38 GREENER GSE
GROUND HANDLING INTERNATIONAL FEBRUARY 2013 Smooth operator
After several years of development, coupled with the input from a consortium of eight companies, a new vehicle is virtually ready for the ramp. Alwyn Brice reports from the cockpit.
axiBot (tæ
k.si.bot): n. a vehicle for towing an aircraft that is controlled by the pilot; v. (trans.
and intrans.) the action of towing through use of the TaxiBot If TLD, Airbus, Israel Aerospace Industries, Lufthansa Leos, Boeing, Ricardo, Siemens and Silver Atena get their way, then we have a new noun and verb about to enter the handling industry’s lexicon. Some readers will know a little about the gestation of this vehicle and its raison d’être. Conceived back in 2007 as an alternative to the traditional taxi- ing procedure, a process that sees an aircraft employ an engine as it heads on to stand or departs the gate, the TaxiBot was mooted as something that could reshape conventional thinking on the subject. The idea was simple enough: do away with the need for the running of a jet engine and at a stroke you reduce CO2
emissions, lessen the threat
of FOD, save on Jet-A and cut down on personnel. There’s more: such a solution, one that sees the pilot take control of the tow vehicle, would mean no added weight to the aircraft (as is the case with other alternatives to the standard pushback procedure); no modifications to the aircraft and no significant changes to the airport environment and infrastructure. Furthermore, it would mean that the answer could be applied to both narrow and wide-bodied aircraft.
If that sounds like a tall order to
achieve, you’d be right, because until now, no-one has come up with a viable alternative to an aircraft taxi-ing under its own power. True, there are at least three companies offering an electric motor solution that drives either the front or the rear wheels, and whilst this is a compact answer to the problem, nonetheless the drive does require fitting – and it does add weight to the aircraft. The TaxiBot’s references are impeccable, as can be seen from the above list of participating companies, and it is to the credit of the creation that so many disparate entities have been able to overcome language barriers and create a workable solution. At this point one might well ask about the necessity for such an application: after all, there’s nothing on the horizon that suggests that a green towing solution is going to be a future requirement airside, is there? The short answer to that is no: but any regular reader knows that increasingly, the ramp is growing greener by the year. Thus the TaxiBot might be argued to be a little ahead of its time; but time, as we all know, has a habit of moving on… And so to Chateauroux, late last year, to see the application at first hand. The day in question dawned foggy but improved later and the rain held off for those assembled. Viewed up close, the TLD-manufactured tug is, to all intents and purposes, akin to most other pushbacks that you’re likely to encounter on the ramp. You have to investigate further to find out where all
The fruit of five years’ development, the TaxiBot in action
factor: on average (and it is very difficult to be dogmatic in this area, of course), a taxi-ing period can be summarised as around 19 minutes. That’s on a good day: such manoeuvres can take up to three hours when things go awry. The more time that is spent waiting in a queue, then the greater the pollution, the more chance there is of FOD intake, and so the greater the consumption of aviation fuel. The TaxiBot renders all of that past tense. An operator in the tug starts it up and then the pilot takes over, using the two braking pedals and the small hand tiller to steer. In so doing, the pilot is effectively manoeuvring the nosewheel, which when held in place becomes part of the turret. This assembly permits the tug’s wheels to turn. At Chateauroux, from inside the aircraft cockpit and perched behind the pilot, my impression is one of the aircraft taxi-ing under its own power. Speed is shown on the dashboard and the system, one feels, will be quickly embraced by the pilot. Communication between the pilot and
On that topic, what about pollution? The brains behind the TaxiBot have commissioned studies in this area and estimate that the annual cost of taxi-ing works out at around US$8.7bn. That’s a staggering sum; more frightening still, perhaps, is the calculation that suggests such activity is responsible for 23m tonnes of CO2
those tens of millions of dollars (and the consortium is, understandably, a little reticent on this figure) have been spent. The big difference lies in the structure that is built under the nosewheel cradle. Here there is a revolving turret assembly: once the nosewheel has been “collected”, it becomes a part of this rotating dish and any input from the pilot is reinforced by this assembly, which in turn governs the wheels of the tractor. For a narrow-body application (as was used on the day), a four wheel tractor suffices: when the bigger version enters production (2015 was given as a tentative date), a six wheeled chassis will be employed. Whilst this much is visible to the onlooker, there are other elements that are more covert. In all, two diesel engines are fitted to the TaxiBot and there is a total of eight electric motors, two per wheel, that assist in the reduction of CO2
.
. Added to this is the time
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