One thing about Mifnet is; great questions always seem to pop up. You guys
set my brain on overdrive, couldn't stop. What's unique about this is that
it involves both engine & airplane, plus up to three authorities.
I do have some thoughts on this but primarily from the perspective of what
the FAA/EASA/CAA might do about the problem as opposed to the operational
issues.
In general, just from the numbers (11 events in 15 years) I doubt they had
a safety of flight problem so it was OK to continue BUT it's bothersome
that they had to shut the offending engine down to wake it up. I'll bet the
cockpit crew kept their eyes on it.
Beyond that, obviously I'm afraid there's a lack of information for me to
point to cause-effect-correction. One sure thing, OEM will (should) be TOLD
to isolate the problem & fix it, maybe with a "*We're very disappointed
that you haven't already fixed this*" meeting/call. So I had some fun with
who might do what more generically - manufacturer vs authorities.
AND, this is funny, the flight was almost last night and they knew
immediately that the cause was a cracked soldered joint?? Wait for
confirmation and ask why the software fix wasn't already on the airplane -
another "wait for confirmation."
Short answer:
- The manufacturer should have been on this 8 failures back. The
FAA/EASA/CAA must decide if there's an immediate safety issue and, based on
the failure type, safety exposure (somewhere between catastrophic and
ho-hum), and probability, they might team up with the OEM, form a plan, and
track it.
- My fingers couldn't stop typing, thus the short answer. As I was
pounding this out it occurred to me that I had the makings of a Kilroy
article, so thank you.
Actually, since the A380 is European, the responsibility & actions, up to
possible airworthiness directives, EASA (Airbus) or UK CAA (RR) will be
first, followed by the FAA through the bilateral if they agree, which is
normally the case. Of course each authority must be prepared to exercise
their autonomy, kinda like China CAAC did after MAX #2 accident.
IN THE WEEDS:
This can get twisted pretty quickly, there are plenty of questions from a
handful of directions. But ultimately any control unit that may have a
solder joint crack will have to be replaced. Should there be an
airworthiness directive? Maybe, maybe not. *Regardless, I can guarantee the
manufacturer will be told to fix the problem and there be no argument from
the OEM*.
1. Original design: What redundancy do the engine controls have? The
e-mail suggests at least 2 electronic (FADEC). Are there 3, maybe a
mechanical back-up?
2. WHY did the pilots have to shut the engine down just to get a
control reset? The engine should have just kept on ticking without a peep.
Any answer from the OEM will not be satisfactory, it must be fixed.
3. The root cause needs to be determined. Was it the supplier? Is it
from a bad batch of solder? Have the parts been mishandled?
4. We know Part 25 (transport airplane certification) requires
a positive rate of climb with one engine out. Will there be a safety issue
if more than one control fails? We're talking probabilities here - in this
case it appears to be very low.
5. Safety: If there IS back-up, why did the engine lose thrust and *not*
revert to #2 (or #3) control?
- The e-mail says there's a software fix, which is nice BUT it might
also mask future failures, what we call a latent failure. If the second
control fails and suddenly there's no control, will it shut
down, spool up,
go crazy, etc? Very bad, a word search in Part 25 shows that
phrase 8 times.
- That latent failure should at least light up a caution in the
cockpit
- Related, why did the crew have to do a shut-down & restart? That's
ridiculous.
1. Who is accountable: Are the controls part of the engine or airplane
TC? More of an administrative question to figure out who owns it.
2. Ops, safety + design: Was it reasonable for the crew to continue on a
long flight with a known glitch aka non-airworthy?
3. Safety + design: Are the failure rates of 11 (maybe 12 with this
event) in 15 years related to cycles or flight hours? Either one is
actually not bad IF the crew in each case was able to work through the
problem. BUT it may be an engine control problem equivalent to a crack in
an airframe primary structural element.
- What bothers me is the fact that there were ~12 failures of a damn
critical unit. It should have been in work 8-9 failures ago.
- Every manufacturer should have regular safety reviews with
FAA/EASA/CAA, monthly is normal. But pick up the phone NOW if it's
serious. The famous 3 questions: a: What happened? b: WHY did it happen?
and, c: What are you doing about it?
- For each unit, when it happened is another question related to a &
b because things like failures grouped together, or spread out
through the
15 years, phase of flight, did ANY failure lead to an emergency
situation,
etc. Dig dig.
To set the stage, Part 3 defines "*airworthy*" as ".*..the aircraft
conforms to its type design and is in a condition for safe operation*." (my
*emphasis*). It uses the word, *and*, not *or*. Part 3 applies to all
our regulations, Parts 1-199, there's no escape. So strictly speaking,
when a solder joint fails, it doesn't conform to its type design so it's
not airworthy.
So, even though that control doesn't conform to its design after a solder
joint failure, is it unsafe? We have that last line in the e-mail you
forwarded - "*A software fix initiates a channel changeover to avoid a loss
of thrust control event*." back to latent failure. That implies there are 2
channels on each of four engines, good news. BUT there was a loss of thrust
out of LAX, so was that software fix in place? I have to assume no because
if YES, the software failed.
So if I'm the authority with accountability, my actions at a minimum would
be:
- Drill down into each failure. OEM should have been working on this
problem after maybe 2 or 3 failures, asking if the failures were random or
do we have common causes = a trend?
- Is the OEM on top of this? Did they have guilty knowledge = bad actor?
Is their process robust? Is the OEM competent?
- At some point authority & OEM will agree to elevate this issue with
more frequent reviews.
Anecdote: In my last FAA tour I was the program manager for a major bizjet
manufacturer, WAG 300 models in service. They had a problem with maybe 40
airplanes that was not quite over the line into an unsafe condition because
of exposure (# of airplanes) and borderline type of failure, they had a fix
in hand. That's where the safety & probability aspects of the problem were
largely driven by fleet size, less so by reliability.
We had many conversations about it and reached an agreement to track the
correction % in the affected fleet and watch for any additional failures.
After a time, we were down to 1 or 2 holdout airplane owners, which meant
we couldn't close it out but on the flip side the exposure was very low.
The OEM pushed as hard as they could with wealthy & spoiled customers. We
even discussed having a call with me as "The Entire FAA". I didn't have
authority to make demands but I could certainly have explained the
situation, and it would be appropriate to inform them an AD was not out of
the question if they held out. I suspect they reached an agreement on costs
but after a while the OEM got down to zero and we closed it out.
This anecdote reflects the fact that I had a lot of discretion to make the
decision to recommend an AD, and I kept my management informed. The
airplane in question was not in the US so we had to work directly with that
authority because I couldn't do a thing without working through them. Good
news, the 3-way relationship was very strong, the OEM was competent and the
trust was high. So we were actually able to have a very positive exercise
dealing with a potentially dangerous issue.
Mike Borfitz
On Sun, Jul 13, 2025 at 12:42โฏPM Jack Keady via Mifnet <
mifnet@lists.mifnet.com> wrote:
>
> keady - interesting as LH brings in more 747s at LAX than A380s
>
> Mike Borfitz might understand all this
>
> Airline Secrets Exposed
> <https://www.facebook.com/AIRLINESECRETS?__cft__[0]=AZW_Y0B-xS-qxK1MUcUDY8jmbRlF38XcSX8wygoQQy-y8UBLZpOpM2pR_FX53W7g7bVgz0BVgpyacN-xQvM13YNtJ9CFcadyu1Og0ZkDpmauMgXQk9Z9-GnRpraJXEHVFHSwcSTxdYo753hWuaMD48oAgu8EObKh6AWHUjuKWwsbnbtN-Q_k7Z3SbyqgP4fncrNFY2QJ43lnPPc4m4efOAJIryVbz1z0VDxT3K8u8jB_VQ&__tn__=-UC%2CP-R>
> tonpSodesru9f7gghth1798c1f0mc5g69ffic9024402467612h3l0igc70f
> <https://www.facebook.com/?__cft__[0]=AZW_Y0B-xS-qxK1MUcUDY8jmbRlF38XcSX8wygoQQy-y8UBLZpOpM2pR_FX53W7g7bVgz0BVgpyacN-xQvM13YNtJ9CFcadyu1Og0ZkDpmauMgXQk9Z9-GnRpraJXEHVFHSwcSTxdYo753hWuaMD48oAgu8EObKh6AWHUjuKWwsbnbtN-Q_k7Z3SbyqgP4fncrNFY2QJ43lnPPc4m4efOAJIryVbz1z0VDxT3K8u8jB_VQ&__tn__=%2CO%2CP-R#?fge>
> ยท
> Information to hand about a potential solder joint crack, associated with
> throttle control, causing an A380 to lose engine thrust after takeoff at
> Los Angles on 14 June 2025
> The Hydro-Mechanical Unit (HMU) a mechanical device responsible for
> regulating and controlling fuel flow from the aircraft's fuel system to the
> engine was later replaced plus the Electronic Engine Control (EEC) engine
> computer
> IMPORTANT NOTE: Although we have received suggestions to advocate some
> relevance
> PLEASE "try" to avoid making direct connections and/or implications of the
> above event with the Air India 787 accident without scientific evidence
> The Lufthansa Airbus A380 flight to Munich LH453 was climbing out of Los
> Angeles when the #3 eng thrust reduced to about 30%. The crew moved the
> thrust lever to idle, then to 30%, but received no reaction from the
> engine. The crew decided to shut the engine down and it restarted
> successfully. The aircraft continued to Munich without further incident for
> a safe landing
> Rumor has been received that Rolls Royce found that the event was
> consistent with an ADFX (Avionics Full-Duplex Switched Ethernet) fault
> linked to a solder joint crack.
> Allegedly in the past 15 years eleven such loss of thrust control
> occurrences have been registered, which were caused by erroneous software
> behaviour due to cracking solder joints.
> In autothrust mode the Electronic Engine Control (EEC) receives the power
> settings via the ADFX interface. When the fault exists potential erroneous
> or intermittent data used by the EEC leads to thrust fluctuations. A
> software fix initiates a channel changeover to avoid a loss of thrust
> control event.
> Airbus A380 - MSN 177 D-AIMN
> Serial number 177
> Type 380-841
> First flight date 06/11/2014
> Test registration F-WWSR
> Plane age 10.7 years
> Seat configuration F8 C78 W52 Y371 Seat
> Hex code 3C65AE
> Engines 4 x RR Trent 970
> Reference https://avherald.com/h?article=52a359df&opt=0
> <https://l.facebook.com/l.php?u=https%3A%2F%2Favherald.com%2Fh%3Farticle%3D52a359df%26opt%3D0%26fbclid%3DIwZXh0bgNhZW0CMTAAYnJpZBExd2FteW9JT3dRcDBVV3VTSQEe91xHSPMjdWFUsjVQWDxy3cRQMgHbFCfpO_MWcBpDR-SeoPb3eNIpXfF_JS0_aem_a7J-WcS_JujxrDAD8HVJdg&h=AT3KLtYKSZfDk6JpSP43lBkoVsVhP0uuUVurOFTLGdRuRGacu-Pm1iCf1bsHfRYXEwakIUGbimNk4bogFFHpOM0TMhBXNV2Eu9Z3dAE91CJ0I-WrAOyngRofOfEsxMv_eu9k_U--W7LgNl2qvX9Vpk67ACnO3A&__tn__=-UK-R&c[0]=AT14c6mRTgTBzV6nLrdzTQ3v-ccDkDLjS28ESmKO4khDNvYtfWNSr0kEw9ozaOvC4JYRmc5jn3xZtNAbfOwOS1UeSTRKSig78TH98e0_t7dlASymNAJiJMuN7q-cH0b_ByvxBWpu8FfGLs5X0qu9DXkc1HFrznSS42cvQR6ahCAgtX6Uqf4W3nPxc3cGCtPe84Qrjf9g0EkhyOYdwC4Y2UZFNsxgxkOdWk1lrO3hciI-NIjhPSCBX04eh8o>
> Airline Secrets Exposed
> Community Service
>
> --------------------------------------------------------------------------
> Revised: 20250507
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--
Mike Borfitz, DER
Cell 206-714-8797
e-Mail: m...@borfitz.com
Kilroy Aviation LLC
Website: WWW.FAAODA.COM <http://www.faaoda.com/>
Kilroy is available for aviation regulatory and safety issues
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