Farnborough Air Show

Marshall/Slingsby linkup is a good composites fit

 - July 17, 2010, 3:11 AM

Many of the invited guests who witnessed the unveiling of the Taranis unmanned combat air vehicle at BAE Systems’s Warton plant last week won’t have
realized the important role of a small company based in the Yorkshire moors. Marshall Slingsby Advanced Composites has produced airframe structures for all of BAE’s unmanned developments in the last decade. The company is also making low-cost composite parts for seven other aerospace majors.

The Slingsby name goes back 80 years. The UK company manufactured sailplanes followed by the T76 Firefly primary trainer at rural Kirkbymoorside. It was owned, in turn, by Vickers, ML Aviation and Cobham until a management buyout in 2006. Then, last year, Slingsby became the first-ever acquisition by privately held Marshall Aerospace (Hall 4 Stand A11).

“Their culture is compatible with ours, and we can blend our skills in metals with theirs in composites,” explained Phil Windred, managing director of Marshalls’ technology, products and services division.

According to Stephen Boyd, managing director of Marshall Slingsby Advanced Composites, the company has developed the skill to produce composite structures without recourse to expensive autoclaves. “We cure under vacuum but in an oven, and we prefer resin transfer infusion to resin transfer molding,” he explained.
Slingsby does have a 50-foot-long autoclave, however, into which the wing of BAE’s Mantis UAV will just fit. Some of Slingsby’s more sensitive work for the UK defense industry is done at a second site at Prestwick in Scotland, which was opened in 2008.

Boyd described Prestwick as a bold move, but it has evidently paid off, since turnover has risen by 40 percent in the past few years. The company was unprofitable until it made the transition to composite design, engineering and manufacture, he noted. Today, it gains 60 percent of its revenue from the aerospace industry, with the balance gained from the marine and rail industries, and aftermarket services.

Working to the outer mold lines and load cases provided by BAE Systems, Slingsby designed and produced the Raven and Corax experimental UCAV and URAV [unmanned reconnaissance] airframes in only 12 months. Then came the Herti, a multipurpose UAV that BAE has developed from a Polish glider design. Slingsby re-engineered the structure so that the all-up weight could be doubled.

When BAE began pitching the Mantis UAV for long-endurance surveillance missions, Slingsby produced, in only two months, the mockup that was unveiled here two years ago. It has since produced the wing, T-tail and control surfaces for the demonstrator, which flew last October. The company was unwilling to talk about its role in the Taranis UCAV, pending last week’s official unveiling.

Slingsby has done other work for BAE Systems. Using carbon fiber and other hybrid pre-impregnated materials, it manufactures by hand the inner and outer pilot helmet shells for the Eurofighter to the very high tolerances required to hold the helmet-mounted display optronics in exact position. The company also claims to be producing the world’s first composite stealthy submarine propulsion ducts, rudders and hydroplanes–for BAE’s Astute series now entering service with the UK Royal Navy. It also makes stealthy shields for the anti-aircraft guns on the Navy’s Type 23 frigates.

For Bombardier, Slingsby provides the propeller spinners for the Dash 8 Q400 regional airliner, using pre-impregnated cloth to produce a structure that can withstand a bird strike at more than 250 knots. “Carbon fiber would have been lighter, but more brittle,” Boyd explained. The company also produces the carbon fiber air-conditioning plenum chamber and ducting for the Dassault Falcon 7X business jet, trim panels for the interior of the Lockheed Martin C-130J airlifter and an auxiliary seat-cum-fuel tank for the AgustaWestland Lynx helicopter.

Boyd noted that the company aims to provide a total project management solution, from design to delivery. This can be for rapid prototyping, as in the work on BAE’s UAVs, or for series production. Just ahead of the Farnborough show, Boyd said he was expecting a rolling seven-year contract for C-130J trim panels to be concluded, and a production order for Herti airframes via BAE Systems.