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markis10

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I'm sure there are measurements somewhere on the net, but it's not something that would be in any of my books.

You can certainly hear aircraft in the cruise from the ground though. I live near the Melbourne - Sydney track, and they go past here at up to F400, and they are all audible.

The fans of maths can let themselves loose here with some basic formulae :

Attenuation of Sound Waves

There is an ISO standard in regards specific atmospheric attenuation calculation of sound waves:

http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=17426
 

Wests Tigers

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That's what I thought! (Brushing up on my Attenuation of Sound Waves manual).

Enough to say, living in a city, one doesn't appreciate the silence of rural/non-city living and the marvel of hearing big jet engines 10 kilometres up in the sky!
 

Skyhigh777

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harvyk

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JB

I found this youtube of a 1/15 A380 model flying. Shame it is in SQ livery. I have only been able to listen to this without sound so far, so I do not know what those little engines sound like.

Ferngesteuert Gigantic A-380 Singapore Airlines Schlemmer Michael Hausen am Albis 2013 - YouTube


That is very cool...

As for hearing jets at crusing, I live under SYD-MEL and I can't hear them at all when in CBR, but I can every so often hear them if I really try when we head out to the near by farms. I do have to say I'm surprised by the number of 4 engined jets which seem to fly that route.
 

workingman

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Mar 9, 2011
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I have not read the links, but I can imagine the wind direction/speed would have an affect on what you can hear. I live about 10KM from WLG and about 2km to the side of the flight path and the wind certainly affects how much I can hear of planes landing or taking off. I also live fairly near a railway line, and most days I never hear anything, but if there is a southerly or no wind (yes we do get windless days in Wellington) then I can hear the trains.
 

mjt57

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Training Captains are just that. Sometimes they fly as the Captain, sometimes in the right hand seat (with either a command trainee, or an out of recency Captain in the left (i.e. me in a week or so))

Does this mean, then, that CASA has cleared you for flying duties? If so, good stuff!
 
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I have an ask the pilot question about Ferry Qantas flights

When old Qantas planes go to retire in Victorville or elsewhere, the aircraft is ferried from Australia.
Recently a 767 retired there.
Does a twin engined jet still have to comply with ETOPS transpacific if its a ferry flight.
Do cabin crew accompany the flight to at least make cups of tea and perhaps other technical reasons?
 

petercr

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Sep 23, 2012
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Another one for JB... was out walking the dawg yesterday and a couple of JQ A320's flew over within a period of about 10 mins and it sounded like the engines spooled down, up and down again. Is this common on the way in to land? (we're probably about 10 mins out of BNE for planes coming in from the north and landing on runway 01)
 
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mannej

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I will steal a post from another thread.

Not sure if it has been posted before but saw this clip of a Thai A380 landing that could have gone very wrong very quickly.

LiveLeak.com - Thai Airways A-380 dodgy landing at Narita

How difficult is a landing such as this one, what type of limits would be placed on the attempt before you would have to go around, and would you ever see a QF A380 at NRT?
 

flychrisfly

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Hi

If an airport had a really long runway (10kms or 20kms) would it be possible/expected for the "V1" call to not be made before takeoff, since the point of no return is in theory much further down the runway?
 

jb747

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How difficult is a landing such as this one, what type of limits would be placed on the attempt before you would have to go around, and would you ever see a QF A380 at NRT?
Narita can be a bugger of a place with crosswinds. I'm glad I only ever took the 767 there, as it's the best aircraft I've flown with regards to crosswinds. YouTube is full of videos from landings there.

How hard are they to do...potentially very hard, especially if it's gusty as well as strong.

It's a bit hard to say exactly what has happened. He seems quite stable coming into the flare. The wing drop seems to have been caused by spoiler and aileron rise (i.e. control inputs). I suspect that as he has put in rudder in the flare, that he's simultaneously put in some right aileron to counter the rudder, but has over cooked it.

There are already lots of limitations, and I'd expect he was well inside them. They aren't really there to help you, just to allow the hanging later.

I very much doubt you'll ever see a QF 380 there...thank goodness.
 
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jb747

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If an airport had a really long runway (10kms or 20kms) would it be possible/expected for the "V1" call to not be made before takeoff, since the point of no return is in theory much further down the runway?
There are a set of rules by which Vspeeds are calculated...and they would effectively discount much of your super runway. In the balanced situation that is normally used, V1 is chosen so that the distance taken to continue and reach 35 feet is the same as the distance taken to stop.

Whilst we normally do not consider an abort beyond V1, it is not actually the refusal speed. It's really the first speed from which we can continue the takeoff with the loss of an engine. Generally it is far safer to take a dead engine flying than it is to carry out a high speed abort.

There is also a minimum speed for V1. It can't be below Vmcg (minimum control speed on the ground). If you have a failure, and continue, you have to have enough control authority to actually keep it pointed in the right direction on the ground (that number will be somewhere around 120 knots for a 747/380).

So, before someone asks, 'what about three engined ferries'. Firstly they're basically a dumb idea, but they get around the Vmcg problem by not apply all of the thrust until they are above Vmcg...so, start off with two engines at TOGA, and feed in the power from the third as the speed increases. Uses LOTS of runway.
 
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MichaelD

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May 13, 2011
Posts
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JB,

I have two questions;

1. In the movie World War Z, a ladder is extended from the floor of an airplane's coughpit whilst it is on a taxiway, picking up our heroes. Does such a ladder exist in any aircraft or was this Hollywood poetic license?

2. I noticed the other day that 717s have their engines mounted at the rear of the aircraft instead of under the wings. I have also seen aircraft with 3 engines, with 1 in the middle of the tail. Why would engines be placed there instead of the more usual under wing position?

Thank you.
 

markis10

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That brings back memories - McDonnell-Douglas DC-10s...

KLM still operate 4 MD-11s in passenger config if you want to refresh the memory :mrgreen:, or if you really want a DC10, hop it to Bangladesh where Biman will still operate one for the next week!
 
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