The sky's the limit

The research was conducted amongst 64 aerospace professionals at the Farnborough Airshow 2014, with additional information taken from ADS Group.

According to the study, over a quarter (27%) of aerospace professionals felt the UK’s wealth of skills would be the biggest driver of industry growth. Strategic vision for aviation growth at national and regional levels (23%) and capital available for investment (22%) were also ranked as essential factors for increasing market share. A further 15% of those asked felt government support, such as enterprise zones would be a key catalyst for driving market share and 13% said the same about private sector innovation.

Almost a fifth (19%) of the aerospace professionals rank China as the country as offering the greatest growth opportunities for aerospace and aviation related exports from the UK within the next five years. This was closely followed by India (17%) - potentially due the rapid growth of the Chinese and Indian aviation industries in recent years. Brazil (7%), the US (7%) and France (4%) complete the top five.

Rob Watson, on behalf of the Farnborough Aerospace Growth Forum, comments: "The findings highlight widespread confidence in the potential for the industry to continue its strong growth pattern.  The sector has been one of the fastest growing in the UK economy over the last five years and has contributed greatly to local economies and employment.”

The aerospace industry is growing quickly, partly due to the increasing number of commercial flight operators and partly as the result of the cutting-edge research and development carried on in the defence and aerospace sector.

From space to defence

It costs, on average, $50,000 to send a kilogram of anything into space. It may seem expensive, but then interplanetary travel is not cheap. NASA's Mars Exploration Rover Mission sent two 185kg rovers, Spirit and Opportunity, to the Red Planet in 2003, at a total mission cost of over $820m.

For contact with Earth the Rovers used a High Gain Antenna Gimbal (HGAG). This consisted of low gain (LGA), high gain (HGA) and ultra high frequency (UHF) antennas. The LGA is omni-directional, useful for when the rover's orientation is unknown, the UHF is only usable when the orbiting Odyssey spacecraft is directly overhead and so the HGA is used predominantly, set up on a two-axis gimbal.

It necessary that the gearing system provide smooth, zero backlash, repeatable movements with absolute accuracy. Low weight and a small volume are essential but at the same time a high torsional stiffness and torque ratio is needed to cope with the parasitic losses of the gear train whilst articulating on a 40-degree slope.

A harmonic drive, referred to mechanically as a strainwave gear, fulfils this role perfectly. It differs from conventional planetary gear in that the gear teeth form the outside edge of a flex spline, leaving the central area to be bored into a hollow shaft to allow data cables and other services to pass through, whilst allowing continuous rotation. This prevents cable wrap and is essential for both the HGAG and the Pancam Mast Assembly (PMA) a high resolution panoramic camera which can rotate through 360 degrees.

It is clear that equipment designed for the harshest use in space, is world-leading when used on Earth in areas such as military and defence applications. There is however a caveat, that of research and cost.

There has been a trend over the last few years with OEMs increasingly ordering commercial off-the-shelf (COTS) products to lower the cost. Whilst this lowers the cost it also means that products are not always specified to exact requirements. This problem has given rise to modified off-the-shelf (MOTS) products. Here, the lower cost of the COTS product can be combined with the customisability of a bespoke product.

To tackle this problem, Harmonic Drive has developed a programme called Solution Kit. The same high-performance units, available off-the-shelf, can be ruggedised to suit custom requirements, from seal corrosion protection and windings rated to a custom voltage, to high temperature lubricants, special feedback sensors and surface protection.

The benefit of using products designed for space is that they have already undergone a rigorous process of testing and development. Finite element method (FEM) analysis allows products to be thermally, structurally and dynamically tested in an on-line simulator environment, many modifications can be made digitally, to save on modelling costs.

After this comes the lab and field testing stages. Harmonic Drive has installed a cryogenic test chamber, which allows gears to be tested down to -196C in liquid nitrogen.

Rocket payload attitude control systems

Pressure controllers from Alicat Scientific have been selected for use in NASA sounding rockets to control payload attitude. Alicat PC Series absolute pressure controllers provide the speed, accuracy and durability required for this mission-critical function.

The payload sections of some NASA sounding rockets are required to achieve pointing accuracies of finer than 1 arc second (1/3600 of a degree). Conventional attitude control systems (using solenoid valves) introduce too much shock and vibration, and are imprecise. NASA contractor Northrop Grumman turned to Alicat for a solution that would work with its delicate optical instruments.

The Alicat PC Series absolute pressure controllers are used to directly feed the payload’s attitude control jets. The four pressure controllers are fed from a common gaseous argon manifold at approximately 160psig, with a stock Alicat mulitdrop RS-232 sending set-point commands to the controllers. As soon as the rocket passes 100km in altitude, all controllers are brought up to 5 PSIA with both pitch and yaw moments balanced. The spacecraft’s attitude is then modified by modulating the pressure commands sent to the Alicat controllers.

Alicat’s control precision enables commanded pressure changes in increments as small as .00234psi or as large as 150psi, with extreme speed. NASA’s testing demonstrated the controllers accurately track a 5Hz sign wave, correlating to a response time faster than 32ms. As there are no backup systems for altitude control, the Alicat pressure controllers are mission-critical pieces of equipment.

Full flight simulator

Moog has successfully delivered to Sogitec Industries the vibration platform and control loading system to support the training of NH90 pilots on a FFS (full flight simulator). Sogitec Industries, a subsidiary of Dassualt Aviation, was awarded a contract from NAHEMA (NATO Helicopter D&D Production and Logistics Management Agency) for the design and production of six NH90 full flight simulators. The training systems are to be delivered to the French Army and Navy in 2015, including an FFS for the Army Aviation.

The Moog Vibration Platform is integrated into a mechanical frame assembly to provide realistic levels of vibration in vertical, lateral and longitudinal directions to reproduce specific NH90 helicopter feel and offer more realistic cueing. The controls of the vibration platform, control loading system and seat have been designed to support the correct spectrum, amplitude and trend of vibration through the desired operating envelope on a vibration mass of 1200kg.

Power over Ethernet Gigabit switch

Israeli provider of military-grade Ethernet connectivity Techaya has won a tender to provide a leading Ministry of Defense (MoD) with a compact, rugged, 8-port, MIL-STD, Power over Ethernet Gigabit switch - MILTECH 910PoE. The Ultra PoE switch provides up to 60W per port, eliminating the need for additional power sources, and is especially designed to provide data connectivity and power PoE-enabled to moving or stationary platforms operating in extreme and harsh environmental conditions.

Applications include cameras, sensors, tactical mobile wireless access points, mobile command posts, mesh nodes and other devices. The MILTECH 910PoE can drastically reduce space requirements and wiring complexity usually associated with providing power supply to remote locations or moving platforms.

Portable pitot-static testing

The new ADTS500 Series from the Druck product line of GE Measurement & Control introduces Bluetooth with a remote touch/swipe screen, hand terminal to provide an easy-to-use, compliant, portable and accurate means of pitot-static instrumentation testing.

"This new range of pitot-static test instruments has been purpose-designed to be especially easy to use, to help aircraft operators reduce engineering time for standard maintenance, trouble-shooting, leak testing and emergency aircraft-on-ground situations,” explains Mark Singleton, product manager at GE. "At the same time, it helps provide compliance with aircraft technical regulations and with manufacturers’ aircraft maintenance manuals (AMMs).”

The instruments are ideally suited to RVSM (Reduced Vertical Separation Minimum) and airspeed validation. In addition, smooth vacuum/pressure control of high flow rates simulates steep rates of climb, catered for by Druck’s proportional control technology, coupled with a large pump capacity. Available in four versions, operation is remote and - when wireless - there is no need to run cables or hoses to the cockpit. 

Composite wing testing

Moog has been selected by Bombardier Aerospace (Belfast) to supply an aerospace test system to undertake a full-scale structural test on the CSeries aircraft advanced carbon fibre wing.

The system will be used to carry out fatigue testing of the composite structures of the wing. This testing forms part of the CSeries aircraft certification test programme. Bombardier has manufactured a wing to facilitate the fatigue tests. This is similar to the production article, but without the wing tip, systems and control surfaces.

The test system comprises an Active Load Abort System, an upgrade from a 12 to 24 channel Aerospace Control and Monitoring System, Machine Controller and Structural Test Actuators with Servo Valves. Each actuator is equipped with an Active Safety Manifold, which forms part of the overall Abort System controlled by either a G761, or a high flow D661 servo valve, depending on the location of the actuator on the wing structure and its specific flow demands.

The Active Load Abort System is an independent multi-channel safety system that, in the event of a primary loading system failure, uses a Moog Machine Controller to synchronously unload the structure over a common time period, while maintaining the desired load distribution. The System will protect the test article preventing undesirable and unrepresentative loading being applied to a unique test article, which has already accrued valuable fatigue testing hours.

Measurement system for carbon fibre aircraft wing box sections

Oil & gas pipe measurement specialist Optical Metrology Services (OMS) has developed a non-contact, laser-based dimensional measurement system for aircraft wing boxes (horizontal stabilisers) and other similar shaped systems.

The OMS Wing Box CHECKER measurement system can be customised. The customer required a system that could accurately internally profile four 12m long cavities inside the wing sector within a time period of four hours for a commercial aircraft. Made from a special carbon fibre composite, these wing box sections are complex in shape, with tapered ends and are split into multiple internal sections/compartments.

These sections taper down to 100mm x 100mm at the smaller end. In addition, the measurement system had to be capable of measuring the corner radii of the box wing sections, which are absolutely critical as these are stress concentration points.

Using expertise gained from the development of similar automatic internal weld scanning tools for measuring the dimensions and profiles of welds in oil and gas pipes, OMS completed the design of the Wing Box CHECKER system within four months.