Fuel tank inspection:
A job that calls for eagle eyes

General overhaul for an Airbus A340
On a "Walk-through" in the tank

After six years of operation, the Airbus A340 is due for an overhaul. As part of this IL-Check, the fuel tanks are inspected carefully from the inside for leaks or damage. Certain parts, such as the tank suspensions, can be inspected by aircraft mechanics only in the course of a so-called ”tank walk-through.” In Hamburg, there are 220 mechanics qualified to carry out this inspection.

The colleagues themselves must submit to an annual check-up: the examination by a physician covers a wide range of points, from claustrophobia tests to weight checks. A slender waist is just as necessary as narrow shoulders, for the mechanics enter the tank through holes leading into the interior of the wing which are only 60 x 45 x 25 centimetres. There are six tanks here, each one separate from the others, which can hold a total volume of 140,000 litres of kerosine. Special overalls without collars or pockets prevent the workers from getting caught or even stuck during their work in the tank. 

On the stomach towards the wing-tip

The space in a tank is very narrow: things really get tight towards the tip of the wing. The workers lie on their stomachs, as the tank is only 30 centimetres high. While they are working in the interior of the wings, the mechanics are supported by a colleague with whom they stay in constant touch by using a cable headset. This is the only way to ensure that help can be provided immediately in case of an emergency.

The inspectors spend up to five hours a day in the tank, naturally with breaks at regular intervals. The risks to their health would otherwise be too great: although a tank is ventilated for at least eight hours after being emptied, the odour remains overpowering. No one can stand working with a compressed-air hammer without ear protection, either.