As true industry insiders, members of MRO Network Daily’s substantial readership see evidence of innovation in the aerospace manufacturing sector on nearly a daily basis.
So which OEM might readers consider the most innovative manufacturer globally? Obvious contenders might be Airbus, Boeing, Bombardier, CFM International, Embraer, GE Aviation, Honeywell, Lockheed Martin, Pratt & Whitney, Raytheon, Rockwell Collins, Rolls-Royce or Safran, to name but a few. (Sorry if I left your company’s name out: it wasn’t intentional.)
But another company, one which often flies a little under the radar, is surely worth considering for the title of ‘Most Innovative Aerospace Manufacturer in the World’.
This week I attended Pratt & Whitney’s annual media event, as I do every year. As in most other years, the event was held in and around P&W’s headquarters in East Hartford, Connecticut.
But this year I and the other reporters who attended the event received what turned out to be quite a pleasant surprise.
I was somewhat puzzled at United Technologies Corporation’s decision to put up all the reporters at the Sheraton at Bradley International Airport, located about 20 miles away from East Hartford in the town of Windsor Locks. But all became clear to me when the detailed agenda for the two-day event was distributed.
For the first time, P&W’s UTC sibling United Technologies Aerospace Systems (UTAS) was heavily involved in the proceedings. UTAS, Windsor Locks’ biggest employer, used the entire first day of the event to showcase its vast product range and, more importantly, its massive resources and capabilities for technological innovation and development.
Among the many, many aerospace products UTAS makes are pilot controls, environmental control systems, landing gears, ram air turbines, carbon brakes, ejection seats, spacesuits, bleed-air systems, nacelles, electrical power generators, power distribution systems, digital engine controls, fuel controls, fans, electrical starters and primary flight control actuators. The list goes on and on.
Now a company with 41,000 employees, UTAS – the result of a long line of mergers among aerospace companies located in the USA, Europe and elsewhere – has some 8,000 engineers working for it, at 70 research sites in 14 countries. About 30 per cent of these engineers have advanced degrees or PhDs, according to Geoff Hunt, vice president of engineering for UTAS.
Hunt says the company allocates three-quarters of its engineers to incremental development work on its existing product lines – UTAS has about 90 in total – and holds the other quarter centrally, in centres of excellence, which are applied-science laboratories.
These labs – of which UTAS has hundreds – focus on developing entirely new technologies in areas such as advanced materials (including nanomaterials), additive manufacturing, thermoplastic and ceramic composites, brake design, wireless connectivity among integrated aircraft systems, power generation and distribution, power storage, engine power extraction, thermal management, and solid-state electronics for sensors and controls.
Because of its engineering R&D resources, UTAS was awarded some 900 patents in 2015. That is “awarded”, not “filed applications for”.
According to Hunt, UTAS invests $2bn every year on R&D, much of the spend going into its many development facilities. Two widely disparate examples of these are the company’s new icing wind tunnel in Burnsville, Minnesota; and its Hurricane Mesa Test Facility, a 12,000-foot-long supersonic test track in Utah which UTAS uses to test its aircraft ejection-seat designs.
One of the dozens, if not hundreds, of major aircraft system design challenges for which UTAS is researching technological solutions is the need to create more integrated propulsion systems.
As engine bypass ratios grow, providing new engine designs with greater propulsion efficiency and thermal efficiency, fan diameters are increasing and their core sizes are shrinking.
However, notes Hunt, the drag created by an engine design increases by the square of the increase in bypass ratio it offers. Accordingly, nacelle size has to be shrunk in order to minimise the drag increase.
At the same time, the aerodynamic efficiency loss in the air flowing along the engine’s bypass duct can be as much as 3 per cent, according to Hunt. It is critically important to control bypass-duct aerodynamic losses in order to ensure the engine’s overall fuel-efficiency.
The more fuel-efficient an engine becomes the less fuel it uses. This means smaller amounts of fuel are pumped to and around the engine. Since fuel is vital as a heat sink in managing the thermal energy produced by the engine, more efficient heat exchangers are required for more fuel-efficient engines.
Additionally, says Hunt, the electrical power-generation loads on engines are becoming proportionally greater as their cores get smaller.
Power offtake for aircraft electrical needs has traditionally been handled by integrated drive generators (IDGs) using constant speed drives to draw power from the engine’s high-pressure spool.
The ‘high spool’ is used for this purpose because the ratio of the highest to the lowest rotation speeds at which the accessory needs to operate when drawing power from the high-pressure spool is only about 2:1, according to Tim White, president, electric systems for UTAS.
Were an IDG to draw power from the engine’s low-pressure spool (the ‘low spool’) instead, the ratio of highest to lowest accessory operating speeds would be around 5:1. This would create a much more complex design and engineering challenge when designing the IDG’s gearing, White says.
However, new aircraft designs require much more electrical power than their forebears. Where the Boeing 767’s electrical-power requirement is a few hundred kilowatts, the Boeing 787 – which doesn’t use engine bleed air to power its environmental control system and other systems, but uses electrical power instead – requires just under 1.5 megawatts, according to Hunt.
Increasing the electrical-power load on an engine’s high-pressure spool while shrinking the engine’s core makes it more probable the engine will suffer a compressor stall, says White.
Combining a growing electrical-power requirement with the need to minimise the chances of the engine suffering a compressor stall, while also making the nacelle as streamlined as possible, means it is now making sense for UTAS to conduct intensive research into low-spool power generation.
Because the low-pressure spool turns much more slowly than the high-pressure spool, drawing electric power from the low-pressure spool greatly reduces the chances of the engine’s compressor stages stalling, White says.
A geared-turbofan design such as the PW1000G, where the IDG could draw power from the engine’s relatively slow-turning fan drive gear shaft or its relatively fast-turning low-pressure spool, would be particularly suitable for low-spool power generation.
UTAS has invested $3bn in the past decade on researching and developing more electrical systems for more electrical aircraft such as the 787, according to White. In the process it has been awarded more than 1,000 patents on its new aircraft electrical systems technologies, and the company is awaiting patent awards on several hundred more.
Taking into account that this is just one of the areas UTAS is researching and recalling the fact it designs and manufactures different kinds of aircraft systems in 90 discrete product lines, along with UTAS’ claim that it is twice as large as any other aircraft-systems OEM, readers might deem UTAS worthy of consideration as the most innovative aerospace manufacturer of all.