How rich to own and operate a Spitfire?

[Confabulous]

Anyone know if the story that the Hurricane was negatively stable in pitch is true?

[IO540]

Wot you mean like a Tomahawk?

[Lowtimer]

Haven't flown either personally but from reputable historical and modern reports quite a lot of Spitfires and Hurricanes are / were unstable in pitch. There is a lot of variation between individual aircraft, not just because of major mark differences but also because of individual bits of kit fitted or not fitted. During WW2 a great deal of hardware tended to be loaded into aeroplanes over their service lives, most of it steadily moving the CG back. Radios, IFF sets, extra this, bolt-on that, etc. The Shuttleworth Sea Hurricane was seriously tail-heavy and unstable in pitch until they got rid of the tail hook and replaced it with a lightweight composite replica. The consensus on a well set up Hurricane is that it is just about pitch-stable in most modes of flight but very weak, possibly slightly divergent in a full-power climb. Deakin's Avweb piece on flying the Hurricane here is quite illuminating.
http://www.avweb.com/news/columns/185849-1.html
As for the maintenance requirement... well, it depends what you call maintenance. You're not having to re-arm them and re-charge the oxygen systems these days. but on the other hand you are paying a great deal more attention to care of the engine and prop than would have been the case in WW2. If you have to fly through a rain shower with wooden prop bladed, you may well end up having a pre-emptive refinish of the blades rather than end up having to replace them at hideous expense in a few months' time. During WW2 nobody needed to think like that. Lots of pre-heating, oil analysis, a near-fanatical inspection regime, and a generally pre-emptive approach to anything going even slightly wrong, for wear, for corrosion etc., is what keeps a highly tuned machine going safely, for which the expected service life at time of original manufacture was a maximum of few years and a few hundred flying hours. Just the cleaning, in order to spot any unusual dribbles or stains, or any defects that might be hidden, and to keep the aeroplane looking nice, is a major task.
According to a P-51 crew chief in Flight Journal here - http://www.flightjournal.com/article...crewchief1.asp
a P-51, which he regards as a low-maintenance aeroplane compared to a P-38 or P-47 still takes lots of TLC even when new. His comment on a maximum plug life of 15 to 20 hours is, just by itself, a fairly serious source of labour hours, when you consider the time taked to remove, properly inspect, clean, gap and refit 24 plugs without damaging anything, including yourself, in the process.

[High Wing Drifter]

Lowtimer,

but on the other hand you are paying a great deal more attention to care of the engine and prop than would have been the case in WW2. Lots of pre-heating, oil analysis, a near-fanatical inspection regime, and a generally pre-emptive approach to anything going even slightly wrong

This reminds me a comment that Martin Brundle made after the recent Imola GP where there wasn't a single retirement inspite of engines needing to last two full weekends. He basically commented that i appears that previous year's unreliability problems stemmed from the constant preventive maintenance Probably apples and oranges, but food for thought (pardon the pun).

[Lowtimer]

I think that's a very good point in some contexts. Assembling and disassembling things, it often makes them go wrong or wear out, especially if they are engineered to very fine tolerances as modern machinery often is. I used to rebuild crossflow Ford engines in Mark 1 and Mark 2 Escorts, A-series lumps and old XKs all the time, and with some love and care it was not very hard to make one that fitted together better, ran smoother and lasted longer than they came out of the factory. But there's no way I'd take apart the major moving components of my 94,000 mile BMW diesel straight-six, even if I had the facilities. I might in the fullness of time replace the injectors but I don't think it would be improved for a hand rebuild that included re-ringing, replacing the main bearings, or any of the things we used to do quire routinely. I'd never be able to hand-build an engine of that power and economy to be absolutely oil-tight and emissions compliant the way it is now, it would just not be as good as it has become by running-in from a factory build. But for lower tolerance old-fashioned things, pre CNC tooling, machines characterised by deliberate oil consumption, big parts and grease nipples everywhere, they can usefully absorb quite a lot of maintenance without being seriously disassembled, and indeed be designed to receive it.
There's a really good article on "disturbing things" by Bud Davidsson, here:
http://www.airbum.com/grassroots/GrassrootsKarma.html

[TwoDeadDogs]

Hi all
Sometimes I wonder if those aircraft are over-maintained. After all,virtually all of them have been rebuilt with modern materials. There should be no reason why one couldn't operate them in a modern fashion,ie; leave out the excessive fettling and just fly them and fix what's actually broken,using an intelligent modern maintenance schedule. Perhaps people need to have a little more faith in aluminium and steel and a little less obsession with analysing everything to death.I can understand minding the engine carefully but surely there's scope for a bit more flexibility.
regards
TDD

[bingoboy]

Assuming you've the cash and will to buy and fly a Spitfire then surely the first hour is very expensive and every one after that a lot cheaper. (Unless the £50 insurance is of the by the hour type)

[yakker]

HWD, the reason the engines have been more reliable is not due to maintenance but the engineering design. At the cutting edge of technology parts are designed so the engine lasts one race, but with the new rules the penalty for engine failure is quite severe. As a for instance the cylinder head bolts are now made from different materials, different machine processes to make sure they do not fail, the cost of these bolts is 8 times the originals!

Lowtimer, if your BMW was being raced then the engine would benefit from being stripped and rebuilt, just as the Escort engines did. However the starting point would be better as modern parts are better quality and accuracy, but a road car engine is still only built to a standard. For instance, a crank from a modern engine is better balanced but still not as good as it could be, back to costs again.

With regard to aircraft engines, I do sometimes think we over maintain them. After all a Merlin engine has been run long enough to know its weaknesses, and surely these weaknesses are the only points we really need to keep an eye on. Our Yak had another engine fitted at 500 hours, when the 'old' engine was running well. In the USA they are run on condition, and have clocked thousands of hours with no problems.

[Dannyboyblue]

Well if anybody fancies a project,,,,,,,,

I have an 80% replica for sale, pm me if youre interested.

Chatting to mark hanna while he was refueling his spit in dundee in 1997 we chatted about costs, he said maitenance costs alone took 70% of his budget. I think he put 350 litres of avgas in for a 2 hour flight! They are expensive beasts.

Good old mark, sorely missed