For cargo operators, there is no risk of passenger jet bridges impacting with their aircraft, but there remains the signifi cant hazard of high loaders going ‘bump in the night’ with the freighters they are serving. At its European hub at Leipzig/Halle, DHL has worked closely with GSE manufacturer JBT to mitigate this potentially very costly hazard
Leipzig/Halle is DHL’s largest express hub, busier even than its other worldwide hubs in Cincinnati and Hong Kong. Each weekday, it will handle approximately 60 scheduled flights, loading and unloading many different freighter types. Christian Bergfelder, director network airside – Europe for DHL, estimates that on an average weekday night each of the hub’s 36 high loaders will be positioned at one of the integrator’s freighters (widebody B757 or narrowbody B737) six times, with the pressure on to achieve the rapid turnaround so vital to an express service provider’s operation.
But that pressure can have unwanted consequences. The DHL team identified that in the winter season of 2011-12 alone there were four collisions at Leipzig/Halle involving DHL high loaders with freighters, one of them quite severe. In each case, the left-side handrail on the high loader had not been retracted – in other words, operator error was the cause.
Of course, the human element can’t be taken out of the loading/unloading operation, but ways had to be found to help the operator and prevent such collisions – not least because of the heavy cost incurred by way of damaged aircraft, as well as consequent delays to operating schedules. The immediate response was to employ marshallers for all high loader positioning (a requirement that continues today), but a longer term answer also had to be found.
The solution, Bergfelder says, was identified in talks between DHL and its high loader supplier at the airport, JBT AeroTech. All of DHL’s high loaders at Leipzig/Halle were retrofitted with JBT’s Aircraft Proximity Detection (APD) collision avoidance system that incorporated four main elements: the existing handrail was fitted with a sensor that tells the driver whether it is in the extended or retracted position; a new handrail was fitted that came with a pressure sensor that stops the unit’s forward motion when actuated; a hand throttle, in addition to the foot throttle, was introduced that allows for precise positioning at slow speed; and a new wheel position indicator was added to show the driver whether or not the vehicle’s wheels are in the correct centred position for a straight approach to – or reverse away from – the aircraft.
With the sensor preventing forward movement of the vehicle when a handrail is extended, there have been no collisions of these units with the aircraft they service since February 2012, Bergfelder points out, adding that the anti-collision technology has been “a valued addition from a cost and risk-mitigation point of view”. He highlights the relatively small cost of retrofitting a system like APD in comparison to the very expensive collisions that might otherwise result, and has declared himself all in favour of rolling out anti-collision technology across as many DHL self-handling operations as possible.
Other DHL stations do seem to have seen the benefit and acted accordingly. According to JBT’s senior sales account manager Central & East Europe, Christian Eitner, the manufacturer has also sold its APD system to DHL in Paris and the UK’s East Midlands Airport and is currently awaiting a final decision from DHL Brussels and DHL Copenhagen.
Eitner believes that APD is just one example of JBT’s biggest strengths – its equipment and systems are modular, and can be combined and customised in order to meet the specific needs of a client. “Just as you can retrofit a standard (JBT) Tempest de-icer into an A380-capable unit with a (JBT) field kit or a 1997 Commander 15 (loader) into a modern, green technology electric Commander 15 – to name just a couple of examples – APDs can be adjusted to whatever the customer wants from the system.”
The APD system can, he continues, not only monitor the loader’s approach to the aircraft, but also keep an eye on pretty much anything that the buyer wants its driver/operator to pay attention to during a loading/unloading operation. This can involve very few elements or it can incorporate the monitoring of “the entire process of interacting with an aircraft”.
And how can that be achieved? Eitner explains: “The basic APD set consists of a PLC (a Programmable Logic Controller, which interprets the various information provided by the sensors around the vehicle and alerts the operator where necessary), a hand throttle and a radar. With that you can monitor (as other solutions do) the approach and docking with the aircraft.”
But alongside that core array, customers can opt for a large number of options that either enforce recommended operational procedures or indeed take control away from operators for certain functions – options that, as we have seen, DHL has availed itself of at Leipzig/Halle. Potential capabilities include monitoring of the angle of the vehicle’s wheels (loaders can swing quite heavily when reversing and hit wings or aircraft engines), monitoring and/or actually retracting handrails; monitoring the presence of people in dead areas around the loader; and limiting speed when in close proximity to another object.
COMPOSITES: UNSEEN DAMAGE
As DHL knows to its cost, any collision between a loader and an aircraft can cost money – plenty of it – and have a damaging impact on operating timetables. But with the introduction of new composite aircraft types – most notably the B787 ‘Dreamliner’ and A350 – there is potentially a much greater danger. A loader operator might accidentally hit such an aircraft, probably at no great speed, see no damage and therefore not report it. However, damage is much less visible on these composite airframes and, as a result, hundreds of lives could potentially be endangered if structural integrity has been compromised.
With APD, says Eitner, loader operators are not only more precise with what they do but can also feel more confident in their work. When a collision has occurred and there is the question of responsibility to be decided, having vehicles equipped with APD will suggest to those apportioning liability that the operating handling company has done all it can to mitigate the risk.
JBT has installed more than 120 APD kits on its loaders positioned around the world, with customers such as Air France, Air Canada, Nordic Aero, Avianca and SAS, as well as DHL.