PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Spectators Balcony (Spotters Corner) (https://www.pprune.org/spectators-balcony-spotters-corner-52/)
-   -   Taxiway Centerline (https://www.pprune.org/spectators-balcony-spotters-corner/412341-taxiway-centerline.html)

themidge 16th Apr 2010 21:46

Taxiway Centerline
 
How do aircraft stay on the centerline so accurately? Do all modern aircraft have cameras to assist with this? Before the cameras, were there any other aids or was it down to skill?

olivermbs 16th Apr 2010 22:59

Most airliners are not not equipped with taxi-cams, generally pilots get a feel for where the nosegear is (the MD11 for example has the nose gear quite far back). Newer aircraft, such as the Boeing 777 or Airbus A380 have a gear cam displayed in the cockpit, mainly because of the aircrafts wingspan/width.

HEATHROW DIRECTOR 17th Apr 2010 07:02

themidge.. You might as well ask how cars stay in the middle of motorway lanes. Aeroplanes are much bigger, but properly trained crews can steer them extremely accurately by using Mk 1 eyeball.

amesmj 17th Apr 2010 08:12

Hi All, this is my first post, and just on this same subject, can you tell me how pilots steered the concorde on the center line, when it had such a long nose?, were nose wheel cameras fitted ?

HEATHROW DIRECTOR 17th Apr 2010 09:28

Concorde's nose could be tilted down for taxying. Otherwise see my previous post.

mad_jock 17th Apr 2010 09:38

You generally use a feature which you can see to run along the taxi line which keeps you on it when you first start taxing. Then its all done by experence and it looking right.

Eg on the Jetstream 31/32 (I know its only icle) you run the bolt on the windscreen wiper pivot along the line and you will be bang on the taxi line. In fact its the most usefull thing the wipers do on that aircraft because they sure as hell don't remove any water from the screen.

bfisk 17th Apr 2010 10:48

I just look outside. Works a treat. :ok:

leewan 17th Apr 2010 20:25

Have a look at this official video for 777 drivers. There are two parts to it. Used to wonder before I joined this industry as well.
YouTube - 777 taxi tutorial 1

themidge 18th Apr 2010 22:51

Cheers for the responses everyone. I assumed there were some useful references you could use. Come on Heathrow Director, In a plane there is generally more plane in front of your 'steerable wheels' than there is car when you're driving. (And behind too!)

HEATHROW DIRECTOR 19th Apr 2010 08:43

themidge..... I'm sorry... what I was trying to convey was that to an experienced, well trained pilot it is no different from steering any other vehicle. As has been mentioned, there are various "cues" to assist. When I first learned to drive I wondered how it was actually possible to reverse round a corner.... until my instructor pointed out the little pin he had fixed into the rear window lining. All I had to do was to keep that in line with the kerb and all was well. (I've been driving 50+ years and have just dispensed with the pin!!).

deltahotel 19th Apr 2010 10:13

It's not as silly a question as I first thought! It is all visual references peculiar to individual pilots n planes. From the left seat of my 757/767, if I drive the centreline just outside my right knee, that works well. Then look as far ahead as poss (bit like a car) for straight lines and gentle turns. For sharper turns eg 90deg onto stand or with narrow taxiways you have to go deep into the turn (remember the nosewheel is behind you) and then use the tried and tested TLAR technique which is honed by experience on type. (That Looks About Right).

Hope this helps

DH

oldpax 19th Apr 2010 11:08

older types!
 
How about large taildraggers?!

leewan 19th Apr 2010 11:32

The 747, I personally feel, must be the most difficult a/c to taxi. The cockpit is so high up and it comes with small windows. Wonder how the tech crew feels when they taxi them in small airports. I read somewhere that Boeing actually build a contraption on the 70s to help pilots get used to the feeling of taxing up so high !
On a sidenote, does anyone know whether the B748 comes with taxi cameras(GMCS) ?

Pugilistic Animus 19th Apr 2010 20:10

because if you're not on center line,...then it's obvious that they were painted wrong in the first place:}

Scarbagjack 20th Apr 2010 05:26

Hey...great question with great replies!
Wondered that myself a few times. Good reading.

aus_interloper 20th Apr 2010 06:14

hehe same here, that video was interesting, if not a little clinical ;)

TomU 20th Apr 2010 08:05

But why then...
 
What I have always wondered (and I shall probably get beaten up for asking, but never mind), is why some pilots taxi exactly on the centreline, so that the nosewheels go 'thump thump' over the taxiway lights? It can be quite harsh when you are sitting in the vicinity of the nosewheels.:bored:
I heard tell that the offset NLG of the Trident was so designed to avoid this, but doubt the story. (The other explanation being that someone in the drawing office put their coffee mug on the blueprint, and smudged it :rolleyes:)

deltahotel 20th Apr 2010 09:52

Centreline lights. The trick is to get on them (just to prove you can) and offset just a little. If yr smack on the centre the lights go between the nosewheels with very little bump. What sounds silly, but is hard is judging speed when yr that far from the ground (even 75/76) and you have to use the GPS groundspeed readout.

Smudger 21st Apr 2010 20:56

From the left seat, I put the centreline under my right testicle. Works a treat. If there are centreline lights banging the poor nosewheel I offset to one side or the other, much more comfy.


All times are GMT. The time now is 13:35.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.