Green on the ground - Frankfurt am Main International Airport

18 July 2016

Frankfurt am Main International Airport, operated by Fraport, has long been at the forefront of technological innovation and is heralded as a leader in the challenging sphere of green aviation initiatives. Bernhard Scholz, Fraport’s senior executive manager for fleet management and ground support equipment, discusses the nitty-gritty of the airport’s eco drive.

Frankfurt am Main International Airport is Germany’s largest commercial airport and the third-busiest in Europe. In 2014, this bustling hub handled 59.6 million passengers and around 2.1 million tons of freight. On average, each visiting passenger aircraft only spends an hour on the ground.

“We have unique requirements,” says Bernhard Scholz, senior executive manager for fleet management and ground support equipment (GSE) engineering at Fraport, the airport’s operator. “We have huge amounts of traffic and very tight turnaround times.”

That means ground handling must be rapid and extremely well organised. To facilitate operations, airport operator Fraport runs a vast fleet of specialised GSE: 1,700 motorised units and 10,000 towed units that represent an investment of around €250 million.

Fraport is renowned for its willingness to innovate, and these vehicles are no exception.

Towbarless tractors are a standout example, with Fraport pioneering their use over the past two decades. Rather than using a traditional towbar, the tractors pick up and locate aircraft nose-gear wheels within the vehicle itself during towing. The lack of a towbar means a solid, more reliable connection to the aircraft and reduces load on the nose gear. That permits far higher towing speeds and eliminates the need to stock a host of aircraft-type-specific towbars. It also dispenses with the need for second operator that has traditionally acted as the cockpit ‘brakeman’ in case a towbar detaches.

“We want to avoid any landing gear damage, and towbarless is the best way to do that,” says Scholz. “You can also travel at up to 40km/h whereas a standard towbar tractor is limited to 15km/h.”

Towbarless tractors can be far lighter than the 70t needed to generate sufficient tyre grip in towbar machines, and their one-person, cab-based operation is safer. Sensors continuously monitor and control the pick-up device during towing, immediately alerting the driver if there are any malfunctions.

However, Scholz is wary of placing too much reliance on sensors for delicate tasks such as placing aircraft steps or loading ramps. He gives the example of automated systems that are not nimble enough to compensate for aircraft movement as heavy cargo is loaded.

“We are very open to look at any industry solution that can help prevent aircraft damage,” says Scholz. “The problem is that sensors are not fail-safe. Here at Frankfurt, we find we damage more aircraft with sensors than without because they malfunction in unforeseen ways.”

Sensor failure due to weather conditions is the prime reason, with water, snow and ice causing the most problems for high-tech equipment. Fraport’s preference is to put money into training instead.

“We have stopped using automatic systems and have very few damage incidents,” says Scholz, noting that regulatory bodies like the EU and IATA have contradictory guidelines in this area. “We just put down a safety shoe under the aircraft door. With good training, this is the easiest, simplest and best way.”

Hybrid savings

Reducing cargo-transporter fuel consumption is another example of Fraport’s vehicular innovation. When the transporter and its trailers have accelerated to cruising speed, the operator puts its engine into neutral.

“We call it a ‘sailing’ operation,” says Scholz. “It reduces fuel use by around 30%. We had the idea, implemented it and it’s now the industry standard.”

Reducing energy use, emissions and noise are goals not just for ground handling, but for for all other operations and facilities at Frankfurt as well. Here, Fraport has again long led the way by reducing the use of polluting auxiliary power units.

“We have mobile units for heating and air conditioning, plus stationary and mobile units for ground power,” says Scholz. “We have 60 diesel back-up units that we can use if there is any problem with airport power or the stationary units.”

To help reach its green goals, Fraport is increasingly adopting electric vehicles. Diesel-electric hybrid vehicles have already been in operation for more than 15 years, and nearly 200 hybrid tractors are currently in use. For long-distance towing, the diesel engine is switched on; aside from that, it’s battery only.

Purely electric vehicles started arriving at Frankfurt with the commencement of the E-Fleet project in 2009. In 2015, Fraport partnered Lufthansa within Germany’s E-PORT AN initiative to develop different electromobile technologies and procedures, and test them in day-to-day aircraft handling activities. Fraport’s growing electric fleet now includes pallet-lifting vehicles, pushback and tow tractors, a container transporter and passenger stairs.

“We’ve invested a lot of money to improve our equipment and implement them in standard ramp operations,” Scholz explains. “We now have multiple tests running with different electrical vehicles. To help charge the batteries, we have solar panels on top of the steps to increase the operation time.”

He points to the airport’s high loaders as the most successful electric-only units in operation with Fraport; 11 of them are now in day-to-day use. Multiple charging stations on the ramp let operators top up the batteries between unloading stints so the units can work all day.

“Not only are there zero emissions, but we also have higher operational efficiency and save a lot of money on fuel,” he explains, noting that electric-vehicle operating costs are around two thirds that of a diesel unit.

Electric tractors promise further emissions reductions by cutting the fuel burned during pushback and taxiing. The IAI and Airbus estimate the typical fuel consumption for a Boeing 747 on a 17-minute taxi before take-off is around 1.0t, with nearly 3.2t of CO2 emitted.

However, the prototype tractors have so far struggled due to the sheer amount of energy required to tow large aircraft; an A380 has a take-off weight of around 600t. So far, the electric tractors can only work for around 30 minutes before needing to charge their batteries for eight hours.

“That’s not very efficient for a ramp operation where you need to handle 600 pushbacks every day,” says Scholz. “Battery life is the bottleneck. If capacity and charging time are improved, then electrical drives are possible for everything.”

Whatever, wherever, whenever

Rather than the vehicles themselves, however, the greatest GSE efficiencies have come through Fraport’s in-house-developed TWS vehicle management system, which has been perpetually upgraded since 2001. Onboard communication and tracking units constantly transmit vehicle location and a host of other status data via GPRS or Wi-Fi to a central server.

Towbarless tractors can be far lighter than the 70t needed to generate sufficient tyre grip in towbar machines, and their one-person, cab-based operation is safer.

If a vehicle shows an alarm for low oil pressure, low water or overheating, ramp staff might not respond in time. However, with the use of TWS, central managers can respond quickly and, if necessary, remotely shut the unit down to prevent damage.

If the vehicle is low on fuel, an alert is generated and forwarded in real time, and the system can automatically generate a fuelling task to send to the right operator. The same goes for electrical assets. “Instead of low fuel, it’s low battery,” says Scholz. “Then we can tell our operators: take these units to the next charging device.”

Built-in geo-fencing functionality means specific areas can be defined as prohibited so warnings are given when specific GSE units enter a no-go zone or leave their allocated areas.

“I can find equipment very easily, even if it’s all over the ramp,” explains Scholz. “I also can spot misuse, and if the unit leaves the airport, I get a signal too – maybe it has been stolen.”

The onboard units can register movements and impacts even if the engine is off. They can also control vehicle speed and issue an alert if it exceeds the speed limit for an area. All historical operational data is available to help evaluate usage and operating times.

“If there’s an incident or airlines want to check on how the ground equipment is maintained, I can immediately tell them everything they could possibly want to know about a unit’s condition, operating time and maintenance history,” explains Scholz. “In the past, it would take a couple of hours to gather that information.”

Maintaining a budget

The TWS system interfaces with the maintenance software, monitoring unit usage and predicting the next maintenance date, again alerting managers when required. Intelligently adding location to this data means TWS can generate an alert if a service unit is mistakenly left in the workshop area or, following maintenance, is not picked up quickly and put back to work.

With an annual maintenance budget of around €20 million, improvements like this save serious amounts of money. TWS also greatly reduces the amount of man-hours needed to monitor and administer the GSE fleet manually. Overall, TWS-driven increases in use have seen a 10% reduction in vehicle numbers at Frankfurt. That and the lower maintenance costs have so far saved close to €1 million annually. Those benefits will only increase as more fleet vehicles are added to the 450 that are currently TWS equipped.

With Frankfurt being the first airport registered under ACI Europe’s Airport Carbon Accreditation Programme, Fraport’s ground handling innovation is steadily turning its low-carbon ambitions into reality, cutting emissions while raising efficiency and saving money.

In recognition of its leadership in ground handling and green energy initiatives, Fraport has won numerous industry awards – most recently, Air Transport World’s Eco-company Partnership of the Year Award for its work in E-PORT AN with Lufthansa. With the green ethos a fundamental part of the ethos that underpins the airport’s operation, more will surely follow.  ?

Frankfurt Airport has been leading the way in technological initiatives for ground support equipment, including towbarless tractors.
While Fraport, Frankfurt Airport’s operating company, is very forward-thinking in terms of ground support equipment, staff training is still a vital part of its provision.
One of the airport’s most successful initiatives has been reducing cargo transporters’ fuel use by ‘sailing’.

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