REFLECTIONS ON STATIC AIRCRAFT RESTORATION
Chapter 4 - Objectives and Work
Malcolm Lambert

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922 If, after your initial assessment, you have decided to go ahead and work towards restoring your project you then have to discuss how far you actually want to go with it. Important to let your management team know your objectives before you start as they might have a completely different idea of your time scale than you do. Considerable extra time will be involved if, as with WF922, you want to have the aircraft as an up and running working exhibit, or even to ground run the aircraft. If you realise as you progress that your goals are either unachievable or indeed become more likely as you discover that everything is intact, talk it through with the museum management as they might discover that they have a real gem on their hands that they need to plan ahead for.

In the case of WF922 after its recovery from Marshalls and a rudimentary assembly the aircraft only saw some cosmetic cockpit attention and very little else. Now this itself was a blessing in disguise for me as it meant that I had an almost untouched airframe that had made only one ground move from being a flying machine. So my objectives (after discussion) were to restore the aircraft to as fully operational a state as I could. Now running engines etc might float some people's boat but it doesn’t mine. I have stood alongside too many cartridge started, running Avons in my service career to be enthralled by the noise or smell of them ever again. So that was a path that we agreed never to pursue. Apart from that the health and safety aspects of ground running engines were far to deep for me to want to get involved with. If however that is your driving ambition and you aspire to the dizzy heights of engine running please check with the powers that be that it is within their remit and insurance and that they have someone who is qualified and has the necessary engineering experience to help you. A lot of organisations view engine running and taxying of aircraft as a definite area to avoid so it might form part of your initial assessment of suitability before you get involved.

Hydraulics
Anyway, I wasn’t above getting my hands dirty on the hydraulic side of the project. After remaking the connections on the wing breaks, ie undercarriage, flaps, air brakes, I fitted a new hydraulic hand pump and filled up the reservoir. Although not trained as an airframe fitter I had had a fair bit of hydraulic experience in helping out during hangar servicing and I knew that once all of the nitrogen pressures are exhausted hydraulics are just a slow electrical circuit - and best of all you can see the leaks. Leaks there were aplenty but mainly due to me not wanting to over tighten the unions due to their age. The forward flare bay door ram had to be replaced because it leaked very badly but all of the rest of the systems operated and still operate via the hand pump on a regular basis.

So you can see that with such things as hydraulics or pneumatics aircraft constructors make it easy to join things up. Providing that you check that the object at the end of the ram is free to move and wont cause any secondary affects (like raising the wheels) there is no reason why, when staged and taken slowly, an aircraft system cannot be given some life (if that’s what you want). Just one caveat though, as you might run up against a case of hacksaw over-enthusiasm left over from the aircraft move. To avoid wasting a lot of hydraulic fluid make sure you check that there are no pipelines that have been attacked in this way. If they have and access is possible just put in another in line-joint and record its location. I had a case on WF922 where a pipe had been broken close to a transport joint with no access to the other side. Luckily it was a brass pipe so with the aid of an insert to give it strength I was able to solder a new pipe in place. I then cleared the aircraft as suitable for hand pump use only.

Electrics
I have often been asked about the criteria to use and the checks to be made before re-establishing ground power to an aircraft that has been supposedly silently corroding for the best part of 35 or more years. Luckily I was trained and worked on Canberras and fully understood the various rewiring stages that they underwent during their service career. Most, if they survived, were almost completely rewired at some stage with a post war cable with a rot-proof (not mouse proof though) glass fibre outer sheath, only small areas were left with original rubber covered wiring. If you take an early example of a Meteor for example with original rubber covered wiring there would be no safe method of applying power to the aircraft as the rubber outer sheath just crumbles to dust over time and leaves exposed inner wiring. So I knew from the outset that the aircraft should be OK to apply power, with perhaps the exception of any badly water filled junction boxes that I might run across.

Once again harping back to the over-engineering that took place I was fairly confident that if I could apply power most of the contactors and relays should work. I’ll continue in this theme although it isn’t chronologically correct as I did the airframe first. If you have the aircraft Vol 1 to hand it is quite easy to familiarise yourself with the loom marking system used on the aircraft. If not you must make a careful note of all the sleeve markings to ensure that you match up the correct plug and sockets when the time comes.

Several plugs had been removed on WF922 and some plugs even taken apart, these had to be replaced or made good and re-connected. The pilot’s main panel was by this time re-populated with the correct instruments in the correct positions. A good way to ascertain the correct location of instruments in an aircraft panel actually fitted to an aircraft is to look at the yellow sleeves on the instrument plugs. These will give a good indication of what instrument went where, very important when you have a mix of avionic instruments to locate. Blind flying panel instrument locations can often be found from either the Pilots Notes, aircraft manuals or an internet source. Every aircraft even of the same mark will almost certainly be different so nobody is going to categorically say you are wrong unless you are doing a “Classic”. The port console on WF922 was missing completely but the plugs were intact and bagged, therefore the cockpit area was deemed safe.

Inspection after inspection of junction boxes and contactors in all the fuselage areas took some time but had to be done. Looms and plugs in the rear hatch were inspected during the airframe anti-corrosion treatment that was on going as well. All supply circuit breakers to engine and fuel services were open circuited and there was no further reason why I shouldn’t give it a try. Now you don’t just get the nearest Houchin ground power unit and plug it in to a museum aircraft, a little more subtly is required than that. I obtained a couple of 12v 4 A/H lead acid batteries that are used to power burglar alarms, wired them to give me 24 volts ready to use on the original battery terminals. The thinking behind this being that if I had a direct short circuit the batteries would run down very quickly before any damage could ensue, but that they would have enough power to sustain the battery circuit breaker whilst I did the visual walk and smell around inspection.

Fire extinguisher to hand and without any fuss (except one trusted companion), the batteries were connected. A walk round to the cockpit, finger on the Battery Isolation switch and a very satisfying “clunk”, from the side hatch as the battery contactor closed when the switch was operated. On and Off again to make sure it was going to stay working and then a glance around the cockpit to see the results, generator lights were on and bright which was a good indication that there was no short circuit, voltmeter reading about 23 volts, most importantly no smell of burning or anything in distress.

A walk-around and climb in to all the compartments proved fine so after about five minutes I switched it all off and declared the aircraft electrics safe to carry on with. A lot further down the line, with two switched-mode power supplies in place to provide the power, a completely scratch built port console, serviced invertors, re-wired lighting console, fabricated working camera control panels, the whole aircraft is regularly powered up. Radios crackle in to life, instruments erect, night flying checks can be completed, and we now even have a film-less but working F52 camera.

A certain degree of self-help and imagination is required when trying to source equipment for any project, your idea of what is a 'must have', might not be the same as the museum’s. Remember they are usually on a budget which doesn’t stretch to exotic items that perhaps don’t enhance the aircraft's external appearance. Make a wish-list of items that you require and when you visit other establishments you can leave it with them. A lot of swapping of parts does go on, but be prepared to make the odd donation here and there as well - others have wish-lists too.

The above fulfilled one of my promised objectives to the museum, to have the electrical systems fully and safely working for the museum exhibit. A long process that was documented and photographed every step of the way for the whole two years. Anyone who wants to or has not already read the quarterly reports can do so on the Canberra Tribute site of course (hyperlinks at the top).


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