37 Years ago today: On 27 November 1983 an Avianca Boeing 747 crashed while approaching Madrid, killing 181 out of 192 occupants.

Date:Sunday 27 November 1983
Type:Silhouette image of generic B742 model; specific model in this crash may look slightly different
Boeing 747-283B
C/n / msn:21381/311
First flight:1977-08-24 (6 years 3 months)
Total airframe hrs:20811
Engines:Pratt & Whitney JT9D-70A
Crew:Fatalities: 19 / Occupants: 19
Passengers:Fatalities: 162 / Occupants: 173
Total:Fatalities: 181 / Occupants: 192
Aircraft damage:Destroyed
Aircraft fate:Written off (damaged beyond repair)
Location:12 km (7.5 mls) SE of Madrid-Barajas Airport (MAD) (   Spain)
Phase:Approach (APR)
Nature:International Scheduled Passenger
Departure airport:Paris-Charles de Gaulle Airport (CDG/LFPG), France
Destination airport:Madrid-Barajas Airport (MAD/LEMD), Spain

Avianca Flight 011 took off from Paris-Charles de Gaulle (CDG) at 22:25 for a flight to Bogotá (BOG) via Madrid (MAD).
The Boeing 747 climbed to a cruising altitude of FL370. At 23:31 the crew contacted Madrid ACC, receiving clearance to continue to the Madrid VOR via Pamplona, Barahona, and Castejón. Fifteen minutes later the flight was cleared to descend to FL190. At 23:52 they were cleared down to FL90: “Avianca 011 está pasando Barahona, proceda ya directo a Charlie Papa Lima, y continúe descenso para el nivel nueve cero, cambio.”
After contacting Madrid Approach ar 23:56 they were cleared for a runway 33 approach. After reaching FL90 at 00:00 they were cleared further down. Madrid Tower at 00:03 then cleared the flight to land. Instead of turning right at the Madrid VOR, the crew initiated a turn short of the VOR beacon. The aircraft descended below the MDA for that area.
The right main gear and no. 4 engine contacted a hill at an altitude of 2247 feet and a speed of 142 knots. Three seconds later the aircraft impacted a second hill at a speed of 135 knots and a 4,9deg. nose-up attitude. Six seconds after contacting the second hill, the aircraft (at 126 kts) hit the ground with the right wing, which broke off. The Boeing cartwheeled, broke in five pieces and came to rest upside down.

Probable Cause:
PROBABLE CAUSE: “The pilot-in-command, without having any precise knowledge of his position, set out to intercept the ILS on an incorrect track without initiating the published instrument approach manoeuvre; in so doing he descended below all; the area safety minima until he collided with the ground. Contributory factors were: a) Inaccurate navigation by the crew, which placed them in an incorrect position for initiating the approach manoeuvre.; b) Failure of the crew to take corrective action in accordance with the operating instructions of the ground proximity warning system.; c) Deficient teamwork on the flight deck.; d) Imprecise position information supplied to the aircraft by APP.; e) The APP controller, in failing to inform the aircraft that radar service had terminated, did not maintain a proper watch on the radar scope.” (Accident Investigation Board, Spain)