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-   -   B737MAX Recertification - Archive (https://www.flyertalk.com/forum/united-airlines-mileageplus/2031779-b737max-recertification-archive.html)

PVDtoDEL Mar 15, 2019 10:52 am


Originally Posted by MSPeconomist (Post 30890695)
Then I'd go with Australia.....and I don't want those black boxes to come to the USA since if either data cannot be extracted or there's an error made when doing so that destroys some of the data, this would be so much worse for Boeing and the FAA/NTSB. I trust them, but I don't want even the slightest risk of the investigation being viewed as rigged in any way.

OTOH, IMO it's almost criminal that the black boxes weren't immediately sent for analysis as soon as they were found. Plans for where to send them should have been arranged in advance instead of waiting for days (with those MAX 8s still flying around and/or being grounded) before even asking Germany.

The stated justification for sending the boxes to Europe is to minimize the time zone difference between Ethiopia and the location where the data is being recovered. With this justification, sending the boxes to Australia makes no sense.

tryathlete Mar 15, 2019 11:17 am


Originally Posted by bocastephen (Post 30890680)
Not looking good so far - early news indicates the jackscrew was found in a position that indicated a full nose-down attitude, similar to the Lion Air crash. This is a contributing factor to the urgent grounding that took place in the USA.

Something shoved that airplane nose down with such veracity the pilot was unable to bring it up.

So now my question is thus - what pilot reports exist that indicate similar behavior by automated flight control systems that the pilot was able to override and restore normal attitude? Do such reports exist that might indicate a trend showing a serious, dangerous defect, and at the same time, pilot error in mishandling the defect with these two crashes?

So it seems runaway trim response by FP would eliminate the MCAS continuous addition of nose-down trim until it hits max and there’s no more trim.

LarryJ Mar 15, 2019 12:40 pm


Originally Posted by surram (Post 30890670)
Many thanks EWR764 for your detailed explanations. Appreciate it. The "flaw" reference that I made is the 'inherent aerodynamic instability in the MAX' - based on the opinion of Captain Girish Kaushik - the excerpt from the link below:

It's not an instability. It's a difference in control feel.

The new engines on the MAX have higher residual thrust at idle. They've also been mounted higher and farther forward. The result is that in steep turns, and high angles-of-attack, the control wheel forces in the pitch access are lighter than they would be on a 737 NG. The MCAS system adds a nose-down bias, in this situations, in order to produce a similar control feel across all models.

Boeing didn't initially include information on the MCAS system because it is invisible to us in the cockpit. We can't see it. We don't know when it is operating, and there's nothing we can do about it. There was already an applicable procedure to follow in case of invalid MCAS activation--the runaway stabilizer procedure. I know a lot more today about MCAS than I did prior to these accidents but that knowledge doesn't help me if I were ever faced with a similar situation. It's nice to know but what good does that do for me?

bocastephen Mar 15, 2019 12:41 pm


Originally Posted by tryathlete (Post 30891070)

So it seems runaway trim response by FP would eliminate the MCAS continuous addition of nose-down trim until it hits max and there’s no more trim.

Or what is causing the trim response - is it a computer software malfunction, the software confused by bad inputs due to a hardware issue, or an actual mechanical failure or breakage?

The condition of the crash site is not helping matters, apparently there is widespread looting and theft, and the Ethiopian govt did not secure the site properly and is still not doing so.

EWR764 Mar 15, 2019 1:03 pm


Originally Posted by bocastephen (Post 30891407)
Or what is causing the trim response - is it a computer software malfunction, the software confused by bad inputs due to a hardware issue, or an actual mechanical failure or breakage?

The condition of the crash site is not helping matters, apparently there is widespread looting and theft, and the Ethiopian govt did not secure the site properly and is still not doing so.

The FDR will be able to tell us what the AOA sensors were reading (and feeding) to the flight control computer from takeoff to impact. That will be among the first places investigators look (assuming the data can be obtained) to begin to rule out the Lion Air scenario.

Crashes into poor, rural areas are susceptible to pilferage from the accident scene. I'm currently involved in a case where an aircraft plunged into the ground in a remote area of a relatively impoverished nation, and what little wreckage there was had been pretty well picked over by the time investigators got to it. Anecdotally, I heard investigators were out scouring scrapyards for a ~50 mile radius to see if people were attempting to sell aircraft parts they had found, and sure enough, some key pieces of wreckage were recovered this way. Getting to a crash scene and securing the site is priority #2 after rescue/firefighting operations, for many reasons.

The other, absolutely absurd thing that just came to mind is the same-day photo op of Ethiopian CEO Tewolde Gebremariam, in business-casual attire, picking through pieces of wreckage in the impact crater. Once it is clear that rescue is impossible (within the first, say, 3-4 seconds of surveying the site) and there's no further risk to lives and property, that scene has to become airtight. I can understand the PR interests of presenting the CEO as sympathetic and engaged in the investigative process, but that was ludicrous. Similarly, after the Lion Air crash, passenger belongings were simply dumped on tarps and friends/family were turned loose to sift through the piles for their loved ones' belongings. Pretty sickening.

For those reasons, and many more, I have tremendous faith in the reliability of the NTSB's processes in handling major crash investigation. There's nobody in the world better at what they do (and this is coming from someone who, to earn a living, actively looks for ways to criticize NTSB findings) so it is upsetting for me to see the integrity of the American investigative board and aviation regulator blithely called into question over partisan politics. We're better than that.

764toHI Mar 15, 2019 1:42 pm

I agree. It's incredibly disheartening to see Chairman Sumwalt on TV, but he seems to be objective and incredibly experienced.


Originally Posted by EWR764 (Post 30891496)
For those reasons, and many more, I have tremendous faith in the reliability of the NTSB's processes in handling major crash investigation. There's nobody in the world better at what they do (and this is coming from someone who, to earn a living, actively looks for ways to criticize NTSB findings) so it is upsetting for me to see the integrity of the American investigative board and aviation regulator blithely called into question over partisan politics.


Weatherboy Mar 15, 2019 2:45 pm

Where are they now?
 
Does anyone know where UA's Max fleet is now? Unless they ferried them away, I imagine there's a bunch in Hawaii.

EmailKid Mar 15, 2019 3:10 pm


Originally Posted by Weatherboy (Post 30891883)
Does anyone know where UA's Max fleet is now? Unless they ferried them away, I imagine there's a bunch in Hawaii.

Here you go:

Flightradar24 UA fleet.

I'm not about to click on all the frames, but you can if you are so inclined.

It shows the last few flights - just click on B39M, and all the 737-9 MAX frames pop up (suggest "open in new window/tab" unless you want to go to main UA page after each lookup).

EWR764 Mar 15, 2019 3:19 pm

The two MAXs in Hawaii are ferrying (empty) nonstop to IAH. The rest of the fleet will eventually be at SFO and IAH where UA has plenty of ramp space to park the fleet for the time being.

silentbob1974 Mar 15, 2019 3:51 pm

I couldn't tell if there's a separate thread to discuss this, but have folks generally been successful at changing their flight on a 737-9 MAX for a reservation that's 3+ months away without incurring any fees (assuming origin/destination and travel date remain the same)?

HNLbasedFlyer Mar 15, 2019 4:02 pm


Originally Posted by EWR764 (Post 30892017)
The two MAXs in Hawaii are ferrying (empty) nonstop to IAH.

Surprised they'd burn all the extra fuel to get them to IAH versus parking them at SFO.

FlyngSvyr Mar 15, 2019 4:26 pm


Originally Posted by silentbob1974 (Post 30892108)
I couldn't tell if there's a separate thread to discuss this, but have folks generally been successful at changing their flight on a 737-9 MAX for a reservation that's 3+ months away without incurring any fees (assuming origin/destination and travel date remain the same)?

In the short term after the EA incident UA was allowing people to move to a different airframe without change fees. But now that the MAX 9 is grounded, any future flights that show it as a possible airframe shouldn't be considered gospel. Even if a MAX 9 was not shown, there is always the possibility of a future swap in.

Once the MAX series is cleared to fly again, I highly doubt UA/SW/AA is going to have an official policy allowing pax to switch for free out of fear of flying on the MAX series. Maybe an unofficial policy for a while if you call in and complain enough, but eventually the "fear factor" will pass.

altbg Mar 15, 2019 6:16 pm

Interestingly enough some of them were ferried to HOU instead of IAH. Any one know why? Not enough parking space at IAH?

EmailKid Mar 15, 2019 8:10 pm


Originally Posted by altbg (Post 30892468)
Interestingly enough some of them were ferried to HOU instead of IAH. Any one know why? Not enough parking space at IAH?

Believe they do some maintenance work at HOU - not sure which models. My educated guess would be that UA management anticipates some sort of fix that would be performed there.

mduell Mar 16, 2019 7:48 am


Originally Posted by LarryJ (Post 30891402)
I know a lot more today about MCAS than I did prior to these accidents but that knowledge doesn't help me if I were ever faced with a similar situation. It's nice to know but what good does that do for me?

I know you're not speaking on behalf of the union or airline, but man I wish you were the union spokesman.


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