# Airline Tug Wont Go In Reverse. AC Motors and electrically controlled.



## Dennis Alwon (May 9, 2009)

Your links don't work


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## SkyLeaseMx (Jan 25, 2012)

*Sorry Here Is New Link*

http://imageshack.us/g/685/imag0376v.jpg/


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## wildleg (Apr 12, 2009)

never worked on one, but on manlifts that's usually a bad relay or a bad controller switch. should be pretty easy to identify whether or not the motor is getting power in the reverse.


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## dronai (Apr 11, 2011)

How many HP do they have to be able to push the Aircraft ? 

The Airbus 8380 Tug actually lifts the front wheel of the Aircraft off the ground !


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## dronai (Apr 11, 2011)

Find a schematic, you have everything number tagged already.


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## John Valdes (May 17, 2007)

dronai said:


> Find a schematic, you have everything number tagged already.


You are learning fast! :thumbsup:


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## SkyLeaseMx (Jan 25, 2012)

There are no schematics or user manual. This tug was made by a company that soon went out of business afterward and you dont see too many around now. I got part of it number tagged and upon coming in the next day someone had taken my multimeter. Look at my link to the pictures. in this picture http://imageshack.us/photo/my-images/163/imag0378j.jpg/ r1 flips when put in reverse but r2 does not. they are both wired from the same relay so both should flip together. i switched the wiring from one to the other and vice-versa and then r2 flipped but not r1.


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## frenchelectrican (Mar 15, 2007)

Can you post the unit plus model number I think there is a way to get around this.

Due this is simauir to Diesel Electric locomotive.

Now if my memory serve me right There is at least two interlock switches for both foward and reversing contractors.

It is basic troubleshooting once you figure out the interlock and power reversing contractors.

Dronai., I know you ask how many CV ( Horsepower ) and the CV rating of that tugger as OP posted that is 350-400 CV Cummins 855 series engine ( Generator prime mover are rated pretty high simaior to marine ratings )

BTW they use the same fuel as turbine engine run on it. 

Merci,
Marc


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## mikeh32 (Feb 16, 2009)

My brother works on them, and his friend is an engineer on them... 

Let me see what i can get for you

shoot me a pm too, cause i wont remember


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## SkyLeaseMx (Jan 25, 2012)

frenchelectrican said:


> Can you post the unit plus model number I think there is a way to get around this.
> 
> Due this is simauir to Diesel Electric locomotive.
> 
> ...


Yes that is exactly correct. it is a cummins 855 series inline 6 and there are 2 of both the interlock switches and power reversing contactors. My question is what would cause the contactor to not lock? Have you ever had such happen? Ive ordered a new relay as one was broken but could it be that simple? And as to the unit it is a Unit Rig 80000 lb Pushback Tractor but there is no model number. When the company was still around they built them to order so i guess they found no use in assigning a model number or any diagrams or manuals =/ I have not been able to find any information online at all.


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## nolabama (Oct 3, 2007)

I gotta agree with frenchelectrician on this one. Figure out what locks the two together and your golden. And yes it could be simply a relay.


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## SkyLeaseMx (Jan 25, 2012)

Thank you all or your help! i figured out that the power from the generator wasnt making it from the first relay over to the second and since the part is nowhere to be found i reversed the wiring so the good relay now relays the power to the second and its running fine. now to fix the crab steering!


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## JRaef (Mar 23, 2009)

SkyLeaseMx said:


> Thank you all or your help! i figured out that the power from the generator wasnt making it from the first relay over to the second and since the part is nowhere to be found i reversed the wiring so the good relay now relays the power to the second and its running fine. now to fix the crab steering!


SkyLeaseMx 
Junior Member

Join Date: Jan 2012
Location: *North Carolina*


Wow, I just flew out of Charlotte yesterday! And to think, my plane may have been pushed around by a defective tug! 

LOL, keep up the good work!


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## bgleason (Mar 3, 2012)

If you know the dynamics of the relay, you can more than likely find a replacement for it. Doesn't necessarily have to be the same MFG. May take a little research or a good supply house will do the foot work for you.


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## bgleason (Mar 3, 2012)

Also, never count out ebay. Never know what you can come across on there. I've found obsolete PLC cards and such that replaced ones that we have had crap out on us.


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