As far as making an airliner recoverable you would have to decide if
the several tons of system to do this would not be better spent in
other areas.

The particular car I drive has the best breakdown record of any car
mainly because of its oversized battery.

The military might find such technology more usefull.

Ballistic recovery systems have had
successes on light planes and ultralights Otherwise, I have told him
that the
above have been proven to be impractical and even dangerous.

What is impracticable about them in larger vehicles. Be precise.

You pretty much hit the nail on the weight and safety; and of course cost,
unless madated. Commerical operators will spring for a 3000# entertainment
sustem for an airliner but not a 200# system that guards against electrical
shorts such as the one that brought TWA 800 down accoring to a recent
documentary on US TV. Also the overall cost has to be hustified in terms of
potential lives saved. The airlines use $2.6 million as a figure to calculate
cost vs benefit according to tht same documentary..