SCENE: Inventory Check for Ground Support Equipment

IDENTIFICATION DETAILS

Name of Equipment: Universal Passenger Step.

Model Designation: the UDS-2. The UDS-2 is the designation for the diesel-powered version of the self-propelled universal passenger step.

Manufacturer: The manufacturer is FMC.

MANUFACTURING AND SERIAL DATA

Serial Number:

The chassis number (Nº Chassis / Chassis Nbr.) is 05058.

Manufacturer Date: 05-2005.

OPERATIONAL STATUS

Working Hours: The total accumulated working hours for this specific unit cannot be determined 

Condition / Operational / Refurbished: The equipment is used.refurbished 

The equipment described is the FMC Universal Passenger Step, available in two self-propelled models: the UDS-2 (diesel powered) and the UES-2 (electric powered),. These steps are designed for universal use, capable of servicing the passenger doors of various aircraft, including the B-727 and B-737, up to the rear doors of the A-300 and A-330/340.

Here are the key technical specifications and components of the equipment:

Dimensions, Capacity, and Performance

The design of the UDS-2/UES-2 emphasizes stability, safety, and load capacity.

Approximate Weight (with cabin and battery):

• Diesel (UDS-2): 6,420 Kg (14,156 lb).
• Electric (UES-2): 6,950 Kg (15,325 lb).

Drive System and Power Unit

The equipment utilizes a modular vehicle configuration, allowing easy adaptation between the diesel and electric versions.

Diesel Version (UDS-2):

• Engine: Standard power unit is a Deutz F4L1011 F diesel engine.
• Transmission: Uses hydrostatic transmission where the engine is coupled to a variable flow hydraulic pump, driving a hydraulic motor coupled directly to the front axle.
• Electrical System: 24 VDC system, powered by two batteries charged by the engine alternator.

Electric Version (UES-2):

• Motor: Electric drive motor is 80 VDC, 13 Kw, spline coupled, connected to the front axle differential box.
• Battery: One 80 VDC, 440 A·h lead acid battery supplies power,.
• Controller: Features an electronic type speed controller (General Electric series is standard). The controller incorporates regenerative braking when the accelerator is released.

Chassis, Axles, and Brakes

• Chassis: Purpose-designed by FMC, constructed from precision welded standard steel sections and plates.
• Axles: The front axle is both the drive and steering axle, incorporating a center-mounted differential box. The rear axle is a non-driven beam axle that pivots at the center and is cushioned by rubber block suspension.
• Suspension: Axle suspension is provided by double “floating” rubber blocks on the front axle and rubber block cushioning on the rear axle.
• Brakes: The foot-actuated service brake acts on all four wheels (disk type on front, shoe and drum type on rear). A negative type parking brake acts on the front drive wheels.

Stairway and Hydraulic System

The stairway assembly is mounted on the chassis using four articulated joints designed to transmit loads directly to the stabilizers or wheels.

• Stair Mechanism: The stairway consists of two telescoping stair flights, moved directly by a single acting, single stage hydraulic cylinder, This simple system eliminates the need for chains or telescopic rods.
• Safety Locks: The stair flights are self-locking via an automatic mechanical latching system. Hydraulic and mechanical safety locks are incorporated, along with a mechanical ratchet lock provided at each step height.
• Platform Features: The wide upper platform (3 meters access width) allows the aircraft door to be opened without repositioning the step. The front section of the platform is spring mounted to cushion impact during positioning and eliminate any gap between the door sill and the platform,. All platform parts that contact the aircraft are protected with tubular rubber bumpers.
• Hydraulic Fluid Capacity: The hydraulic tank capacity is 90 lts (23.7 Gal).

Safety Devices

The equipment includes several safety features mandated by guideline documents such as IATA AHM 910, 913, 915, and 920:

• Emergency Stop: A self-lockdown red pushbutton is located on the instrument panel.
• Drive Interlocks: Drive capability is disabled if the stabilizers are extended or if the parking brake is applied. Starting is disabled unless the drive joystick is in the neutral position.
• Emergency Operation: A manually operated hydraulic pump is provided for emergency retraction of stabilizers, lowering the mobile flight, and releasing the parking brake for towing in case of power failure,.
• Brake Failsafe: The parking brake is automatically applied during power failure.

(Note: The technical documentation confirms the UDS-2’s approximate weight (with battery, without cabin) is 6,120 Kg, matching the Empty Wt. on the plate, and details its high load capacity, allowing 2,050 Kg on the platform.)