In December 2012, the BBC's More or Less radio program asked the Open University's engineering department to determine "how many Lego bricks, stacked one on top of the other, it would take for the weight to destroy the bottom brick?"[44] Using a hydraulic testing machine, the engineering department determined the average maximum force a 2×2 Lego brick can stand is 4,240 newtons; since an average 2×2 Lego brick has a mass of 1.152 grams (0.0406 oz), according to their calculations it would take a stack of 375,000 bricks to cause the bottom brick to collapse, which represents a stack 3,591 metres (11,781 ft) in height.[44]

In 1997 they had an architectural competition for a new 430,000 ft² (40,000 m²) passenger terminal, designed to serve 3.5 million passengers a year, north of the original airport. KHR Architects won the assignment and completed the construction in co-operation with COWI, and at the end of May 2002 the new passenger terminal was put to use, as the first phase of the future expansion, which is scheduled to take place north of the start and runway, while air cargo services, business and private aviation will continue to be served from the existing buildings south of the runway. In connection with this expansion, the largest since the beginning of the airport, it was with effect from 1 January 1997 turned into a Joint-stock company, Billund Airport A/S, with the former members Vejle County and municipalities Vejle, Kolding, Grindsted, Billund, and Give as shareholders.


Primary concept and development work takes place at the Billund headquarters, where the company employs approximately 120 designers. The company also has smaller design offices in the UK, Spain, Germany, and Japan which are tasked with developing products aimed specifically at these markets. The average development period for a new product is around twelve months, split into three stages. The first stage is to identify market trends and developments, including contact by the designers directly with the market; some are stationed in toy shops close to holidays, while others interview children. The second stage is the design and development of the product based upon the results of the first stage. As of September 2008 the design teams use 3D modelling software to generate CAD drawings from initial design sketches. The designs are then prototyped using an in-house stereolithography machine. These prototypes are presented to the entire project team for comment and for testing by parents and children during the "validation" process. Designs may then be altered in accordance with the results from the focus groups. Virtual models of completed Lego products are built concurrently with the writing of the user instructions. Completed CAD models are also used in the wider organisation, for marketing and packaging.[33]
Attention then shifts to construction of the three aircraft. When I first spied this set I assumed that the two red jets were the same, but closer examination reveals a number of differences. First up is a red jet with a canard wing configuration as seen in the Saab Viggen amongst others. The lower fuselage is fashioned from a number of double and triple inverted 45 degree slopes with a pair of 1 x 14 Technic bricks running through the centre; there’s no obvious reason for Technic bricks to be used in this situation – standard 1 x 14 bricks would have done the job just as well - so I assume that LEGO just happened to have a bunch of them lying around…. A printed black 1 x 2 tile in the cockpit represents the instrument panel, while a substantial air intake is attached on either side of the fuselage at a 90 degree angle by way of brackets.
Unlike the City set, there is no control tower or truck that services the plane. Instead, there is a passenger check-in/baggage carousel, a rolling staircase to gain access to the plane, plus the airport entrance that includes a gift shop and a café (or, one could argue, something that is very much like many other Friends sets out there). There are only three mini-dolls in this set compared to the six in the City set.
Manufacturing of Lego bricks occurs at several locations around the world. Moulding is done in Billund, Denmark; Nyíregyháza, Hungary; Monterrey, Mexico and most recently in Jiaxing, China. Brick decorations and packaging are done at plants in Denmark, Hungary, Mexico and Kladno in the Czech Republic. The Lego Group estimates that in five decades it has produced 400 billion Lego blocks.[41] Annual production of Lego bricks averages approximately 36 billion, or about 1140 elements per second. According to an article in BusinessWeek in 2006, Lego could be considered the world's No. 1 tire manufacturer; the factory produces about 306 million small rubber tires a year.[42] The claim was reiterated in 2012.[43]

The final two minifigures are the Biplane Pilot and the intrepid Wing Walker. Both of these minifigures share the same white torso which is printed with a flight suit design overlaid with dark red and bright light orange flames plus a logo over the left breast. The torso design is superb and it can at present only be found in this set. Both minifigures are provided with a reddish brown aviator cap and dark bluish grey goggles, and the pilot (below left) also gets an alternative to this headgear in the form of medium dark flesh mid-length hair which has only ever appeared in five sets in this colour. 
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