A very different operation is BAE Systems’ Nimrod maintenance program which operates from small pre-World War II hangars in the UK. Here, Nimrod military aircraft are subject to in-depth work over periods of at least three months and just two can be accommodated in each hangar. Aircraft are always jacked, leveled, and docked. A recent internal HSE review highlighted a requirement to improve over-wing working practices. As a consequence, several alternatives were considered, as Gary Matthewman explains: “We looked at bespoke steel, mobile docking rigs with two operating levels – but they proved to be very expensive and inflexible. Anyway, safe access onto wings remained an issue, as docking really only gives safe access to undersides. This is fine for removing flaps and leading edges but leaves operatives on top of wings at risk, for example when removing panels, performing surface inspections, and guiding crane removal/installation of fuel tanks and thrust reversers.
“Using vacuum-based systems to mitigate risks with fall arrest for wing access works well for us, and is much easier and safer to install than mobile docking – and a fraction of the cost. Most of our operatives have been in the job for many years but they soon familiarized themselves with the new regime. Being able to use the Wingrip system with fuel tanks open is essential and the multi-user capability particularly useful.” The system consists of two end-anchor vacuum pads with a single or pair of cables spanning between them and intermediate pads as needed. Installation and removal are safe and straightforward for a single worker to carry out, as vacuum pads weigh less than 13.2 pounds (6 kg). Each pad is positioned and vacuum locked in place, then the stainless-steel safety cables connected and tensioned at one end.
Simple and portable solutions
Various systems offer different operational characteristics: for example, up to four workers can use the Wingrip® system – two per cable – wearing full body harnesses with a safety lanyard and work positioning rope. This allows hands-free movement along the whole cable length, with shuttles gliding over intermediate anchor pads. As an alternative to cable systems, a vacuum pad can also be used as a single fall protection anchor point for one worker on wings, fuselage, or stabilizers. Quickly and easily installed, and highly portable, single-user systems are particularly suited to line maintenance and other short-term, temporary work. In the case of Wingrip, an adjustable work positioning rope provides a safe working radius of 9.84 feet (3 m) and is particularly helpful to locate the worker for comfortable hands-free working. Where necessary, two vacuum pads can also be used to triangulate and fix the worker’s position. These systems can be used in wet or dry conditions, in or outside hangars, and can be stowed on aircraft for transportation to other sites – including in theatre by the military.
Latchways plc, Devizes, Wiltshire, UK
Tel: +44 1380 732700
Fax: +44 1380 732701
Flexible Lifeline Systems presents the Wingrip Vacuum Anchor Horizontal Lifeline System. Powered by shop air or nitrogen, the system is intrinsically safe and includes all user equipment. The...