An article by Michael Gubisch, originally published in Aircraft Technology magazine
Components for hangars in overseas locations need to fit in 20ft or 40ft containers for export and are simply bolted together on site.
Except for cranes and height-scaling equipment, which can be difficult to obtain in remote areas, only minimal tools and low-level skills are required.
According to Rollo Reid, technical director, economy is what defines the company’s buildings.They are simple, reliable constructions, with efficient use of material that results in minimum eaves height, small ground loads and less demanding foundations.
Also inside the building, Reid aims at keeping the costs down. Whenever possible he advises his clients to choose a tail-in maintenance layout, because this allows the docking system to be built from the ground up.
Ceiling-suspended alternatives add to the building height, strength specification for the roof construction, and the required building accuracy.As a result such docking systems can be substantially more expensive, sometimes even more than the hangar itself.
For example, in a 100- (330ft) clear span hangar where the deflections of the roof and crane assembly are limited to the span divided by 1000, such a crane can oscillate as much as 100mm (3.94in.) in windy conditions — “a lot when fitting an engine to a wing!”.
This is why he reckons that most customers prefer ground-mounted cranes or forklifts.
Sprinklers also appear to be ‘unnecessary ballast under the ceiling’. Reid says they hose everything inside the hangar rather than target a fire directly.
With exposed equipment access bays and maintenance openings as well as dissembled structures and components on the aircraft, this could potentially lead to more water damage than harm from fire or smoke.
He recommends foam canons all around the building, which are operated manually during working hours and run on automatic mode at night time.
Asked about recent trends in hangar design and construction, Reid responds “no one has ever made a hangar and said ‘it’s too big’ ”. No wonder the hangar builder not only welcomes the A380 introduction but also the growing investment in new MRO facilities in upcoming economies.
In his opinion, commercial MRO companies are interested in cost-effective maintenance factories rather than the “state airlines who buy ego-extensions for their director boards and architects — and these days there are more of the former than the latter.”
One of Reid’s latest projects is a maintenance complex of three interlinked hangars. Each with an open span of 91.5m (300ft), 275m (900ft) wide in total, and with a clear height of 26m (85ft) — for Lufthansa Technik in Malta that went “up in a blink of an eye.”
Construction of the LTM hangars.
The hangar is 280 metres wide in three clear spans of 91.5 metres. It is 90 metres deep with a clear height of 26 metres under all the steelwork, fronted with 18 electrically operated door leaves, the largest two doors being 26 metres high by 91.5 metres wide.
In addition to Lufthansa and Air Malta aircraft, customers include: Spanair, AirOne, BMI, Germanwings, Fly Niki, Privat Air, Arik Air, Wizz Air, SunExpress and Livingston Energy Flight.