Airbus

The RAF goes green

David Learmount , , , , , , , , , , , , ,

With a 90min Airbus Voyager test flight out of its Brize Norton base, it seems the Royal Air Force has chalked up a world first.

On 16 November the Voyager, the military tanker/transport version of the A330-200, took off with its Rolls-Royce Trent 772B turbofans burning pure, 100% sustainable aviation fuel. Many airlines have operated different types with a mix of standard aviation fuel and SAF – usually less than 50% – but no-one is believed to have used pure SAF before.

On board were an RAF crew supplemented by representatives from the SAF manufacturer BP, Airbus Defence & Space, and engine manufacturer R-R. FlightGlobal has reported a statement by Airbus experimental test pilot Jesus Ruiz, who was the aircraft commander for the test: “From the crew perspective, the SAF operation was ‘transparent’, meaning that no differences were observed operationally. The test plan was exhaustive and robust and has allowed us to compare SAF with JET [A]1.”

RAF Voyager tanker/transport (Crown Copyright)

BP crafted the SAF from used cooking oil. This being a flight operated in British airspace by my alma mater, the RAF, I have an unaccountably earnest desire to learn that the cooking oil came from the deep-fryers of English Fish & Chip bars. Given that Capt Ruiz confirms the flight went without a hitch, it seems BP successfully ensured the fuel was not contaminated with salt and vinegar!

Joking aside, this is a very welcome achievement, as is the RAF’s stated objective for sustainable flight. Chief of the air staff Air Chief Marshal Sir Mike Wigston says the RAF is committed to achieving net-zero air operations by 2040, a decade ahead of the present global aviation target.

How to infuriate a traditional Boeing pilot

David Learmount , , , , , , ,

Today I was replying to a message from a good friend in Maryland, and found that I’d written to him what I have wanted to put up here for a while.

He had picked up on something I wrote in FlightGlobal/Flight International a month or so ago about Boeing CEO Dave Calhoun’s thoughts on the kind of control interface that would be best for pilots flying Boeing’s next clean-sheet-of-paper aeroplane in tomorrow’s skies.

This is what I suggested to him:

“I don’t actually know what Boeing will do with the pilot’s “joystick” or yoke equivalent in its next-generation aircraft. My observation that you picked up on was based entirely on the musings of Boeing’s new boss Dave Calhoun when he suggested they might need to have to do a complete re-think of how to tomorrow’s pilots should interface with tomorrow’s aeroplanes.

The thing about the airline piloting job now is that it has drastically changed. Even aircraft originally designed in the 1960s, like the 737 series, in their latest versions put just as many computers between the pilots and the flying control surfaces as Airbus does with its FBW fleet. So any remaining efforts to fool the pilots into believing that the control feedback they feel is the real thing is just artifice. And like any part of the system, the artificial feedback can fail and thus mislead.

The only aeroplanes in which Bob-Hoover type stick-and-rudder skills were ever really needed is manually controlled aerobatic machines flown in perfect VMC during a display. Modern combat aircraft, built for aerodynamic instability so as to be manoeuvrable, have had FBW sidesticks for decades, and the pilot’s main task is to direct the mission and its defence, not to use finely-honed skills to keep it flying. The stick is just a device for pointing such an aircraft where you want it to go.

In an airliner you were never supposed to handle it as if you were Bob Hoover flying a display. Nowadays, if you have to fly it manually at all – and 99% of the time you are told not to – your job is ABSOLUTELY NOT to fly it by the seat of your pants, it’s to select the attitude/power combination you need to get you elegantly from where you are to where your passengers wish to go. I can tell you from experience, a spring-loaded sidestick is an easier device than a yoke for selecting an attitude, and as for selecting power, throttle levers do the same everywhere, back-driven or not.

So I’d guess Boeing probably will go down that track. Pilots who still need to be flattered by being presented with controls that look like the old fashioned ones but do not work like them are no longer in the right job!”

No pilot/aeroplane interface is perfect. But choosing the best one for the next Boeing is going to be an interesting job for Calhoun.

Egyptair MS804: significance of ACARS messages clarified

David Learmount , , , , , ,

Airbus is not, at present, able to give specific advice to A320 operators based on information available from the Egyptair MS804 investigation, according to a report by Flightglobal senior journalist David Kaminski-Morrow.

Data transmitted by the aircraft’s ACARS messaging unit to the Egyptair operations centre is insufficient to point to a cause, he reports, explaining: “Airbus has already informed operators, via two accident information bulletins, that the available data is limited and that the analysis of the transmissions does not contain enough data to determine the accident sequence, Flightglobal has established.”

The Flightglobal report continues: “With the inquiry unable to conclude whether a technical flaw contributed to the crash, the airframer has been unable to provide any immediate advisory to operators.

“Although seven ACARS maintenance messages transmitted in the space of 3min – between 02:26 and 02:29 Egyptian time – hint at the possibility of smoke and heat in the forward fuselage, there is no confirmation that the time-stamp of the messages correlates with the order of the trigger event and no clear indication of the precise time interval between them.”

The unknown factor is the “trigger event” referred to. The ACARS messages (see earlier blog entries) and the circumstances of the crew’s loss of control over the aircraft do not provide specific evidence to indicate either sabotage or a fault as the trigger event.  But whichever it was, it appears to have generated fire that caused progressive electrical failures, and the crew’s loss of control over the aircraft ensued soon after that.

Floating wreckage and body parts recovered from the water where the aircraft crashed into the Mediterranean Sea north of Alexandria, Egypt, so far provide no clue as to whether sabotage or another cause brought the aircraft down. And the search coordinators have released no information about how widely the wreckage field is spread. This can be an indicator of whether the aircraft came down in one piece or had broken up in the sky, but after time the clues can be lost because the floating wreckage can be spread by sea currents and wind.

All this makes the recovery of the main wreckage and the flight data and cockpit voice recorders from the sea bed vital for the understanding of what caused the loss.

 

Missing Egyptair flight MS804

David Learmount , , , , ,

It’s tempting to speculate that the loss of Egyptair MS804, an A320, was caused by sabotage because that’s what happened to the Metrojet flight out of Sharm el-Sheikh last year.

But, in the last decade, several aircraft have quietly gone missing during cruising flight without being brought down by explosives or in-flight break-up. The most obvious example was an Air France A330 that went missing in the south Atlantic in 2009, but there are others. And there is no information yet which would rule in or rule out either of those scenarios.

Greece’s Defence Minister Panos Kammenos has told a news conference that soon after entering Egyptian airspace, the A320 had turned “90 degrees left and 360 degrees to the right” before descending and disappearing off radar at 15,000ft. If that information is confirmed – and I have no reason to doubt it – the flight had clearly been destabilised, but the cause of the destabilisation is not known.

The aircraft’s last known position is over the Mediterranean south-east of Crete and south-west of Cyprus, but still more than 100nm off Egypt’s northern coast. Fairly soon some useful information is likely to become available because several military units – ships and aircraft – have been committed to a search of the area.

If, for example, there is a floating wreckage field and it is very widely dispersed, it will suggest an in-flight break-up.

But breakup can happen for reasons other than an explosion – although history and modern experience says that’s highly unlikely.

The aircraft and its “black box” recorders are almost certain to be found because, after other aircraft losses in the sea, recorders have been recovered in working condition from deeper waters than this.