Nightmare scenario from a pilot's PoV
I wrote this for my friends who like to pick my brain (7,000hr ATP) when a major crash happens. Total electrical failure at night over the mountains is up there with dual flameout in a blizzard for nightmare scenarios. In the following, I assumed that LaMia lost or couldn't find the ILS when the gens dropped offline.
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Medellin is one the worst places in the world to have a major electrical problem. If they lost the panel (flight instruments, lighting and generators) they'd only have a junky little magnetic compass for direction, airspeed, and altimeter. One of them would have to hold a flashlight and go back/forth between heading and the altimeter. I did this during captain upgrade and it's crazy difficult in a familiar setting with a flat airport at sea level. They'd also have to guess at the power settings based on their speed and pitch (nose high/low). The next step would be to get a radar vector to RNG @ 9.5 miles south of the airport and have ATC (air traffic control) tell them when they were over the VOR (radio station). This assumes their backup battery is fully charged and they have one good radio. No comms is death.
Then they'd have to use the PoS compass to fly outbound from RNG down to 11,000 ft. and make a turn back to the VOR. Then cross it and pray they are directly over the station. This is WW II style of navigation, which killed thousands in bad weather. Modern radar from ATC is not terribly precise for this maneuver either, even 75 years after it was invented. The U.S. has the good stuff (precision approach radar) but only on certain military bases. I got to practice with it once flying into Yuma, but it's a rare ATC service. The life saver with the PAR technology is that it's like looking down a gun barrel at the airplane. They can give detailed course corrections, like turn left 2 degrees, descend 50 ft., etc.
Back to the Lamia flight deck, now they have to manage a 750 fpm descent while doing the flashlight dance and a ton of mental processing is spent trying to correct speed/power while flying blind. Then they have to pray they shot the gap between the two hills at 8,100 ft. heading north to the airport. The backup compass bounces, esp. in bad weather and it's hard to hold a heading within 5 degrees, and easy to be off course. There was no wind on the surface, but all planes drift and there is roughly a 3 mile buffer each side of the approach center line. It's easy to drift several miles off course and ATC would have trouble seeing it and warning the pilots, if at all. The news stated ATC lost radar contact when the plane was at 15,000 ft.
This would be a stressful approach under normal conditions (with an autopilot which they probably lost) and worse late at night after a long flight in weather. I have to test this scenario on my PC sim and see if I can make it to 223 ft. above the airport without crashing on the first try. There was a cloud layer 1,500 ft. above the surface, which would make the airport impossible to see and require a full instrument approach. From the crash photos, it looks like they clipped a ridge then slid into a ravine and stopped halfway up the next hill. It's an old school, sturdy, British design which is probably why there are survivors. Lastly, there was financial stress on the company being out of Venezuela, so I'm curious about their maintenance history. The BAC 147 is a notorious hangar queen and hard to maintain.