Ethiopian airliner down in Africa

[DaveReidUK]

BBC News reports that the recorders are being sent to a European agency for processing and analysis (presumably either the French BEA or UK AAIB). It also stated that the AAIB had been accredited to the investigation, so they may well go to Farnborough.

The NTSB, as a party to the investigation, had (not unreasonably) been pressing for the recorders to go to the USA, but despite their fierce independence from the FAA, it would seem that the latter's decision to allow continued operation of the Max in the USA (not to mention Trump's comments) may have had a bearing on the decision.

[futurama]

Originally Posted by A30_737_AEWC

Like you, I found myself perplexed by what a 'Continued Airworthiness Notice to the International Community' (CANIC) was supposed to be. I'd never heard of them before and there's not a register of them that I was able to find on the FAA website. I think it was rather telling that when I read about the 737 MAX CANIC in the media and tried to find a copy of it for myself, an FAA Twitter 'tweet' provided a link to the document. It hardly looks likes it's a legal airworthiness document (like an AD, NPRM, etc.). It sounds more like a 'child of the social media age' being promulgated by 'tweet' and being crafted by the 'brand managers' of the organisation whose product is found to be wanting in a crisis.

CANICs are not new. The FAA issues several of them each year, dating back maybe 10 years. It's part of an internal FAA communication process to give a "heads up" to other XAAs about an upcoming safety action, and may be issued prior (or concurrent to) an NPRM or an AD.

[Less Hair]

Shouldn't they be on their way already? How long does this need to take? Aircraft are grounded because the crash circumstances are not enough known yet.

[Whispering T-Jet]

Originally Posted by canyonblue737

"Does anyone have any information on instances of irregular MCAS activation that have been successfully handled?"

The day prior to the Lion Air crash the accident aircraft suffered from MCAS activation due to the faulty AOA. The Captain of that flight ran the runaway stabilizer procedure and cutout the stab trim and then was able to complete the flight normally. As far as I know no MAX aircraft has had a MCAS activation since the Lion Air crash until (potentially, there is only tenuous circumstantial evidence at this point) the Ethiopian accident.

Whilst that crew proved they could actually fly, they then made an appalling "airmanship" decision to fly hundreds of miles over high terrain to Jakarta with an effectively jammed stab and no autopilot instead of returning to the 10,000' RWY in Bali 20-30 nm away. Furthermore the incident was not fully written up in the tech log. Commercial pressure maybe....

At this point MCAS has NOT been implicated although something - voice reports from other aircraft indicate unreliable airspeed - happened. It seems probable they didn't even make flap retraction height (thereby discounting MCAS unless they retracted flaps below flap ret. ht.).

While we are waiting for some actual CVR/DFDR facts maybe you would like to read about Ethiopian's last 737 prang here: https://www.bea.aero/docspa/2010/et-...b100125.en.pdf which in one sentence can be summarised as: pilots can't fly.

I'll get on a Max tomorrow if flown by say, Southwest.

[DaveReidUK]

Originally Posted by slip and turn

Yes, Dave, that was an interesting graphic you posted but did not your plots only commence at the end of the runway?

I didn't include the ground roll in my graphic simply because my interest was in what happened from rotation onwards.

One question about how the transmitted pressure altitude is auto-calibrated prior to flight. Clearly a complex aircraft like this on the ground at a well charted licensed airfield knows exactly where it is and at what altitude, so does it continuously calibrate itself whilst it is on the runway up to the point WOW and groundspeed, and GPS data tell it it may be airborne?

Nothing so complicated.

The aircraft simply transmits either a Ground Position ADS-B message, which for obvious reasons doesn't need to contain an altitude, or an Airborne Position, which does.

[whitefriars]

Originally Posted by A. Muse

BBC News reporting 'Black boxes to come to Europe' for expert analysis

....And surprise, surprise.....

American air safety experts are trying to persuade their Ethiopian counterparts not to send the flight data to crash investigators in London, The Wall Street Journal reported. Instead, they want it examined by the National Transportation Safety Board in the United States.

[oldchina]

Wouldn't be surprised if the recorders are on their way to the BEA in Paris. The engines were half French.

[positiverate20]

Originally Posted by ManaAdaSystem

So the Americans have had 5 cases of control issues after takeoff on the MAX. At least two happened when they engaged the auto pilot.
There appears to be several issue with the MAX.
Only time before it’s grounded world wide.

Here's a couple of extracts to look at

REPORT- trim after AP is turned on: December 2018

Noted on preflight, a write up, for a cycling trim situation on the inbound leg. With no faults noted by maintenance, it was cleared. First Officer (FO) and I discussed the situation as one of the threats possible, with emphasis on being alert for the cycling trim situation to possibly repeat. Reviewed applicable procedure for a possible runaway trim scenario. Upon takeoff, Autopilot A was engaged at approximately 1,200 FT AGL. As flaps were retracted and airspeed began to increase, additional trim inputs were immediately noticed by both pilots. With flaps now up, FMC called for 250 KTS. Aircraft pitched to 260 KTS with trim inputs, then re-pitched to 240 KTS. The trim system would activate for 1-2 seconds and then immediately reverse itself, trimming in opposite direction. I directed FO to ask for intermediate stop on climb, where we then stopped at FL230. Advised ATC we were experiencing a trim system problem, but the aircraft was stable and trim stopped fluctuating once a stable and level pitch was attained. I chose not to declare an emergency at this time as we did have a stable aircraft, but contacted dispatch via radio, and informed dispatcher of the situation, that it was a reoccurring event, and that I was not comfortable taking the aircraft to ZZZ1 with a primary flight control system not operating properly. Therefore I would return to ZZZ. Dispatcher brought Maintenance Control in I believe at that point and I gave them a description of the problem. We then completed those calls, informed ATC of our desire to return to ZZZ, and no emergency being declared at this time. The trim problem immediately reappeared when given a descent to 11,000, executed via Level Change on the Mode Control Panel. I was flying and at that point disconnected the autopilot, and hand flew the remainder of the approach to the landing. No trim problems were noted with autopilot disconnected. Maintenance ACARSed us several times, requesting us to attempt to troubleshoot the failure and gather information. I elected to not do this. I knew I had a failed trim system and did not wish to engage a deeper problem if something else went wrong with the system while troubleshooting. In addition we [were] now under 15000 FT, in the terminal area, and I was hand flying the aircraft. Too many distractions, as well as a potential bigger problem if something else went wrong. We both put on the table the trim motor / elevator jackscrew failure a few years back that happened to another carrier. That situation was perhaps the final reason I did not want to troubleshoot the failure. We finally told Maintenance Control via ACARS. "We are busy ", as they were now a distraction with their requests as we were near or under 10,000 FT. Aviate, Navigate, Communicate. That is what I start every brief off with a new pilot at the beginning of a trip.

REPORT- trim after AP is turned on: November 2018

It was day three of six for me and day three with very good FO (First Officer). Well rested, great rapport and above average Crew coordination. Knew we had a MAX. It was my leg, normal Ops Brief, plus I briefed our concerns with the MAX issues, bulletin, MCAS, stab trim cutout response etc. I mentioned I would engage autopilot sooner than usual (I generally hand fly to at least above 10,000 ft.) to remove the possible MCAS threat.

Weather was about 1000 OVC drizzle, temperature dropping and an occasional snow flake. I double checked with an additional personal walkaround just prior to push; a few drops of water on the aircraft but clean aircraft, no deice required. Strong crosswind and I asked Tug Driver to push a little more tail east so as not to have slow/hung start gusts 30+.

Wind and mechanical turbulence was noted. Careful engine warm times, normal flaps 5 takeoff in strong (appeared almost direct) crosswind. Departure was normal. Takeoff and climb in light to moderate turbulence. After flaps 1 to "up" and above clean "MASI up speed" with LNAV engaged I looked at and engaged A Autopilot. As I was returning to my PFD (Primary Flight Display) PM (Pilot Monitoring) called "DESCENDING" followed by almost an immediate: "DONT SINK DONT SINK!"

I immediately disconnected AP (Autopilot) (it WAS engaged as we got full horn etc.) and resumed climb. Now, I would generally assume it was my automation error, i.e., aircraft was trying to acquire a miss-commanded speed/no autothrottles, crossing restriction etc., but frankly neither of us could find an inappropriate setup error (not to say there wasn't one).

With the concerns with the MAX 8 nose down stuff, we both thought it appropriate to bring it to your attention. We discussed issue at length over the course of the return to ZZZ. Best guess from me is airspeed fluctuation due to mechanical shear/frontal passage that overwhelmed automation temporarily or something incorrectly setup in MCP (Mode Control Panel). PM's callout on "descending" was particularly quick and welcome as I was just coming back to my display after looking away. System and procedures coupled with CRM (Resource Management) trapped and mitigated issue.

From FO perspective
Day 3 of 3 departing in a MAX 8 after a long overnight. I was well rested and had discussed the recent MAX 8 MCAS guidance with the Captain. On departure, we had strong crosswinds (gusts > 30 knots) directly off the right wing, however, no LLWS or Micro-burst activity was reported at the field. After verifying LNAV, selecting gear and flaps up, I set "UP" speed. The aircraft accelerated normally and the Captain engaged the "A" autopilot after reaching set speed. Within two to three seconds the aircraft pitched nose down bringing the VSI to approximately 1,200 to 1,500 FPM. I called "descending" just prior to the GPWS sounding "don't sink, don't sink." The Captain immediately disconnected the autopilot and pitched into a climb. The remainder of the flight was uneventful. We discussed the departure at length and I reviewed in my mind our automation setup and flight profile but can't think of any reason the aircraft would pitch nose down so aggressively.

[SLFinAZ]

Originally Posted by jimjim1

Let someone else's fingers do the walking

https://www.documentcloud.org/docume...-737-max8.html
https://assets.documentcloud.org/doc...r-737-max8.pdf
"Contributed by: Cary Aspinwall, The Dallas Morning News"
HTML has some summary material (metadata) not in the pdf.

ASRS Reports for 737 max8
A 737 Max 8 captain noted problems on takeoff
An unidentified captain says the Airworthiness Directive does not address the problem in November 2018.
An airline captain called the flight manual for the Boeing 737 Max 8 "inadequate and almost criminally insufficient."
A co-pilot reported an altitude deviation in November.
Co-pilot said after engaging autopilot, aircraft pitched nose down.
Co-pilot reported that aircraft pitched nose down on departure.
A Boeing 737 Max 8 goes nose down suddenly during takeoff, pilot reports incident.


I have recently found bing search to be worth a look. Google finds it too.
[asrs database "max 8"]

Amazing reading.

Basically what it confirms is that for competent well rested crews the potential MCAS issues are a minor speed bump. Doesn't mean that it isn't a very real issue but the bottom line specific to Lion Air is simple and compelling....crew error. As for the current tragedy we really don't know enough but it doesn't have any of the trim related oscillation seen in Flight 610...

At some point the various regulatory agencies will need to figure it out.

[Ian W]

From Positive Rate

Here's a couple of extracts to look at

Interesting that there are other trim problems than MCAS for the Max8. Neither of the ASRS reports would be due to MCAS as they occurred with autopilot engaged and MCAS is disabled when autopilot is engaged.

[Skyborne Flyer]

interesting speculation from reddit thread

I just read an interesting post on the reddit 737 MEGA Thread about possible internal Boeing reports on the AOA/MCAS failure. Not that reddit can be trusted as 'professional' source of information, but now days anything seems to be fair game as far as where valid info might pop up...

Some info leaking down the engineering community grapevine, I have it second hand from a buddy working for one of the subcontractors, reportedly a memo was circulated internally at Boeing as early as AUG 2018 of potential failure modes tied to MCAS-AOA programming logic[...]

Take if for what it is, but am curious if any of the experts might chime in to the plausibility of the failure mode talked about?

[Cows getting bigger]

Originally Posted by SLFinAZ

Amazing reading.

Basically what it confirms is that for competent well rested crews the potential MCAS issues are a minor speed bump. Doesn't mean that it isn't a very real issue but the bottom line specific to Lion Air is simple and compelling....crew error.

Yeah right. Give someone a dog that wants to bite and don't tell them about Gnasher's habit, then blame them when the dog actually does bite.

[MemberBerry]

Originally Posted by JamesT73J

I think in the case of the Lion Air flight, the preceeding crew had little problem dealing with abnormal MCAS trim intervention.

By "little problem" you mean fighting against MCAS for about 5 minutes, just like the next crew, before using the cutoff switches? Because that's what the released FDR traces from the previous Lion Air flight show.

[GLIDER 90]

Yes very sad news with both crashes happening, but I'm afraid I don't have any faith in the glass cockpit aircraft. Should have stuck with the flight analogue instruments.

[Sucram]

Originally Posted by ReturningVector

As far as I know, the 737 acc altitude is 1500' AAL, so flap retraction will be even higher up. I can't find any exemptions to NADP1/2 in the aerodrome information. Am I missing something?

Sorry youre wrong, there is no noise abatement required at Addis, company standard is thrust reduction and flap retraction at 1000 aal

[A0283]

video of what is supposed to be the crash on Instagram

Some (personal) notes...

One of the video examples was the Bagram crash...
Many websites use photos from other accidents and aircraft types... happens all the time...
you need a big set of photos in order to be able to judge a single photo...

On the crash site itself two big diggers and a shovel have been used to 'alter the landscape'...
They have been digging deep, looks like more than 10 meters now...

From the available photos you dont seem to see big parts at a distance...
this would suggest that the plane crashed relatively intact...
which counters witness testimonies...

Witness testimony quality varies a lot. Even pilots standing next to an accident happening have been know to be completely wrong.
And it is not unusual to have dozens of witnesses 'seeing it wrong', which is unintentional and the reasons why are known...
The most unexpected witness may turn out to be the best... a Papua aboriginal is a wellknown example...

Crashes can eject material 'back' and light materials can go far...

FDRs and CVRs can often be read quickly... enough for a first impression...
but like everything above... you have to validate and check and crosscheck and ...

there are reasons why accident investigations takes as long as they do,
even without government shutdowns...

+++

requiring time does not absolve investigation leads from updating the public on progress,
aerospace investigation is brilliant in separating fact finding from analysis, and analysis from conclusions,
the more facts are published the sooner the better,
you dont learn only from accidents from your own types designed or flown, you also learn from the others,
that approach has made aerospace as incredibly safe as it is,

[CONSO]

post 1041 ...

Interesting that there are other trim problems than MCAS for the Max8. Neither of the ASRS reports would be due to MCAS as they occurred with autopilot engaged and MCAS is disabled when autopilot is engaged.

Hmmm . . . . SUPPOSED to be disabled... but if not ?????

[DaveReidUK]

Originally Posted by Skyborne Flyer

I just read an interesting post on the reddit 737 MEGA Thread about possible internal Boeing reports on the AOA/MCAS failure. Not that reddit can be trusted as 'professional' source of information, but now days anything seems to be fair game as far as where valid info might pop up...

Take if for what it is, but am curious if any of the experts might chime in to the plausibility of the failure mode talked about?

The thread talks about a probe design issue that manifests itself under certain flight conditions.

If that was the case, would we not see it on random Max aircraft at random intervals, rather than on the same (Lion Air) aircraft on four consecutive sectors?

[RTM Boy]

Originally Posted by Less Hair

Shouldn't they be on their way already? How long does this need to take? Aircraft are grounded because the crash circumstances are not enough known yet.

Reuters reports 'A decision where in Europe to send the black boxes would be taken by Thursday, the airline said'. This suggests to me some argument between various interested parties about who should carry out the downloads and analyses and where. Perhaps the implications for Boeing weigh heavy on this decision? The same article says 'Norwegian Air said it would seek recompense for lost revenue and extra costs after grounding its 737 MAX aircraft. “We expect Boeing to take this bill,” it said.'

The article also says 'In November, two incidents were reported to the NASA-run Aviation Safety Reporting Database that involved problems in controlling the 737 MAX at low altitude just after take-off with autopilot engaged, according to documents first published by the Dallas Morning News and verified by Reuters. “We discussed the departure at length and I reviewed in my mind our automation setup and flight profile but can’t think of any reason the aircraft would pitch nose down so aggressively,” one pilot said. In another case, the pilot said: “With the concerns with the MAX 8 nose down stuff, we thought it appropriate to bring it to your attention.” Boeing did not respond immediately to a request for comment.'

I sincerely hope this doesn't become a political football with safety-critical decisions being influenced (still?) by the nationality of the parties involved.

https://uk.reuters.com/article/uk-et...-idUKKBN1QU15D

[positiverate20]

Originally Posted by Ian W

From Positive Rate


Interesting that there are other trim problems than MCAS for the Max8. Neither of the ASRS reports would be due to MCAS as they occurred with autopilot engaged and MCAS is disabled when autopilot is engaged.

Yes there are quite a few trim reports including numerous when electric trim is inoperable. Off the track a wee bit here, but, I found this report by a FO clearly confused by automated trim- except it's on a 737-700 in November 2017?

At the gate, I adjusted the trim setting for a flaps one takeoff. It was a normal taxi to the runway. As FO, I was the Pilot Flying. As we climbed through 400 feet AGL, I noticed the trim switch on my control wheel was not operating. I called for Heading Select as per the departure procedure and at 1000 feet AGL called for "Set Speed" and "Climb Thrust". (Still no trim response from my control wheel trim switch.) As we climbed out the "speed trim" seemed to be picking up the slack and providing adequate trimming. As I called for flaps up I expected the speed trim to stop operating and again tried to trim through use of the control wheel trim switch; still nothing. I asked the Captain to try trimming forward on his trim switch. His was also inoperative. I requested VNAV at 3000 feet AGL.

As power and speed was increased there became a pronounced nose high flight control pressure. The trim wheel continued to intermittently rotate. My thought was that the "Speed Trim" was still somehow still active and was interfering with normal trimming. I waited to see if speed trim would catch up. It did not and excessive forward control wheel pressure continued to be required to maintain 250 knots in the climb. We were then cleared to 13,000 feet. We leveled off and began to troubleshoot the problem. I asked the Captain to take the controls while I re-adjusted my seat for better leverage on the control wheel. At that point the Captain and I agreed that he would fly the aircraft and I began working the check list, radios, and we would return to the departure airport.

Although we still had reasonable control over the aircraft, I explained the problem to Approach Control and that we would need to return to the airport. I requested a straight in ILS Approach with vectors since the weather at the departure airport reported at 10 miles and 1000 feet and slight right cross-winds. I selected the ILS Approach to the departure airport as listed in the approach section of the FMS. The Captain was busy flying (without autopilot due to the trim issue) as I was setting up the radios, minimums, requesting landing information, talking to Flight Attendants and making the PA announcement that we would be returning to the departure airport; while still trying to do that "Pilot Monitoring" thing. I thought I was still in the "Green". Apparently, I wasn't.