Eagle Tugs TT & USAT Military Technical Brief


Published on

Technical Brief on our TT series and USATS.
Military/Business Jet class AWD aircraft tractors.

Published in: Automotive, Technology, Business
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Eagle Tugs TT & USAT Military Technical Brief

  2. 2. Why are Eagle aircraft tractors superior to any other tractor for military aircraft towing? Commercial Products – With 20 years of experience of continuous product improvements, Eagle aircraft tractors have unequalled reliability; which is reflected in the only 3-year/3,000 hr warranty on the market. All Wheel Drive (AWD) – With equal weight distribution, Eagle AWD aircraft tractors weigh 1/3 less than RWD tractors. This makes Eagle aircraft tractors a better option for air transportability and operation on unimproved surfaces. Designed as Aircraft Tractors – Eagle aircraft tractors were designed from the ground up specifically to move aircraft. Most other tractors in the industry were designed to tow baggage or other GSE. Eagle Tugs designs its aircraft tractors using precise Drawbar Pull (DBP) calculations and testing, assuring that its aircraft tractors are rated correctly to move each load. On the needs of the Military, First Sergeant JT Lee, 160th Soar: “As a military vehicle it has to be air-liftable,” and, “It has to be able to go into undeveloped areas.”
  3. 3. Aircraft Tractor Design NATO STOCK NUMBER 1740 01 461 4279 Example of low profile design and direct Example of the ergonomic design (easy hitch view of the Eagle AWD TT-series. ingress/egress) of the Eagle AWD USATS-6
  4. 4. Military Aircraft Towing Technical Brief This Technical Brief explains the details behind the design features of Eagle aircraft tractors which make them superior for military aircraft towing: 1. All Wheel Drive (AWD) vs. Rear Wheel Drive (RWD) – Discusses the operational differences as they pertain to aircraft towing. 2. Drawbar Pull (DBP) – Discusses how drawbar pull is calculated and how it applies to military aircraft towing. The proper method to DBP testing is also discussed. 3. Aircraft Tractor vs. Baggage Tractor – Discusses the operational differences between an Eagle aircraft tractor and a baggage tractor, and why Eagle aircraft tractors are the best option for military aircraft towing.
  5. 5. All Wheel Drive (AWD) vs. Rear Wheel Drive (RWD) The 2 major benefits of AWD aircraft tractors when moving military aircraft: 1. AWD aircraft tractors weigh 1/3 less than RWD tractors and still achieve the same towing capacities. a. Less weight is better for air transportability b. Less weight is better for operating on unimproved surfaces 2. With equal weight distribution, there is no loss of steering with AWD aircraft tractors as with RWD tractors which tend to be too light in the front end.
  6. 6. Proven in theater operations: Below Afghanistan
  7. 7. All Wheel Drive (AWD) vs. Rear Wheel Drive (RWD) To better understand the advantages of AWD, the following physical laws must be defined: Tractive Effort (TE) – The force that a tractor is able to deliver to the concrete through its wheels. Coefficient of Friction – The ratio of the force required to initiate Tractive Effort (TE) with regards to the weight over the tractor drive tires. The ratio is .90 for pneumatic rubber tires on dry brushed concrete, which means that 90% of the available power is transferred to the concrete to move the load. Drawbar Pull (DBP) – The measurement of smooth lineal force resulting from the rated Tractive Effort (TE), adjusted by the Coefficient of Friction (COF).
  8. 8. All Wheel Drive (AWD) vs. Rear Wheel Drive (RWD) Proper weight distribution above a tow tractor’s drive wheels is calculated as follows: RWD – Must have an equal amount of weight over the tractor’s drive wheels as the required amount of Tractive Effort (TE) force. Also, in order maintain effective steering, the front steer-axle must weigh at least ½ the weight of the rear axle. - A lineal pulling force of 8,800# TE multiplied by .9 COF = 8,000# DBP. So, in order to develop 8,000 lbs. DBP, a RWD tractor must weigh 8,800# over its drive wheels (rear axle only). Additionally, in order to maintain effective steering, the front steer- axle must then weigh 4,400#. The result is that an 8000# DBP, RWD tractor must weigh 13,200#. AWD –An AWD aircraft tractor needs 8,800# over its drive wheels, but since both axles are drive axles, the total weight needed for an AWD aircraft tractor is 8,800#. Also, the weight to maintain effective steering is also accomplished with ½ the tractor’s weight over front steer-axle. The result is that an 8,000 DBP, AWD tractor must only weigh 8,800#, or 1/3 less than a RWD tractor generating the same DBP.
  10. 10. All Wheel Drive (AWD) vs. Rear Wheel Drive (RWD) Proper weight distribution above a tow tractor’s drive and steer wheels also assure proper, safe steering. - Most RWD tractors do not demonstrate the necessary 2/3 weight over the drive wheels, and 1/3 weight over the steered wheels, which at times may result in a lifting of the front steered wheels, and a loss of traction. Even with proper weight distribution, pushing at angles beyond 45 degrees with RWD tractors results in a right or left skid challenge, caused by the doubled weight of the rear drive axle. Due to the fact that the rear drive axle generates all of the Tractive Effort (TE), it tends to overpower the steering. - AWD drive aircraft tractors exhibit none of these steering problems. With equal weight distribution over front and rear drive wheels, AWD aircraft tractors naturally overcome the resistance caused by turning an aircraft beyond 45 degrees.
  11. 11. The only Aircraft Engineered AWD Tractors in this weight class. AWD allows for even chassis weight distribution for greater control and smooth pushbacks.
  12. 12. Drawbar Pull (DBP) and Proper Testing Eagle Tugs prides itself on its 40 plus years of designing and manufacturing tow tractors. This experience has helped us to design tow tractors that are weighted and powered appropriately to push or pull their required and marketed weights. A key to our design is how we calculate our tow tractors’ towing capacities, by applying the US Aviation Certification SAE AIR 1316 specification to our Drawbar Pull (DBP) calculations, and the method we use to test the DBP capacities. We calculate the true DBP capacity of our aircraft tractors and make sure the towing capacity we market for our tractors is true in all weather conditions, for all plausible surface grades, and for all potential weights of aircraft our tractor may move. The Eagle Tugs’ testing protocol requires a gradual and consistent application of power, while recording DBP, until wheel slip or torque converter stall is achieved, indicating maximum DBP on that surface.
  13. 13. Drawbar Pull (DBP) and Proper Testing
  14. 14. Drawbar Pull (DBP) and Proper Testing DBP testing shall be smoothly accelerated without jumping and/or jerking
  15. 15. Aircraft Tractor Design Torque conversion and gear ratio to move expensive aircraft smoothly and safely. All Wheel Drive and Unibody welded chassis creating an extremely smooth push back in all conditions and environments. . AWD TT & USATS aircraft tractor (NSN 1740 01 461 4279). Key Features: 1. 3 Year /3,000 Hour Warranty 2. YANMAR Diesel Engine 3. All Wheel Drive for controlled smooth pushback in all weather conditions 4. Low-profile design under 47” for maximum visibility and safety 5. Ergonomic and safe “slide in and out seating” 6. Intuitive Automotive Controls (Mil standard 1472 human engineering) 7. Average unit produced in less than 4 weeks 8. Standardized parts and tires for PM and replacement 9. Custom color and graphics (your corporate logo & colors) available . On Reliability, First Sergeant JT Lee, 160 th SOAR: “Right now we’re getting around 2,500 hours between failures and I think the only thing we’ve had to do on it besides oil changes and changing filters is to replace a steering hydraulic pump. They could probably last forever.”
  16. 16. Baggage type tractors used in this weight class.. Lacking All Wheel Drive Non ergonomic operators station Reduced visibility due to height Reduced front end control No direct line of sight to hitches Eagle Aircraft Tractor Design Ex ingre Example of low profile design and direct hitch view of the Eagle AWD TT-series
  17. 17. Aircraft Tractor Design NSN 1740 01 461 4279
  18. 18. Over 20 years of in-theater operations. NSN 1740 01 461 4279
  19. 19. Operating in the following partial* list of organizations: Alaska Air National Guard Brazilian Air Force Canadian Defense Forces US Air Force US Army 160th SOAR US Coast Guard JCC-Iraq/Afghanistan Kennedy Space Center Michigan Army Natl. Guard NASA Romania Army Land Forces Royal Saudi Air Force Taiwan National Police Turkish Air Force US Marshals Service U.A.E. Air Force *Eagle supplies many classified organizations as well
  20. 20. Aircraft Tractor Design Matrix Eagle AWD Aircraft Standard (Baggage) The Eagle Aircraft Tractor Tractors Tractor Advantage Not required, too AWD provides controlled Only AWD tractors in All Wheel Drive 4,000-12,000 lb DBP expensive for pulling traction on all surfaces/Lighter baggage weight Better for maneuvering around Low Profile Only 38-48 in. tall 55-60 in. or taller aircraft. Less chance for accidental damage to aircraft Mid-operator, w/ low profile Slide in and out, ergo Climb up and down, strain Ergonomics design on operator design, allows for easy ingress/egress Direct front/rear No front hitch vision, must Direct operator visibility for Visibility hitch/nose wheel vision use mirrors safer, more efficient operation through sight tunnels Same size front and Large rear and small front Same size tires/Equal weight Tire Size/Steering rear tires with equal tires, often too light in the distribution allow for controlled weight distribution front end steering when moving aircraft Proprietary power train Cost competitive market, Properly selected power component relationship results Reliability train relationships must use lower cost in smooth operation and components reliability
  21. 21. Aircraft Tractor Design Aircraft tractor design versus standard (baggage) tractor design conclusions: • Standard (baggage) tractors are intended to pull carts, not multi-million dollar aircraft. These are clearly two different operations with separate sets of requirements. • Standard (baggage) tractors compete in a very price competitive market, in which manufacturers have to control costs in order to compete. This formula does not work when you try to apply it to moving aircraft, in all weather conditions, day in and day out. Lower cost tractors, when used at their maximum capacity for prolonged use, are much less reliable. • Aircraft tractors, designed specifically to move aircraft, with towing capacities directly matched with the weight of the aircraft, are much more efficient, safe and reliable. Providing lower through-life costs. • Not only do the features of AWD aircraft tractors provide operators the proper equipment to safely and efficiently accomplish their jobs, the added reliability alone makes Eagle AWD aircraft tractors the right choice for moving military aircraft.
  22. 22. Utility Standard Aircraft Tractor Design Eagle Tugs was approached by members of the Army Special Forces out of Ft. Campbell KY. The “160th” has been using the Eagle AWD TT-8 (8,000 lb. DBP) aircraft tractors for several years. The 160th had a need for a utility aircraft tractor that was AWD, that could move Army helicopters, but that could also carry up to a 2,000 lb. payload. The 160th chose Eagle Tugs because of the reliability of its aircraft tractors, especially when deployed overseas in less than ideal operating environments under mission critical conditions. Based on the needs described by the 160th, Eagle designed a utility aircraft tractor with the same reliable AWD power train as the TT-series. The new design is named USATS, for Utility Standard Aircraft Towing System. Key features: • AWD – The only AWD aircraft tractor in its weight class • Flexible – 6,000 lb. DBP unloaded, up to an 8,000 lb. DBP loaded • Utility – Can carry up to a 2,000 lb. payload on a 60” X 90” deck • Ergonomic Operation – Slide in and out design. No climbing. • Reliable – The only tow tractor in the industry with a 3-year/3,000 hr warranty
  23. 23. USATS-6
  24. 24. Presented by: Justin Akinleye - Director of International Sale Justin.akinleye@eagletugs.com Manufactured in the State of Michigan: Eagle Tugs 26111 Northline Rd Taylor, MI 48180 USA Global Sales Office: Potters Bar UK European Distributors: Franke Care System Hamburg Germany www.franke-cs.de Sales Agents: Throughout the world. www.eagletugs.com