Emergency AD issued for loss of pitch control incidents on A320 aircraft. According to Airbus, it’s a similar bit flip vulnerability to the 737 MAX, caused by solar events.
In the case of the MAX, the flip could inadvertently drive the stabilizer. For Airbus, it’s in the elevator control computer (ELAC).
The fix is a software revision and for some aircraft, hardware revision as well. Also affected are A319 and A321.
I try hard to have evidence-based opinions, but here’s where I go against the numbers: I just don’t like the whole concept of fly-by-wire. Yes, I know it’s been certified through a rigorous process and that in the alternative, physical cables can break or get jammed.
But goddam, I hate the idea of getting killed in a plane because a single errant gamma ray flipped a bit in my airplane’s computer. I have this weird superstition that I’m going to meet my end in some strange, unlikely way and maybe that will be it. Or perhaps I’ll be the first person to die of hunger in a Waymo after a bit flip makes all the doors lock permanently in a dark, deserted parking lot.
For now, I’m glad my plane has physical controls. And not only are they physical, there are multiple redundant backups. I guess I’m now officially old enough to be old-fashioned.
I’m not familiar with the exact nomenclature of Airbus components. But reading the EAD, it almost looks like they’re directing the removal of the latest version of the ELAC and replacing it with the prior version. Any airplane with the older version(s) is fine, but if it has the new version, either as a result of being built that way or the new-version part swapped in later, it’s gotta be reverted before further flight other than very limited ferrying.
Again, I may very well misunderstand the labeling of their parts. But clearly there are (at least) two variants of ELAC and one of them is not OK.
You are.
OTOH, ref the cited article, American has 340 (!) affected Airbusses and expects to flash all their software in just 2 days. Image new hardware had to be designed, fabricated, and installed on 340 jets? We’d be taking years to get them all updated. Meanwhile everybody would be flying around with the defect waiting to strike.
That is an excellent and unexpected point. I’m reminded of recent-ish heavy equipment that will switch controls with a menu selection (You can choose which joystick does which movement) since they are now drive by wire. Pretty cool–old school operators that were trained on Cat vs Case protocols can set their equipment up how they like. Choose Boeing yokes or Airbus side-sticks at your convenience…
Are these your comparison, or Airbuses, or some article writer?
Point being the MAX problems were not a bit-flip error. They were a result of no reasonableness checks on the readings coming from a non-redundant sensor that would cause single channel GIGO. Then when the sensors on those two aircraft went wacky, the computer (singular) believed the wacky reading and did stupid stuff. Garbage In Garbage Out.
Still an overall failure of design and implementation of a software intensive hardware system. In that sense all these bugs of modern hybrid aircraft are flavors of the same shortcoming.
That is correct. The ELAC gets regular software updates. The AD reverts the L104 software back to the L103 version, so it’s something in L104 that is vulnerable and it’s not a hardware issue. The very latest A320 family have another ELAC version that doesn’t appear to be affected by the AD. If I’m reading the mod status of our fleet correctly, two are unaffected and the rest will require a software downgrade. It seems to be a quick process if the ELACs have downloadable data capability.
That was replying to:
Octopussy (1983) is on. I’ve just been treated to seeing the BD-5J. I’ve always loved that airplane, since dad was building a BD-5A in the ‘70s.
A friend of mine has a BD-5J. It’s converted from a prop I believe.
I’ve shared this story before. Dad ordered his kit when the BD-5 still had a V-tail, but the kit was upgraded to the standard tail. He was extremely meticulous, and did things like polish the lightening holes in the wing spars even though they would never be seen again. Anyway, a friend told him he could get a jet engine from a drone. He’d supply the engine for a 50% share in the airplane. (Jim Bede was having trouble sourcing the engine dad had paid for.) Dad called Jim Bede and asked him about the feasibility of putting a jet engine in the BD-5. ‘No way. Can’t be done,’ said Jim Bede. A couple of years later, he came out with the BD-5J.
I had the pleasure of witnessing a test for a new system in a cockpit which installed a couple of PBA (push button annunciators) so it was necessary to evaluate glare and distraction etc. A simple system but a necessary compliance test.
I was with a type rated pilot in a cockpit with blacked out windows and we fiddled with different lighting and a few scenarios and as much as I regularly sit in these planes in full light to verify certain features this was the first time it was a simulated night flight situation and it was actually really cool! The pilot was fun to chat with too, to learn his perspective on things.
And this whole experience 100% confirmed to me that the entire cockpit lit up at night is ridiculously overwhelming for me and the world is better off without me as a pilot! As simple as our test scenarios were, and as prepared as I was for the features I was examining, everything else was just so much information and I openly admit I don’t understand how you guys process it all. So. Many. Labels.
Anyway, fun day, looking forward to other opportunities, but nope, I’m not landing this plane of you both eat the salmon.
A USAF pilot pal of mine, now a (retired?) pilot for UAL (formerly CAL) was a St. Louis native and for awhile in the late mid-late 80s was the factory demo pilot for BD-5Js based out of Spirit of St. Louis Airport (KSUS) Chesterfield, Missouri | KSUS where Bede then has his HQ and kit factory.
He’d previously flown F-15s. He said the DB-5J was great fun to fly, was dangerously underpowered, and was a crash waiting to happen for anyone who wasn’t well above average in skill, cunning, and self-preservation.
Take that FWIW. I trust his POV, but others might find fault with his perspective.
AIUI, the BD-5 could be dangerous in a stall. The turbulent air from the stalled wings would ‘blank out’ the stabilator.
It was also fast, but not high powered. which was backwards from lightplanes that were not fast, but were relatively strong within their narrow airspeed stall-Vne envelope. It also promised lots of G capability without the guts to back it up.
Many ways to end up praying for the putt-putt engine to carry you out of what seemed like mere ordinary reasonable exuberance. Oops.
That might have been more of an issue with the V-tail version? I don’t know, just edumaguessing. My colleague/friend did his own jet conversion and flight testing program to get certification. He didn’t mention any gotchas but I didn’t really ask either. He’s heavily involved in vintage aircraft flying so is well used to coping with unusual aircraft.
I don’t think so. The V-tail got dropped pretty quickly. Just looking at the positions of the wing and the stabilator, plus the short distance between them, I could see the stab being awash in turbulent air. [IANA aeronautical engineer.]
I love the look and the concept of the BD-5 (any version), and I have the dad connection. But given my choice of unusual homebuilts. I’d really like a Quickie Q200 (same as the Q2, but with a Continental O-200).
Wasn’t the BD-5J unrecoverable if the engine shut down? Not enough weight in the front of the plane to nose the plane down at slow speeds?
Update on Airbus safety notice.
no mention of aircraft attempting to become lawn darts
Airbus: Flights resume as normal after software update warning
Thousands of Airbus planes are being returned to normal service after being grounded for hours due to a warning that solar radiation could interfere with onboard flight control computers. The aerospace giant - based in France - said around 6,000 of its A320 planes had been affected with most requiring a quick software update. Some 900 older planes need a replacement computer. French Transport Minister Philippe Tabarot said the updates “went very smoothly” for more than 5,000 planes. “Fewer than 100 aircraft” still needed the update, Airbus had told him, according to local media
A jet doesn’t provide any extra flow over the tail, so it would have the same stability power on or off. Never flown one, but what I’ve heard of BD-5 is that it has a high stall speed and poor recovery characteristics. So not a good plane to be in when you lose an engine.