One ongoing problem I have yet to solve is how to pump air into the landing struts. The manual mentions that a tool is required with a spindle to depress the valve. I would like to make a tool but the valve has a male thread around 13.25mm ie bigger than a Schrader and I am yet to determine if the thread is metric, american or something else. Nothing I have tried has been a perfect fit so far and quite a few engineers have now scratched their heads over this.
January 2019
One problem fixed during the annual check was the very stiff operation of the flaps. In the picture the rear seat has been removed to reveal the flap jack screw. With some fresh lubrication the system works a treat. We rarely practised forced landings due to the effort of moving the flaps but now intend to do a few more. Still no luck fixing the flap indicator but counting the turns works for us.
Annual Check 2018
This year I have decided to do things a little differently. In the past we have flown the aircraft to Farley Farm and the excellant Mike Smart has taken care of the ARC renewal. Locally Mike Powell was available and we are able to do the check at Tibenham with G-EJBI in her hangar. It has given both myself and Andrew a great opportunity to get invoved. We are awaiting a couple of oil hoses and should have her finished this week.
Tail Wheel 2
It’s amazing what you miss, preflight checking the same plane the same way each flight. It took another pair of rather more qualified eyes, to point out the rather high level of corrosion on our tail wheel assembly. The original assembly had been removed (see earlier Tail Wheel post), powder coated and rebuilt. This was fitted but unfortunately the torsion rubber seemed to be ‘weak’ and the tail height was much too low. Between the two assemblies we have enough servicable parts to go flying but would like to source a replacement rubber. I am not sure if this is an available spare part or maybe it could be fabricated.
Annual Maintenance
Our next trip after Donauwörth was to Farley Farm for annual maintenance. I flew down in the left seat, must have all of 5 hours logged on type now! The idea was that I would go back down and help out with some of the work but when I called Mike a few weeks latter, somewhat surprised, G-EJBI was ready to be collected. Well not quite, she would not start. It was off with the old ‘lightweight’ starter motor and a new ‘heavy’ one fitted. I will discuss G-EJBI’s new found reluctance to start in a latter post. Here is a picture of D-EBLI which has been at the farm for a few years now, would love to see her back in the skies.
Tibenham Local
At the 50 hour check, Tony made a passing comment, that temporary repairs have a habit of becomming permanent. Well, we did replace all the SCAT hoses but the battery earth cable is still a work in progress. I need to source a secondary door lock before next months annual check, I have bought about 5 locks thinking they will be ok but they don’t seem right, an original item would be best. Pictured here is Andrew at Tibenham before a local flight.
More Screws
OK, so I am still banging on about the variety of sizes of screws all over the airplane. The lower wing to fuselage panels are somewhat over engineered with a large number of fixings which is just as well considering the number which are the wrong size or stripped thread. I am replacing with the correct size but have found an aviation source for M4 x 16 raised slotted stainless difficult to find.
Metric Screws
Taking the lower cowling off to replace the SCAT hoses revealed that the biggest assortment of metric and UNF hardware you could imagine was being used to fasten the cowling. It appears to be pretty commonplace that metric hardware will gradually become diluted over time. I replaced some #10 UNF screws with their M5 metric equivalant, they are a little wider (.2mm) and now the correct length plus LAS were selling them at 8p (now 45p) which was a bit of a bargain!
Door Latch
The Bölkow 207 has, or should have, a secondary door latch on each of its rather large doors. G-EJBI latches are either missing or not working so I have been trying to find some replacements. So far I have bought four different latches and for one reason or another I am not happy with them. The original is in the picture and would love to find one of these.
50 Hour Check
Back to Farley Farm for a 50 hour check. Andrew and I stayed with the aircraft, the idea being to help out and learn what was involved. Not too sure we were much help but we enjoyed ourselves and learnt a lot. We stayed overnight as a few little jobs cropped up that required attention, one being a leaky exhaust gasket, and some repairs to the scat hose. Should do wonders to reduce the carbon monoxide level.