Self-contained Electric Taxi System


The Self-contained Electric Taxi System (SETS) that Delos Aerospace is developing provides for magnetic braking and ground maneuvering of aircraft without the need to run the main engines.

1. Potential Benefits for the Air Transport System

Significant Cost Reductions
 Reduced operational and MRO cost structures
• Guaranteed energy cost savings due to the elimination of fuel burn for taxiing and other ground movements. For example, an A320 type commercial aircraft burns 172 gallons of jet A in taxiing per flight x 3.84/gal = 660 USD/ flight x 2205 flights/year = 1.5 MM USD per annum per aircraft.
• Elimination of the cost of tugs and the associated cost of ramp area storage and the required services and personnel to support them wherein the O&S cost for a single tug is 238,000 USD per annum per aircraft. It furthermore, reduces ramp area congestion that can lead to reduced accidents and injuries thus reducing insurance cost (unknown).
• Elimination of the cost associated with excessive wear and/or damaged equipment and aircraft due to the use of tugs is approximately 195,000 USD per annum per aircraft.
• Elimination of the cost associated with aircraft delays due to the slow towing and pushing speeds of tugs that introduce delays in aircraft movement of + 10 min thus increasing turn-around times. ( approximately 441,000 USD per annum per aircraft, based on $20/min operating cost)*passenger airlines & cargo carriers
• Elimination of the cost associated with turn-around delays due to having to wait for an extra 15 min to allow the friction-based brakes to cool before the aircraft can take off again, which significantly affects the capacity utilization rate of aircraft. (approximately 661,000 USD per annum per aircraft, based on $20/min operating cost)*cargo carriers
• Decreases the MRO cost structures for jet engines, tires, wheels, brakes, and landing gear structures. (approximately 260,000 USD per annum per aircraft combined as a conservative estimate)
• The total combined cost savings are approximately 3,374,000 USD per annum per passenger aircraft and 4,015,000 USD per annum per cargo aircraft
Performance Increases
 It enhances passenger comfort, reliability, operational effectiveness and safety.
• Higher levels of effective braking are achieved due to the control dynamics being 100 times faster and the lack of brake fade.
• Pre-rotation of the wheels eliminates the impulse stresses applied to the main landing gear thus extending the meantime before replacement while increasing passenger comfort by eliminating the jolt experienced when the tires are spun-up at touchdown.
• Pre-rotation also eliminates the generation of particulate air pollution from the tires and brake dust (7.5) grams per landing. Also there is the depositing of reverted rubber on the runway that significantly reduces the friction coefficient during rainy conditions and requires removal by the airports and the rubber particulate and brake dust generated reduces the clean engine performance of the aircraft engines that ingest the particulate matter.
• It provides a fail-safe feature wherein braking effort is available when landing on a dead stick which is not currently the case.
• Allows for the use of the tire as a sensor to determine the friction coefficient to apply max braking effort during aggressive or emergency braking wherein the deceleration rate is limited only by the friction coefficient of the contact surface.
• Allows for de-rating takeoff engine thrust when used to assist during takeoff, which significantly increases the lifetime of the main engines.
• Allows for simple installation, diagnostics, maintainability, logistics and sustainment support significantly increasing the performance levels of the aircraft.

2. Likelihood of public acceptance is high due to the reduced environmental impact and increased level of safety and comfort.

3. Radical content
Our technology makes it possible to conduct ground movements of aircraft with greater efficiency, economy, maneuverability, and safety at higher speeds with input from the flight deck under the pilots command and control. This is accomplished using in-wheel motor/generators within the landing gear wheels wherein the weight of the aircraft provides the normal force required to produce the tractive effort essential to generate the levels of torque needed to conduct ground maneuvering of aircraft at a desired speed.
During landing events the landing gear tires are pre-spun to match the relative ground speed thus eliminating the sliding friction wear of tires which generates particulate pollution that is ingested by the following landing aircraft affecting the clean performance of the engines and eliminates the depositing of reverted rubber onto the runway which reduces the available friction coefficient in rainy weather conditions.
At touchdown the motor is converted into a generator thus converting the kinetic energy of the aircraft into electrical power that is stored onboard the aircraft that can be used by the aircraft to power the in wheel motor/generators and/or other systems.
There is noise and jet blast or prop wash associated with the use of main engines for taxiing and noxious emissions that directly impact human health and safety. Moreover, taxiing with main engines results in wasted fuel burn and shortens the flight life of the main engines and increases the possibility of foreign object damage or FOD which can significantly increase overhaul cost.
The slow towing and pushing speeds and lack of maneuverability of tugs can cause delays in aircraft movement( + 5 to 10 min) along with the fact that the tug driver is controlling the push back or towing of the aircraft leaving the pilot of the aircraft without direct command and control as to movement that can prove to be dangerous wherein for example the application of the aircraft brakes by the pilot may cause severe loads to be transmitted to the landing gear which can cause excessive wear and/or damage which happens from time to time.

4. Physics credibility
The basic physics of magnetic braking and motoring has proven itself within the ICE train and requires an engineering effort to transition the technology into an aircraft that requires certification testing as it is a safety critical system.

5. Time-scale for incubation
We foresee an incubator time scale of 2 years.

6. The achievement reached in the incubator
The expected deliverables are at least 3 prototype iterations of fully tested in-wheel motor generators with a final demonstration prototype that is capable of functioning as required for taxiing and conducting aircraft braking requirements within the defined operational requirements.

7. Related and supporting capabilities
The related supporting capabilites is within the area of computer science and computer modeling for the generation of computer simulations and analysis to support the prototype construction.

8. Budget required for incubation is 10 MM USD which includes the hardware, software, personnel and tooling setup for testing and data collection and feedback into the computer models to refine and improve the predicted performance parameters and meshing requirements of the multi-dimensional physics computer simulation runs.

9. Partnering needs for incubation.
We seek to partner with a company with experience constructing computer models within electromagnetics, thermal, CFD, and mechanical stress analysis

10. Scalability of the idea.
The application scale is from a small private jet to an A380 wherein all aircraft can benefit from the use of magnetic braking and ground maneuvering that the SETS provides fro aircraft.

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