing gear. The D-box is a crucial part of the wing structure, carrying much of the loading, especially relieving the centre wing load in the areas where wheel wells and other large cut-outs are located. The root rib completes the load path between the D-box and the wing root attachment points at frames 5 and 10. The rear spar acts as a shear member and does not transfer bending load to the fuselage. There is thus no redundancy should the main spar develop problems. The engine bearer is constructed as a truss consisting of tubular members and a strong U-frame.
Frames 5, 10 and 19, the four longerons, the engine bearer, the main spar, D-box and the wing root rib form the main structural members of the airframe. Of course, no structural component on the airframe is unimportant. Every part has been designed with a purpose. The main structural members are vital to the structural integrity of the airframe. To rebuild these parts requires exact knowledge of their geometry, materials, special processes and build procedures. The drawing set available to the team is large but lacks much information. The drawings do not cover the special processes and techniques required to construct and assemble the various parts and assemblies, nor is the drawing pack complete.
Many components damaged from the crash will have to be reverse engineered. That means the existing component will be measured and a new drawing generated. The applicable material for the part needs to be identified by chemical analysis, hardness tests and other means. Although most of the airframe is constructed from aluminium, different types and grades of aluminium are used throughout. Much of the airframe is made from sheet metal. Blanks are cut, pressed, formed and rolled to take on the required shape of the final component. A further set of drawings will be necessary to outline the geometry of the blanks. Processes need to be established for each of the construction steps. Some materials need heat treatment, while others will be kept in a freezer to preserve their malleable state until required.
Many components will be built up of several parts, all of which need to come together accurately. The components will then find their way into assemblies with tightly controlled interface geometry. To this end, jigs and special tools will be required all along the production line to ensure that the correct geometry is maintained. The jigs and tools need to be designed and built too. All of these activities will be covered by a Quality Management System. Quality assurance starts right at the beginning. Parts recovered from the crashed aircraft need to be inspected, repaired, reworked and recertified. Parts recovered for reverse engineering need to be controlled. The reverse engineering process must be controlled with various quality checks along the way. Even the original drawings need to be controlled. The Spitfire was built in many marks and variants. The drawing pack issued on this project must be checked and verified to apply to this particular aircraft.
On the technical front, the project team is coming to grips with all the requirements, checking the drawings, checking bills of materials, establishing relationships with technical specialists locally and abroad, seeking suppliers and evaluating the airframe in its present state. The requirements for the new workshop are being set up. Its planning covers the layout of the workshop, zoning for special functions, storage and control of parts and materials, the type and quality of tools and jigs required, power supply, health, safety and environment and others.
We are currently seeking the release of the damaged Merlin Engine from the SAAF to carry out detailed inspection/diagnostics to enable a repair policy to be decided and cost analysis of spare parts and repairs required.
Wings, Engine Frame, Running Gear, Tailplane
Future works have been defined for these assemblies and will proceed given release by the project managers and space in the workshop area.
Project Management and Paperwork
In January 2016, we were advised to halt the stripping process until control systems were in place.
As the Project grew and we continue to negotiate with many of the Aero Industries major players, we learn many valuable lessons regarding their policies and requirements if they are to assist us as we progress. With this strategy in mind, the project has made a considerable effort to entrench internationally accepted ‘best practice’ project management principles and governance into the management of the project and is guided by the PMBOK 5th Ed.
This provides a gated project lifecycle process which encapsulates the nine knowledge areas of project management and links to quality assurance, the duty of due diligence and, importantly, an auditable trail in terms of project documentation, project costs and quality control. The project has carefully scoped the project with the development of a WBS (Work Breakdown Structure) and has aligned this to the ATA standard, which is internationally accepted. A detailed project charter has been produced to provide a preliminary delineation of roles and responsibilities, an outline of the project objectives, and an identification of the main stakeholders. The document serves as a reference of authority for the project’s future. A PEP (project execution plan) has also been developed and provides the governing document that establishes the means to execute, monitor, and control the project. The execution plan serves as the critical communication vehicle to ensure everyone is aware and knowledgeable of project objectives and how they will be accomplished. The plan is the primary agreement between SAAF and the FSAAFM/Spitfire Restoration team. It will remain a living document and be updated to describe current and future processes and procedures, such as integrating safety into the restoration process. The project is developing a detailed project schedule for the Spitfire project incorporating the WBS codification and is based on an agreed approach that defines the major work packages of the project.
As detailed by the Project Managers and Engineers above, we expect to push forward with the stripping process shortly.
To our friends, the technicians/engineers
We know that you all have an eternal desire to have a spanner in your hand and keep busy. We have designed splinter projects in the last few months and will continue like this.
|Air Show Preparation – Completed||Rotating Plynth for model Spitfire – Completed|
|Workshop Restoration – In progress||Stores Identification – Cleaning, repairing, labelling|
|New Workshop Planning||Proposed skill training sessions.|
|Procure/Build aircraft slave trolley||Dressing the dummy – obtain spitfire pilot clothing|
|Scrapyard Challenge||Gathering/Cataloging imperial spanners, tools and machines.|
|Assisting the “Friends” with other projects|
More ideas are always required, as are your skills, advice and assistance. Your networking is also needed. Please shout the words ‘Spitfire’ at all your gatherings. Let’s keep the names rolling in!