I swim with a man who spent 30 years at United Airlines in the maintenance department. We talked about the tragic plane crash in Medellin. He told me the following:
1) The pilot broke a basic rule of aviation that every pilot should know. You never plan a flight that goes to the maximum range of the aircraft. On every flight, unexpected things happen and one needs to keep a good reserve of fuel to cover things like bad weather where you have to wait a long time to land or divert to another airport, etc. This flight was at the maximum range of the aircraft.
2) When there is an engine failure on a passenger aircraft, all hydraulics and electronics shut off. (Like if your engine went out while you were driving your car and your power steering and power brakes fail.) Now here is something amazing that I didn't know after flying over 48 years on military and civilian aircraft. At the point of engine failure, the pilot is supposed to activate a propeller that deploys below the bottom of the body of the aircraft. The wind spins this propeller. Electricity is generated to allow the pilot to control the aircraft and have full use of electronics. This is to allow the pilot to glide the aircraft to a landing on the airfield or a safer place where there will be less damage to the aircraft and injuries to the passengers. The pilot failed to deploy this propeller.
3) The pilot in this case was the owner of the aircraft leasing company. He should have known better.