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BreninTW
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Pushback Using MLG -- B737

Mon Dec 04, 2006 3:28 pm

When I was in New Zealand earlier this year, I saw a B737NG being pushed back -- using the MLG. I've always thought that the NLG was used for pushback, I've never seen this before.

Questions: Why use the MLG instead of the NLG? Is this common?

I snapped a pic which is at: http://public.fotki.com/irltrucks/tr...06/queenstown_oamaru/img_5904.html
 
tbanger
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RE: Pushback Using MLG -- B737

Mon Dec 04, 2006 4:55 pm

Been using them in SYD Domestic terminals and I also believe MEL for a couple of years now. Rather than have a tow driver and a starter, you just have the starter do both as the tug is remote controlled.

I believe the pilot steers!
 
Tristarsteve
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RE: Pushback Using MLG -- B737

Mon Dec 04, 2006 8:02 pm

Quoting Brenintw (Thread starter):
Questions: Why use the MLG instead of the NLG? Is this common?

The main reason is that all you have to do is turn the wheel. There is no need to lift the aircraft or steer so the machine is much simpler.
I had it demonstrated in ARN about 10 years ago, but we ended up with TBL instead.
 
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HAWK21M
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RE: Pushback Using MLG -- B737

Mon Dec 04, 2006 8:11 pm

Optional.
However out here We never use it.It requires Good communication between Flt deck & Grd to know when & how much to steer the NLG.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
Curmudgeon
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RE: Pushback Using MLG -- B737

Tue Dec 05, 2006 5:45 am

That unit is called a "Power Push", and is in fact remote controlled. The engineer conducting the pushback does require good communication with the pilot, and simple commands like "steer left" etc are used.

The unit attaches to the main gear, drives on command, and detaches itself and drives away, all by remote.

There is a seat and conventional controls that is used for driving the unit between gates.

These were sold as a cheaper alternative to tugs and tow bars and a driver + engineer. Industrial and other factors have limited their widespread use. I don't know how they perform in snow.

Cheers
Jets are for kids
 
airfoilsguy
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RE: Pushback Using MLG -- B737

Tue Dec 05, 2006 7:21 am

The unit is located behind the main landing gear so wouldn't it be pulling rather then pushing? Also, the engine seems to be running, that would be a very windy place to be sitting if the thing had a driver..

Oh, by the way, nice birds  Wink
It's not a near miss it's a near hit!!
 
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BreninTW
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RE: Pushback Using MLG -- B737

Tue Dec 05, 2006 10:15 am

Quoting TristarSteve (Reply 2):
but we ended up with TBL instead

What is TBL?
 
tbanger
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RE: Pushback Using MLG -- B737

Tue Dec 05, 2006 5:44 pm

Quoting Brenintw (Reply 6):
What is TBL

Tow Bar Less.


View Large View Medium
Click here for bigger photo!

Photo © David James Clelford



Above is a towbarless tug. has a driver, but no towbar.

[Edited 2006-12-05 10:08:33]
 
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HAWK21M
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RE: Pushback Using MLG -- B737

Tue Dec 05, 2006 5:47 pm

Quoting Curmudgeon (Reply 4):
The unit attaches to the main gear, drives on command, and detaches itself and drives away, all by remote

Whats the Attach mechanism like.Also what would the Capacity of this unit be approx.

Quoting Airfoilsguy (Reply 5):
Also, the engine seems to be running, that would be a very windy place to be sitting if the thing had a driver..

Engine would not be running on that side.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
Tristarsteve
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RE: Pushback Using MLG -- B737

Tue Dec 05, 2006 6:11 pm

Quoting Curmudgeon (Reply 4):
I don't know how they perform in snow.

That is its best feature. The Mainwheels stay on the ground, and the Powerpush just rotates them. The problem with a TBL is that it lifts the nosegear and then drives out. On many aircraft the weight on the nosewheel is very small, and we used to have trouble getting traction. We have now got rough gravel glued to the pushback area to get a grip.
A normal towbar tractor is much better as it weighs so much, but a TBL is very light weight and needs the aircraft weight to get a grip.
 
Pihero
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RE: Pushback Using MLG -- B737

Tue Dec 05, 2006 9:24 pm

The powerpush is generalised on AF stations in France for the single-aisle fleet.The economical savings are quite enormous as they use very little power for the job and only one operator.
This is how we use it :
1/Connect the PPU -as it is called - to the left gear.The motor turn a set of rollers, which, being in contact with the tyres, force them to turn, therefore moving the aircraft.
2/Start engine #2 in order to get some hydraulic power.
3/Commence push. The pilot indicates the direction to which the nose will point and the ckeared taxiway line colour (here in CDG, we have a yellow centerline and a blue and an orange).
the operator then directs the pilot with clear steering indications : "Steer left...more left...less left...tiller to neutral..."
4/Disconnect the PPU
5/Start #1 engine.... and away you go!
Plese note that the nose gear safety pin remains in place all the time.
Contrail designer
 
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jetmech
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RE: Pushback Using MLG -- B737

Tue Dec 05, 2006 9:34 pm

Quoting Pihero (Reply 10):
Plese note that the nose gear safety pin remains in place all the time.

G'day Pihero  Smile,

Are you referring to the nose gear steering lock out pin or the nose gear retraction lockout pin?

Regards, JetMech
JetMech split the back of his pants. He can feel the wind in his hair :shock: .
 
Pihero
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RE: Pushback Using MLG -- B737

Tue Dec 05, 2006 9:46 pm

Quoting JetMech (Reply 11):
Are you referring to the nose gear steering lock out pin

hello, JetMech,
Yes. I've seen so many ways of calling that damn pin : by-pass pin. safety pin, lock-out pin, the thing there  Smile etc...
Contrail designer
 
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HAWK21M
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RE: Pushback Using MLG -- B737

Tue Dec 05, 2006 10:09 pm

Quoting JetMech (Reply 11):
Are you referring to the nose gear steering lock out pin or the nose gear retraction lockout pin



Quoting Pihero (Reply 12):
Yes. I've seen so many ways of calling that damn pin : by-pass pin. safety pin, lock-out pin, the thing there etc

Out here its called the Nose gear Steering Valve bypass pin.  Smile

regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
N1120A
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RE: Pushback Using MLG -- B737

Mon May 30, 2016 12:01 am

Quoting Brenintw (Reply 6):
What is TBL?

Tow Barless. Also known as a Super Tug.
Mangeons les French fries, mais surtout pratiquons avec fierte le French kiss
 
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Florianopolis
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RE: Pushback Using MLG -- B737

Mon May 30, 2016 12:45 am

Quoting Pihero (Reply 12):
Quoting JetMech (Reply 11):
Are you referring to the nose gear steering lock out pin

Yes

As long as we're resurrecting threads....

How does the pilot steer the nose gear if the NWS pin is installed?

[Edited 2016-05-29 17:47:41]

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