The cradle must be raised and the driver must be sitting before the vehicle can drive above creep speed.
"Tronair has been fully invested in their customer’s satisfaction and nothing has stood in their way of keeping our units operational and in service," says Brian Wemple, manager, customer service support for Piedmont Airlines Inc. "They have provided excellent support to our operation and they have been readily available to assist us with any concerns regarding the operation and maintenance of the JETporter SoftCapture units."
Of course, the Softcapture, no matter how innovative, just goes along for the ride so to speak. Tronair has also engineered a number of features into the electric vehicle to efficiently and safely perform pushbacks and towing all day long.
"I have been impressed with Tronair’s ability to engineer this device to meet the design requirements and provide the documentation necessary to gain carrier approvals," says D. Scott Barninger, director, ground support equipment, US Airways Express.
Direct Drive Train System: Two 10-hp 48V DC motors are directly connected inline with the brakes and torque hubs for maximum mechanical efficiency. The maximum combined torque capability for break-away at the gear hub output (36:1) without programmed limits is 6,500 foot-pounds.
Solid rubber traction tires mount to the opposite side of the drive hubs. Digital logic controllers are used to control the drive train.
“Basically, the JETPorter’s direct drive system has less moving parts that other models that use a chain drive,” Kurzdorfer says. “Less moving parts means much less maintenance costs.”
Steering System: There’s more to the direct drive system that comes into play to steer the vehicle. The motors are driven by two separate controllers. The controllers are linked together through a “proportional steering module,” and the PSM delivers the throttle signal to each controller. The signal is based on foot throttle position and steering wheel position.
A hydraulic rotary actuator connected to the steering axle and leaf spring suspension provides a “fifth wheel-type” steering – giving the vehicle a true zero degree turning radius, reduced tire wear, and increased traction and control on snow and ice.
“You can turn on a dime,” Kurzdorfer adds. “The vehicle’s two rear wheels are centered in a way that you can actually rotate about the cradle. That makes it much easier to operate in tight situations.”
The low profile of the vehicle also helps it fit under the bodies of most large cabin aircraft for tighter hangar stacking.
Overload System: The drawbar pull can be controlled by programming maximum amperage limits for a given output. The input signal is provided by a three position selector switch, used as an aircraft type selector. The present limits are set for drawbar pulls of 5,230 pounds and 6,140 pounds. A lower value can be programmed to allow for 3,900 pounds.
Regenerative Brakes: The electric vehicle is charged in part throughout the day thanks to the vehicle’s main regenerative braking system. But the vehicle actually has a total of three redundant braking systems. A foot pedal-actuated brake operates as a secondary braking system. And the emergency/parking brake system is automatically set anytime the operator leaves the platform or when the vehicle loses electrical or hydraulic power.
One-Man Operation: “With the SoftCapture, aircraft pushback and towing can be improved to a one-man, automated operation,” Kurzdorfer says.
Without the strap going on or off, Kurzdorfer figures that alone saves a couple of minutes for each pushback. One hundred pushbacks a day adds up to 200 minutes saved times 365 days.
JETporter, a Tronair company, announces it has received formal approval from Cessna Aircraft Company for the use of JETporter towbarless tugs with Cessna aircraft.