Basis for Calculations

These calculations are based on:

• the transcript of the voice traffic between the crew of A84-231 and the Ground Controller for the mission;
• the fact that the LKP of the aircraft was reported by a radar station (from an as yet undetermined location) as 15deg 45 min NORTH and 107 deg 40 min EAST and that this radar station reported that the aircraft disappeared from the radar screen at 2022 hrs. See here for some background regarding the location of our phantom radar site. Can you offer any advice as to where it may have been located? If so, here is my e-mail address.

Basically the method that has been used to determine the Release Point (RP), being the point after which the aircraft turned left on to a heading of 120 mag (and disappeared shortly thereafter) is to project the track from a known point to intersect the back bearing of the route out of the target area, through the reported LKP. The data that has been examined appears to be fairly consistent, however, to assist in verifying (or refining) the LKP it would be of benefit if we could discover the coordinates of the target, Target No. 6736S. Would the Frag Order for the mission contain the the coordinates of the target?

OTHER POINTS THAT REQUIRE URGENT ATTENTION ARE LISTED AT THE BOTTOM OF THIS PAGE AS "HELP REQUIRED AND FUTURE REQUIREMENTS."

Stages of the Mission

For the purpose of this analysis the subject portion of the mission has been broken into six stages as follows:

• STAGE 1: HANDSHAKING
• STAGE 2: POSITIONING THE AIRCRAFT
• STAGE 3: RECYCLING THE GDB BEACON
• STAGE 4: LINING UP THE AIRCRAFT
• STAGE 5: THE BOMBING RUN
• STAGE 6: GOODBYE

Outcomes

The available facts are sufficient to reasonably establish the following:

• timings for Stage 1,
• the duration of and the track for Stage 2,
• the duration of and the track for Stage 3 and 4,
• the duration of and the track for Stage 5, and
• the duration of and the track for Stage 6.

Major Assumptions - Please check the validity of these and e-mail any comments to me.

• That the Da Nang TACAN facility (Channel 77) was located at 16 deg 02 min NORTH and 108 deg 12 min EAST.
• That the legs of the tracks are of approximately the same distance, track by track, unless specific detail to the contrary is available.
• That True Air Speed equalled Ground Speed.
• That the aircraft remained on a constant heading while not under the control of Hanig during Stages 3 and 4.
• That the aircraft maintained a constant speed of 400 knots for most of Stages 2 to 6. (See later.)
• That the reported LKP at 15 deg 45 min NORTH and 107 deg 40 min EAST is sufficiently accurate for use as a known point on the track of the aircraft. See here for further discussion.

Major Deductions

• The calculated RP is at 15 deg 49.5 min NORTH and 107 deg 32.1 min EAST but the actual RP was most likely somewhere back along the heading of 204.5 deg so as to give the aircraft time to swing onto the heading of 125 deg. I have no way of estimating the distance required to wheel a Canberra Bomber through 80 deg or so - enter "the pilot!"
• Target location for this mission was forward of the RP on a bearing of 204.5 deg mag and would have been within 4.1 nautical miles of the RP, based on calculation of the Impact Point in a Vacuum (VIP) - enter "the navigator!"
• The location where the aircraft ceased communications with the Ground Controller (and its location when, seconds later, it disappeared from the radar screen) is centred on a point at 15 deg 46.1 min NORTH and 107 deg 37.0 min EAST.

HELP REQUIRED AND FUTURE REQUIREMENTS.  Volunteer here.

• Expert opinion is required to test the assumptions used in this analysis. See above for the major assumptions.
• The assistance of an experienced Canberra bomber pilot or navigator would be most beneficial.
• The location of the planned Release Point (RP) would give us the point where the aircraft broke left to commence Stage 6.
• The location of the Target No. 6736S would assist in refining the RP.