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[UPDATED] 2 die in Tesla crash - NHTSA reports driver seat occupied

EVNow

Well-Known Member
Sep 5, 2009
11,540
32,145
Seattle, WA
We will probably never know, but my guess is this was a case of hitting accelerator when the driver though he was hitting the brake.

Reads like he was pressing the accelerator till the end and never slammed the brakes. So, possible he hit the accelerator instead of brake when turning.

With the assistance of the EDR module manufacturer, the NTSB Recorders Laboratory repaired and downloaded the fire-damaged EDR. Data from the module indicate that both the driver and the passenger seats were occupied, and that the seat belts were buckled when the EDR recorded the crash. The data also indicate that the driver was applying the accelerator in the time leading up to the crash; application of the accelerator pedal was found to be as high as 98.8 percent. The highest speed recorded by the EDR in the 5 seconds leading up to the crash was 67 mph. [3]
 

Dan D.

Member
Dec 7, 2020
854
1,059
Vancouver, BC
Did he crawl, or was he bounced back there? In high impact collisions, bodies don’t necessarily stay where they were initially situated. We still don’t know enough to speculate. Seat belts generally keep you from impacting with the steering wheel, so I’m wondering if he did what my mom was fond of doing back when seat belt alerts first started coming into vogue, leaving The seatbelt buckled in all the time while she just sat on top of it so the car would stop nagging her. I eventually convinced her to stop doing it, but I know of a couple of people who still do that crap, even though it’s just stupid.
"was he bounced back there". No way. They hit a tree head-on, the car resting against it - no rebound. He bent the steering wheel over. Behind the wheel is where he started and where he was after crashing, airbags vent as they inflate and you collide with them, they cannot push a heavy body which possesses considerable forward momentum. The miracle is he was able to get out of that position at all.
 
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SMAlset

Well-Known Member
Mar 4, 2017
9,242
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SF Bay Area
Don’t you think if they weren’t wearing seat belts that at nearly 70mph they would have flown through the windshield. Also re-read the autopsy reports and damage to torso area in particular, sure there’s some consistency with injuries and setbelt use. Driver also ended up seated in rear seat in normal seated position and front seat was in upright position.

My suspicions would be that upon 67mph impact passenger restrained still lurched forward. Found with arms at dash. Likely died on impact. Driver even restrained also lurched forward. Tall guy and head/chest hit steering wheel with force to bend it. I’d guess he was knocked out initially and since battery fires upon impact don’t ignite immediately (ie. in Mt. View Model X, similar speed I think into solid object), driver impaired (and drunk drivers do sometimes walk away from horrible accidents due to relaxed body) came to after a few minutes and fire and toxic smoke had started entering the cabin and he managed to get unbuckled and crawled to back, collapsing into the rear seat while trying to breathe. I think the air sucking fire and smoke filling the cabin made it impossible to do much more at that point. With his head up near the roof (found sitting upright from what I recall from accident/autopsy reports) it would have been suffocating him.

I’d have no problem with a change to rear seat door locks. Not at all. We have a 2017 Model S and while we read the manual before picking up and acquainted ourselves with the car when we got home, we were both surprised by its rear door hidden latch location and made a point of finding it ourselves in the car. I just don’t think he had a chance to even find the latch. Heck pulling down one of the rear split seat, moving further from the fire and trying to exit out the trunk would have been doable under normal conditions.
 
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SMAlset

Well-Known Member
Mar 4, 2017
9,242
10,118
SF Bay Area
Reads like he was pressing the accelerator till the end and never slammed the brakes. So, possible he hit the accelerator instead of brake when turning.

I know they said in the last 5 seconds his foot was on the accelerator (fully almost) but don’t think we know if he might have tried braking before then, like if an animal crossed in front of him.
 

Dave EV

Active Member
Jun 23, 2009
1,909
1,585
San Diego
So, in 400' they accelerated to 67 mph, tried to turn but couldn't (assuming its too tight for 67 mph ?) and crashed. Less than 700' in all. What a tragedy.


HWY21FH007-update-overhead-fig1.jpg

I ran some rough calculations - looks like the radius of the curve is around 72 meters. Maybe if he took a racer's line (outside-in-out) about 90 meters.

Assuming the car can pull 0.9g, max speed is 56-63 mph. At 67 mph, on a perfect path using all the road, that's 1.02g. Using the middle of the road (which they appear to have been doing), that's 1.27g. So it's no wonder they slid off the road, they were going too fast.
 

Zacster

Member
Sep 11, 2017
278
138
NYC
One thought I had on the accelerator being pressed is that the regenerative braking changes the way you use the pedals. I almost never use the brake pedal myself although my reaction is still to use it in quick braking. He could have been disoriented about what he was doing based on his new normal driving habits.
 

SomeJoe7777

Marginally-Known Member
Mar 28, 2015
2,199
5,803
Houston, TX
I ran some rough calculations - looks like the radius of the curve is around 72 meters. Maybe if he took a racer's line (outside-in-out) about 90 meters.

Assuming the car can pull 0.9g, max speed is 56-63 mph. At 67 mph, on a perfect path using all the road, that's 1.02g. Using the middle of the road (which they appear to have been doing), that's 1.27g. So it's no wonder they slid off the road, they were going too fast.

The Model S is deceptive in it's stability. Being so responsive and quick, as a driver you will come to think that the vehicle is glued to the road. However, it also weighs close to 5000 pounds. Once you manage to lose grip on all 4 tires, the weight of the car makes it very difficult to recover.

This car lost traction on all 4 wheels due to the excessive speed as you've calculated, and then understeered straight off the road, pure and simple. The only possible opportunity for recovery was to remove power and bleed off speed on the concrete, but once the vehicle left the roadway and was in the grass, there was virtually no way to regain control. At that point, it's 5000 pounds of metal that's sliding at 67 MPH and it's gonna behave exactly like physics predicts -- not going to change direction and not going to stop until it hits something.
 

Dan D.

Member
Dec 7, 2020
854
1,059
Vancouver, BC
I ran some rough calculations - looks like the radius of the curve is around 72 meters. Maybe if he took a racer's line (outside-in-out) about 90 meters.

Assuming the car can pull 0.9g, max speed is 56-63 mph. At 67 mph, on a perfect path using all the road, that's 1.02g. Using the middle of the road (which they appear to have been doing), that's 1.27g. So it's no wonder they slid off the road, they were going too fast.
Agreed, those numbers are what I get also. The driver could have made that corner before at 55mph but 67 was too much.

Dunes.png
 
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MikeyC

Member
Aug 19, 2019
411
587
Florida
Some new questions arise from this latest information. EDR recorded that both front occupants were wearing seatbelts at the time of impact. Yet earlier investigations found that all seatbelts were unbuckled at the scene (after impact). That would certainly indicate that at least one of them was trying to get out which would back up the evidence that the driver was found in the rear seat of course. Next, it sounds like the "impact" of a persons body is what deformed the steering wheel. Is this expected when we know the driver was buckled? I mean, while wearing a seatbelt, is it possible enough mass (kinetic energy) could make it through the seatbelt (and airbag) to bend the steering wheel with the seatbelt on?

Mike
 
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mongo

Well-Known Member
May 3, 2017
13,787
44,160
Michigan
Some new questions arise from this latest information. EDR recorded that both front occupants were wearing seatbelts at the time of impact. Yet earlier investigations found that all seatbelts were unbuckled at the scene (after impact). That would certainly indicate that at least one of them was trying to get out which would back up the evidence that the driver was found in the rear seat of course. Next, it sounds like the "impact" of a persons body is what deformed the steering wheel. Is this expected when we know the driver was buckled? I mean, while wearing a seatbelt, is it possible enough mass (kinetic energy) could make it through the seatbelt (and airbag) to bend the steering wheel with the seatbelt on?

Mike
The airbag must react against something... So all the force of the driver against the airbag will get imparted to the wheel. Three point restraints do not prevent right shoulder lead torso twisting, plus the curve of the road would push the driver away from the shoulder attach point.
 

bobby g

Member
Mar 13, 2020
367
210
The Inland Empire :)
"was he bounced back there". No way. They hit a tree head-on, the car resting against it - no rebound. He bent the steering wheel over. Behind the wheel is where he started and where he was after crashing, airbags vent as they inflate and you collide with them, they cannot push a heavy body which possesses considerable forward momentum. The miracle is he was able to get out of that position at all.
Agreed and with both belts buckled, it would have taken human action to move at all.
 

SMAlset

Well-Known Member
Mar 4, 2017
9,242
10,118
SF Bay Area
I thought there was early discussion partially based on reports that they couldn’t tell if the seatbelts had been used for certain because the front of the car experienced such high temps that the seatbelt material had burned/melted away, and they were hoping to pull seat and seatbelt info from the car’s recordings of data.

Me, believing the driver had survived the crash and came to, I thought being a doctor and with his good friend there with him, he would have tried to check on him (vitals etc), maybe even releasing his seat belt in an effort move him at first. But he realized the friend had passed from the impact, and the fire and smoke forced him to retreat to the rear. Again, no idea, even after the NTSB report, if we’ll know more of what the driver’s actions were.
 
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SMAlset

Well-Known Member
Mar 4, 2017
9,242
10,118
SF Bay Area
Wouldn’t a firm grip holding and pushing forward on the steering wheel at time of impact with body weight behind the arm muscles be enough to push the circular wheel portion in one direction while the car’s impact force pushing in the opposite direction on the steering column be enough to deform the wheel even with airbag deployment?
 

Occar

Member
Jun 20, 2019
164
265
TN
Assuming the car can pull 0.9g

I assume you got this from some skidpad test, but that's a bad application of that value. Skidpad numbers are only valuable for direct comparison with other vehicles. They in no way give you the max controllable lateral acceleration for arbitrary curves. I'm not saying your conclusion is necessarily wrong (too fast for the curve), but your reasoning is based on a completely arbitrary number in regards to this specific scenario.
 

Dave EV

Active Member
Jun 23, 2009
1,909
1,585
San Diego
I assume you got this from some skidpad test, but that's a bad application of that value. Skidpad numbers are only valuable for direct comparison with other vehicles. They in no way give you the max controllable lateral acceleration for arbitrary curves. I'm not saying your conclusion is necessarily wrong (too fast for the curve), but your reasoning is based on a completely arbitrary number in regards to this specific scenario.
Yes, it's a skidpad number. 0.9g is a pretty typical number for a sedan. Yes, it's comparing two completely different road surfaces - with the skidpad normally being a fairly decently clean/prepped surface so it should represent a number that a vehicle can sustain in good conditions.

Obviously with this being real world, the actual lateral forces the car would be capable of on this particular road is likely to be lower. Also, it's not clear what condition the tires/wheels were in, either. Maybe it had fairly fresh PS2s. Or maybe it had bald, generic all-seasons.

Lots of variables - the intent was to see if the car had any chance of holding the corner at the reported speeds. All signs point to no.

If you have reason to believe otherwise - let's hear it.
 
Mar 18, 2016
176
149
SF Bay Area
This may have been discussed, but the timing of the latest news release from CNBC was about one day after earnings, and about 6 months after the accident, which was reported about two weeks before Q1 earnings. At first glance, the original report had inferences that Tesla may have been "at fault", no driver in the seat, autopilot on, etc. Then, 6 months later, the day after an earnings blowout despite daily upward revisions to earnings estimates, CNBC reports driver in the seat (according to "officials") and someone in the car was over the legal BAC limit. Way to come clean CNBC, 6 months after the fact. Phil, their EV expert has zero credibility with me.
 

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