GB, CPB; The Aviacsa #4 engine failure was due to oil starvation (maintenance error).
Although the indications to the crew were of three engines inoperative (collateral damage), in fact only two stopped (#3 & 4).
The landing was made with without hydraulics – no flaps, airbrake, spoiler, and main brakes. The pitch trim was inoperative, several instrument failures, holes in the fuel tank, fuselage, and wing mainspar, and there was a small fire in the cabin!
The 146 has suffered multiple engine failure/shutdowns events. All, except one birdstike, were associated with high altitude icing (and subsequent crew action); all engines have been modified to provide enhanced anti-icing.