known as the area inertial navigation system (AINS). It enables the
aircraft to be flown from one position to another with great accuracy.
Prior to departure of a flight the AINS aboard the aircraft is
programmed by inserting into its computers the co-ordinates of the
departure and destination points (in degrees of latitude and longitude)
together with those of specified waypoints en route. In the case of the
Antarctic flights (which were engaged on what may be described as a
return trip without touch-down) the southernmost waypoint, like each of
the intermediate positions, was really a reference point to which the
pilot knew the aircraft would be committed if it were left to follow the
computer-directed flight track. And as mentioned the southern point for
the preferred route to the McMurdo area was a ground installation at
Williams Field.

During 1977 the co-ordinates for each waypoint which comprised the
Antarctic routes had not been stored on magnetic tape for automatic
retrieval and insertion into the navigation computer units of the
aircraft. Instead the flight plan was dealt with manually and upon issue
to the aircrew at the time of departure was manually typed by the pilot
concerned into the aircraft computer units. When the Air New Zealand
ground based computer was used in 1978 to produce computerised Antarctic
flight plans they followed the same format as those that had been
produced earlier. But before the ground computer could be programmed it
had been necessary for an officer of the navigation section to prepare a
written worksheet containing all the waypoints and their respective
latitude and longitude co-ordinates which then were transcribed from the
worksheet. And by reference to the original flight plan used in February
1977 this was done by Mr Hewitt, one of the four members of the
navigation section at airline headquarters. He said in evidence before
the Royal Commission that when he went on to take from his written