Aircraft General Discussion

If I remember my (very basic) supersonic aerodynamics the story goes something like this. In the 1950s it was known that the drag of a supersonic aerofoil was very dependent on span, so the ideal planform was a short, but wide, wing; have a look at the F-104 Starfighter. However, a wing like this is hopeless at low, sub-sonic, speeds, leading to very high takeoff and landing speeds, thus needing very long runways. It was also known, as a curiosity, that a delta wing, at high angles of attack, could produce a large vortex on the leading edge, lowering the pressure on the top of the wing and greatly increasing the lift. Once this effect was established as viable, detail design of Concorde commenced. It also explains why Concorde has a long undercarriage, lands in a very nose high attitude, and hence needed the droop nose so the pilot could see ahead.

I watched Concorde land at Farnborough in 1976, prior to the SBAC show. The aircraft was presumably fairly light, but the pilot made two low passes and then landed, using almost all of the 6000ft runway. At that time the static load test rig for Concorde was still operational at Farnborough, and as part of my training course we had a tour of it.

Andrew

A very frequently reproduced photograph in books on aerodynamics is Concorde heading straight at the camera on a damp day with a dark unfocused background. It shows an enormous vortex over each wing.

As for the F104 Starfighter, it was the ultimate first generation supersonic aircraft: Went very very fast with no range and did nothing other than kill its pilot (particularly if he was German).

JA

Deconvolution in Astra Image, brilliant at pulling out fine detail, much better than normal sharpening, it uses deconvolution the technique that they used to salvage good results from the Hubble before adding correcting mirrors.

Sadly the free version 3 is no longer available

Neil

One way to keep the (Concord[e]) weight down Bob - `… a few plastic covered balsa wood toilet seats …’

Drifting further OT - Thanks for your greeting and advice Norman. In this case my lighting comes from two LED clip-on bench lights one on either side, See picture.

They hardly get warm, so fire should not be an issue. I have lowered the lights, and a couple of diffusers should make the difference. This form of lighting might also produce some better images from the polished brass of my skeleton clock. As you can see, the shaft extensions of a couple of wood clamps make useful stands.

Your son seems to be in the right place currently. The Melbourne weather has been bitter and damp. I’m waiting for it to improve so that I can spend more time in the garage copying old prints and capturing images of my skeleton clock.

Thanks for your delta-wing notes Andrew. As always, you explain the situation clearly enough for so blokes like me can understand it.

Ah! Neil. I thought `sharpen’ was smart, but Astra Image Deconvolution is amazing.

Regards to all,

Sam

B U double G RRRRRRRRRRRR

Not quick enough to the camera as the Vulcan just flew over the house at reasonably low level probably 1 to 2k ft

Bob

Terrible news, a Hawker Hunter has crashed into cars on the A27 at Shoreham airshow

Sadly there appear to be several casualties.

Neil

.

The video of that loop looked sickeningly familiar ... Took me back instantly to 1992 when I watched a Spitfire do the same thing at the Woodford Airshow ... Mercifully, on that occasion, none of the public was hurt.

MichaelG.

I like the Concorde photos. It used to bank over my house in Poole when the Bournemouth air show was at Hurn. I never got to make Concorde parts except for the candlestick jacks that I believe supported the wings when the under carriage was being maintained. I did work on the Super guppy mentioned but only on a replacement wing holding fixture.

Edited By David Clark 1 on 22/08/2015 17:54:23

Every year those old planes become a year older, the pilots on average a year younger (relatively) / less experienced with old planes and their limitations yet they are expected to open them up and show them off to the assembled audience. I wouldn't want to ban old planes from flying but what would you expect to happen with time when these circumstances combine? The probability of an incident can only increase surely.

When I lived near Duxford I liked seeing the bombers and fighters circling overhead but I used to feel nervous all the same.

Tragic and shocking outcome with many people affected.

The pilot was an ex Harrier pilot, and (I think) current airline pilot. Ian S C

Yes, hardly a spring chicken. We''ll have to wait and see what the AIB come up with. A few years ago an experienced pilot fatally crashed a FW190 on t/o or landing, despite his long record of flying THIS aircraft, it transpired Wind Shear was the cause, not a lot he could do about that, wonder what the air movement was/is above the road?

Regards Ian.

Physics ... doesn't change!! Temperature, pressure, air density but, particularly, 'topping out' a vertical manoeuvre too low and the bottom of the pullout will hurt!! The lessons are there to be learnt - Abingdon F4 , Hunter demo to the Swiss Air Force by a senior test pilot (almost). Overcooking things to please a bunch of goggling thrill-seekers is, ultimately, always going to end badly.

As one who had to clear up the mess from these and similar events, it is NEVER worth it

rgds

Bill

I must admit that if I won a competition to fly in an old classic aircraft like a spitfire I would politely decline

Having seen apparently cohesive metal snap like balsa wood on my lathe after a lot of use (fatigue) has made me very wary of old metal

Modern replicas would be better IMO

It's big business though, and I love to see the oldies that still fly

As somebody who helped restore old aircraft at Duxford albeit for static display I was fortunate to see how flying aircraft are restored and maintained I can tell you that airframes are stripped bare and then new material replaces the material removed if there is any damage or corrosion, rivets are replaced and all parts for the mechanicals have finite life just like modern aircraft, they are required to have there own type of MOT, a good case in point is the Vulcan, its not ending its flying this year because of any structural problems its because the companies that look after the engines, avionics, undercarriage structures cannot support the repair and servicing of these components any more so the aircraft cant fly, every vintage aircraft spends more hours in a hanger annually being checked, serviced or repaired than it does actually flying

Martin P

A competition to fly in an old plane? Good idea, I have always wanted to fly in a EE Lightning, next best but regretably impossible TSR2

I'd be fighting my way to the front of the queue. I'm even considering paying for the privilege. Might as well spend the pension money before that 'nice' Mr. Corbyn confiscates it.

It seems that it is still possible to fly in a Lightning at Thunder City in South Africa. They stopped for a while after a crash a few years ago. However, it is eye-wateringly expensive. Last time I looked it was around $20000 for a short flight. The Lightning was an interceptor, so it didn't have, or need, much endurance.

Andrew

I missed out on a flight in one of the B17's that were used to make Memphis Bell, I had moved away and changed my job so had to stop volunteering at Duxford, the film crew were looking for extra's to man the gun positions in the aircraft and all my crew mates on Mary Alice the museums B17 put themselves forward and flew in several of the aircraft, jealous or what

Martin P

After the Hunter crash (plus the Swiss Airshow collision), I expect to see the inevitable media frenzy about Air Displays this week.

Edited By V8Eng on 23/08/2015 22:21:20

Kwill, I managed to get a flight in a lightning T5 just before I was de-mobbed in the 80's. Awesome!!!

From latest low level film, it gives the impression of a flame out and trying to spool the engine up but not enough height.

Regards Ian.