1. WheelTug® Pushback Time Savings
Prepared 5 July 2016
All values represent industry averages
With access to airline/ACARS data, WheelTug can prepare a customized
analysis and report – for information on collecting this data see
Appendix A: ACARS Data Collection on page 13

2. Page 3 of 13
1. WheelTug Pushback Time Savings Opportunity

3. Page 4 of 13
2. Summary
The airline industry is constantly striving to optimize all facets of its operations. Currently, there are few ways to cut
ground time that do not also negatively impact the passenger experience (e.g. through the use of stairs instead of jet
bridges). Airlines who have optimized their ground operations ahead of the competition have realized significant gains.
However, even the most aggressive among them have seen diminishing returns.
WheelTug opens up new opportunities to optimize ground operations while improving the passenger experience. As
such, it offers a unique opportunity to give first‐movers a significant jump on their competition.
Pushback is inefficient and complex. Even when everything goes perfectly, the process involves: connecting the tug, and
safety pin; establishing communications between pushback functions; pushing back the aircraft; disconnecting the tug
and possible communications links; removing safety pins; securing permission to start rolling; and actually beginning the
aircraft taxi. In addition, there are many opportunities for delay ‐ from bathroom breaks to a lack of tug availability, to
broken towbars to jet blast from nearby aircraft.
In just one minute, an aircraft with WheelTug can pushback without a tug. Depending on procedures, this can be done
without ground crews.
WheelTug can also save passenger (de)boarding time. Because the engines
remain off throughout the gate operations, the aircraft can turn at the
gate and use both doors for passenger transfer, as shown below. United’s
TED subsidiary showed that dual jet bridge operations save an additional
13 minutes/flight. This operation is available to many Asian airlines due to
the pre‐existing dual jet bridges at many terminals. (For more information
on two‐door operations, see 7. WheelTug Procedure (Dual Door) on page
9.)
The individual stages of conventional and WheelTug pushback operations
are examined in the following sections.
Figure 1 Dual Jet Bridge Operations

4. Page 5 of 13
3. Stage 1: Doors Closed to Pushback Start
Description
Beginning of Stage  Doors Closed
Procedure  Check passenger compliance
 Attach tug
 Prepare wing‐walkers
 Establish communications (between pilot, tower, wing‐walker,
driver, marshal)
 Secure pushback clearance
End of Stage  Pushback Begins
Causes of
Delay
Eliminated by
WheelTug
 Tug readiness delay (WheelTug requires no tug)
 Ground crew readiness delay (with Taxi‐Cam pilot can see without
wing‐walkers)
 Before‐start checklist (with WheelTug, this can be done during
pushback)
Reduced by
WheelTug
 Tower clearance (without jet blast, aircraft will reduce obstructions,
opening up movement opportunities. Operations without jet blast
can also speed other aircraft)
Unaffected by
WheelTug
 Passenger compliance checklist
Opportunities  The ability to avoid delays can preserve take‐off slot or enable an
earlier slot
Average Current Time 4:00
2. Pushback Begins1. Doors Closed
0:00 4:00
Activities
Ground crew and
tug positioning
Tug connection
Comms link
connection
Tower clearance
(can be slowed by
jet blast)
Complete
passenger
preparation
(depending on
market)
Ground Crew & Tug
Wing Walker
Wing Walker
Tower
Ground Crew
Tug
Average Time:
4:00

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4. Pushback Beginning to Pushback End
Description
Beginning of Stage  Pushback Start
Procedure  Using the tug, the tug driver pushes back the aircraft with guidance
from other ground crew such as wing‐walkers, as well as the flight
crew
 Pushback must be to a location where engines can breakaway the
aircraft without danger to other aircraft or ground crew/vehicles
 There are various risks during pushback (including collisions, braking
miscommunications and tug/towbar failure) that can delay or even
damage aircraft. This risk represents the bulk of the cost of pushback
 The tug, communications links and safety pins are disconnected
End of Stage  Tug disconnects and drives a safe distance from the aircraft
Causes of
Delay
Eliminated by
WheelTug
 Towbar and tug failures
 The disconnection process
 Tug/ground crew distance requirements
Reduced by
WheelTug
 Distance aircraft must be pushed away from other
vehicles/crew/aircraft
Unaffected by
WheelTug
 NA
Opportunities  By reducing blockage time, WheelTug equipped aircraft can create
new pushback opportunities
 By eliminating sources of delay, pushback times can be more
precisely predicted and scheduled
Average Current Time 4:00
2. Pushback Begins 3. Pushback Ends
4:00 8:00
* All times are averages. Variances are provided on
detail sheet.
Ground Crew & Tug
Wing Walker
Wing Walker
Activities
Pushback
Tug & Comms
Disconnection
Safety pin
removal
Ground crew
departure
Average Time:
4:00

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5. Pushback End to Taxi Start
Description
Beginning of Stage  Pushback End
Procedure  This procedure varies greatly by airline
 Many go through pre‐taxi checklists at this point
 Many require engine start and/or taxi start clearance from the tower
due to jet blast risks
End of Stage  Aircraft advances throttle settings to commence taxi
Causes of
Delay
Eliminated by
WheelTug
 Engine‐start checklist/process
 Tower approval for engine‐start; there is no engine‐start to begin
forward taxi
Reduced by
WheelTug
 Tower approval for taxi‐forward; breakaway jet blast is a non‐factor
Unaffected by
WheelTug
 NA
Opportunities  WheelTug can stop and immediately begin its forward roll. As there
is no jet blast, the process can be completed with a single pushback
clearance; dependent on airport approval
Average Current Time 1:30

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6. WheelTug Procedure (Nose-in)
Description
Beginning of Stage  Doors Closed
Procedure  Standard passenger compliance
 Tower approval for pushback – possibly combined with taxi approval
 Pushback from gate – entirely autonomously if equipped with TaxiCam
 Pushback only to necessary distance for physical clearance
 Taxi forward without delay
End of Stage  Aircraft begins forward taxi
Future Time 1:00 to 5:30 – depending on passenger compliance and tower clearance
Tower clearance can be sped up by WheelTug’s minimal ramp blockage
time and area
1:00 – 5:300:00
Tower clearance
(sped by reduced jet
blast)
Complete passenger
preparation
Taxi back with
WheelTug &
TaxiCam camera
system
Taxi forward with
WheelTug
1:30

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7. WheelTug Procedure (Dual Door)
Description
Given dual jet bridge availability, WheelTug can also speed traditional turnaround, not just pushback times.
Beginning of Stage  Arrival at ramp
Procedure  Drive aircraft into ramp area
 Turn sideways, a procedure that is only possible with WheelTug
 Unload passengers through both doors
 Reload passengers through both doors
 Complete standard checklists and secure tower approval
 Turn sideways and drive out – moving forward – from the gate
End of Stage  Aircraft leaves the ramp area
Opportunities  Because the aircraft is always moving forward and its jets are off, the clearance
process can be accelerated
Future Time Savings Dual door jet bridge operations can save an additional 13 minutes, on top of gate
departure savings.
Figure 2 Historical Dual Door Jet Bridge Operations (SFO) Figure 3 Potential Dual Jet Bridge Operation (Kuala Lumpur)
Turnaround Time (TAT)
Reduced by 13 minutes
Total Ground Time (TGT)
Reduced by 20‐28 minutes (including TAT benefits)
Arrival Passenger/Aircraft Handling Departure

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8. Airline Impacts
8.1. Summary
With WheelTug, between 4 and 20 minutes will be cut from each aircraft cycle. Average aircraft time/narrowbody
operation is 160 minutes. A significantly greater amount of time can be cut from schedule padding due to the uneven
nature of pushback times, enabling new scheduling and routing opportunities.
The benefits are three‐fold:
Benefits Explanation Value
Reduced Costs When aircraft and crews are not in active use, they cost less. $41/minute
Increased ASM/aircraft When aircraft require less time to conduct operations, they can
increase operations
Varies by route
optimization
Increased Passenger
Satisfaction
Passengers who aren’t forced to sit and wait for pushback are
happier passengers; especially once they realize they have a
choice
$96/minute
Total $137/minute
8.2. Reduced Costs
According to Airlines.org, United States airlines face $81 in direct expenses per additional operating minute.
1
This
expense is lower for pushback because fuel and maintenance costs are lower during this period (though FOD risk is
higher). With fuel costs in the airlines.org summary adjusted to $10/minute and the maintenance costs eliminated, the
per‐minute direct operating costs are $41/minute.
In addition to fuel and maintenance costs incurred through regular aircraft usage, WheelTug can eliminate pushback
cost and risk, reduce brake wear, reduce maintenance reserves for leased aircraft, reduce engine maintenance cost and
in‐flight fuel consumption due to reduced ramp‐area FOD, cut taxi fuel expense and reduce the cost of missed take‐off
slots. None of these benefits are included in this summary.
8.3. Increased ASM/aircraft
With WheelTug, no additional aircraft ownership costs are necessary to add or extend flights. Like slimline seats,
WheelTug is an inexpensive way to add Available Seat Miles (ASM).
8.4. Increased Passenger Satisfaction
During pushback, laptops must be stowed and passengers are forced to sit and wait. This period, which we call
“Pushback Prison”, can be dramatically cut – but only by WheelTug airlines. Those who adopt the system will free their
passengers from “Pushback Prison” and be rewarded for it.
The FAA values passenger time at $0.74/minute. With an average load of 130 passengers, passenger time is worth
$96/minute.2
1
http://airlines.org/data/per‐minute‐cost‐of‐delays‐to‐u‐s‐airlines/
2
https://www.faa.gov/regulations_policies/policy_guidance/benefit_cost/media/econ‐value‐section‐1‐tx‐time.pdf

10. Page 11 of 13
8.5. Conclusion
WheelTug time savings (based on direct operating costs and increased passenger satisfaction) are worth $137/minute.
New routes could offer additional benefits in the form of new Available Seat Miles without additional capital investment.
As shown below, total WheelTug savings would range from $700k/year to $3.6 million/year.
WheelTug Total Savings
Value/Minute: $137 USD Nose‐in Savings (min) Two Door
Savings (min) Minimum Maximum
Time Savings/Day/Aircraft 14 27 73
Value/Day/Aircraft $1,918 $3,716 $9,950
Value/Aircraft/Year $690,000 $1,340,000 $3,580,000

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9. Total Savings
Savings/Flight
Area Value/Flight
Savings Immediately Realized
Pushback $125
Fuel $50 (10/minute with 5 minutes estimated/flight)
Brake Wear $20
Savings Progressively Realized
Time (nose‐in only) $548
Time (dual‐door boarding) $1,439
Engine Maintenance $15
Savings/Year
Savings Detail
$‐
$500,000
$1,000,000
$1,500,000
$2,000,000
$2,500,000
1 2 3 4 5 6 7 8
Nose‐in Operations Savings Dual‐Door Operations Savings
Flights/Day 4.5
Days/Year 360
Year 1 2 3 4 5 6 7 8
Pushback 125$ 125$ 125$ 125$ 125$ 125$ 125$ 125$
Fuel 50$ 50$ 50$ 50$ 50$ 50$ 50$ 50$
Engine Maintenance 10$ 12$ 15$ 15$ 15$ 15$ 15$ 15$
Brake Wear 20$ 20$ 20$ 20$ 20$ 20$ 20$ 20$
Sub-Total (excluding time) 205$ 207$ 210$ 210$ 210$ 210$ 210$ 210$
Time (minimum w/nose-in operations) 137$ 274$ 548$ 548$ 548$ 548$ 548$ 548$
Total (Nose-in) 342$ 481$ 758$ 758$ 758$ 758$ 758$ 758$
% of Dual Boarding Value Realized 5% 9% 14% 18% 22% 26% 31% 35%
Time (dual-door boarding) 226$ 439$ 790$ 866$ 942$ 1,019$ 1,095$ 1,171$
Total (Dual-Door Boarding) 431$ 646$ 1,000$ 1,076$ 1,152$ 1,229$ 1,305$ 1,381$
Year 1 2 3 4 5 6 7 8
Nose-in Operations Savings 554,040$ 779,220$ 1,227,960$ 1,227,960$ 1,227,960$ 1,227,960$ 1,227,960$ 1,227,960$
Dual-Door Operations Savings 698,301$ 1,047,133$ 1,619,526$ 1,743,178$ 1,866,830$ 1,990,482$ 2,114,135$ 2,237,787$
Savings/Cycle
Savings/Aircraft/Year
Operational Values

12. Page 13 of 13
10. Appendix A: ACARS Data Collection
WheelTug can provide detailed, airline‐specific analysis with the provision of ACARS data. Below are details necessary
for flight operations to facilitate the ACARS data request:
Type of ACARS data to be sent for pushback computation:
a. OOOI : Out Off On In information —> these are usually transmitted through DEP and ARR SMIs (and sometimes)
the Mxx SMIs
b. Doors closed data: this information is available on some custom ACMS reports on A320 (usually REP<46>) ‐
transmitted through DFD SMIs ‐
c. Parking brake released: this information is generally taken from the OUT information
d. Engine start reports: these are generally sent every 25 flights to ground, with FlightWatching uplink request we
can get more metrics on ENGINE START at pushback ‐ transmitted through DFD SMIs
e. Initial throttle forward data : this information is available on some custom ACMS reports on A320 (usually REP
<46>) ‐ transmitted through DFD SMIs ‐
f. error messages : REJ and SVC SMIs : these are necessary to get feedback from live uplink queries to get more
metrics from aircraft operations
g. ACMS report <46> (custom ACMS report generally installed on ACMS customized by SR Technics ‐ transmitted
through DFD SMIs)
Forwarding messages from aircraft to FlightWatching servers should be done from airline ground infrastructure
This can be setup easily with airline’s ARINC avinetmail tool, HERMES tool or SITA tools (SITATEX or AIRCOM server).
Sending data to FlightWatching’s IATA address can be done in two different ways:
1/ e‐mail forwarding to tlsfw7x@flightwatching.avinetmail.net (remains on private and secured ARINC/SITA network).
2/ Forwarding TypeB messages directly to TLSFW7X (ground to ground transmission): no double signature accepted
IMPORTANT : We recommend initializing ACARS data with a single aircraft before rolling out data collection to an entire
fleet.
FlightWatching’s Terms and Conditions shall apply to all of the products and services supplied by FlightWatching SAS.