[sarathlal]

Air India flight AI665 was carried to runway using 'TaxiBot' at terminal 3 of the IGI airport, thereby becoming first airline in the world to use Taxibot on a commercial Airbus flight.

TaxiBot is a pilot controlled semi-robotic tow-barless aircraft tractor used as an alternate taxiing equipment. Read more at: TBHP link on TaxiBots (Delhi Airport to get TaxiBots)

"The use of TaxiBot on the Air India aircraft at Indira Gandhi International Airport today morning is the first such usage on any Airbus aircraft worldwide. Really an achievement to be proud of. A giant step forward towards a cleaner environment,"

Ashwani Lohani (Air India chairman and managing director) said.

Source: https://twitter.com/airindiain

[fhdowntheline]

I thought the whole point of using personnel on the ramp was to be alert ,avoid any errors and prevent ramp accidents. Who is going to watch out if/when the taxibot goes awry?

[Jeroen]

Originally Posted by fhdowntheline

I thought the whole point of using personnel on the ramp was to be alert ,avoid any errors and prevent ramp accidents. Who is going to watch out if/when the taxibot goes awry?

The taxibot still has a driver for pushback and emergencies.

On modern well organised airports planes taxi to the gate under their own control and guided by automatic guidance to come to a complete stop with no need for any ramp personnel.

Many airports still have lots of staff out there waving little sticks about, checking clearances of Wing tips etc. But really that is outdated and very often redundant. But on many American airports you will still see these guys. More because of the unions than an operational need.

It is all about ramp routines and discipline! If well designed and organised you need very few people on the ground.

When leaving the gate, again on modern airports will see one guy operating the pushback tug and he can be in direct communication with the cockpit and pilots. He and he only checks for clearance, obstacles etc. Very often you will see a second person helping out on the push back. Walking along the tug.

The pushback with the taxibot is no different . Thetaxibot in under normal control of the driver.. Once the push back is completed the pilot takes control and uses it to taxi to the ramp. The taxibot driver is there for safety/emergencies.

The taxibot is not about reducing man power. It still has a driver. Taxibot is about noise and pollution control and to some extent to safe fuel.

I thought taxibots had been in operation for some time at Frankfurt airport and Delhi airport already. It was discussed on some of the aviation related threads I seem to recall.

http://www.lufthansa-leos.com/taxibot

Jeroen

[wbd8779]

I guess you can't have engine start-up before the taxi bot detaches - and doing that after you reach the take off line up is another headache in terms of time and efficiency. Not sure what would happen if one of the engines go AWOL and you have to be towed back to the gate .
This concept has been discussed for long , but they are serious issues to be addressed before it becomes mainstream. everything nowadays is touted as a giant step to "save the enviorment " does this taxibot run on thin air

[Jeroen]

Originally Posted by wbd8779

I guess you can't have engine start-up before the taxi bot detaches - and doing that after you reach the take off line up is another headache in terms of time and efficiency. Not sure what would happen if one of the engines go AWOL and you have to be towed back to the gate .
This concept has been discussed for long , but they are serious issues to be addressed before it becomes mainstream. everything nowadays is touted as a giant step to "save the enviorment " does this taxibot run on thin air

Yes, you can not start engines till it detaches. You also need to have ramp space for the taxibot to move back from wherever it was detached from the plane. Taxiramp leading up to the runway entry point tend to get very congested with planes lining up one behind the other. Not sure if a tug or taxibot is allowed to drive back on the same ramp, or needs a separate road.

It is rare for engines to have start up problems, but it does happen occasionally, due to engine or other problems that only become apparent when the engines are started up.

There has been concern about not being able to run the engines long enough for them to properly warm up. Depends on the plane/engine, but most operating procedures call for at least 3-6 minute warm up before take off. Planes need very little power to taxi, but they use an awful lot of fuel doing so. A fully loaded Jumbo 747-400 will taxi with all four engines idling and it will still reach speeds over 45 km/h and you might find yourself having to ride the brakes. It does take a bit of initial power to break away from standstill, but once it rolls, the throttles go back to idle.

[sarathlal]

Originally Posted by Jeroen

I thought taxibots had been in operation for some time at Frankfurt airport and Delhi airport already. It was discussed on some of the aviation related threads I seem to recall.

Jeroen

This thread is one such discussion: https://www.team-bhp.com/forum/comme...-taxibots.html (Delhi Airport to get TaxiBots)

I quoted it in the post, but not that visible with rest of the text

[fhdowntheline]

How is it different conceptually from the practise of towing by regular tow truck till the runway ( sometimes done for heavy load/ long haul ).

[Jeroen]

Originally Posted by fhdowntheline

How is it different conceptually from the practise of towing by regular tow truck till the runway ( sometimes done for heavy load/ long haul ).

The main difference is that the taxibot is controlled by the pilot. I still have not been able to figure out exactly how, but the pilot controls steering and speed of the taxibot.

Steering seems to done though the normal tiller but I have no idea how they control speed. They claim no real modification necessary on the plane. But unless they establish some sort of (digital) connection I do not see how you could control it.

Would like to understand this better myself

Jeroen

[Jeroen]

Update I just found this video which gives some answers

https://youtu.be/6HxrUm9s8NI

Pilot steers by using normal tiller. So the tug just follows the steering movement from the nose wheel.

Speed is set by the tug, based on predefined taxi speeds. So no direct control by the pilot

Jeroen

[arijitkanrar]

Originally Posted by Jeroen

Update I just found this video which gives some answers

Pilot steers by using normal tiller. So the tug just follows the steering movement from the nose wheel.

Speed is set by the tug, based on predefined taxi speeds. So no direct control by the pilot

Jeroen

Thanks for this!
After seeing the video a few questions come to mind.
The Taxibot steers when when its steered by the airplanes nose wheel. This means that the nose wheel is steered by the aircraft itself. So most likely the APU is running if the main engines are off to power the hydraulics. Would the APU be able to handle this additional load for extended taxiing periods?

If the engines have to be started just prior to take-off, that would mean that the only way to start would be using air from the APU? Does that mean that the Taxibot cannot be used if the APU is not functional? Also it would mean that aircraft that dont have a APU start capability cannot use Taxibot?

[Jeroen]

Originally Posted by arijitkanrar

The Taxibot steers when when its steered by the airplanes nose wheel. This means that the nose wheel is steered by the aircraft itself. So most likely the APU is running if the main engines are off to power the hydraulics. Would the APU be able to handle this additional load for extended taxiing periods??

Your typical APU on a commercial jet air liner, provides electrical, hydraulic and pneumatic power. It has got plenty of capacity to power the steering, be it electric and or hydraulically operated on top of all the other system it is powering.

Originally Posted by arijitkanrar

If the engines have to be started just prior to take-off, that would mean that the only way to start would be using air from the APU? Does that mean that the Taxibot cannot be used if the APU is not functional? Also it would mean that aircraft that dont have a APU start capability cannot use Taxibot?

I agree it would not be practical to tow an aircraft to the runway only to have to also tow a starting cart as well. So using the taxibot in case of a non functioning APU does not make sense.

Also, without APU you can not really taxi with the taxibot either. Because you need power to steer, power to brake, you need the air conditioning to run and a bunch of other systems that needs to be powered up when you start moving a plane etc.

These days most, if not all commercial air planes (jets and propeller) tend to have an APU. By and large very reliable. But yes they do occasionally break down and planes do fly with inoperative APUs. In which case they can not use the taxibot.

Anorak fact: The famous Concorde did not have an APU! (It was to difficult to fit into what was already a very tightly packed airframe, and there would have been fuel penalties due to the extra weight.

So the most advanced commercial aircraft in the world had to rely on good old fashioned starters cart external air conditioning and power when at the gate too. As it flew on only a handful of major airports around the world it was not a problem.

But it would have meant that Concorde Passenger would sit without air conditioning from the moment they push back started, till they had main engines started.

[Sutripta]

What is the advantage? I mean between the bot part and operator part?

Who decides whether a taxibot can be used -DGCA? AAI? Or no restriction on use?

Do the pilots need any extra certification? Any changes in pay?

Aircraft commonly operating in India: ATR - does it have an APU?

Regards
Sutripta

[Jeroen]

Originally Posted by Sutripta

What is the advantage? I mean between the bot part and operator part?

Not sure I understand your question. Taxibot is all about noise and pollution control

Originally Posted by Sutripta

Who decides whether a taxibot can be used -DGCA? AAI? Or no restriction on use?

Not sure, but I would assume the regulator and relevant airport authorities have a big say in this

Originally Posted by Sutripta

Do the pilots need any extra certification? Any changes in pay?

From what I have seen/read pilots do need training, which most likely means there is some form of official sign off. No idea about changes in pay.

Originally Posted by Sutripta

Aircraft commonly operating in India: ATR - does it have an APU?

As I recall in standard configuration ATRs do not have an APU. But one of the engine has a so called propeller brake. That allow the pilot to fix the propeller, prevent it turning, whilst the turbine is still running and providing electrical, hydraulic, pneumatic power. So effectively it comes down the same.

I think, depending on configuration APU can be installed in an ATR

Jeroen

[Sutripta]

Originally Posted by Jeroen

Not sure I understand your question.

Why the pilot and not the human bot 'minder'?

As I recall in standard configuration ATRs do not have an APU. But one of the engine has a so called propeller brake. That allow the pilot to fix the propeller, prevent it turning, whilst the turbine is still running and providing electrical, hydraulic, pneumatic power. So effectively it comes down the same.

From what I know engine on > pilot in cockpit, in charge. Can be limiting.

Regards
Sutripta

[Jeroen]

Originally Posted by Sutripta

Why the pilot and not the human bot 'minder'?

Not sure, there is surprising little information to be found, even on the pilot forums. I have found that the Taxibot system is certified under a so called supplementary type certificate by a.o. EASA. It covers taxibot operations for specific planes under FAR25. (Regulations applicable to planes over a certain weight)

I just do not know, but I feel it might be due to regulation it needs to come under control of the pilot. The pilot is responsible (and has trained for) taxing.

Towing operations, other than push back, are normally not conducted on the normal in use taxiways. They are kept away from normal taxi traffic, need to adhere to a specific towing regime (regulations) which is not the same as a taxi regime.

So my gut feeling is that it something along those lines. As taxibot operations from gate/apron to the active runway are regarded as normal operational taxi under pilot control, it needs to be under the pilot control. Does that make sense to you, any other considerations perhaps?

Originally Posted by Sutripta

From what I know engine on > pilot in cockpit, in charge. Can be limiting.

Yes, if parked at the ramp and you would want to leave the engine on with nobody in the cockpit. (Which is perfectly normal when operating on normal APU.)

As I read it, see above, taxibot gets approved per aircraft type. Not sure if an ATR with a brake rotor would qualify?

Jeroen