52 Years ago today: On 2 December 1970 a Cargolux Canadair CL-44 crashed into farmhouses near Dakha, Bangladesh, killing all 4 occupants and three on the ground.

Date:Wednesday 2 December 1970
Time:10:00 GMT
Type:Silhouette image of generic CL44 model; specific model in this crash may look slightly different
Canadair CL-44J
Operator:Cargolux
Registration:TF-LLG
MSN:36
First flight:1964-03-25 (6 years 8 months)
Engines:Rolls-Royce Tyne 515
Crew:Fatalities: 4 / Occupants: 4
Passengers:Fatalities: 0 / Occupants: 0
Total:Fatalities: 4 / Occupants: 4
Ground casualties:Fatalities: 3
Aircraft damage:Destroyed
Aircraft fate:Written off (damaged beyond repair)
Location:10 km (6.3 mls) NW of Dhaka-Tejgaon Airport (DAC) (https://cdn.aviation-safety.net/database/country/flags_15/S2.gif   Bangladesh)
Phase:Approach (APR)
Nature:Cargo
Departure airport:Tehran-Mehrabad Airport (THR/OIII), Iran
Destination airport:Dhaka-Tejgaon Airport (DAC/VGTJ), Bangladesh

Narrative:
The Canadair CL-44J transport plane departed Luxemburg Airport at 14:00 GMT on December 1 and flew to Hamburg in Germany were it was loaded with 27,5 tons of child food. These Swiss Red Cross supplies were to be flown to Dhaka, East-Pakistan (now Bangladesh) to help victims of floodings.
A refueling stop was made in Tehran, Iran, were it left the following day at 01:30 GMT. About 10:00 GMT, the pilot lost control of the airplane while on approach to Dhaka-Tejgaon Airport. The CL-44 crashed into farmhouses. Three persons on the ground were killed, along with the entire crew of four.
It appeared that the hydraulic gust lock system activated in flight, causing the controls to lock. It was speculated that hydraulic back pressure had built up caused by a malfunctioning switch valve when hydraulics were armed on descent.