Lovely… Presuming the second half is filmed from the rear gun turret of a what… Lancaster ?

They saved Europe from the Germans…can we borrow em for a week?

Very impressed at how well they keep those machines. Also a good reminder of days gone by that shouldn’t be forgotten.

Amazing views!

Lovely piece of formation flying, amazing aircraft-Leo Mckinstry’s Spitfire, Portrait of a Legend is worth reading on the history of the Spit.
Irish aircorps has one, as far as I know, but the two seater trainer mark.

Great video for today – the 68th anniversary of D-Day!

Can anyone explain why the prop on the first plane to the left of the camera plane appears to be turning very slowly, almost as if the engine has stalled…. Just wondering.

Fantastic view, pity about the weather

Is it not the frame speed as opposed to the shutter speed? frame speed of commercial tv being 25 frames per second syncing with the prop speed making the prop appear to stand still when at a sub multiple of the frame speed. I’ve been thinking about this since watching the video and wondering how to arrive at an approximation of the engine speed. It seems that a reduction gearbox of .48 to 1 was fitted between the engine and the prop. Also the aircraft is fitted with a three blade prop so must be an early model. Not sure that the same blade is being synced always.

Mart_n. thanks for your posts, most interesting. I have tuned a guitar by using a free pc oscilloscope program and a microphone. One also sees harmonics (multiples of the fundamental frequency) on an oscilloscope That is another interesting subject as there are different methods of tuning, and different standards of pitch.

I was looking at the camera and assuming the camera was taking frames (Individual pics) at a rate of 25 frames per second then there would be 60*25 pics or frames per minute. 1500 framesper min. Playing around with the figures and again assuming that the film is syncing with every second rotor blade ( to get the rpm to fall within the egine spec of the spitfire which ithe final calc must do) gives a prop speed of 1500*0.66. Dividing that by 0.48, the gearbox reduction gives an engine speed of 2062.5 rpm. If the assumptions and calculations are correct correct the airspeed will come out at about 240 mph.
Pausing the video the prop appears to be a three blade prop so again I assumed that it is an early spitfire fitted with a non variable pitch prop.

When I was working in a telephone exchange (1971) the speed of the ringing machines ( motor generators) used to be checkecked with an instrument that looked like a tuning fork with two wings mounted between the forks with a slight gap between them. The gap was opened and shut according to the frequency of the tuning fork and when sighting through the fork the rotor was strobed and appeared still. A frame was therefore frozen in time, and if all the marks appeared still then the ringer was running at the right speed. I dont think the same black mark appeared in the same position each time, hence the need for muliple marks.There were multiple black marks on the rotor. The frequency output of the ringing current was 16.66 hertz. I can’t remember the tuning fork frequency but I think it was a harmonic of the ringer output, hence the number of black marks that were needed to sync.

Finally tv standard was 25 frames per sec interlaced which gave the impression of 50 frames per sec which made for flicker free viewing. (TVs seem to process the signal received a bit more now but that’s another story I think)
That’s why I came up with the assumption of syncing on every second rotor blade of the prop to get the engine speed with in limits and arrive at an airspeed approximation. (the 3 rotor blades would be analogous with the black marks on the ringer)

A strobe on a 4 cylinder car can be synced with either number one cylinder or number four cylinder so the strobe is running at half crankshaft speed, ie one flash every two revs of the crankshaft, a sub multiple of the fundamental frequency to make the timing mark appear still.

I may stand corrected but that’s what brainstorming is all about! If anyone knows the actual airspeed I would be glad to know!

I think that’s as close as its possible to get at from the assumptions made, but if one knew all the facts then it should be possible to arrive at an accurate figure.

Jaysus…that’s one big front garden the Queen has….

Propeller on that nearest plane at the start seems a bit hit and miss on a few occasions :-)

Don’t think the Russians flew Spitfires so no, they didn’t save Europe from the Germans.

Yawn Yawm zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz