Jumbo Driver and Rainboe - I agree. The Wright brothers didn't have a Radio Altimeter. either.
If the wings were undamaged and contained some fuel, and the engines working and still controllable to some degree, that was all the crew needed to land on an airfield that they could see. Anything else was a bonus.
There may be very valid reasons why the crew got themselves into the position that they did, time will tell, but trying to blame electronics and computer systems is like the Supermarket clerk being unable to work out my change because " the computer is down"
Must go, my mobile phone has apparently received a text, and I need to find a passing 5 year old to work it for me.