LONDON—Aircraft docking systems can substantially boost an MRO's profitability, especially if they are tailor-made to enhance the business. The advantage such systems provide can be considerable, according to Robin Wohnsigl, president and CEO of Laurentian Aerospace Corp., who is backing his belief with hard cash. His new MRO is not only investing in an automated, laser-guided, self-positioning docking system for its state-of-the-art maintenance hangar in Plattsburg, N.Y., but it also has acquired Contec Multidocking Ltd. (CML), the company that made the system.

“Making money from MRO has much to do with providing aircraft mechanics with the right tools to get the job done efficiently,” says Wohnsigl. “That's why widebody heavy maintenance has declined in North America, because local MROs have failed to invest in equipment that makes it profitable. For example, it can take up to two shifts to erect access frames and scaffolding around a widebody airframe,” he says. Some checks require technicians to jack and level the aircraft before moving platforms nearby, which also takes time.

“So, a docking system that can automatically adjust itself to fit accurately around a widebody airframe within one hour and retract just as quickly can save up to a day on both the front end and back end of a check-time that operators can use to generate an additional $400,000-500,000 in revenue,” says Wohnsigl.

CML already has supplied three automated docking systems to Emirates Airlines, which, like the system it's building for Laurentian, will feature laser-guided platforms that slide to within 1 cm of a fuselage.

With main structures made of steel, suspended frames of aluminum and platforms of composite materials, most modern docks in use can be partially assembled off-site. Erection of the dock, which can take up to two months, and automated systems testing, which can take about six months, can increase total design-to-installation time to more than eight months. Moreover, a fully automated, custom-built docking system that can accommodate a mix of widebody airframes can cost $20 million-$30 million, while manually adjusted ones are considerably cheaper.

There also must be sufficient hangar space for the system to retract, so that aircraft can be moved in and out. If so, MROs will likely need to modify or build purpose-built hangars for larger airframes–the cost of which, Wohnsigl believes, often stop them from making their operations as efficient as they could be.

Specifications

Thomas Spriesterbach, head of Airbus A380 maintenance at Lufthansa Technik (LHT), has a different view on efficient docking systems, having led the team that specified the docking system for LHT's new widebody maintenance hangar at Frankfurt Airport.

“For us, it was key that the docking specification was shaped by the people who would use it,” Spriesterbach says. “For research, we looked at numerous automated docks in different MRO facilities, and on two occasions, system failures stopped their operation. Why have a system which needs its own maintenance crew to keep it working?

“In our experience, docking can be manually positioned just as efficiently as automated systems. Once the aircraft is in the tail-dock, platforms can be placed in less than 10 min. Moreover, mechanical problems are simpler to fix than software or electronics glitches. Our approach is to keep it simple,” says Spriesterbach.

Based on LHT's business case, it made functional descriptions of the tasks required and then refined them to formulate the dock specification. This resulted in a 200-pg. specification to accompany requests for proposals.

In Spriesterbach's opinion, docking system specifications must define

• which aircraft sections require docking (tail, wings, fuselage etc.);

• whether docking positioning should be automatic or manual;

• labor requirement and elapsed time for installation and removal;

• accessibility for landing gear and engine maintenance;

• connections for electrical power and high-pressure air;

• the dock lighting system;

• suitability for stripping and painting aircraft; and

• flexibility for different aircraft types and sub-types.

The company contracted to turn LHT's requirements into a structure capable of accommodating A380s, Airbus A330/340s and Boeing 747s was Dutch specialist NIJL Aircraft Docking B.V., which has built these systems since 1966.

“A docking system specification will depend on the business case and the desired application,” says Chris Emmink, NIJL's business development and sales manager. “So, we work with the customer to achieve a design that fulfills [them]. In most cases, we want a preliminary design to determine the general arrangement and see how it might fit within the building.”

NIJL designers create initial concepts on computers and progressively develop them. A virtual 3D model is then generated in a pre-production drawing application and tested with virtual aircraft. For LHT's tail-dock, this model lets designers incorporate mechanics' suggestions, such as additional shelves for tooling and components to keep them off the floor, eliminating potential hazards.

Depending on requirements, NIJL can refurbish existing docking or replace it with a new system, but much depends on hangar size and existing layout, says Emmink. At London Heathrow Airport, for example, British Airways is modifying the roof and doors of a hangar to accommodate large widebodies, while inside, NIJL is building two new combination nose-docking systems that adapt to fit Airbus A380s, A330s and A350s and Boeing 747s and 787s.

Other challenges for docking OEMs include designing docks for hangars whose roofs are not designed to support additional weight. In these cases, the docking must be as lightweight as possible, yet remain stable to comply with safety regulations.

Nose-in or tail-in preferences tend to be based on historical practice. For example, BA and KLM prefer a nose-in position for their widebodies, while LHT prefers tail-in. Demand for automated and self-propelled units, says Emmink, is rising mainly in Asia. European MROs still prefer manually moved, traditional designs. Powered, roof-mounted platforms suspended from telescopic arms are becoming more popular but, despite their maneuverability, they provide limited under-wing/fuselage access and are better for rapid maintenance tasks involving few mechanics.

Flexibility

Fixed hangar layouts are becoming rare as MROs embrace to mobile, combination docking systems that accommodate all-narrowbody or all-widebody aircraft types.

For example, MAS GMR Aerospace Engineering Co. Ltd has ordered two complete 737/A320 combination tail docks for its new operations in Hyderabad, India. Both of these tail-docks will be built in two equal sections and, while one dock features motor-driven sections, the other dock's halves will be moved manually.

Turkish Technics has ordered eight narrowbody docking systems for its $500 million Habom MRO complex at Sabiha Gökçen Airport near Istanbul, which will focus on airframe heavy maintenance. The systems comprise one combination tail-dock; one complete dock covering nose, wing, tail, engine and fuselage; and two partial docks for nose, wing and tail access.

Under a joint-venture agreement, these docking systems will be designed and engineered in the Netherlands but built in Turkey. The first four docks are due to be operational when the first hangars open in the fourth quarter, followed by the rest in 2012.

To complement its new widebody tail-dock, LHT has jointly developed a flexible wing-docking system with German industrial robot specialist KUKA. This system features self-propelled, adjustable lifting platforms measuring 4m wide and 5m long that are driven and positioned by the on-board aircraft mechanic. Each platform's electro-hydraulic omni-drive system enables exact positioning. When required, the platform can be angled or raised to up to 8m. Special tooling can be carried on these platforms to facilitate replacement of heavy components, such as flap-tracks. Three lifting platforms are employed in this state-of-the-art hangar, together with four more self-propelled platforms for under-wing work.

Training

Docking systems training usually is included in the dock provision contract, together with an operator's instruction manual that covers maintenance. Training time depends on the operator's experience level. NIJL's Emmink says training 10-15 people to operate a new dock for a new aircraft type would typically take five days. Training generally consists of a half-day of system and layout familiarization, followed by 3-4 hr. of supervised, hands-on instruction. Classroom sessions may be necessary for built-in electrical and/or hydraulic systems.

Laurentian's Wohnsigl says CML has not yet designed the training package for its automated docking system but aims to progress operators through checklist-based, hands-on training. This could involve moving dock sections to metal targets placed where the aircraft will be, supervised from the hangar control room via CCTV and voice communication.