Worrying: The Boeing 737 MAX Has Hit Another Design Flaw

Boeing’s beleaguered 737 MAX aircraft has received another blow today, as the FAA have discovered another major issue with the flight controls. Despite working on fixes for several months, it appears far more work is needed before the jet can return to service.

Boeing 737 MAX
There is yet another problem with the MAX. Photo: Boeing

The aviation industry has been abuzz today with the worrying news that Boeing have found another flaw in their 737 MAX jets. It appears that the procedure which Boeing have put in place to correct an inadvertent MCAS ‘nose down’ situation just doesn’t work.

Now, Boeing is faced with needing to develop another software fix for the plane, which will clearly set them for much longer than anticipated. Not only that, but with the world media reporting yet another Boeing mistake, public trust in the plane maker has reached its lowest ebb yet.

What’s the problem?

Initially, reports from the FAA were somewhat vague, with no particular reason given other than that a fault had been identified. However, over the course of the day, more information has come to light regarding the nature of the fault.

Flight Global reports that the issue is related to the ‘runaway stabilizer’ procedure, which is what Boeing is calling it when the plane noses down in response to erroneous activation of the MCAS. This procedure is intended to help pilots regain control of the aircraft and take it out of the nose down position.

Lion Air 737 MAX
The MCAS is considered responsible for the disasters at Lion Air and Ethiopian. Photo: Flickr user
Bathara Sakti

According to CBS, during flight tests in a simulator, FAA pilots found a problem with the trim functionality. In testing the simulator in a situation where the nose was being pushed down, pilots found that it took too long for the nose to be returned to the normal position, despite following all the correct procedures.

The BBC quoted an unnamed source as saying,

“During simulator testing last week at Boeing, FAA test pilots discovered an issue that affected their ability to quickly and easily follow the required recovery procedures for runaway stabilizer trim (i.e., to stop stabilizers on the aircraft’s tail moving uncontrollably). The issue was traced to how data is being processed by the flight computer.”

As such, Boeing is being asked by the FAA to format another software update in order to fix this latest identified defect.

What’s next for the MAX?

The FAA have demanded that this software issue is fixed before any airborne flight tests of the software updates are conducted.  While it seems to come down to a ‘data processing issue’, the consequence of such a software glitch could have been deadly in real life.

The FAA have released the following statement regarding the current situation.

Video of the day:

According to their statement, they will only lift the ban when they deem it safe to do so, which could mean the MAX is grounded for much longer than anyone originally thought. As a result, Standard are reporting Southwest Airlines have extended their cancellation of the MAX through to October. We expect other operators will follow suit soon, although at this point, even October is looking somewhat optimistic.

Southwest Boeing 737 MAX 8 aircraft
Southwest have removed the MAX through to October. Photo: Southwest.

This comes as the IATA meet in Montreal with world leading aviation authorities to discuss how to return the plane to service. Clearly, they’re going to have a fair bit more time to mull this problem over.

What do Boeing have to say about this?

It seems Boeing are happy with the FAA’s decision, and agree that more work needs to be done. In a statement, the plane maker said,

“The safety of our airplanes is Boeing’s highest priority. During the FAA’s review of the 737 MAX software update and recent simulator sessions, the Federal Aviation Administration (FAA) identified an additional requirement that it has asked the company to address through the software changes that the company has been developing for the past eight months.

“The FAA review and process for returning the 737 MAX to passenger service are designed to result in a thorough and comprehensive assessment. Boeing agrees with the FAA’s decision and request and is working on the required software.

“Addressing this condition will reduce pilot workload by accounting for a potential source of uncommanded stabilizer motion. Boeing will not offer the 737 MAX for certification by the FAA until we have satisfied all requirements for certification of the MAX and its safe return to service.”

Boeing 737 MAX
Boeing will not offer the plane for certification until they have ‘satisfied all requirements’ Photo: Boeing

This latest development not only jeopardizes the 737 MAX’s timely return to service, but it looks like it will hit Boeing where it hurts too. Boeing stock was down a massive 6% following the break of the news, affecting their profitability and ability to keep paying those sizeable dividends.

Leave a Reply

8 Comment threads
11 Thread replies
Most reacted comment
Hottest comment thread
13 Comment authors
newest oldest most voted

OK, so let’s summarize here – the Boeing approach to introducing stellar new aircraft: – Shoddy, rushed design to start off with; plane is aerodynamically unstable (displaced center of pitch due to larger engines); poorly developed MCAS – severe shortcuts taken in fundamental software architecture / points of failure; don’t tell pilots anything about MCAS. – First plane crash, with all on board killed: blame the pilots, do nothing else. – Second plane crash, with all on board killed: blame the pilots, attempt to do nothing else, but eventually get forced into grounding the plane as a result of pressure… Read more »

Frequent flyer

A great summary! You just forgot to discuss the important issue of rebranding! The difference between Airbus and Boeing is that Airbus can play with the idea of a pilotless plane, but Boeing desperately needs the pilots to have somebody to blame when their Maxes crash!




Good point as regards rebranding!
How about the 737 FC (Flying Coffin / Flying Casket)?


I personally like the 737 LawnDart….I know it harkens back to another plane from the 60’s, but it works well.

John J Dinan

Anything made or assembled by people under the influence of drugs (Employees have admitted to smoking POT on their breaks, Boeings second assembly plant in South Carolina) or any other performance altering substance should not be put into public service.


More fascinating news from Reuters: Boeing expects that it will be September before the newly discovered MAX problem is fixed. That’s 6 months after the grounding started, and at least 2 months after the “early July” that we were hearing earlier this week.

Never Fly 737 Max

Agree this is fascinating and it’s all happening in 737 Max simulators at the moment. Boeing also admitted the Max simulator 2 months ago had bugs and didn’t reflect the flying characteristics fully of the aircraft!

Fix it for the simulator – who is going to be in the aircraft as they “test” just how safe this plane is? Not me for at least 5 years!


Basically designed flaw from beginning. Modified flying coffin is still a flying coffin.


Also, did Boeing’s professional testing program somehow miss this latest ‘software’ problem or did they find it and hope that they could hide it from the FAA so they wouldn’t have to fix it?
If that’s the case how many more ‘glitches’ are there waiting to be found?
And was the FAA anything this thorough when they were testing the NG?


These are very good questions, which are more thoroughly elucidated in the following link (from Leeham News). It seems that the newly discovered problem is a fundamental (and catastrophic) shortcoming of the Flight Management System. It should have been detected before now! As expected, Boeing is trying to play down its significance.


Reports from Forbes are saying that the software is causing a hardware lockup and the FAA wants Boeing to replace some chips, but Boeing insists they can do it by rewriting software.
Pretty soon I expect to see band aids, duct tape and bubble gum covering holes in the Max’s…


It’s an incredulous state of affairs how Boeing are trying to down play the serveity of what is now surfacing.


Boeing disaster in making. Two documentaries made by Al Jazeera TV network.
The first one 8 years ago, the 737 NG:
And the second one 4 years ago on 787 Dreamliner development and production:
Goosebumps anyone?

Azman Shah

Boeing should do something to overcome the problems of 737. Perhaps reintroduce a new 707 or 727 that can replace the 737 max and trouble free like the 747. If not Airbus 320 or similar model will take the place of 737!


737 MAX: A Software Fix Might Not Be the Complete Answer A very talented mechanic in the food processing industry once explained to me that there would always be those who knew how to do a thing (think highly skilled engineers in the case of the 737 MAX) and those who knew what to do; think generalists with less specialized knowledge, but across a wider range of disciplines, those whose talents and interests allow them to “think outside the box”. I think this element may be missing in the search for solutions in case of the 737 MAX. A few… Read more »