Want to Buy A Bridge?

Oct. 1, 2002
Product Profile

Want to Buy A Bridge?

Four critical factors for selecting a regional boarding bridge.

By Todd Tanner, Boarding Bridge Product Manager, FMC Airport Systems

October 2002

While commercial air travel continues to produce disappointing numbers, the current boom in regional jet service is generating the brightest growth opportunities in the industry. Taking full advantage of these opportunities, however, depends upon choosing boarding bridges that will increase regional service profitability, not reduce or eliminate it. Fortunately, after a few years of using regional boarding bridges, the industry is starting to identify several areas absolutely essential to their successful performance. Based on this experience and analysis, this article briefly examines four critical "make-or-break" factors to consider when specifying and purchasing regional bridges that will enhance operations and profitability.

Just as it helped give birth to the boarding bridge more than 40 years ago, concern for passenger safety still ranks as the number one factor in assessing competing regional bridge designs. This concern goes beyond the given of pure humanitarian considerations. It also relates directly to reducing liability risks and lessening the likelihood of litigation and lawsuits.

One key aspect of maximizing passenger safety centers on eliminating tripping hazards throughout the bridge. First, the cab floor that docks to the aircraft doorsill should be self-leveling and adjustable. The greater the angle from the rotunda end of the bridge down to the doorsill of the aircraft, the more important a self-leveling floor becomes. Without one, passengers step out onto a floor that slopes relative to the tarmac and aircraft interior, increasing the potential for falling.

Next, the bridge floor itself needs careful examination. In particular, one must consider whether the floor design eliminates or minimizes protruding hinges, cavities, and seams — all potential catch points for heels, as well as the accumulation of debris, ice, and snow. An alert comparison of available designs in the market will reveal considerable differences among suppliers.

In regional bridges, cab handrails also contribute substantially to passenger safety. Their configuration and structure should keep passengers out of harm's way by guiding them to cab areas meant for passenger traffic. Handrails should be configurable to the type of aircraft served and should guide passengers away from heated sensors and pitot tubes on the aircraft fuselage. In general, handrails that extend right up to, or, in some cases, just inside, the fuselage greatly ease the transition between aircraft and bridge. And, to comply with ADA (Americans with Disabilities Act), handrails should run the full length of any transition ramps in the tunnel section of the bridge. This is not the case in all bridge designs.

Another extremely important issue for investigation is fire safety. While admittedly rare, ramp fires and fuel spills of various types do occur. When fire erupts, the boarding bridge must be capable of providing a safe route of hazard-free, emergency egress for passengers. If not, the potential for loss of life, serious injury, and resultant financial liability becomes considerable.

Various manufacturers build regional bridges to different levels of fire resistance and robustness. But, since they all face the same fire risks, regional bridges at minimum should adhere to the critical industry-standard design test for bridges servicing larger aircraft — the NFPA (National Fire Protection Association) 415 fire code. It makes good sense for purchasers to request reliable independent certification that the regional bridge design complies with these fire test provisions. Compliance can also help expedite approvals from local inspection officials.

Necessary precautions to ensure that passengers move safely from the bridge to the aircraft and back again amount to indispensable elements of regional bridge designs. Carefully analyzing these elements plays a leading role in prudent bridge selection.

Selection considerations must give equal weight to the safety of those who maintain and operate regional bridges. Work-related injuries, like passenger injuries, prove difficult and are frequently very costly for all parties involved.

Regional bridges that eliminate manually-placed floor ramps help to reduce operator back and finger injuries. Look for a bridge supplier with a design that requires no manual floor ramps to augment docking operations and adapt to varying aircraft. Repetitive placement and removal of ramps creates injury opportunities that can and should be avoided.

Careful evaluation can also bring to light significant differences in service door designs.

Also vital to service door design evaluation is the transition between the exterior landing and the interior tunnel section of the bridge. Because this area must accommodate heavy foot traffic and movement of various supplies, it should provide a smooth, natural, door-like transition. Some regional bridge designs impose an unexpected five-inch step at this critical interface, confronting personnel with a definite hazard for tripping and potentially serious injury.

One last thought regarding the safety of the design for operator and maintenance personnel: How easy is the bridge to maintain? Look for the location of electrical service points, high-voltage cabinets, etc. Some bridge designs put these critical maintenance areas inside the bridge for dry, environmentally-controlled and well-lighted working conditions. Others do not.

Passenger boarding bridges are one of the most common sources of damage to commercial aircraft on the ground. Damage claims routinely run to the tens of thousands of dollars per incident. There can be little question, then, that doing the most possible to protect regional aircraft should be a major focus of regional bridge design.

A few things to evaluate:

  1. Can the final few inches of gap approaching the aircraft be closed mechanically rather than through movement of the entire bridge? Some currently available designs do this through actuation of floor pieces, with no need to telescope bridge tunnels and move drive bogies. This gives the operator very precise, refined control, minimizing the potential for aircraft damage.
  2. Are there adequate sensors for protecting the prop and spinner of propeller-driven regionals? Some bridge designs use infrared or laser sensors; others use fixed-cable sensors. Careful selection evaluation should include comparisons of the merits of these design options.
  3. How does the operator drive the bridge? Some regional bridges use a step-function drive - moving forward, then laterally, then forward again in a staircase manner. This approach makes it very difficult to maneuver the bridge around handrails and steps. Other designs synchronize the telescoping and lateral swing motions of the bridge, letting the operator drive the cab in a straight line, along any selected vector. This option greatly enhances the ease and control of docking the bridge to the tricky interface points of regional aircraft.
  4. Does the bridge have variable speed control? Look for a bridge with motors controlled by variable frequency drives and a variable speed control stick. Regulating bridge speed through simple pressure on a joystick adds an additional degree of precision to the docking effort.

What other features does the bridge offer to protect aircraft? Some options to seek:

  • A lift-away, tip-up floor that will not crush the top step and handrails of a CRJ or other aircraft should the bridge be mis-parked.
  • Full sensors/tape switches across the cab floor that stops the bridge in case of contact with the floor or handrails on the aircraft.
  • Diagnostic capabilities at the control station to facilitate emergency maintenance.
  • Sensors that slow the bridge as it closes on the aircraft.
  • Close proximity and orientation of the operator to the actual docking point, for enhanced visibility that greatly decreases the likelihood of mis-parking.

A regional boarding bridge qualifies every bit as much as a capital item as does any other major asset. The return on investment (ROI) that it supplies depends directly upon the quality and the duration of its performance life.

This basic reality underscores the importance of analyzing the engineering and design of a candidate bridge, as well as the available data on in-place installations.

The evaluation should take a close look at the overall structural robustness of the bridge. Like their counterparts servicing full-size jets, regional boarding bridges must already handle such add-ons as 400 Hz inverters, 28 VDC power supplies, and pre-conditioned air units. What capacities does the bridge have to carry these loads, both statically and dynamically? On a larger scale, what kind of life span and return on investment will the bridge likely provide? Does the design realistically support classification as a 5-year, 10-year or even a 20-year asset? Or, does it have life-cycle-shortening weaknesses that could require it to be replaced after a relatively brief time?

At the core of this entire discussion is the fact that all of the evaluation factors detailed here can prove indispensable to assuring an adequate return on a major investment. Reduced life cycles, higher than expected maintenance costs, claims for passenger or employee injuries, compensation for damage to aircraft, and other adverse results from inadequate design and manufacturing can all devastate ROI.

But, there is still one more pivotal criterion in this area: the depth, availability, and dependability of on-going support after the sale. Does the manufacturer have the in-place resources to stand behind its product on a long-term basis? Does it have a reputation for minimizing after-sale problems and for promptly solving any that do occur? Does it tend to behave as an on-going partner with its customers or as an outgoing supplier, eager to disappear once installation is complete?

To justify its cost, a regional bridge must keep performing for at least a decade or two. To protect your investment, you should feel certain that you will not end up having to handle any portion of that time alone.

Keeping these four factors in mind when evaluating regional boarding bridges will help the buyer to select the best bridge design for the given operation and to gain the greatest value from the bridge purchase. On the other hand, failure to consider adequate protections can turn an apparent low price into a nightmare of liability and unanticipated hidden costs.