What doomed Aerion Supersonic?

posted on 27th May 2021 by Edward Robertson
What doomed Aerion Supersonic?

The troubled supersonic aircraft designer announced it was ceasing operations on May 21. Now, former head of marketing and JMComm principal Jeff Miller argues a number of issues have coincided to bring it to its current state.

Jeff Miller

While it may be too soon to write Aerion’s epitaph, things aren’t looking good for the supersonic aircraft designer. It announced on May 21 that it was ceasing operations after being unable to secure financing to launch production of the AS2 business jet.

Having helped introduce the company in 2004 and served as its head of marketing until just after Boeing’s large investment in 2019, its demise leaves me deeply saddened. I have no insider knowledge on what led to its collapse. But I have some observations.

Aerion was founded the year after Concorde stopped flying, when many dreamed of a supersonic renaissance. Today’s investor class is more excited about electrically-powered urban air mobility concepts. As venture capitalist Peter Thiel famously noted, “We wanted flying cars, instead we got 140 characters.” Well, now they do have flying cars.

The first Aerion design – and perhaps its most capable – was its twin-engine, generically named Supersonic Business Jet (SBJ). That aircraft, with a super-midsize cabin and a range of about 4,000 miles, was ideally suited for the main international routes of the time, which were trans-Atlantic. Business aircraft travel to Asia was in its infancy, and no business jet could fly those routes nonstop.

Moreover, the SBJ was designed around the still commonplace, low-bypass Pratt & Whitney (P&W) JT-8D engine, allowing the aircraft to cruise at Mach 1.6. Other business jets of the era—the faster ones—were optimized around Mach 0.80, so the SBJ was twice as fast. That presented a compelling value proposition. Placed on sale at the 2007 Dubai Air Show, the company instantly took 50 Letters of Intent.

When a military contract fell through, P&W took the JT-8D out of production, necessitating an Aerion redesign. Also, the engine was nearly obsolete at that point due to noise and emissions considerations.

The SBJ evolved into the trijet AS2 with moderate bypass GE engines that addressed both takeoff noise and emissions issues. But the physics of higher bypass imposed a Mach 1.4 speed limit on the aircraft, while supersonic range of 4,200 nautical miles (nm) did not improve by much.

Meanwhile, a new generation of intercontinental jets offered 7,500nm range and more than 6,000nm at .90 Mach. The AS2 could only offer about a 50 per cent speed advantage on perhaps twice the fuel flow at twice the purchase price. And only about a 25 per cent speed advantage over land while flying in a proposed boomless cruise mode, which further reduced range.

Still, had it entered the market it would have pioneered a range of technologies that would have helped Aerion bootstrap itself to more capable supersonic airliners. Boeing would likely have been interested in that and might have invested to save Aerion had it not been enmeshed in a series of crises.

With Boeing financially incapacitated, Aerion appears to have been at the mercy of a fickle investor community. A rumored special purpose acquisition company (SPAC) apparently fell through. Sovereign wealth funds and other potential investors may have held back out of environmental concerns—issues Aerion partially addressed through promises of 100-per-cent biofuel capability, reliance on nascent carbon capture technology and the promise to plant 100 million trees.

In any case, investors may have wanted a sooner and surer payback than a business jet by the end of this decade and a promised near hypersonic airliner in perhaps the 2040s.

Now the focus is on Boom and its Overture airliner. Will it have the staying power to put a supersonic airliner in production? They, likewise, will need to raise billions—and find a clean, quiet Mach 2 engine that currently does not exist as far as we know.