OT - View inside the A380 office

[Evan]

It almost sounds like the old Tupolev Tu-154 which was very loud and very fast. When I hear it coming it is already overhead. I don't hear the incipient boom every time but it is always loud. Sometimes they throttle down to begin decent into Vancouver so I know that's where they are headed.

This is our airport. It was built in WWII as an alternate for the US Military. The runway is 4 feet thick. It is also an alternate for the Shuttle since when it lands at Edwards it flies not far to the west of us on reentry. If they had to do an abort once around and couldn't make it to Edwards this is on the list in part because this airport is very easy to secure. It's on top of a plateau with only one way up.

Think you could land here in a pinch? BTW, it's uncontrolled.

[A.K. Boomer]

Boy Id like to sit my fat little ass down in those seats - get some ceiling and "wag the tail on that dawg" Just kidding....


Unreal "office" Pete, I could barely find the cup holders - What a checklist you guys must have to go through -
People would become a little more patient in understanding slight delays if only they could see a pic of that cockpit...

I was just trying to figure out what those dome like structures were in the middle of the console when I realized the letters above them and concluded they are just a hand rest to keep stability...

[PeteF]

I see what you mean about the clearway Evan!

Trust me the cup holders get well used, they're just behind the tiller and normally contain cups full of bad coffee

Regarding the checklists, remarkably enough they're getting smaller with each generation of aircraft. Likewise people are generally so computer literate these days the Flight Management Computers are now produced with QWERTY keyboards instead of the old "seek and destroy" ABCDEF style. How times change 'eh.

Yes if only people had even the remotest idea of what goes on behind the scenes of getting them from point A to point B; from the people who design and built the aircraft right down the chain. Instead it's all about buying a ticket for half the cost of what their taxi ride to the airport costs in a clapped out Ford Falcon with half a million miles on it, and then bitching like they're just had their first-born taken if they don't get their first choice of meal

[Evan]

So what happens when an aircraft the size and weight of the A-380 is cruising along at maximum cruise heading south west and suddenly encounters the northeast flowing Jet Stream at FL300 or so? Temporarily it can add 100 knots or more to the IAS. We are located where the Jet stream is very frequently overhead.

Talking about times changing the last time I flew on an A320 was in 1997 coming back from Europe. We were flying in the frontmost seats and the captain had left the door open during the flight. I wandered up to the door and asked if I could observe for a while and he invited me in to chat. Saw some beautiful noctilucent clouds on the way over the greenland icecap.

[J Tiers]

Dunno about Evan's noise, but which twin engine widebody (or engine type) is the one that has the very loud "throaty whine" during takeoff and climbout from the airport?

We are near the airport, about 4 or 5 miles, and when one particular type of aircraft passes over after turning south, it is much different sound than most others.

Most have a typical roar, this type has a whine superimposed on that. Not the old time "jet whistle" sound, like some executive jets, it is a much lower tone.

[A.K. Boomer]

Talking about times changing the last time I flew on an A320 was in 1997 coming back from Europe. We were flying in the frontmost seats and the captain had left the door open during the flight. I wandered up to the door and asked if I could observe for a while and he invited me in to chat. Saw some beautiful noctilucent clouds on the way over the greenland icecap.

It makes you realize all the cool stuff that we've lost since 9-11,

all the changes we've had to make and most are in the form of becoming more robotic and less human.

[lakeside53]

We sure have.. In 1991 I sat in the right seat of BA 747 for an hour as we went close to the North Pole flying from Tokyo to London... Nice... Incredible view of the Northern lights all around.

Chance of doing that today is pretty much zero.

[moe1942]

[QUOTE=krutch] I like the panic grab handle by the window, is that the emergency exit?
QUOTE]



That's used to adjust the rear view mirror.

[PeteF]

So what happens when an aircraft the size and weight of the A-380 is cruising along at maximum cruise heading south west and suddenly encounters the northeast flowing Jet Stream at FL300 or so? Temporarily it can add 100 knots or more to the IAS. We are located where the Jet stream is very frequently overhead.

Flying into a jetstream like that happens from time to time. When you're flying at very close to the aircraft's maximum altitude for that weight, the maximum speed and stall speed can be quite close to each other. The two limits are represented by a striped red and black line on the airspeed part of the display, colloquially called "the bricks". When you suddenly fly into a strong headwind you'll see the thrust come off, possibly back to idle if the windshear is strong enough. The speed MAY go up into the bricks, but the aircraft won't suddenly go supersonic if that's what you're suggesting. Conversely suddenly flying into a strong tailwind the speed drops suddenly but this is a bit more serious as the thrust is already up close to maximum. This is one of the reasons conservative pilots won't fly up in this area and will stay a couple of thousand feet lower to provide more margin for error.

Pete

[Evan]

I am not suggesting that the aircraft is going supersonic. However, parts of the aircraft may be very close for short time. The shock wave doesn't suddenly appear at Mach 1. As speed approaches Mach 1 the airflow begins to compress closer and closer to the surfaces where it travels the fastest. The incipient shock wave begins to form as a leading region that is ahead of the surface and exhibits a large pressure change over a small distance. The closer the velocity is to Mach 1 the more compressed that region of sudden pressure change becomes and the more it stands away from the surface. At Mach 1 it stands perpendicular to the point of compression as the shock wave is propagated along the sudden pressure drop at the speed of sound.

Well before that happens the sound that is propagating forward is more and more "trapped" in the compression region. This concentrates the acoustic energy which is travelling ahead of the aircraft at a velocity equal to the difference between mach1 and the velocity of the aircraft. If there is a head wind then the velocity of the head wind is also subtracted from the forward velocity of the sound.

If the aircraft is flying 100 knots below Mach 1 in a 100 knot head wind the sound it emanates will be retarded according to the velocity of the aircraft and the velocity of the head wind after it leaves the aircraft. The sound will assume some of the characteristics of a shock wave.