Random facts about planes..

[dvs_dave]

uncinqsix said:

dvs_dave said:

The Boeing 777-200ER is the longest range commercial airliner. In 2005 it set a non-stop record of Hong Kong to London. The long way round. Over 13,400 miles, and 22hrs. Quite incredible.

[pedant] That was the -200LR wasn't it? [/pedant]

LR That's what I meant to say.

[Jos Notstoppen]

texaxile said:

I recall, with slight embarassment that on a Lockheed Tristar there were 5 toilets at the rear of the plane. They could be opened from the outside by using the end of a teaspoon which fitted into a small slot on the plastic "occupied" sign above the handle.

I managed to find this out by locking myself in one of the toilets deliberately after a fight with my older brother on what seemed like a 2 day flight to Muscat via everywhere except Muscat itself. After I'd been sat in the toilet for about half an hour a Hostess opened the door and took me up to the cockpit, where I was told off by the Captain but allowed to stay and watch for a while but told "Not to touch anything".

The Tristar rear loos were known as "Penny lane" by aircrew. There was also a nickname for the rear cabin section that I cannot recall, this aircraft type often operated the BA Saudi routes and often at the time filled with oilmen returning home and drinking (lots of) booze for the first time in months.
All aircraft toilet doors are openable from the outside, a couple of different ways known to the aircrew just in case the is a fire or emergency. (there are attendant call buttons in the loo). I recall once when I was aircrew, the toilet fire alarm going off, a couple of us dashed down, fire extinguishers in hand, opening the door to find a middle aged lady, half dressed. She had set off the alarm with hair spray. As someone else pointed out, loos also have 2 or 3 oxygen masks, I was told because there maybe parent and infant(s) in the toilet at the time.

[eccles]

Dr Jekyll said:

eccles said:

dvs_dave said:

The Boeing 777-200ER is the longest range commercial airliner. In 2005 it set a non-stop record of Hong Kong to London. The long way round. Over 13,400 miles, and 22hrs. Quite incredible.

And the long range tanks were designed and made in Cambridge.

Marshall's I take it? They do seem quite clever in Cambridge.

Yup.

[IroningMan]

dvs_dave said:

Prawo Jazdy said:

dvs_dave said:

That sawing noise you often hear on Airbus aircraft whilst taxiing is the power transfer unit (PTU) operating. Often only one engine is used for taxiing to save fuel, so in order to provide hydraulic power to the hydraulic system normally driven by the other engine, the PTU, driven by the running engine's hydraulic system provides that power instead.

Almost like a balancing system between the two separate circuits that also allows them both to function when only one engine is operational.

There's an electronic pump that can supply the system run by engine 2. There's three systems on an A320. The third is powered by an electric pump in normal operation, and by the RAT (mentioned in a previous post) if the electric pump fails.

For those interested here's a more detailed description of the system.
http://renewedpilot.com/2012/01/25/whats-the-loud-...

Still sounds like a handbrake to me.

[CanAm]

Atomic12C said:

CanAm said:

Without any power any aircraft can glide for some distance.
"Some distance" being likely to be a whole lot further for a Lockheed U2 than a Cessna 172.

A typical sparrow bird has a lift to drag ratio of 4:1, whereas an albatross is much more efficient with 20:1.
A modern glider which demonstrates the most efficient of wing profiles can have a lift to drag ratio of 60:1.

We have the Cessna at 9:1, the Gimli Glider Boeing 767 at 12:1 and I was very disappointed to find the U2, despite its very high aspect ratio wings, only has a glide ratio of 23:1; the rather stubby winged Messerschmitt Me163 (aspect ratio of less than 5:1) had a glide ratio of about 20:1, though to be fair gliding was an important part of its design brief.

So the U2's glide ratio is only 2.5 times better than the not very aerodynamic Cessna; but when you start your glide at 70,000 feet you have a definite advantage. One managed 300 miles after an engine failure!

[maffski]

Eric Mc said:

nonsequitur said:

At the Smithsonian Institute in Washington DC, there is the original 'Spirit of St. Louis' aircraft that Lindbergh flew across the Atlantic. Amazingly, it has no forward vision, only the two side windows.

The aircraft on which it was based, the Ryan Brougham, DID have a normal forward facing windscreen. However, in the "Spirit of St Louis", the space between the engine and the cockpit was taken up with a large fuel tank - thereby removing any room for a windscreen. Instead, Lindberg had a periscope fitted to allow some limited forward vision.

To be fair there wasn't much to run into.

[Eric Mc]

It made landing and taking off tricky.

He actually hit some telegraph lines when taking off from New York.

[Dr Jekyll]

1909 aero engine, it's a V8 with fuel injection.

[Eric Mc]

Some were better than others. For 1908, that propeller looks extremely primitive. The Wright brothers props of 1903 look more advanced -

[Atomic12C]

CanAm said:

e have the Cessna at 9:1, the Gimli Glider Boeing 767 at 12:1 and I was very disappointed to find the U2, despite its very high aspect ratio wings, only has a glide ratio of 23:1; the rather stubby winged Messerschmitt Me163 (aspect ratio of less than 5:1) had a glide ratio of about 20:1, though to be fair gliding was an important part of its design brief.

So the U2's glide ratio is only 2.5 times better than the not very aerodynamic Cessna; but when you start your glide at 70,000 feet you have a definite advantage. One managed 300 miles after an engine failure!

Yes it is surprising that the U2 does have a low ratio in comparison to other wings of similar looking, but when you take in to account that the U2 is powered and also will have requirements for a specified performance envelope that is to work at a range of altitudes. temperatures, pressures and angles of attack, then maybe what they produced was more by design intent than lack of aerofoil knowledge for lift performance?

I'm guessing they could have gone for a more 'lifty' profile but would then have encountered more drag, which then would have meant more fuel, less range etc. etc.
The typical problem (or benefit) you run in to called 'circle of returns' within aerodynamics when one factor is altered, which then has knock on affects to all other factors within the design.

Similarly, if they had opted for more aspect ratio on the wing, it would have resulted in lower roll rate, more drag, more wing flex (if not wing flex then more weight for strengtheners) etc. etc.

[conkerman]

The least thing you want in a U2 is more drag reducing the cruise speed at 70000 ft even closer to the stall speed.

[Eric Mc]

The U2s long wings weren't primarilly to give it a good gliding performance.

[Ginetta G15 Girl]

Atomic12C said:

Yes it is surprising that the U2 does have a low ratio in comparison to other wings of similar looking, but when you take in to account that the U2 is powered and also will have requirements for a specified performance envelope that is to work at a range of altitudes. temperatures, pressures and angles of attack, then maybe what they produced was more by design intent than lack of aerofoil knowledge for lift performance?

The major component of Drag on any wing is Induced Drag (also known as Lift Dependant Drag). This arises primarily from the formation of the wing tip vortices - basically the air from the higher pressure region below the wing tries to move into the lower pressure region above the wing by climbing over the wingtip. In so doing it forms a vortex which produces drag (it takes energy to form and maintain the vortex).

There are a number of ways of reducing these vortices (or delaying their onset) such as eliptical wings (eg Spitfire), wingtip tanks (eg Jet Provost), winglets (such as fitted to modern airliners) or, more commonly, the High Aspect Ratio Wing (ie a high length to chord ratio - long and thin) such as on the U2.

Given that the U2 was designed to operate at very high altitude in a region close to 'Coffin Corner' (ie where the Critical Mach Number and Stall Speed are close together), then a means of reducing drag such as a High Aspect Ratio Wing makes a lot of sense.

Edited by Ginetta G15 Girl on Wednesday 19th April 13:06

[tobinen]

Dr Jekyll said:

eccles said:

dvs_dave said:

The Boeing 777-200ER is the longest range commercial airliner. In 2005 it set a non-stop record of Hong Kong to London. The long way round. Over 13,400 miles, and 22hrs. Quite incredible.

And the long range tanks were designed and made in Cambridge.

Marshall's I take it? They do seem quite clever in Cambridge.

IIRC, Marshall Aerospace developed Concorde's nose as well.

[Atomic12C]

Ginetta G15 Girl said:

The major component of Drag on any wing is Induced Drag (also known as Lift Dependant Drag). This arises primarily from the formation of the wing tip vortices - basically the air from the higher pressure region below the wing tries to move into the lower pressure region above the wing by climbing over the wingtip. In so doing it forms a vortex which produces drag (it takes energy to form and maintain the vortex).

There are a number of ways of reducing these vortices (or delaying their onset) such as eliptical wings (eg Spitfire), wingtip tanks (eg Jet Provost), winglets (such as fitted to modern airliners) or, more commonly, the High Aspect Ratio Wing (ie a high length to chord ratio - long and thin) such as on the U2.

Given that the U2 was designed to operate at very high altitude in a region close to 'Coffin Corner' (ie where the Critical Mach Number and Stall Speed are close together), then a means of reducing drag such as a High Aspect Ratio Wing makes a lot of sense.

Edited by Ginetta G15 Girl on Wednesday 19th April 13:06

Thanks Ginetta Girl.
I remember doing a small piece on wing tip vortex drag on my Degree course many years ago.
I was looking at the effects of vortex drag on the yaw stability and control of the rudder for a glider concept - looking at how much rudder adjustments in size and angle would be needed if the glider were to reach certain dive speeds etc.

[nonsequitur]

One of the VC10's advertising slogans was ' Try a little VC tenderness', due to it's alleged, for the times, quiet engines.

The upper deck of the first 747's was a lounge for first class passengers. Later it was converted to first class seats and utlimately, economy.

The first film shown to passengers on BOAC was 'Perfect Friday', 1970, starring Ursula Andress and Stanley Baker. There was a sequence involving a BOAC aircraft.

[Dr Jekyll]

nonsequitur said:

One of the VC10's advertising slogans was ' Try a little VC tenderness', due to it's alleged, for the times, quiet engines.

Not exactly. The theory was that since the passengers were in front of the engines the engine noise would be less for them.

[nonsequitur]

Dr Jekyll said:

nonsequitur said:

One of the VC10's advertising slogans was ' Try a little VC tenderness', due to it's alleged, for the times, quiet engines.

Not exactly. The theory was that since the passengers were in front of the engines the engine noise would be less for them.

And it worked! Except if, like me, you were a rear galley slave, then the engines were right outside the galley loading door. Had an engine surge once, and it's true what they say, adrenalin is brown.

[CanAm]

Ginetta G15 Girl said:

The major component of Drag on any wing is Induced Drag (also known as Lift Dependant Drag). This arises primarily from the formation of the wing tip vortices - basically the air from the higher pressure region below the wing tries to move into the lower pressure region above the wing by climbing over the wingtip. In so doing it forms a vortex which produces drag (it takes energy to form and maintain the vortex).

There are a number of ways of reducing these vortices (or delaying their onset) such as eliptical wings (eg Spitfire), wingtip tanks (eg Jet Provost), winglets (such as fitted to modern airliners) or, more commonly, the High Aspect Ratio Wing (ie a high length to chord ratio - long and thin) such as on the U2.

Given that the U2 was designed to operate at very high altitude in a region close to 'Coffin Corner' (ie where the Critical Mach Number and Stall Speed are close together), then a means of reducing drag such as a High Aspect Ratio Wing makes a lot of sense.

Edited by Ginetta G15 Girl on Wednesday 19th April 13:06

Is it true that a Lightning (BAC not the Lockheed one) got up to 88,000 to intercept a U2 and if so (i) how the hell did it manage and (ii) was the pilot in standard issue flying suit?

[CanAm]

nonsequitur said:

Dr Jekyll said:

nonsequitur said:

One of the VC10's advertising slogans was ' Try a little VC tenderness', due to it's alleged, for the times, quiet engines.

Not exactly. The theory was that since the passengers were in front of the engines the engine noise would be less for them.

And it worked! Except if, like me, you were a rear galley slave, then the engines were right outside the galley loading door. Had an engine surge once, and it's true what they say, adrenalin is brown.

I recently flew in a KLM Fokker70 which is also rear engined. Having what would have been called the 'window seat' had there actually been a window and being on the last row the engine was next to my left ear. It was not particularly quiet!