Buzzed by Spitfire!

Edit: Unfortunately I cannot find a detail photo of the item in question.

... However, this might help avoid any misunderstanding.

MichaelG.

Edited By Michael Gilligan on 17/06/2014 12:59:08

Slaving away on the repetition lathe this afternoon for work, I heard aircraft engines, big 'n' heavy. Given that there is an airshow at Duxford this weekend, it seemed worthwhile running out into the garden. Worth it indeed, I watched the Lancaster fly right over the bungalow at about 1000 feet, accompanied by the Hurricane, but no Spitfire I could see. They would have flown right through the ATZ at Bourn, but that may well have been a salute to the Lancasters and their crews that were based at Bourn during the war.

Andrew

At home four miles north of Shuttleworth Museum, had a hurricane and another pass between us heading towards Cambridge way earlier this afternoon.

Martin P

Spitfire just gone over Chalgrove heading east.

Mike

Saw a Spitfire fairly close up yesterday. I was towing a glider prior to launching a competition grid. As we were climbing through 1500 feet a Spitfire flashed by head on, about 500 feet above and a couple of hundred feet to the left, heading towards Duxford. The Spitfire had D-Day markings, so presumably Griffon powered.

As a little light relief I also flew into RAF Wyton yesterday afternoon to retrieve a glider; not been there before. The approach and tower ATC were very friendly and gave clear instructions, fitting us in between the RAF training flights. They even delivered the glider pilot back to his glider in a big red fire engine along with three firemen in full protective gear to give us a hand. I expect the short trip in the fire engine burnt more fuel than I used doing the retrieve.

Andrew

I've often wondered - what sort of 'mpg' do you get with a light aircraft?

Neil

What sort of 'mpg' do you get with a light aircraft? Not sure;but a racing RR Merlin at Reno manages achieves about 0.44 mpg or 210 gph (big imperial gallons not the US kind)

The Unlimited class RR Merlin powered racers go flashing around the Reno racecourse mighty fast. Four hundred eighty miles an hour is 8 miles a minute, and the elite racers take about 70 seconds to cover the 9.1 mile Reno course. If you could take a souped P-51 racer flying the circuit at Reno, slow time down, and examine just one second, what would you find?

In that one second, the V-12 Rolls-Royce Merlin engine would have gone through 60 revolutions, with each of the 48 valves slamming open and closed 30 times. The twenty four spark plugs have fired 720 times. Each piston has traveled a total of 60 feet in linear distance at an average speed of 41 miles per hour, with the direction of movement reversing 180° after every 6 inches. Three hundred and sixty power pulses have been transmitted to the crankshaft, making 360 sonic booms as the exhaust gas is expelled from the cylinder with a velocity exceeding the speed of sound. The water pump impeller has spun 90 revolutions, sending 4 gallons of coolant surging through the engine and radiators. The oil pumps have forced 47 fluid ounces, roughly one-third gallon, of oil through the engine, oil cooler, and oil tank, scavenging heat and lubricating the flailing machinery. The supercharger rotor has completed 348 revolutions, its rim spinning at Mach 1, forcing 4.2 pounds or 55 ft³ of ambient air into the combustion chambers under 3 atmospheres of boost pressure. Around 9 fluid ounces of high octane aviation fuel, 7,843 BTUs of energy, has been injected into the carburetor along with 5.3 fluid ounces of methanol/water anti-detonant injection fluid. Perhaps 1/8 fluid ounce of engine oil has been either combusted or blown overboard via the crankcase breather tube. Over 1.65 million foot pounds of work have been done, the equivalent of lifting a station wagon to the top of the Statue of Liberty.

In that one second, the hard-running Merlin has turned the propeller through 25 complete revolutions, with each of the blade tips having arced through a distance of 884 feet at a rotational velocity of 0.8 Mach. Fifteen fluid ounces of spray bar water has been atomized and spread across the face of the radiator to accelerate the transfer of waste heat from the cooling system to the atmosphere.

In that one second, the aircraft itself has traveled 704 feet, close to 1/8 mile, or roughly 1.5% of a single lap. The pilot's heart has taken 1.5 beats, pumping 5.4 fluid ounces of blood through his body at a peak pressure of 4.7 inches of mercury over ambient pressure. Our pilot happened to inspire during our measured second, inhaling approximately 30 cubic inches (0.5 liter) of oxygen from the on-board system, and 2.4 million, yes million, new red blood cells have been formed in the pilot's bone marrow.

It's the world's fastest motorsport. Don't blink!

Saw THE Vulcan bomber pass overhead some time around the 5th or 6th Aug. Can't recall exactly where I was but it would have been somewhere in the Yorks / Lancs (Pennines) area. Very majestic and ominous.Presumably on a test run or heading to an air show.

Last saw one in the flesh at an air show just outside Doncaster in the mid to late eighties. Took off and immediately went into what looked like a vertical climb. You could almost feel the noise in your bowels. A phenomenon I'll never forget that!

Murray

Neil,

We cruise our old Beagle Pup 150 at 95 knots and burn a little over 30 litres per hour. That makes it about 16mpg. (How about that for a mixture of units?)

But the Pup is rather blunt and modern composite technology will do much better.

Regards,

Trevor

I have a hazy recollection that the RF3 that I used to fly did 50mpg at 100mph. However, it was a pretty small engine; a converted 1200cc VW Beetle engine.

Earlier this evening I did an out and return from Gransden Lodge (west of Cambridge) to Rougham (east of Bury St. Edmunds). Straight line distance is 120km there and back. I did a bit of detour each way around Cambridge to avoid the airport, and a heavy rain shower on the way back. So let's say total distance was 130km, about 80 miles. I started full and put in 5.4 gallons when I got back, so 14.8mpg. But life is never that simple; when I got to Rougham I did a quick circuit to make sure I had the correct airfield, as I've never landed there before. I then called an overhead join, and was promptly asked to wait as a student was doing her second solo flight; fair enough. Then followed a 15 minute wait while the student sorted herself out and did a couple of circuits. The total flight time was about 1 hour 20 minutes, but I reckon I wasted 20 minutes in total orbiting. So lets say the trip itself was only 75% of the fuel burn. That gives about 19.8mpg. Not great, but in my defence we have a fine pitch propeller on the aircraft which is good for towing but not so good in the cruise. I also had a glider on the back for almost all of the return trip, which is extra drag.

Cruise speed on the way out was 90knots, and 80knots on the way back. On the way back the engine was doing 2500rpm; With a normal propeller a cruise of 100+ knots would be at 2300rpm.

That's a long winded way of saying the light aircraft mpg are probably a bit lower than modern cars, but of course the cruise speeds are higher. Oh, and the engine technology is archaic. For those unfamiliar with knots 100kts is 115mph.

Andrew

Yes, but what about a Cessna?

Neil

No idea, as I don't fly them - Andrew

Neil,

Cessna 150/152 = 'Between 15 and 22 miles per gallon' (U.S. gallons)

So, say 18 to 26.5 miles to UK gallons.

**LINK**

Regards, (and wishing you happy flying),

Phil

Edited By Weary on 20/08/2014 21:34:57

Normal way of considering fuel consumption with aircraft is by fuel flow, ie., Andrews Pawnee probably cruises at something like 10 gal per hour (never got round to litres), with a constant speed prop it might be nearer 8 to 9gph, A Cessna 180 would be maybe 10 to 12gph.   A  Cessna 172, depending on which engine, and which prop (fixed pitch), could be from 6 to 11 gph, while a Cessna 150 would be around 5 gph with a Continental O-200/ 100hp engine.  It all depends on the individual aircraft, the propeller, how much extra junk you carry on board, ie., the all up weight, even the CofG effects it, if it's too far fore ward or back the machine has to be trimmed  to suit, adding a little drag.  It's all too complicated, maybe that's why gliding is so popular.

Some also quote the fuel consumption in pounds per horse power per hour, or just pounds per hour.

Ian S C 

Edited By Ian S C on 21/08/2014 11:40:44

Posting delay - that was meant to be a smartass come-back to the 'racing merlin' post!

Neil

(anybody remember OLR lag?)

So in very broad terms, comparable to a car.

I always wondered as the 'work done' is (again in very broad terms) comparable but you imagine it takes much more energy just to keep the thing 'up'.

Neil

Was buzzed by a Spitfire at last years Halfpenny Green Wings & Wheels (photos) hoping it makes a return at this years show 24th/25th Aug.

Neil,

That's very perceptive of you. In broad terms, when an aircraft is being flown as efficiently as possible the energy expended to stay up and that used against the frictional drag are equal. You might like to see **LINK**. It's an extract from the book "Sustainable Energy, without the hot air" by David MacKay, in my view one of the best works of 'popular' science of recent years.

Regards,

Trevor

50 mpg from a 1200 beetle engine, that is amazing. Never got much better than 30 mpg from my old beetle.

Next on the list is to look out for is the development of electric power aircraft, there are some flying now, even Airbus is in on it with an aircraft called the E-Fan, using two ducted fans, a fight duration of 45 minutes at something over 200mph, recharge 1hr.

Ian S C