Interesting/worrying story from Scotland - ZS with no brakes.

[johnb80]

737 Max is a bad example of software malfunction.

A good example of poor design and testing, it was a combination of poor software and having a single sensor / system with no redundancy.

The crashes were down to a sensor failing without redundancy or fault detection. The software did exactly what it was meant to do, but it was reacting to an erroneous input.

Exactly the point i was making to Tim green.

Exactly right. And mind boggling that the engineers were willing to rely on one sensor for such a safety critical application.

Absolutely, dreadful regime of self certification being allowed too, nightmare situation, bad day at the office for the crews and unfortunate passengers.

 

[Tim Green]

Unfortunately the regime of "self-certification" reached its conclusion with this awful outcome. I'm afraid two planeloads of passengers does not constitute a bad day at the office. Boeing still flying and making billions is an affront to us all.

 

[johnb80]

Unfortunately the regime of "self-certification" reached its conclusion with this awful outcome. I'm afraid two planeloads of passengers does not constitute a bad day at the office. Boeing still flying and making billions is an affront to us all.

I was booked on flight and the aircraft was a 737 max, I refused to take flight, I was warned I would lose my money but I thought it was better than risking my life. I waited, booked a later flight which was on an Airbus.

 

[Tim Green]

Well done you.. I dread to be offered a place on 737max and having to make that awful choice. With Boeings resources I still cannot understand why they chose to compromise their reputation, and that of the previously excellent 737 by such an ill thought modification. The use of software to try to attempt to cancel out poor airframe design is the sort of thing that happens in companies with no cash.

 

[Rolfe]

Still a big question as to whether the Lockerbie bomb really should have caused the mid-air disintegration of a 747 Jumbo Jet. It basically peeled open like an orange.

 

[johnb80]

Still a big question as to whether the Lockerbie bomb really should have caused the mid-air disintegration of a 747 Jumbo Jet. It basically peeled open like an orange.

Explosion, rapid decompression and the speed it was travelling at I would have thought it ripping apart would be a given. Once on the way down out of control, VNE (Velocity Never Exceed) will have been exceeded causing further airframe damage. At least it would have been a very quick end for the people onboard, absolutely tragic event for all involved.

 

[Rolfe]

What actually killed it was overpressure in the restricted space between the skin of the plane and the "inside walls". This caused the skin of the plane to peel open. The AAIB report is quite fascinating when it discusses this unexpected phenomenon and whether it could have been prevented.

I think there was also a weakness in the airframe that caused the plane to break in half very early on.

I'm not so sure about the quick end either. Most of the passengers were alive until they hit the ground. I went to the 25th anniversary church service and at 7.04 the minister just stopped speaking. He resumed at 7.07. That was the time from the bomb going off to the bodies hitting the ground. It seemed like ages in that quiet church. The time of death on the death certificates was 7.07. The report said that while people would have lost consciousness quickly on being exposed to 31,000 feet with no oxygen, many would have regained consciousness as they fell into breathable air. It's absolutely horrible.

 

[Vince31]

Saw this today on a ZSEV forum FB post (it's not from me)

"Today my wife was driving to work, the car in front slowed down, she obviously braked. Nothing happened. She had to steer off the road to avoid the car in front, so the car ended up on the bank at the side of the road. A few minutes later another motorist stopped to check she was okay and pointed out that the front wheels were still being driven by the motor! Her foot wasn't on the pedal, and she hadn't been using cruise control. We've had this car less than 2 months and already had a breakdown a few weeks ago and now this happened. I've seen the stories about brakes failing before and kind of dismissed it as nonsense but now it's happened to us.

The app shows a brake system warning at the time of the collision, but doesn't really give any extra information."

 

[Fluffykins]

If the vehicle is still in Drive (or reverse) it'll still try to creep even with no foot on the accelerator, in the same way as almost all automatics.
It'll be interesting to see what the final diagnosis is. I know there have been reports if MG5s (IIRC) having an improperly secured brake hose (rear wheel I think), which gets chafed through by the rim of the alloy wheel. If you can have a quick look it might be illuminating.

 

[Coulomb]

Saw this today on a ZSEV forum FB post...

Could this be an anti-EV FUD post on Facebook?

If you can have a quick look it might be illuminating.

The poster didn't have the problem, they merely quoted a Facebook post. It likely never actually happened.

 

[Fluffykins]

The poster didn't have the problem, they merely quoted a Facebook post. It likely never actually happened.

Well, it certainly happened on an MG5, as writ in these hallowed threads:

Rear Flexible Brake Pipes

I had the rear wheels off today and noticed what looks like a piece of poor design. With the suspension hanging, this flexible pipe is being put under an enormous strain. Future point of failure I suspect. The fronts don't have this problem BTW.

www.mgevs.com

 

[tsedge]

If anything like this happens in real life, pull hard and hold on the parking brake, it should come on.

 

[chowbenter]

Has there been any news lately about the original story from either MG Motors or the chap involved? It seems to have gone quiet on the matter.

 

[Lovemyev]

Has there been any news lately about the original story from either MG Motors or the chap involved? It seems to have gone quiet on the matter.

I asked the same question on the last pod cast about two weeks ago and Miles said he was conversant with the situation and gave his own thoughts on the subject, but he had seen no further information from MG on the subject unfortunately.
Surely the insurance company would have completed their investigation by now at least ?.

 

[DudeMG]

I called MG a couple of weeks ago, and please note that the brakes on an MG ZS EV are cables, meaning the only way for the brakes to fail is another issue, like hydraulics.

I've had my MG ZS EV for 12 months, no issues at all.

 

[Lovemyev]

I called MG a couple of weeks ago, and please note that the brakes on an MG ZS EV are cables,

Of course we are making reference to the handbrake on the MG ZS EV here ???.
If so, then just to clarify, the ZS EV’s handbrake is totally electronic and is operated by two independent actuator motors.
The two motors are bolted to each of the rear brake callipers.
When the handbrake is applied, both of the motors turn and this applies a pressure onto the friction brake pad, which then contacts onto the steel brake disc(s).
You can hear the electric motors engage and release with the handbrake is operated.
The MG ZS ( ICE ) has a manual handbrake and IS therefore operated by cables.
I know this information because one of the actuator motors failed on our ZS EV ( Gen 1 ) and the handbrake could not be release from the N/S/R wheel.
The motor was removed by the guy from the A.A. and it has stripped out the drive spline.
I held the motor in my hand !.
Rear calliper and motor both replaced under warranty, but the job had taken almost four weeks due to the slow delivery of parts from China.
Cost of the parts were under £150 plus about two hours of labour I would think.
Four weeks hire cars cost to MG - Expensive !.

 

[dspencer12345]

If anything like this happens in real life, pull hard and hold on the parking brake, it should come on.

But the parking brake is a button in the ZS isn't it?

 

[Susanna]

@dspencer12345 it’s more like a piano key - I think you pull it upwards and hold if you need to stop the car in an emergency.

 

[Lovemyev]

 

[johnb80]

Still nothing in the media about this guys 'horrendous ordeal' with loss of brakes and car not stopping.............. Somewhat suspicious I'd say.