Horizontal Passenger Loading Bridge

To get on board an aircraft one can walk a passenger loading bridge from airport’s waiting room; or climbs up a stairway from the airport the tarmac. Walking the distance between airport's waiting room and aircraft in waiting deserves some muscular effort, and in certain airport to include the climb up or climb down stairways, depend on the embarking or disembarking arrangement for passengers, not to forget to walk the sloping down or sloping up passageway leading to  aircraft cabin. This mean  aircraft passengers have to exert his/her muscular power to get to get seated. So do boarding aircraft right from the airport tarmac. No one of it is an easy undertaking.

One disadvantage boarding aircraft by stairway right from airport tarmac if weather is bad. One can get drench in summer when it showers, or in winter while it snows the air may be very cold to bear. This is the reason why “passenger loading bridge” is in demand by most airports the world over today.   

The problem with a Passenger Loading Bridge, shorten PLB, is angle it makes with a horizontal plane or water surface. If it is too steep, passengers can get slip and fel to floor while walking a sloping down passageway on entering the aircraft, or walking a sloping up passageway the other way round on leaving the aircraft with gradient above the limit.

The sloping down angle of a passageway with horizontal plane depends on: the distance an aircraft makes with airport building, shorten Horizontal Distance (HD); and elevation difference of aircraft’s cabin floor has with the airport’s waiting room, measured from the surface of airport tarmac, or Vertical Distance (VD); as shown in Figure-I. 

Figure-I

Figure-I displays a Retractable PLB, shorten RPLB, connecting the aircraft’s fuselage with airport building. Such a bridge also called a telescopic bridge, because it consists of two components: a Fix Bridge (FB) and a Telescopic Bridge (TB), like a telescope. As can be seen from triangle ABC colored red, AB is the horizontal distance between aircraft fuselage and the airport building, BC is vertical difference between the aircraft’s cabin floor and floor of the waiting room of the airport building, measured from the suface of airport’s tarmac, and AB is the length of RPLB. The angle of RPLB with horizontal plane is:

To safeguard: elderly, women, children, and handicap from getting slip and fall to floor on entering the aircraft, or leaving it the other way round, this angle must be kept to maximum such as: α = 5 degrees. To have this angle right, one have to reduce VD, or increase HD the other way round, much depends on what can be easily carried out.

If for one aircraft’s type, size, make, PLB gives a corect angle say 5 degrees, it will not right    with other type, or size, or make. The VD and HD distances may vary with aircraft’s type, size, and make. For small size aircrafts, VD tends to increase while HD to decrease resulting angle α to rise; meanwhile for big aircrafts, VD tends to decrease while HD to increase resulting angle α to rise. If one wants to reduce angle α any further, the horizontal distance must be increased indefinitely, but this is limited by the maximum length of RPLB.

To get rid of problem raised by RPLB, a new PLB will be introduced called:  the Horizontal Passenger Loading Bridge, abbreviated HPLB. The latter bridge consists of: a Fixed Bridge (FB), and a Telescopic Bridge (TB) with a Bridge Gate (BG), all protruding from the airport building,   known as section-1. Inside the airport building there is another Inner Bridge (IB) with  pair of PEDP (Passenger’s Embarking/Disembarking Platform), known as section-2. At the end of section-2, there is a Personnel Elevator (PE), known as section-3. Figure-II presents the proposal of HPLB for future airports. Figure-IIa is the side view of HPLB, while Figure-IIb is its bird’s-eye view.

Figure-II

As can be seen in Figure-IIa, every HPLB will be supported by three jacks with self adjusment,  called: J-1, J-2, and J-3. Each jack is electronically controlled to change its hight so the floor of  HPLB always levels with the coming aircraft’s cabin floor. The three jacks will in unison move IB, FB, TB, and BG up to meet the incoming aircrafts’ cabin floor of various type, size, and make; or descend them in unison back the other way round to meet another incoming aircrafts’ cabin of floor of various type, size, and make.

To alter elevation of HPLB floor over the airport’s tarmac, two jacks design has been foreseen, i.e.: jack of small range for bottom support, and jack of wide range jack for side support. Every
jack to be equipped with four LD (Lifting Device) and a mechanical drive system backed by simple technology called: 1. Bolt-Nut with Bevel Gear, or 2. Rack-Pinion with Bevel Gear and Worm Gear. A system of mechanical drive will be used to synchronize speeds of every LD in  drive compartment of every jack. A brake induction motor will be provided to move every jack mechanically, in order HPLB floor can be moved up, or be moved down the other way round, to suit demand of every incoming aircraft cabin floor of various type, size, and make.  

All jacks supporting HPLB will never sink by action of gravity, or weight of HPLB along with  passengers walking alongside, unless being driven by its brake induction motors. Same technology also being used to draw Telescopic Bridge (TB) out from the Fixed Bridge (FB), or draw it back in the other way round. Four LDs are installed around four corners of FB and TB back by similar technology: 1. Bolt-Nut with Bevel Gear, or 2. Rack-Pinion with Bevel Gear and Worm Gear. Thesel LDs will in unison draw TB out from FB mechanically, or draw TB back in  the in unison other way round; synchronously driven by a brake induction motor in its drive compartment.

With advent HPLB capable to adjust its floor hight to the elevation of incoming aircraft’s cabin floor of various type, size, and make, future airliner passengers will embark or disembark from aircraft only horizontally; irrespective of its type/size and make.

Figure-IIb is the bird’s-eye view of HPLB. As shown in the drawing, TB can be drawn into FB when the bridge is not performing, and section-1 be park by turning it 90 degrees to parallel with  airport façade.

The Passenger Embarking/Disembarking Platform, abbreviated PEDP, is in fact a high capacity elevator use to ascend passengers from waiting room on the first floor to IB, or to descend other passenger from waiting room on the second floor also to IB in future airports; or the other way round. As is shown in the drawing, a set of PEDP consists of two high capacity elevators being installed in section-2, and installed on either side of IB.  

Except the shape, a PEDP is similar with JE (Jamarat Elevator) in the proposed Mina Jamarat in Mecca, Saudi Arabia, already been described in previous article, also to make use the same technology.

The Passenger Carrying Capacity (PCC) of PEDP depends on design and is proposed to carry 200 to 300 passenger one way up, or the other way down. Having that capacity, a set of PEDP will easily board passengers of large airliner to its full occupancy.

With PEDPs in airports, no muscular power need to be flex by any passengers to get from ground floor (first floor) to IB, also from second floor to IB, or the other way round; because each PEDP is driven by a brake induction motor electricity fed from utility.

From PEDP airliner passengers move to IB after the fence is open, then walk horizontally to aircraft through: FB, TB, and BG, to enter the cabin. Also same passengers do the other way round, on leaving the aircraft’ cabin back to airport waiting rooms on each floor.

A system of electronic control will monitor elevation of IB in section-2 to equal FB FB, TB, and BG, TB, and BG of section-1 over the airport’s tarmac with time. Jacks: J-1, J-2, and J-3 supporting HPLB will execute the result of monitor, should there be intolerable discrepancy. The two sections must keep equal height with the airliner’s cabin floor on the airport tarmac.

Inside airport building, right behind section-2 of HPLB is section-3, a Personnel Elevator is located, abbreviated PE. PE is built for less PCC around ten people. It is a low capacity elevator  for airport personnel only, like: aircrews, mechanic, etc. It also ascend people from ground floor to IB, and from the second floor to IB; or back the other way round. When needed it also help late passengers to board the aircraft. Except for its PCC, a PE (Personnel Elevator) in airports  also like a PE (Pedestrian Elevator) or a HE (Home Elevator), that has already been explained in  previous articles, also implements samilar technology.

To board an aircraft with HPLB begins from the airport waiting rooms. There are at least two waiting rooms in future airports: one on the ground floor (first floor) and another on the second floor;  passengers may wait in both waiting rooms.

To enter the aircraft with HPLB, starts from both airport’s waiting rooms. From waiting room in the first floor, and from waiing room in the second floor, people enter each PEDP in waiting. A tune of music will accompany each elevator as it ascends or descends, to let people in the environment aware of things being done. The first elevator ascend from ground floor to IB and stops after it levels, while the second elevator descends from second floor to IB also stops after it levels. As soon as both PEDP levels with IB, a fence bordering them with IB open immediately, and passengers move horizontally to IB to walk along FB, TB, BG, to enter aircraft’s cabin, finish.

To get off the aircraft with HPLB starts from aircraft’s cabin. After cabin door’s is opened, passengers the walk horizontally to BG, TB, FB, IB, to enter both PEDP in waiting, on either   side of IB, on the left as well as right side. One or both elevator ascend to second floor; or one or both elevator  descend to ground floor, depends on service program extended by airport authority to arrival or departures. With a pair of PEDP in airport, the airport authority can split the arrivals with the transits easily. Each PEDP will stop after it levels with floor of destination, i.e: the first floor and the second floor. Passengers leave after fence bordering PEDP with the waiting room been opened, finish.

Electricity comes from utility by power cable to enter HPLB panel, and be distribute by way of power wiring to brake induction motors in every drive compartment of jack: J-1, J-2, J-3 and TB. In case of power failure, emergency power supply will immediately take over.

With advent of solar panel and wind generator, energies harnessed from the sun and the wind can be used to run HPLB in remote airports after being converted to electricity. Electricity be used to run electric motors, electronic control, computer, and lighting.

To interface operator with HPLB electromechanical system, a Programmable Logic Controllers (PLCs) being used along with control wiring, limit switches, indicators, and push buttons.

As soon as aircraft come to approach, HPLB will sends first radio signal informing the aircraft’s of its identity: type, size, or make. Upon receipt of answer, HPLB responds with the setting of its bridges (IB,FB,TB, and BG) to the elevation required above airport’s tarmac to suit the coming aircraft. Computer inside HPLB already gathered data in its memory for a number aircraft including the one now approaching. As the aircraft get closer, it sends another radio signal informing the real elevation of its cabin floor  on the airport’s tarmac, and HPLB computer responses by correcting bridges’ height down to a fraction of cm. When the airliner comes to a stop on park, TB will extends toward aircraft’s door at the front of fuselage with a swing of BG, to allow the latter  easily nestle with aircraft’s front door.

The “Horizontal Passenger Loading Bridge” has been filed at the Patent Office of The Republik of Indonesia, in Jakarta, Registration number: P0020000203 on April 30, 2007, under the title: “Jembatan Pemuat Penumpang Horizontal”.