Not only is this a very attractive image, it is painfully poignant. Appropriately for this Christmas issue, the Lightning even appears in the shape of a Christmas tree.

The picture was taken by semi professional photographer Ettienne Kotze and shows Lightning ZU-BEX taking off on its second last flight, on the evening of Friday 13 November, from the Test Flight and Development Centre at Bredasdorp. Tragically the Lightning crashed the next day with the loss of the pilot Dave Stock. A full report appears in this issue.

Ettienne took the picture with his Canon 20D. He used a 400mm lens at a relatively wide open F5.6 which means the picture does not suffer from the grain of a high ISO number, even though it has been cropped to fit the page. Shutter speed was 160th of a second, which is about the slowest one can hand-hold a 400 mm lens.

Feature:

Lightning Airshow Crash – what happened?

The Overberg Airshow in November was marred by the crash of English Electric Lightning ZU-BEX and the death of its pilot, the much respected Dave Stock.

Although one cannot jump to conclusions as to exactly what caused the crash, the events unfolded in front of an airshow crowd armed with many cameras. Some of the images tell a fascinating story that has strong similarities to a number of Lightning crashes that happened almost fifty years ago.

A HIGH RISK DESIGN?

The English Electric Lightning was the monster fighter of its time. It was designed as an uncompromising point defence interceptor - essentially a guided-missile armed, air-superiority fighter, optimised to defend mainland Britain against bomber attacks.

Typical of its uncompromising design was its unique engine layout. To minimise the drag of the two engines needed to provide the requisite performance, the designers stacked the engines vertically. They were however staggered, with the lower engine 1.4 metres further forward than the upper. This means that the lower engine has an exceptionally long tailpipe.

By stacking the engines they are effectively tucked behind the cockpit, and with the air intake in the nose, the design achieved the desired goal of minimal frontal area. The twin-engine arrangement provides twice the thrust of its single-engine contemporaries, but for an increase in frontal area of only 50%.

However, like all uncompromising designs, there are significant drawbacks. One of the problems is the lack of space to hold fuel. The Lightning’s fuselage is almost entirely filled by the cockpit, engines and jet-pipes, and thus has minimal space for internal fuel. It was therefore necessary for almost all the remaining space in the airframe to be adapted for holding fuel. Even the flaps are used as fuel tanks, and the landing gear uses narrow tyres that retract outward, to make space for fuel in the thicker inboard wings. This also meant that when the addition of drop tanks for greater range was considered, they could not be placed beneath the wing and were mounted on top instead. When the aerodynamic principle of the area rule was incorporated into the Lightning’s design, a ventral tank was added to the fuselage so the aircraft could carry more fuel and be more aerodynamic.

The other drawback of stacked engines with the fuselage filled with long jet-pipes is that there is minimal space for the complex systems, particularly the hydraulic control systems. The labyrinth plumbing is crammed into a very tight space. Even when the aircraft were new, they were difficult to maintain. This was one of the reasons why they were phased out of service with the RAF relatively early.

Thus, for the purposes of our discussion of the Overberg Airshow crash, the key design features are the long jet-pipe for the lower engine and the densely packed hydraulic system.

When one examines the history of the Lightning, it is clear that there have been an inordinate number of the aircraft brought down by fires in the lower rear fuselage. Judging from the photographic evidence of the Overberg crash, the question needs to be asked if this is what happened to ZU-BEX?