Aircraft belts

With airplane crash most people die and no belts could help. The idea was if we have longer belt path we could reduce the g-force. Anyway, it could be useful for slower vehicles.

My calculation of the speed and g: 

1 there is a difference in g-force direction a human can survive. From 3g in negative to 10g front impact. 

http://en.wikipedia.org/wiki/G-force

but for impact surviving we will count 50g as max level 

http://hypertextbook.com/facts/2004/YuriyRafailov.shtml

With the formulas V=a*t and S=(g*t^2)/2
If we have to stop with 50g from initial 900 km/h (250 m/s) you need 5 seconds and 625m. 

If we hope the pilots would able to reduce the speed to take off level (~200km/h) it is still 1.1 sec and 31m.

So the idea could only help in case the plane may drag on surface for a few seconds - which is likely. 

Here we have airbags - they could be inflated before the impact (assume we have 40 sec to fasten the special belt).  The belts are X shape like in speed cars and have different length. Both of them expand slowly with precise acceleration (mechanism could be in the chair). The orange will release slower and not as far away - working as turning point. The pink one would go further and be softer (like the new car belt type -  inflatable itself). The front could have shape to help lift the passenger. The bottom bag could be piston inflated (on 2nd stage) also to lift the person.  The overall safety effect due to distance.