Random facts about planes..

Author
Discussion

48k

12,981 posts

147 months

Monday 24th April 2017
quotequote all
Dr Jekyll said:
If a pilot couldn't see outside at all and was flying purely on instruments. Would it make any difference if the seat and controls were arranged so s/he was facing backwards? Or sideways?
Personally I think it would make me very uncomfortable. It's quite amazing to learn how disorientated you get - and how quickly - when learning to fly on instruments only.

Ayahuasca said:
V8LM said:
On approach to landing Concorde was on the back side of the drag curve so pulling the yoke back made the aircraft drop faster.
I believe that, on approach, pulling the yoke back will make a lot of aircraft drop faster.
yeslaugh

shakotan

10,679 posts

195 months

Monday 24th April 2017
quotequote all
48k said:
Eric Mc said:
Even more spectacular was the External Tank -

And the massive Vehicle Assembly Building in the background - to give an idea of size, the American Flag on the building is the size of a tennis court and with the right atmospheric conditions it can actually rain inside the building.

The Kennedy Space Centre is a fascinating and awe inspiring place to tour and although I've not been back since the end of the Shuttle programme I would urge anyone to visit if they get the opportunity.
Definitely, revisit, my first attendance was in March 2003, which being in the wake of the Columbia disaster meant the bus tour was somewhat limited.

Revisited in 2015, and it's a completely different animal. The new Shuttle exhibit, particularly the Shuttle launch simulator, is incredible.

Ginetta G15 Girl

3,220 posts

183 months

Monday 24th April 2017
quotequote all
Dr Jekyll said:
If a pilot couldn't see outside at all and was flying purely on instruments. Would it make any difference if the seat and controls were arranged so s/he was facing backwards? Or sideways?
For even highly experienced Instrument Pilots, suffering from the 'leans' is quite common. This can be quite disconcerting and somewhat disorientating (you have to believe what your instruments are telling you and not what your inner ear is screaming at you). I would surmise that sitting backwards would exacerbate any episode of the 'leans' - certainly it was common for Nav studes on the pre-mod Dominie (who sat facing rearwards) to become disorientated.

On the Nimrod MR2 the Navs sat facing obliquely, the sonics operators facing sideways and the radio op facing rearwards. Not for nothing was the a/c referred to as the 'Vomit Comet'.


Ginetta G15 Girl

3,220 posts

183 months

Monday 24th April 2017
quotequote all
Ayahuasca said:
V8LM said:
On approach to landing Concorde was on the back side of the drag curve so pulling the yoke back made the aircraft drop faster.
I believe that, on approach, pulling the yoke back will make a lot of aircraft drop faster.
It's not quite as simple as merely pulling back makes the rate of descent higher.

On all Deltas (as well as a number of swept wing a/c), increasing the angle of attack results in a very large increase in drag. On the approach this means that, if you are high and fast, pulling back will rapidly bleed speed off, as the speed comes off the rate of descent increases (despite not touching the power). Once you are back on the glideslope you then peg the approach speed by lowering the nose.

This is quite un-intuitive to pilots of straight winged aircraft where attitude controls speed and power controls rate of descent.

Dr Jekyll

23,820 posts

260 months

Monday 24th April 2017
quotequote all
Ginetta G15 Girl said:
It's not quite as simple as merely pulling back makes the rate of descent higher.

On all Deltas (as well as a number of swept wing a/c), increasing the angle of attack results in a very large increase in drag. On the approach this means that, if you are high and fast, pulling back will rapidly bleed speed off, as the speed comes off the rate of descent increases (despite not touching the power). Once you are back on the glideslope you then peg the approach speed by lowering the nose.

This is quite un-intuitive to pilots of straight winged aircraft where attitude controls speed and power controls rate of descent.
That's very interesting. I thought the main point of a delta wing on Concorde and TU144 was to allow a higher angle of attack specifically to provide lift at very-much-lower than cruising speed so they could land on normal sized runways.

Markbarry1977

4,027 posts

102 months

Monday 24th April 2017
quotequote all
When I underwent my disorientation training at henlow I can truely understand how pilots on instrument must trust them implicitly. I swore blind I was straight and level but was actually in a constant right spin nose up.

Gandahar

9,600 posts

127 months

Monday 24th April 2017
quotequote all
Random fact - the SR-71 Blackbird was not actually painted black.

It should really be called the SR-71 very very dark Bluebird.


dvs_dave

8,581 posts

224 months

Monday 24th April 2017
quotequote all
Dr Jekyll said:
That's very interesting. I thought the main point of a delta wing on Concorde and TU144 was to allow a higher angle of attack specifically to provide lift at very-much-lower than cruising speed so they could land on normal sized runways.
No, main point was to allow efficient supersonic flight!

At low speed and with a high angle of attack, delta wings generate lift vortices along the top surface which generates the lift needed for low speed flight.

It's very difficult to get the design right, which is why the TU-144, essentially a copy of Concorde, has those little winglets at the front, as it wasn't "that" good a copy. wink

Dr Jekyll

23,820 posts

260 months

Monday 24th April 2017
quotequote all
dvs_dave said:
No, main point was to allow efficient supersonic flight!

At low speed and with a high angle of attack, delta wings generate lift vortices along the top surface which generates the lift needed for low speed flight.

It's very difficult to get the design right, which is why the TU-144, essentially a copy of Concorde, has those little winglets at the front, as it wasn't "that" good a copy. wink
Apart from being a delta the wing of the TU144 looks very different form the Concorde wing, a far simpler shape. I think if the TU144 had been a copy of Concorde it would have worked a lot better.

HoHoHo

14,980 posts

249 months

Monday 24th April 2017
quotequote all
The width of a 737-400 wing is 28.8m which is smaller than the horizontal stabiliser at the rear of a A380 at 30.3m wide




Speed 3

4,486 posts

118 months

Monday 24th April 2017
quotequote all
The real reason they dim the cabin lights on take-off in the dark is to acclimatise your eyes (ie dilate your pupils) in case you have a survivable crash. Nothing to do with unexplained "company policy".

Speed 3

4,486 posts

118 months

Monday 24th April 2017
quotequote all
Carbon brakes wear less the harder you apply them (up to a tipping point near the top of the temp curve)

kurt535

3,559 posts

116 months

Monday 24th April 2017
quotequote all
Dr Jekyll said:
Random question that might throw up some random facts.

If a pilot couldn't see outside at all and was flying purely on instruments. Would it make any difference if the seat and controls were arranged so s/he was facing backwards? Or sideways?
Spirit of St louis had horrendous/nil vision due to extra av gas tanks.

dvs_dave

8,581 posts

224 months

Monday 24th April 2017
quotequote all
Dr Jekyll said:
dvs_dave said:
No, main point was to allow efficient supersonic flight!

At low speed and with a high angle of attack, delta wings generate lift vortices along the top surface which generates the lift needed for low speed flight.

It's very difficult to get the design right, which is why the TU-144, essentially a copy of Concorde, has those little winglets at the front, as it wasn't "that" good a copy. wink
Apart from being a delta the wing of the TU144 looks very different form the Concorde wing, a far simpler shape. I think if the TU144 had been a copy of Concorde it would have worked a lot better.
I'm guessing you're not aware of the somewhat infamous industrial espionage conducted by the KGB on the Concorde program? Rumor has it, blueprints with deliberate design flaws on them were passed to the Russians and they actually made it onto the TU-144. And let's call a spade a spade, the TU-144 was a poor performer compared to Concorde, possibly because of this.

Dr Jekyll

23,820 posts

260 months

Tuesday 25th April 2017
quotequote all
dvs_dave said:
I'm guessing you're not aware of the somewhat infamous industrial espionage conducted by the KGB on the Concorde program? Rumor has it, blueprints with deliberate design flaws on them were passed to the Russians and they actually made it onto the TU-144. And let's call a spade a spade, the TU-144 was a poor performer compared to Concorde, possibly because of this.
I'm aware of it, and that the Soviets later asked for help quite openly but it didn't get them very far, and in any case it was details they were after not the overall design.

The TU144 looks like roughly like Concorde for the same reason an A320 looks like a B737. Looking at the wing shapes it's clear it isn't a copy.

nonsequitur

20,083 posts

115 months

Tuesday 25th April 2017
quotequote all
Speed 3 said:
The real reason they dim the cabin lights on take-off in the dark is to acclimatise your eyes (ie dilate your pupils) in case you have a survivable crash. Nothing to do with unexplained "company policy".
Also, unofficial 'company policy' was to hope that the passengers may nod off in the darkened atmosphere.



greghm

440 posts

100 months

Tuesday 25th April 2017
quotequote all
Dr Jekyll said:
The TU144 looks like roughly like Concorde for the same reason an A320 looks like a B737. Looking at the wing shapes it's clear it isn't a copy.
Very good point here. The height of the wings on the Airbus is much higher than the B737, that allows for bigger engines. It was an improvement.
Look at the Engines of 737, the big ones are not round at the bottom as the design is older.

greghm

440 posts

100 months

Tuesday 25th April 2017
quotequote all
Some facts about the capacity to carry weapons

The B17G could carry 3.6 tons of Bombs.... designed at the end of the 30's


The A-1 Skyraider could also carry 3.6 tons of bombs ... designed at the beginning of the 40's


The F-16 can carry 7.7 tons of bombs

dr_gn

16,140 posts

183 months

Tuesday 25th April 2017
quotequote all
greghm said:
Some facts about the capacity to carry weapons

The B17G could carry 3.6 tons of Bombs.... designed at the end of the 30's


The A-1 Skyraider could also carry 3.6 tons of bombs ... designed at the beginning of the 40's


The F-16 can carry 7.7 tons of bombs
Carry them how far?

Eric Mc

121,779 posts

264 months

Tuesday 25th April 2017
quotequote all
greghm said:
Dr Jekyll said:
The TU144 looks like roughly like Concorde for the same reason an A320 looks like a B737. Looking at the wing shapes it's clear it isn't a copy.
Very good point here. The height of the wings on the Airbus is much higher than the B737, that allows for bigger engines. It was an improvement.
Look at the Engines of 737, the big ones are not round at the bottom as the design is older.
The original 737s were designed to use the much smaller diameter Pratt & Whitney JT8D. That allowed them to use a fairly short stroke undercarriage leg. This proved a bit of a problem when they wanted to fit larger diameter CFM56 engines to the later versions.