The Woracle

On the subject of PDEs - pulse detonation engines - General Electric has just been assigned a US patent for a turbofan that uses a rotating pulse-detonation system, rather than low- and high-pressure turbines, to drive the fan and compressor. Basically, each turbine stage is replaced by a radial array of raked and angled pulse-detonation tubes.

According to the patent, the first ring of PDE tubes (58) is fired first to start the booster compressor (28) turning. Once the booster is up to speed it provides compressed air to the remaining PDE rings (59), which then fire up to drive the fan (20).

As a PDE ring turns, each tube sequentially passes first a port (50) allowing air into the tube, then a fuel injector (52), then the igniter (54), which initiates a supersonic detonation wave (66) to power the ring's rotation.

I'm going to stick my neck out and predict Boeing will not protest the award of the KC-X tanker contract to Northrop and Airbus. Boeing gets debriefed by the US Air Force today (7 March) and will decide over the weekend whether to protest. But I don't think they will find anything to fault in Air Force's source selection from the moment the final RFP was released on 30 January last year to the 29 February announcement that Northrop had won.

But...

I suspect Boeing lost before the bids even went in. I think the last-minute changes that were made before the final RFP was released - subtle adjustments that were made because Northrop was threatening not to bid, and the USAF desperately needed a competition - changed the character of that competition.

Boeing has just come out of its debriefing (7 March) with the US Air Force and issued this statement :

“We spent several hours with Air Force leaders, listening and probing, all in an effort to better understand the reasoning behind their decisions,” said Mark McGraw, Boeing vice president and program manager of the KC-767 tanker. “While we are grateful for the timely debriefing, we left the room with significant concerns about the process in several areas, including program requirements related to capabilities, cost and risk; evaluation of the bids and the ultimate decision.

“What is clear now is that reports claiming that the Airbus offering won by a wide margin could not be more inaccurate,” said McGraw.

“Our plan now is to work through the weekend to come to a decision on our course of action early next week,” said McGraw. “It will be a very rigorous and deliberative process to ensure we’re balancing the needs of the warfighter with our desire to be treated fairly. For decades Boeing has been recognized as a defense company that never takes lightly protests of our customers’ decisions.”

Will I be proved wrong?

As we're talking about tankers...

(US Air Force photo)

I have a soft spot for the blended wing, and Swift Engineering is keeping the dream alive with its cool-looking Killer Bee UAV. Not surprisingly, perhaps, as Swift's chief scientist Mark Page was technical programme manager on McDonnell Douglas' Blended Wing Body. Boeing and NASA continue to work on the BWB, flying the X-48B unmanned demonstrator, but the Killer Bee promises to be quite a different beast:

The debut of a new Cessna piston single is a rare event - as far as I can work out the last one was the Model 177 Cardinal in 1967 - so mark 8 March 2008 in your diaries. That's when Cessna's Model 162 SkyCatcher light sport aircraft flew for the first time (from Cessna Field in Wichita). Cessna hopes the SkyCatcher will be the new 152 and, with its modest price and easy operation, will persuade more people that flying is affordable and enjoyable.

Blackswift may have emerged out of Lockheed Martin Skunk Works' Falcon hypersonic technology demonstration, but DARPA is looking for competitive bids to design and build the unmanned demonstrator, issuing this solicitation in early March:

"The Tactical Technology Office (TTO) of the Defense Advanced Research Projects Agency (DARPA) is soliciting proposals to develop an extended duration hypersonic testbed known as Blackswift. The Government seeks development of a reusable hypersonic testbed that utilizes an integrated air-breathing propulsion system.

The Blackswift flight test program is pursing development and demonstration of near-term (2012) capability. The Government is soliciting original conceptual flight testbed design approaches from the aerospace community that meet or exceed these objectives."

Boeing is still deliberating whether to protest the award of the USAF's KC-X tanker contract to Northrop and Airbus, but has been kind enough to provide the world with an update - proving protests are as newsworthy as contracts. Here are some excerpts:

"As we have gone through this process it has become clearer that this competition was much closer than has been reported, and that raises the stakes if the process was flawed and unfair in any way," said Mark McGraw [KC-767 program manager]. "We have serious concerns over inconsistency in requirements, cost factors and treatment of our commercial data."

Some reports suggest the KC-767 bid was hurt by Boeing Commercial's unwillingness to share spares pricing data in case it harmed its airline business. Boeing responds:

"It was clear from the Request for Proposals that the Air Force was seeking a commercial derivative tanker. However, by treating the Boeing offering as a military aircraft, the process by which the commercial cost/price data provided by Boeing Commercial Airplanes was evaluated has raised significant concerns," McGraw said. "We provided unprecedented insight into Boeing commercial cost/price data...We believe this data was treated differently than our competitor's information."

And, on the subject of whether Boeing misread the requirements and offered the wrong size aeroplane:

"Our proposal was based on the stated criteria in the Air Force's Request for Proposal, with a specific focus on providing operational tanker capability at low risk and the lowest total life cycle cost," McGraw said. "We stand by our offering and believe that it did, and continues to, best meet the requirements."

Boeing has just issued a "tanker factors" backgrounder [download file] giving its take on the US Air Force's assessment of its KC-X tanker bid against the five evaluation criteria. It suggests Boeing is narrowing in on reasons for protesting the award of the contract to Northrop and Airbus. Basically it says:

Mission capability: Boeing's bid had "significantly more strengths" than Northrop's;

Proposal risk: Northrop/EADS's plan to assemble and complete the A330 tanker in the US "should have been assessed greater risk";

Past performance: Both were rated satisfactory, but revelant programmes for Airbus - Australia's KC-30 tanker and the A400M - "are struggling";

Cost/price: US Air Force adjustments to Boeing's "significantly lower" cost estimate deprived it of the benefit of its in-line production approach;

Integrated fleet aerial refuelling assessment: Northrop developed the analytical model used by the USAF and changes to the model "before and after RFP release" allowed a larger aircraft to compete.

It's getting very interesting...

Boeing is to protest the KC-X tanker award to Northrop and Airbus. The company says it will provide details of its protest tomorrow (11 March) when it files with the Government Accountability Office, meanwhile here's what Boeing is saying:

“Our team has taken a very close look at the tanker decision and found serious flaws in the process that we believe warrant appeal,” said Jim McNerney, Boeing chairman, president and chief executive officer.

“Based upon what we have seen, we continue to believe we submitted the most capable, lowest risk, lowest Most Probable Life Cycle Cost airplane as measured against the Air Force’s Request for Proposal,” McNerney said.

So I was wrong. Better put down those tins of Air Force grey paint for now, Northrop.

Surely those can't be KC-X source-selection documents...

What's in, well not a name, not even a number, but in a single letter? $16 million according to a great story by Roxana Tiron in The Hill. That will be the cost of changing all the manuals if the US Air Force gets its way and redesignates Alenia's C-27J the C-27B.

The C-27J Spartan won the US Army/Air Force Joint Cargo Aircraft competition. The Army is to get 54 aircraft, and the Air Force 24, but the USAF gets to designate every US military aircraft and is calling its JCA the C-27B. Why? Because the USAF used to operate the C-27A Spartan, its designation for the C-27J's precursor, the Alenia G.222.

Now we all know B follows A, the same way F-35 follows, er, F-22...and F-117 follows...er...so the Air Force has to be right, yes?

"I'd like to be an F-27J, thank you."

(And you want ample evidence the US Air Force is quite happy to bend its own designation rules when it suits, check out Andreas Parsch's great site designation-systems.net)

Amazing story on Aviation News International about a Cessna Citation Mustang that has been repaired after being heavily damaged - a collapsed fuel tank and two broken wing spars - on its delivery flight:

"The crew...heard a bang at 18,000 feet during the descent into AGC, which was followed by a left-engine low fuel pressure warning. They then noticed distortion on top of the left wing and heard a second bang. The crew continued the descent and landed safely at AGC.

FAA inspectors found that Cessna workers inadvertently blocked the left fuel tank vent with adhesive vinyl, which covered the Croatian registration numbers while the aircraft carried a temporary N-number. This blockage prevented the inflow of air to replace fuel drawn from the tank by the engines, and the tank deformed."

More visual aerodynamics - a nice wingtip vortex in the catapult steam

(US Navy photo)

Gulfstream has launched its G650 widebody business jet. A new Gulfstream is big news and the G650 looks, well, like a Gulfstream. It looks like a pumped-up G550, but it's all-new, including the type certificate, which will say GVI - sixth in an illustrious line stretching back 50 years to the GI (my favourite).

It's bigger, faster and flies further than the G550 - bigger, faster and further enough for Gulfstream to put the G650 into a different market segment (ULRVLJ - ultra-long range very large jet?) and keep building the G550. But where does all that extra speed (Mach 0.925) and range (7,000nm) come from?

Where's the swoopy wing and radical area ruling? The G650 looks so...Gulfstream.

...your harpoon decklock is broken?

"It's mine, I caught it first!" (US Navy photo)

The US Air Force is retiring its Lockheed F-117s, 27 years after the stealth fighter first flew in secret and two decades after it was revealed to the public. I remember being at the formal roll-out - of the last F-117. Must have been 1990. At the Skunk Works in Palmdale, California. I was amazed the thing could fly. "Give me fly-by-wire," Ben Rich said, "and I can make a brick fly." I believed him.

Being based in the UK, I had watched the months leading up to the F-117's public "reveal" with detached interest. I still find it hard to get excited about stealth, but I can't deny the F-117 is an impressive engineering achievement. And its roles in the opening attacks of Operations Just Cause, Desert Storm, Allied Force and Iraqi Freedom are testament to its unique capability.

"Nope, no Bill Sweetman in here" (USAF photo)

...personal, the finalists in this week's Chubby Cheeks competition:

Having just spent two days at Pratt & Whitney's Connecticut facilities, some of the company's fervour for the Geared Turbofan appears to have rubbed off on me. With oil at $110 at barrel and jet fuel at $2.70 a gallon, an engine that promises to reduce aircraft fuel burn by 12%, and noise and emissions by 50%, seems to make a lot of sense.

And those figures are for the GTF at entry into service in 2013. Pratt is promising to continue reducing fuel burn by 1% a year, for a 20% reduction by 2020 - with consequent reductions in carbon dioxide emissions. Conventional turbofans will keep getting better too, but Pratt believes the physics of its geared-fan architecture give the GTF a 6% advantage the others can't catch up with.

Where's the catch? Well there is the gearbox. But, having seen it, I'm inclined to believe Pratt's claims that it has mastered and matured the technology. For a 30,000shp gearbox, it's small - about 18in diameter and weighing around 200lb - and simple. Then there's the torture chamber Pratt has constructed to test the gearbox to its limits, and beyond - like 2.5 times the maximum misalignment caused by gyroscopic forces on the fan during take-off rotation.

Airbus and Boeing are interested, Pratt says, but they are waiting until the company flight tests its GTF demonstrator. Flights on the company's Boeing 747SP engine testbed are planned to begin in late June/early July. By then the GTF could have been formally launched on the Mitsubishi Regional Jet, and perhaps Bombardier's CSeries.

Up till now, airline interest in new engines has been about dramatically reducing their carbon emissions. That has encouraged Airbus and Boeing to consider holding off and waiting for new technology to mature, like open rotors. But with oil prices soaring, fuel burn may take the lead, and airlines may start demanding action sooner rather than later. That would appear to put Pratt and its GTF in pole position.

Working on a Chinook feature, and I found this...

"Shall we dance?" (RAF Chinooks - Crown Copyright)

As if there wasn't enough information, disinformation and misinformation already circulating about the KC-X tanker competition, now the pro-Boeing, anti-EADS tankerblog.com is trying to dirty the water. Claiming to provide "facts and commentary" on the tanker issue, so far it has offered up little other than tired innuendo. At least the authors make clear their anti-EADS stance.

If you want real information, check out Amy Butler's latest report for Aviation Week. She focuses on concerns with the analytical model used by the USAF to evaluate the refuelling effectivess of the rival tankers. I suspect the role this Northrop-developed modelling tool played in the contest could be the pivot on which Boeing's KC-X protest is balanced.

Remember the privately owned ex-Royal Navy Sea Harrier that had to make an emergency vertical landing on only its second flight after being restored for the US airshow circuit? Well Elyse Moody of Overhaul & Maintenance magazine has an update on owner and pilot Art Nalls' efforts to get the beast back in the air.

I recommend you watch the video of the November 2007 emergency landing on Nalls' website - it's a pretty impressive achievement for someone who had not flown a Harrier for 18 years. The problem was a hydraulic failure, and the nosegear collapsed on touchdown. After some airframe repairs, the team is ready to attach the new radome and is waiting on parts to rebuild the hydraulic system. Fingers crossed, we should see the Shar on show circuit.

"Makes you want to rush out and buy a couple of hundred Skyraiders!" says my colleague Kieran Daly of this Embraer picture of a pair of purposeful Super Tucanos. I'm not sure Pratt & Whitney Canada's PT6A, even at 1,600shp, sounds quite the same as a Skyraider's Wright Cyclone, or a Sea Fury's Bristol Centaurus (a personal favourite), but of today's trainer/attack turboprops only Embraer's Super Tucano has that iconic look of a late-era propeller-powered fighter. And it gets used in anger.

Hawker Beechcraft has just put out a nice press release about its achievements in its first year as a private company. Record sales, record backlog etc, etc. What's not included on the list is delivery of the super mid-size Hawker 4000. The official word is "soon", maybe with weeks, but I'm not holding my breath just yet.

I was at Raytheon Aircraft for the rollout of the Hawker Horizon, as they were both called then, back in April 2001. I wrote about its certification in November 2006. But here I am in March 2008 still waiting for the first delivery to a customer. It's been an interesting journey. Don't get me wrong, I think it's a great aircraft and worth the wait, but why so long?

Embraer's board has approved the launch of the MLJ medium-light and MSJ mid-size business jets. They are to enter service in 2012 (MSJ) and 2013 (MLJ). They come hard on the heels of the launches of Cessna's large-cabin Citation Columbus and Gulfstream's ultra-long-range G650. Bombardier has also unveiled, but not formally launched, the mid-size Learjet NXT. So it's a busy year so far for business aviation (four or five all-new jets, depending on how you look at it - and the Mitsubishi Regional Jet has also been launched, but that's not a bizjet). And there's at least a couple more new aircraft in the pipeline...