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Old 3rd August 2015, 20:44   #31
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Default Re: Mahindra XUV500 W8: Severe topple, but Side Airbags didn't deploy!

The car's structure collapsed in a manner that saved the occupants which is a good thing. However still no excuse for side and curtain airbags not deploying. M&M will need to look into this.

Here are tips for people driving on highways in the rain:
  • Try to keep the speeds down trust me, driving in the wet is an entirely different ballgame and remember that once one loses control of the car it is very nearly impossible to regain control. So its always best to travel a good 30% slower than you normally might.
  • Never use Cruise Control
  • If you see a big patch of water, slow down or try to avoid it. Even if you know the road is fine.
  • If you sense your car is aquaplaning, drop some gears to gain engine-braking and DO NOT slam the brakes; let engine braking do its bit to shift weight and slow the car down progressively till you regain control of the car
  • Always maintain accurate tyre pressures

Last edited by IshaanIan : 3rd August 2015 at 20:45.
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Old 3rd August 2015, 21:27   #32
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Default Re: Mahindra XUV500 W8: Severe topple, but Side Airbags didn't deploy!

Quoting a reply from a friend .

Quote:
ESP, ABS, EBD, roll over mitigation" all work only when wheels have traction. When a vehicle is aquaplaning, it does not respond to steering, brake or accelerator input because there is no traction. Only thing that will help is the driver's sensibility in adverse driving conditions. Buying the top most variant which has "all the safety mumbo-jumbo" and expecting never to crash is foolish.

Side and curtain airbags work when the crash sensors detect a side impact, and usually only the airbags on that side are inflated. A roll over would not register the same reading as a T-bone impact since it dissipates energy more slowly.

To set off the side/curtain airbags in a roll-over, you'd need a roll sensor as well as airbags that can stay inflated for longer. If the sensor determines that a roll is imminent, it can inflate the airbag even before the vehicle's door touches the road.

Regards,

Niranjan
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Old 3rd August 2015, 21:46   #33
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Default Re: Mahindra XUV500 W8: Severe topple, but Side Airbags didn't deploy!

Let me be honest here. I feel pretty uneasy when driving on the highways in the vicinity of these nervy Indian tall boys: Xylo/Quanto/Scorpio/Safari/XUV. I try and stay away from them whenever possible. High center of gravity along with rather uninspiring technical prowess of their manufacturers, weigh at the back of my mind.

The erstwhile Scorpio was more than happy to topple, courtesy -- a yawn, cough or sneeze by a passenger. I have seen many of them turn turtle on highways. My ex-colleague had been jolted by once such incident too.

Last edited by B103 : 3rd August 2015 at 21:52.
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Old 3rd August 2015, 23:05   #34
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Default Re: Mahindra XUV500 W8: Severe topple, but Side Airbags didn't deploy!

Quote:
Originally Posted by shankar.balan View Post
When you look at this vehicle, you wonder how anyone at all could have survived!
This is one of the reasons that I am very glad I did not go the XUV route, though I have been an M&M loyalist for years.
It looks like contradiction to me - apologies.
If one sees the car in that shape and learn that the occupants walked out, the car earns one's respect instantly. Isn't it?
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Old 3rd August 2015, 23:18   #35
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Default Re: Mahindra XUV500 W8: Severe topple, but Side Airbags didn't deploy!

Glad to know the occupants of the car are okay.
The curtain airbags not deploying is without a doubt, a technical error, and not a condition of the sensors not getting the intended go ahead.

Firstly, the XUV500 has fancy systems such as Rollover mitigation alongside ESP which shouldn't have let the car lose grip at such measly speeds. Then, even if these systems failed, and the XUV doesn't have a rollover sensor for airbag deployment, hitting that tree should have done it.

I have a feeling this is somehow related to the curtain airbag related recall done by Mahindra. http://www.team-bhp.com/forum/indian...upgrade-3.html (Mahindra XUV500 recalled for side airbag software upgrade)

The statement mentioned that there might be a fault code that could prevent the activation of curtain airbags in certain conditions. My question to you is, was your friend's car involved in the recall?

If it was recalled, but didn't get the software updated then the case is probably solved. But, if it did, or wasn't recalled, Mahindra better be scared.
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Old 4th August 2015, 01:32   #36
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Default Re: Mahindra XUV500 W8: Severe topple, but Side Airbags didn't deploy!

First of all great to know that everyone escaped with minimal injuries except for slip disc on one. Seems like atleast everyone was wearing seat belts otherwise things could have been much worse.

Now regarding the structural integrity of the car, I think the structure did very well to absorb all the impact ~100 kmph. Thats the reason passengers survived and not just by sheer luck. For a car which weighs 1800kg and 5 passengers, you are looking at potential 2+ tons. The amount of energy and momentum involved could have easily resulted in fatal injuries had the structure not dissipated that. I am amused that people expect the car to retains its shape after such an accident and doubting its structure.

Side airbags not deploying however seems like an issue here which needs to be understood and explained. Hitting a tree sideways should amount to a T-bone accident with similar forces. The pic show side entirely caved in due to the force.

Hope Mahindra gives a proper response about this.
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Old 4th August 2015, 01:45   #37
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Default Re: Mahindra XUV500 W8: Severe topple, but Side Airbags didn't deploy!

Firstly, when then the car aqua planes, it aqua planes at that particular moment, I am sure he was not driving over a river for it to continue to aqua plane, of course wrong driver inputs would get you deeper into a rut. I have aqua planed many times and it happens momentarily and then you gain traction back and at that moment systems like Roll Over Mitigation and ESP come into play if you lose control of your vehicle otherwise it's pointless thing to have in the first place. Roll over mitigation works on the similar principle as ABS with targeted braking on individual wheels.

Secondly, the side impact airbags are meant to deploy during a roll over, everyone can't have a front crash always.

Something needs to be investigated here.
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Old 4th August 2015, 02:57   #38
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Default Re: Mahindra XUV500 W8: Severe topple, but Side Airbags didn't deploy!

Firstly, wishing the occupants a speedy recovery both mentally as well as physically who are indeed very lucky to have survived such a horrific crash.

Now coming to the question why the side airbags didn't open.

Attaching a video of the new vitara being crash tested.



The video has a side impact crash test. If we see carefully at the way the impact has happened in the crash test the B Pilar and the floor has been pushed which in turn triggered the side and curtain airbags to open.

Now if we turn back to the XUV we see that the floor of the car and the lower half of the B pillar hasn't suffered much damage in comparison to the rest of the car. The B pillar has in fact bent rather than crumpled.

The floor and the B pillar didn't suffer sufficient damage or get the necessary impact force to deploy the airbags. If the tree hit the B pillar instead of the rear the side and curtain airbags should have deployed. Airbags open when the sensors detect a rapid deceleration or a sudden external force which deploys them in turn.

The front airbags didn't open because the car didn't stop all of a sudden/ suffer sudden deceleration by a frontal impact.

Further i doubt that the XUV has any airbags sensors near the roof. As mentioned in another post for side/curtain airbags to open in such a freak accident a roll over sensor would be required which could sense trouble coming and inflate in advance.

Regarding the ABS/EBD they can't do anything without having contact with the road as soon as the car suffered from hydroplaning it lost all control from the ground leaving the driver aids helpless.



The video shows that the ESP works to give the driver control in situations where a sudden action may lead the car to go in a spin due to understeer or oversteer. But the system can't help when a car is going straight and suddenly loses contact with the ground.

The only question that i can't answer is regarding the TCS which is in place to prevent this very incident. Maybe the module failed or the tyres were too far gone for the Traction control to be of any assistance. If the TCS was working it would have blinked on the dash indicating loss of traction and the driver should slow down in this case. However, i see that the car was doing 90 km/h which means that either the driver ignored the warning or simply didn't know what it meant or the TCS failed.

Here is a video showing Jeremy Clarkson hydroplaning in a bmw 1 series which has all of the driver aids that the XUV had and some more.

Last edited by rockporiom : 4th August 2015 at 03:20.
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Old 4th August 2015, 08:47   #39
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Default Re: Mahindra XUV500 W8: Severe topple, but Side Airbags didn't deploy!

Quote:
Originally Posted by rockporiom View Post
Here is a video showing Jeremy Clarkson hydroplaning in a bmw 1 series which has all of the driver aids that the XUV had and some more.
Reading through the thread I was just about to post this BMW video!

But, the thing I am wondering about is that 'was every occupant of the car belted up'?
If they didn't there is a fat chance that it's the reason the airbags did not deploy.
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Old 4th August 2015, 09:27   #40
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Default Re: Mahindra XUV500 W8: Severe topple, but Side Airbags didn't deploy!

Looking at the condition, it is indeed a miracle that the occupants are safe!
The way the roof has collapsed makes me to think how strong is the cabin structure of the XUV. Aren't they supposed to remain intact upon toppling? What makes the car manufacturers to not pay attention to this aspect, while there is lot of emphasis on being able to withstand the frontal collisions?
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Old 4th August 2015, 09:29   #41
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Quote:
Originally Posted by raj_5004 View Post
That body shell saved all the occupants of the car inspite of the spin and roll over and without airbags. I would call it a well designed body shell.

The XUV has a 4* crash test rating which is not at all bad for a SUV.

I am really curious why the side airbags did not deploy though. Is it possible that the rear passengers did not wear seat belts and that is the reason the side airbags were not triggered?
Agree.. Since the occupants were able to come out from such a crash, I will say that the car's body shell has done its duty. Usually deformity of any part shows that it has absorbed the impact forced on it rather than transfer it to the occupants.

Seatbelts could be a concern here because in modern cars they are linked with airbags. Unless the occupant was belted in, airbags won't deploy.
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Old 4th August 2015, 09:47   #42
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Default Re: Mahindra XUV500 W8: Severe topple, but Side Airbags didn't deploy!

Not all cars have side airbags which are deployed when a car rolls over. The reason why they didn't deploy when the car hit the tree could be that the fuel and ignition was turned off to prevent fire. As for ESP,how will the system work when the tyres have lost contact from the road?
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Old 4th August 2015, 09:58   #43
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Default Re: Mahindra XUV500 W8: Severe topple, but Side Airbags didn't deploy!

The most important thing in a crash is if the occupants have come out safe and not if the airbags have popped or not. If a car has saved 5 people in such a deadly crash at such a high speed, it is amusing to see people abusing the manufacturer for low cost manufacturing!

It has been repeatedly said across many threads and posts in this forum that Airbags will not inflate in EVERY crash. However gruesome the crash "looks", it does not matter. Airbags will inflate only under the preset conditions - occupants being belted up and the crash sensors being activated. In this case, we are not sure of either of this.

Secondly, ESP, TCS, Rollover mitigation, etc. are features which can help the driver avoid a crash, but to a certain extent. Just because the car has rollover mitigation does not mean it will NEVER roll over!

Even before this incident, because of similar accidents, the same accusations were put on different manufacturers like Toyota, Honda and Mercedes!

Examples -

http://www.team-bhp.com/forum/indian...nt-deploy.html (Toyota to pay 25 lakhs for Fortuner Accident (airbags didn't deploy))

http://www.team-bhp.com/forum/techni...eploy-why.html (Frontal Crash - Airbags didn't deploy. Why?)

http://www.team-bhp.com/forum/street...-trap-2-a.html (Bizarre: Honda CR-V airbags don't deflate, become death trap for 2)

Do we want Airbags to inflate at the slightest excuse? Like here -

http://www.team-bhp.com/forum/techni...-accident.html (Brand new Skoda Octavia: Curtain Airbags deploy without impact / accident!)

http://www.team-bhp.com/forum/techni...nding-why.html (Airbags deployed after hitting a dog. Understanding why?)

Frankly, I am pretty sure that the rear seat passengers were not belted up. It is based on my assumption that nobody in India belts up in the rear seats. Will the side airbags inflate if the passengers have not worn the seat belt?

The most reliable safety feature in a car is the driver.

Last edited by raj_5004 : 4th August 2015 at 10:10.
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Old 4th August 2015, 10:01   #44
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Default Re: Mahindra XUV500 W8: Severe topple, but Side Airbags didn't deploy!

Quote:
Originally Posted by RavSam View Post
Reading through the thread I was just about to post this BMW video!

But, the thing I am wondering about is that 'was every occupant of the car belted up'?
If they didn't there is a fat chance that it's the reason the airbags did not deploy.
If the occupants were not belted up and came out of "this" with minor bruises, then car is absolute safe haven or it is just a miracle.

And I agree with most others here, car having many safety features is not a license to driving at unreasonable speeds with scant respect for weather and road conditions.

Very glad to know that all lives are saved. If I were the owner, I would buy an XUV again.
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Old 4th August 2015, 10:12   #45
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Default Re: Mahindra XUV500 W8: Severe topple, but Side Airbags didn't deploy!

People survived is the best thing that happened.
Cant find fault with the XUV here. IMHO excess of 50-60 kmph on a wet road is certainly calling for trouble. I cannot even take it/digest the statement that aquaplaning has happened here, the side of the road seems to be kachha and enough to soak up the water that drains from the other side of the road. One cannot drive at high speed and expect that all safety features of a car would protect their family.Non deployment of airbags should certainly be taken up by M&M and be inquired into.
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