General System Description

The Aircraft Towing Systems (ATS) is an innovative system designed to transport aircraft from the runway via the taxiway to the airport gates and back to the runway.  Upon landing, the pilot taxis the aircraft to the taxiway where ATS system is installed ready for use. Next, the aircraft nose wheel is driven into the ATS pull car, then secured, and finally the aircraft engines are shut down saving fuel and emissions. The ATS system uses special channels with a rail system built beneath the taxiway and powered by electrical motors in the channels to transport aircraft. The pull car moves each aircraft along the channel to the appropriate gate.  At time for gate departure, the ATS pull car pushes the aircraft away from the gate and pulls it along the taxiway and to the runway. Lastly, the pilot starts the engines, drives off the pull car, and positions the aircraft for takeoff.  The entire ATS system is fully automatic, integrated into the ground control system, and ran by the ground control tower personnel. ATS maximizes safety by optimizing airport taxiway traffic, reducing personnel and equipment in and around flight operations, and controlling all aircraft movements during taxi and gate operations.
ATS is comprised of three sub-systems, the taxiway channel, pull cars and software.

Taxiway Channel

The taxiway channel consists of 15-17 meter (16-19 yards) length modules built into the airport taxiway approximately 80 cm (2,6ft) deep and 120 cm (4 ft) wide. Stainless steel doors cover the channel utilizing a brush system to close the gap between the doors, leaving only 10 cm (4 in) gap exposed, which reduces potential Foreign Object Damage (FOD). Channels are designed with a drainage and heating system to keep the system operating during unfavorable weather conditions, such as rain, snow and ice.

Pull Car

The pull car transports an aircraft from the runway to an airport gate and back to the runway. The pull car rides in the taxi channel securely moving the aircraft. The pull car system, including the connection between the aircraft nose wheel and the pull car, is fully automatic. After driving an aircraft into a pull car, no additional actions are required by the pilot, but at all times, the pilot can disconnect from a pull car in case of emergency.

Software

ATS has a fully integrated software system that eliminates most human touch points and errors. The system software completely orchestrates all aircraft movements from the taxiway to the airport gate and back to the runway. The ATS software suite is planned to integrate with the existing airport traffic control system software and is envisioned to be operated by the ground control personnel.

Safety

Each year there are several hundred aircraft collisions during taxiing. Fortunately, most accidents do not endanger passengers’ lives, but still have a negative impact on the daily operations of the airport and airlines. These collisions cause huge financial losses ($50B US annually) and disrupt airport operations impacting passengers.
ATS significantly improves safety by eliminating aircraft collisions with other aircraft and ground equipment!
Multiple, yet independent, aircraft movements occur simultaneously between the runway, aprons and gates. Each arriving and departing aircraft has an assigned taxi pathway leading its assigned gate or runway. The ATS system optimizes traffic on taxi-lanes and stacks aircraft closer together since the engines are shut off during ATS aircraft movement.
The ATS system also eliminates collisions with baggage and towing vehicles. Each ATS pull car is equipped with a radar that monitors all possible collision areas. In case of emergency, the pulled aircraft will be stopped immediately, and the traffic control, pilot and other taxiing aircrafts will immediately receive information about the incident. The system automatically reacts to such a situation and adjusts the movements of other aircrafts accordingly.
ATS systems eliminates most collisions at airports!

System Benefits

ATS maximizes safety by optimizing airport taxiway traffic, reducing personnel and equipment in and around flight operations, and controls all aircraft movements during taxi and gate operations. ATS significantly improves safety of airports and eliminates most aircraft collisions.  This system dramatically reduces fuel emissions since the engines are powered off while taxiing and gate docking, which also eliminates harmful exhaust emissions emitted in the atmosphere.  Airports can potentially sell their fuel emission tax credits and reduce airport ground crew manpower to offset the initial and sustainment costs of the ATS system.  Airline fuel consumption will decrease as a result of airports implementing ATS, which decreases operating costs of airlines.

Reduced Manpower and Ground Equipment

Because ATS is a fully automated system, an airport can significantly reduce ground equipment and personnel decreasing overhead costs. For example, Frankfurt Airport can reduce the number of employees by an estimated 400 people. Some ground equipment, such as tug vehicles, are no longer required since aircraft are moved by ATS pull cars.
Current airport operations require 4 people and 1 tug for every aircraft!

Increase in Airport Capacity

ATS reduces transport time of aircraft between runway and airport gates approximately 30%. ATS increases capacity of airports through quicker movements and increases capability to stack aircraft closer together since the engines are not operating. ATS enables an airport to service more aircraft concurrently.

Faster Aircraft Movements

Attaching and detaching an aircraft from a pull car occurs within a matter of moments. Currently, pushback (an airport procedure during which an aircraft is pushed backwards away from an airport gate by external power or aircraft engine power) is accomplished in an average of 4 minutes. ATS eliminates these 4 minutes because the aircraft remains attached to the pull car while stationary at the gate. During pushback, the ATS system immediately begins moving the aircraft along the channel and does not require stopping until the aircraft is at the runway. This also decreases the chances for collisions with ground vehicles.
The number of flight operations around the world increases every year. Increased flight operations equate to increased airport ground movements at airports. The more aircraft movements, the more time saved creating increased capacity. See chart below:

Gate Optimization

Integration of the ATS ground control system to the flight control tower allows for greater optimization of airport gates and quicker departure times. Planes will not move until their allotted time and slot in the ATS system. ATS greatly reduces negative consequences of human induced errors by optimizing taxi times, gate pushback, and eliminating congestion on taxiways. There is no more waiting on a gate for a gate crew to dock and marshal an aircraft. ATS improves operations during adverse weather conditions such as rain, fog and snow.

Sources of savings:

Reduced manpower

Elimination of tug vehicles, „follow me” cars and other equipment

Quicker aircraft movements

Move efficient gate operations

Increased airport capacity

Taxi Time

Taxi time greatly influences fuel consumption of an aircraft. Approximately 25% of all commercial aircraft are wide-body aircrafts, which consume an average of 70 liters (19 gallons) of fuel/minute during taxiing. The remaining 75% of large commercial aircraft are mid-size aircraft, which burns an average of 22 liters (6 gallons) of fuel/min during taxiing. The overall average of passenger aircraft burns about 35 liters (9 gallons) of fuel/minute. Calculations indicate that fuel required to taxi is 3-4% of the entire fuel consumed for flight operations (take-off, flight, and landing). In addition, fuel used during taxiing results in large amounts of harmful emissions released into the atmosphere. The table below shows taxi times for the busiest US airports:

Fuel Savings

The ATS system is designed to transport aircraft between runway and gate without aircraft engine power. Depending on the type and size of aircraft, fuel usage for 1 minute of taxiing is 20-70 liters (5-18 gallons) per minute. Average fuel usage for passenger aircraft is 35 liters (9 gallons) per minute while taxiing.
For example, an aircraft taxiing 16 minutes will save approximately €224 or $244
Fuel Price $1,70 USD/gal €0.40/Liter
Fuel Consumption 9 gal/min 35 L/min
35 L/min x 16 min = 560 liters x €0.40 = €224
9 gal/min x 16 min = 144 gallons x $1.7 = $244 USD


Design, Installation and Training

Design

ATS World Wide will collaborate with each airport to design an optimal layout for the ATS system to maximize airport capacity and optimize aircraft movement flow.

Installation

ATS system installation is accomplished using a modular installation strategy, which minimizes airport downtime. Taxiway channels are designed to be constructed in 8-hour increments allowing taxiway and/or gates to return to normal operations in between increments. Disruptions to airport operations are further minimized by installing the taxi channels at night. In most European countries, flights are prohibited during the hours of operation 2300 - 0500. This timeframe varies at United States airports. During this downtime, installation is optimal. During an 8-hour break in airport operations, ATS World Wide can install up to 250 meters (273 yards) of taxi channel.

Channel Installation

Channel modules are built off-site prior to installation in close proximity to the airport. First, a modified ‘concrete cutting vehicle’ cuts the channel into the taxiway, second, the foundation is constructed and finally the channel module put in place and secured. After each section is complete, the taxiway can be used for normal airport operations until the entire ATS system installation is complete and operational.

Pull Car Installation

Pull cars are built off-site at a permanent manufacturing facility and delivered to the airport as the channel modules are installed. Pull cars are installed into the channel as required.

Software Integration

ATS World Wide will partner with the airport to determine the optimal taxiway layout of the ATS system then customize and upload the ATS software suite for ground traffic controllers to operate the entire system. The software integration is planned late in the installation project schedule in order to minimize disruptions to airport operations.

System Training

ATS World Wide offers an array of training options for airport personnel, to include a customized simulated system, onsite ATS expertise and classroom training.

Installation Cost Estimate

Implementation of ATS system by airports will require an initial investment costs and operating costs for system maintenance.
Installation Estimates USD Euro
1 m (1.1 yd) ATS system cost $3,121 €2,800
1 ATS pull car cost $78,026 €70,000
Project cost (% of total system cost) 5% 5%
Annual Mx cost (% of total system)   4% 4%
One option to recuperate an airport’s investment in ATS is to charge usage fees to airlines. Estimated fees are less than the cost of fuel burned during traditional ground taxing creating economic benefits to both the airlines and airport system. For this option, airline ATS usage fees are estimated to cost approximately 60% of saved fuel during taxi.

ATS Operations and Maintenance

The ATS system is fully automatic and operated by airport personnel through the airport traffic control system software using lasers on the pull cars to help transport aircraft. Approximately 10 employees are required to operate the entire ATS system at a large airport. An additional 10 employees are estimated to maintain the ATS system for an average size airport. These personnel maintain the system in air traffic control tower, monitor software and hardware functionality, maintain the channel and pull cars, and detach aircraft from pull cars if necessary to transport aircraft by traditional means. The ATS channel and pull cars will require periodic inspections and maintenance. Prior to installation, ATS World Wide will determine recommended spare parts, tooling and support equipment required to operate and maintain the system.

Detaching from ATS System During Transport

At any time during ATS operations, the pilot or ground controller can detach the aircraft from ATS system in approximately 45 seconds or less. The pilot has the ability to disengage the ATS system at his or her discretion. After the aircraft detaches from the pull car it can move under its own power or be towed by traditional means. This event has no impact to other aircraft operating under the ATS system. All other aircraft in the system receive an alert regarding the detaching event and the system will continue to operate.

Required Aircraft Modification

In order to disconnect from a pull car, an aircraft may require minor modification to its software; however, detachment can also occur via ground controllers. No other aircraft modifications are anticipated.

Environmental Protection

Significant reduction in aircraft fuel consumption, due to not operating engines during taxi under ATS, dramatically reduces harmful emissions emitted into the atmosphere. They are as follows:

Carbon Monoxide

Carbon Dioxide

Hydrocarbon

Nitric Oxide

Reduction of harmful emissions help improve the environment. The global use of the ATS system can play a very important role in improving the environment. Airports can apply for government grants for environmental protection by implementing ecological systems such as ATS. The emission reductions may be monetized by converting the savings into emission credits and selling them to companies paying fines for emission violations.
The table below shows savings in emissions of different harmful substances:
Harmful Substance Consumption Emission from aircraft (oz/gal) Emission from aircraft (g/L)
Hydrocarbon 0.06 1.71
Carcinogenic Nitric Oxide 0.16 4.60
Carbon Monoxide 0.73 20.62
Carbon Dioxide 0.13 3.70


Operating Parameters

ATS system has a very high rate of return on investment (ROI) after installing the system. Main parameters influencing the ROI are as follows:

Fuel consumption

Number of flight movements

Taxiing time

Length of taxiways

Number of ground crew required to operate the traditional system

These parameters very for each airport and have significant impact on the ROI. On page 16 is an analysis of three key operating parameters (KOP) - fuel price, number of flight movements and length of taxiing time.

Fuel Prices

One of the major advantages of implementing ATS system for aircraft transport at an airport is significant fuel savings. Aircraft engines (on medium and large airfields) burn an average 35 liters (9 gallons) of fuel/minute. For example, taxi time at Frankfort Airport averages 16 minutes per flight, which translates to burning approximately 560 L (148 gal) of fuel on every aircraft movement. Utilizing the ATS system allows the aircraft to power down engines shortly after landing and conversely, aircraft are not required to use their aircraft engines until reaching the runway for take-off and only perform the required engine run-up just prior to takeoff. Depending on the type and size of aircraft, fuel usage for 1 minute of taxiing is 20-70 liters (5-18 gal) per minute. Average fuel usage for passenger aircraft is 35 liters (9 gal) per minute while taxiing. Prices of fuel have a significant impact on the amount of savings from fuel usage; see graph below.
Crude oil analysts agree the price of oil is predicted to rise in the near future. It may not reach the record levels of $140/barrel, but even at $80-90/barrel, oil prices affect airline costs. With each price increase of crude oil, the ROI for utilizing ATS increases.

Sources of information

EUROCONTROL Headquarters
Contact Person(s) Tel/email Unit
Charles Walker +32 729 3391
NMD/PFR/FNI/CODA
Rue de la Fusée 96, 1130 Brussels
Belgium
Fraport AG
Frankfurt Airport Services Worldwide
Christopher Holschier
Unternehmenskommunikation
Pressestelle, UKM-PS
Stv. Pressesprecher, 60547 Frankfurt am Main
Germany
Fraport AG
Stefan Mauel -Dipl. -Ing. der Luft-und
Raumfahrttechnik,
Leiter der Abteilung
Infrastrukturentwicklung/Luftseite der
Fraport AG , 60547 Frankfurt am Main
Germany
Chicago O’Hare International Airport
Joe Torres
Assistant Chief Airfield Operations
Chicago Department of Aviation-O’Hare
International Airport
City Tower Atrium-Airfield Operations
10510 West Zemke Road
USA -Chicago, IL 60666

ICAO Headquarters, Montreal, Canada
International Civil Aviation Organization
(ICAO)
999 Robert-Bourassa Boulevard,
Montréal, Quebec H3C5H7, Canada

ICAO Headquarters, Montreal, Canada
International Civil Aviation Organization
(ICAO)
999 Robert-Bourassa Boulevard,
Montréal, Quebec H3C5H7, Canada

Dr. ir. H. G. (Dries) Visser
PositionAssociate Professor
FacultyAerospace Engineering
TU Delft, The Netherlands
The Boeing Company
929 Long Bridge Drive
USA -Arlington, VA 22202

Boeing
JohnP Christy
Lead Engineer Airport Operations
USA -Seattle

AAAE American Association
of Airport Executives

Spencer Dickerson, C. M.
Senior Executive Vice President, Global
Operations and Secretary to the Board of
Directors
USA -Washington

Vince Howie
Aerospace & Defense Director
Oklahoma Department of Commerce
900 North Stiles Ave.
USA -Oklahoma City, Ok 73104

VDr. Arvind G. Rao
Assistant Professor
Faculty of Aerospace Engineering
Technische Universiteit Delft
Delft, The Netherlands

Isr. J. A. (Joris) Melkert
Aerospace Engineering
Aerodynamics, Wind Energy & Propulsion
Flight Performance and Propulsion
Technische Universiteit Delft
Delft, The Netherlands

Ir. P. C. (Paul) Roling
ATO Staff
Aerospace Engineering
Control & Operations
Aerospace Transport & Operations
Technische Universiteit Delft
Delft, The Netherlands.
Publications : Roling, PC ,Sillekens,
P ,Curran, R (2015). The effects of
electric taxi systems on airport
surface congestion. s. n. , R (Eds.)
Proceedings of the 15th AIAA
aviation technology, integration,
and operations conference
(pp. 1-10) Reston: AIAA

EGIS
11, avenue du centre
CS 30530
Saint-Quentin-en-Yvelines
78 286 Guyancourt Cedex
France

EGIS
Sylvain STRIFFLING
Responsable Pôle Aéroports
France
AIRBUS France
Fabrice Brégier CEO Airbus
1, Rond Point Maurice Bellonte
31707 Blagnac Cedex
France
Isabelle Devatine-Lacaze
Head of Airside Operations
France
Komatsu Ltd.
Masahiko KURITA
Manager of Service material Division KLTD
Japan
Salon International de l’Aéronautique et de
l’Espace / International Paris Air Show
15-21juin 2015
www. siae. fr

We also thank all anonymous reviewers for their constructive suggestions

Copyright © ATS 2017