Flight Data Recorders were sent to Singapore, but got refused, then sent to Australia for read out and analyses.
In answer to your questions:
Was there a DME?
- there is no DME at Heho.
Was the runway lit (are lights installed)?
- the runwa is not lighted.
Was there an official approach?
- there are NDB approaches (with high minima) to both runways
What were the minima for that approach?
- between 4500 and 5700 ft altitude depending on the charts
What are the restrictions if the NDB was U/S?
- no IFR approach possible
When was the NDB last tested?
- good question, let's say the indication is stable 3 NM inbound
What was the weather on the day?
- fog in the morning, otherwise clear
What were the planning minima?
- see approach minima
What do the airline's procedures say about operating at Heho?
- not much I reckon!
How much fuel was carried?
- usually plenty as fuel is tankered into Heho
What was the technical status of the aircraft?
- reliable sources tell me it left of lot to be desired...
What was the background of the pilots?
- local