Search found 737 matches

by FluidFlow
Tue May 07, 2019 1:14 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 421366

Re: Boeing 737MAX Grounded Worldwide Q2 2019

In the majority of the fatal crashes in the last decade (I'm not saying all) - Crews did not follow procedures that they were supposed to know as part of their type ratings on those aircraft. The certification process assumes those Crews have that knowledge and that is what allows FU's like MCAS to...

Jump to post
by FluidFlow
Tue May 07, 2019 7:43 am
Forum: Civil Aviation
Topic: Why was El Al 1862 doomed to crash?
Replies: 15
Views: 5164

Re: Why was El Al 1862 doomed to crash?

Section 2.4.3 Synthesis gives a good explanation to the problem the crew faced. The right wing just could not generate enough lift compared to the left one and due to control surface problems the resulting roll was not preventable. Landing at 250kn+ is also not an option you ever think of as a pilot...

Jump to post
by FluidFlow
Mon May 06, 2019 6:35 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 421366

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Four additional concerns specific to the 737 MAX were listed in the 2017 report. All were related to certification of legacy systems inherited from the earliest 737 models that were found by FAA technical staff to be noncompliant with the latest safety regulations. These involved a lack of redundan...

Jump to post
by FluidFlow
Fri May 03, 2019 9:43 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 421366

Re: Boeing 737MAX Grounded Worldwide Q2 2019

"I guess the only possibility for Alpha Protection activating would have been a double bird strike taking out two AOA vanes - with the odds of that so low not needed to design around." Double bird strike wiping out equipment on both side of the aircraft? That seems Sully very unlikely Hud...

Jump to post
by FluidFlow
Fri May 03, 2019 4:03 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 421366

Re: Boeing 737MAX Grounded Worldwide Q2 2019

FluidFlow Stop feeding morrisond, I told him earlier on the thread he was wrong, provided the same reference that showed the crew were able to control the aircraft with elevator input. They are trolling, this has nothing to do with MCAS, stop feeding their off topic lies and rants please. Zeke - I'...

Jump to post
by FluidFlow
Fri May 03, 2019 3:07 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 421366

Re: Boeing 737MAX Grounded Worldwide Q2 2019

The write up is pretty fuzzy - but I take it they either got control back by disengaging the computer - which took 45 seconds to a minute or the Captain pulled the thrust back and regained elevator authority and electric trim Authority which they did not have either. However how would the electric ...

Jump to post
by FluidFlow
Fri May 03, 2019 1:54 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 421366

Re: Boeing 737MAX Grounded Worldwide Q2 2019

On the Limitations on the manual backups - someone else posted it's in the MAX training manuals including the procedure that you may need to unload the control surfaces to get them to work in certain situations and that excessive speed is bad. Which is the same as it would be on an Airbus. The FBW ...

Jump to post
by FluidFlow
Fri May 03, 2019 11:38 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 421366

Re: Boeing 737MAX Grounded Worldwide Q2 2019

On the Limitations on the manual backups - someone else posted it's in the MAX training manuals including the procedure that you may need to unload the control surfaces to get them to work in certain situations and that excessive speed is bad. Which is the same as it would be on an Airbus. The FBW ...

Jump to post
by FluidFlow
Fri May 03, 2019 4:45 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 421366

Re: Boeing 737MAX Grounded Worldwide Q2 2019

I don't think that the goal was to make the MAX=NG. Clearly the goal was to make the Max better than the NG. A subsidiary goal was to make the Max fly and handle like the NG. There is nothing wrong with this. The problem was in the execution. They definitely wanted to make it more efficient, the co...

Jump to post
by FluidFlow
Fri May 03, 2019 4:38 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 421366

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Please explain how the age of the aircraft design had anything to do with whether you can augment handling on a new revision. Say you have an aircraft A that has 60 year old design and for example hydraulic controls and the amount of force to move the elevator is 20N. Aircraft B is built after the ...

Jump to post
by FluidFlow
Thu May 02, 2019 4:20 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 421366

Re: Boeing 737MAX Grounded Worldwide Q2 2019

They definitely wanted to make it more efficient, the complete product seems to be worse than the NG as it is less safe. They unfortunately did not make it handle the same Boeing only augmented it, on an aircraft that is grandfathered from a sixty-year-old concept. In my opinion, the aircraft was t...

Jump to post
by FluidFlow
Thu May 02, 2019 3:17 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 421366

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Hi Zeke - Sorry I was thinking of Lufthansa 1829 in 2014 From AVHerald "The Aviation Herald learned that the loss of altitude had been caused by two angle of attack sensors having frozen in their positions during climb at an angle, that caused the fly by wire protection to assume, the aircraft...

Jump to post
by FluidFlow
Thu May 02, 2019 11:41 am
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 421366

Re: Boeing 737MAX Grounded Worldwide Q2 2019

I think the biggest mistake was the goal from boeing that MAX=NG. I am no Pilot, i am no engineer but I know quiet alot about fluiddynamics and in that regard MAX=NG is by no means right. They are two different aircraft. To try to make them equal lead to the death of 350 people. Traing the pilots f...

Jump to post
by FluidFlow
Wed May 01, 2019 3:49 pm
Forum: Civil Aviation
Topic: Boeing 737MAX Grounded Worldwide Q2 2019
Replies: 3768
Views: 421366

Re: Boeing 737MAX Grounded Worldwide Q2 2019

As I understand it, the symptoms of MCAS failure and runaway trim are pretty much identical. Also as I understand it, solution for both is to deactivate the automatic trim and manually trim. Additionally, as I understand it, although there was not specific simulator training for MCAS failure, there...

Jump to post
by FluidFlow
Thu Apr 25, 2019 2:31 pm
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

How is the redundancy on the 757? Modern FBW seem to have at least 3 probes and all the accidents and incidents related to probe failures seem to happen when 2 out of 3 fail similarly and therefore overrule the third probe. If they fail after each other then the aircraft just switches to alternate ...

Jump to post
by FluidFlow
Thu Apr 25, 2019 8:24 am
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

A lot of the rules and regulations in aviation are written in blood. That goes with almost every industry: Seat belts in cars, helmets in Sports, ear protection in construction and production and many many more. Most actions are always taken after shit hit the fan and never before because as we all...

Jump to post
by FluidFlow
Thu Apr 25, 2019 5:42 am
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

At the same time, history shows that insects do block pitot probes and ground crew forget to remove tape from static ports. The failure combinations for pneumatic Airspeed and AoA vane errors are quite numerous and airplane level results are quite complex. Can you think of any crashes - as in full ...

Jump to post
by FluidFlow
Wed Apr 24, 2019 6:49 pm
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

Boeing and the FAA must have missed a way bigger source of error on their 737MAX certification process. This is a no go, because even if the pilots would have saved the two aircraft and reported the incidents, the grounding would have been absolutely justified as the frequency of this incidents are...

Jump to post
by FluidFlow
Wed Apr 24, 2019 3:27 pm
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

BTW both Lionair and ET had no trouble counteracting MCAS initially - they just failed to continue to do so and did not follow the right procedures after the initial counteractions. Well, it's not like they didn't have other things to do. One of the main factors in both crashes may tun out to be th...

Jump to post
by FluidFlow
Wed Apr 24, 2019 1:07 pm
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

Nobody knows what software "patches" were necessary for the A320NEO, A330NEO or 777-200LR/300ER because they are integrated in the FBW system which is designed with proper redundancy and fail safes. For all we know any, or all, of those re-engined models could have just as much of a "...

Jump to post
by FluidFlow
Tue Apr 23, 2019 1:59 pm
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

A poster mentioned a few pages ago, that the NG has 5 different failures that can lead to a runaway trim and the MAX has now 6 due to MCAS. If the 5 failures grandfathered from the NG have the same possi-bility to occur on the MAX plus the new one from MCAS has a possibility to trigger, the chance t...

Jump to post
by FluidFlow
Thu Apr 18, 2019 12:08 pm
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

But before I agree on the sim training, I would like to know how the new MCAS works and how complex the recovery process from a MCAS fault actually is. I 100% agree with you. I just go with the attitude, that if Boeing does not provide full disclosure I prefer SIM-training than the other way around.

Jump to post
by FluidFlow
Thu Apr 18, 2019 8:44 am
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

I think we are over-estimating the force difference. Is it different? Yes it is, but will is cause a pilot that flies between the two to pull back so far it causes a stall? I doubt it, the pilot still has control of the plane. It will be a feel thing. And many pilots may not even notice. Perhaps if...

Jump to post
by FluidFlow
Thu Apr 18, 2019 5:30 am
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

This seems like hysteria imo. Pilots would know to push the nose down in a stall situation. The flight charateristics appear to be similar except in some situations where the yoke will feel lighter. MCAS will assist to make the plane fly like an NG. Without MCAS the plane isnt going to veer straigh...

Jump to post
by FluidFlow
Wed Apr 17, 2019 6:54 pm
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

MCAS is not an anti-stall system. It is a flight augmentation system that was supposed to make the max feel like an NG in certain situations where the MAX will nose up easier than an NG. How is it just possible to allow a transition to the MAX without simulator time when the MAX feels different if ...

Jump to post
by FluidFlow
Wed Apr 17, 2019 1:59 pm
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

A software fix that adds AoA disagree warnings, might consider the airspeed and uses both sensors in addition to the changed activation logic always seemed enough. The rest was hysteria. If MCAS auto deactivates in case of an AoA disagree situation, you do not even need an extra switch to turn it o...

Jump to post
by FluidFlow
Tue Apr 16, 2019 1:56 pm
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

I now read what is provided on this page: http://www.b737.org.uk/mcas.htm The MCAS function becomes active when the AoA exceeds a threshold based on airspeed and altitude. So there must be a table or function that determines when MCAS is needed. So if any three of this inputs is wrong due to sensor ...

Jump to post
by FluidFlow
Tue Apr 16, 2019 11:44 am
Forum: Civil Aviation
Topic: Ethiopian Airlines 737MAX crashes enroute to Nairobi Q1 2019
Replies: 5479
Views: 755865

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

barney captain wrote:

[...]

Respectfully,

BC


Sorry for the strange quote. As you seem to be familiar with the MAX, I would like to ask you a technical question:

Do you know at which AoA MCAS is supposed to be triggered?

Jump to post
by FluidFlow
Tue Apr 16, 2019 6:55 am
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

I have a feeling Boeing does not tell the whole truth about MCAS at what it is supposed to do. While I think its not there to prevent a stall in situations where the pilots give nose up commands in straight flight, its for situations where the plane turns probably at high speed small turning circle ...

Jump to post
by FluidFlow
Mon Apr 15, 2019 6:01 am
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

Something I do not understand is, why Boeing did not design the aircraft properly from the beginning: Airbus slaps new Engines under their aircraft Boeing is pressured to either do the same or build new aircraft Boeing decides we slap new engines under our aircraft as well Boeing designs the aircraf...

Jump to post
by FluidFlow
Fri Apr 12, 2019 5:00 pm
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

The airflow that creates the additional lift at high AoA would have to be partially diverted under the wing. To achieve this the fin would have to be big (along the whole nacelle due to engine placement on the wing). Turning an upward flow down is what we call "lift". :-) You are right th...

Jump to post
by FluidFlow
Fri Apr 12, 2019 11:17 am
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

Like someone else mentioned earlier in this thread - I wonder if it would be possible to add a small aerodynamic feature to the nacelles, pylons or wing root to negate the stall characteristics at certain AoA. Maybe a small fin to break the airflow over the engine nacelles and pylons, so that it do...

Jump to post
by FluidFlow
Thu Apr 11, 2019 11:35 am
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

Also, this begs a question: why do they "still needed automatic trim when you got to that spot."? The column switches are still there. Without MCAS operating they still disable automatic trim if the column is moved opposite of the automatic trim. The switches can't disable MCAS because at...

Jump to post
by FluidFlow
Wed Apr 10, 2019 4:31 pm
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

You know for a fact that lift from the nacelle is ever increasing and would, controls held steady, push the plane into a stall? Or, maybe the lift it generates stabilizes at some low value and doesn’t actually contribute enough lift to get to a stall, all else being equal? The, ahem, authoritative ...

Jump to post
by FluidFlow
Wed Apr 10, 2019 12:33 pm
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

So if I am following all this right, Boeing has created the MAX 8/9 as an inherently unstable aircraft, without any (FBW) computers to control that instability. Then the FAA certified it as the same as an NG, without any NG characteristics, plus a few of its own that Boeing don't know about yet. Bi...

Jump to post
by FluidFlow
Wed Apr 10, 2019 12:23 pm
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

Hey, I follow this forum since a few years but never felt the urge to post something or even register, but due to recent events I wanted to address something and ask a few questions. As I am not a pilot or engineer but have a background in fluid dynamics and computer modelling I am interested to he...

Jump to post
by FluidFlow
Wed Apr 10, 2019 7:40 am
Forum: Civil Aviation
Topic: B737MAX Grounded Worldwide Q1 2019
Replies: 6476
Views: 760261

Re: B737MAX Grounded Worldwide

Hey, I follow this forum since a few years but never felt the urge to post something or even register, but due to recent events I wanted to address something and ask a few questions. As I am not a pilot or engineer but have a background in fluid dynamics and computer modelling I am interested to hea...

Jump to post