RNHF news update June 2009

Taken from the RNHF web site and pasted over the news below.

WE’RE STILL HERE! SUMMER UPDATE – 25 JUNE 2009

Apologies for not updating the website lately. There has been a lot going on and things have been changing faster than I can type! I do like to keep supporters informed and not seeing us at booked shows does ilicit speculation. There are complex reasons, mostly beyond our control and hugely frustrating for all of us in the Flight. However, surprisingly the ‘boys’ are gritting their teeth and getting on with it as fast as they can, retaining their Naval sense of humour in the process.

Firstly the positive news: Howard Read and I spent a few days in Tehachapi, California, visiting ‘Vintage V12’ to check on progress of our Centaurus and buy another as a spare. These are becoming very rare indeed as one or two vital parts become scarce. The ‘new’ engine looked very good indeed, we viewed it in a stripped condition and were able to see all of the internal components. I was very impressed and Howard ran his Chief Engineer’s eye over it appreciatively too. It was in better condition than our present engine and we decided that the new unit should be finished as a matter of urgency with the original to follow at a more leisurely pace. Vintage V12 stated the autumn as the target, but that is dependant on us providing a new set of piston rings. Read more on that subject below. The original engine, you may remember, was pulled just prior to it seizing two sleeves and we had some difficulty removing 7 and 8 cylinders because of ovality in these sleeves. This was caused by heat and the extra side force imparted by the two master con rods. Unfortunately the extra load of the stiff sleeves was transmitted to some of the smaller parts in the gear train causing collateral damage. However, all is recoverable, Vintage V12 have most of the parts required for the rebuild and we are helping source one or two they can’t find.

Whilst on Sea Furies, VX281 is looking very much better for a coat of paint and eagerly awaits roundels and codes. In the meantime she will be booked in for the road trip back to North Weald to be mated with her engine, which looks better than new after a full strip, measure and inspect. The timeframe is uncertain and dependant on other factors, but it should happen fairly soon.

Swordfish LS326’s Pegasus engine was rebuilt, mounted on Deltair’s test bed and run at Lee-on-Solent to great jubilation, starting easily and running smoothly. However, subsequent oil samples indicated that ferrous material was being ‘made’ in the engine which could only really come from piston rings or cylinders. The engine was therefore stripped to investigate, but no conclusive evidence of enhanced wear found. In the meantime a report from our Materials Integrity Group indicated that the rings we had been using were made of incorrect specification material, containing chrome and copper and with the wrong ‘grain’ structure, so it was decided that we wouldn’t go any further until we could make some new rings from the correct material. Therein lies the problem I’m sorry to say, in that the correct material cannot be sourced in the UK and our order with a Polish smelter has produced no metal in the last 9 months! The same metal is required for the Centaurus, for whom an order was placed. At the time of writing we believe there are enough billets to make one set each of Pegasus and Swordfish rings available very soon. Fingers firmly crossed. Once the metal is here it will take two weeks to manufacture the rings and probably another week or so to reassemble the engine and put it through a test programme before fitting to LS326. We all sincerely hope this happens before the season is finished and could realistically be as soon as mid August.

The Sea Hawk was about to receive its ‘new’ engine when we were put back a pace or two by being told we couldn’t use a Nene 10 (donated by a T33) in place of a Nene 103. It appears there are small differences in the Nimonic alloy used in the rotating assembly, a slightly different RPM regime and slightly different power output. In these days of litigation and responsibility for public safety our engine authority were unable to put in the design effort required to underwrite what they saw as a major modification. Disappointing not to have been told earlier, having spent two months preparing the engine, but we nonetheless got on with repairing the Mk 103 and indeed completed its rebuild in very quick time. It was fitted and ground run, proving to produce full power at lower temperatures, and taken for a couple of taxi tests. Unfortunately on one of these runs a wing fold hydraulic coupling failed, squirting fluid all over the hardstanding. Access to this part was impossible without removing the wing, so off it came and repairs carried out in fairly short order. Halfway through this work an Urgent Technical Instruction was issued, requiring us to remove all hydraulic jacks for NDT and repainting! This was not connected to the Sea Hawk particularly, but as the result of another investigation into a problem with an Andover undercarriage, where pitting corrosion was a factor in a jack failure. We are halfway through removing the undercarriage as I type and should have the job done in a couple of weeks. The nose undercarriage I am assured is awkward, needing Dickie Dawes’ small frame and thin arms to effect removal!