Follow-up questions answered by Capt Bowyer

17.08.07

Questions submitted by Martin Shough and answered by email:

1. With reference to your flight track, could you indicate the positions/times:
   1. of the plane at the time when you last saw the objects disappear in haze
      I lost sight when the aircraft descended through 2000 ft. You should be able to determine this from the radar plot.
   2. of the plane when you noted that the bearing to the object(s) had rotated westward to 20 deg
      Probably at about the same time.
2. Can you describe again the relative angular positions of the two objects at the time when you last saw them? If ------ and --- represent the large and small objects, which of the following (if any) is most nearly correct?
   
   
   1. ---------
      ----
      
      
   2. ----
      ---------
      
      
   3. ---------
      ----
      
      
   4. ---------
      ----
      
      At last sight the closest object was in my one o'clock the second at about 12 o'clock and appeared smaller and to the left of the closer object due to the relative perspective. Remember that the aircraft position is not a constant. Relative headings are changing constantly as can be seen by the plot. I would say position c.) except reversed. The smaller object finally appeared higher and to the left of the closer and therefore larger object. i.e. --- _ _ _ _ whereas at first sight they were _-_-_-_ .
      
3. At the time when you last saw them, how far above the bottom one was the top one, in terms of a fraction or multiple of its own length?
   As a multiple of its own length of the farthest object I would say perhaps 6 to 8 times.
   Very difficult to say due to the offset angle between both objects.
   
4. When first seen, was the first object visible against the sky or against the sea?
   Visible against the sea.
   
5. At what position/time during descent would you estimate that you could no longer distinguish the horizon?
   The horizon was visible at all times. The haze layer itself forms a horizon as it disappears off to the horizon! The sea and the haze layer merge at the horizon. At 2000 ft items or objects at or on the top of the haze layer are shrouded by the dirt in the air.
   
6. When both objects were in view together towards the end of the sighting, was one of them, or both of them, or neither of them, visible at any time above the horizon, and if so by what angular distance (in terms of some fraction or multiple of its own length)?
   At the time of last sighting both objects were visible on the horizon i.e. the haze horizon which coincides with the actual horizon. Both objects disappeared from my view simultaneously at 2000 ft.
   
7. At what position/time after the second object appeared were both objects visible simultaneously in the same binocular field of view?
   Immediately. Only due to the relative position of my aircraft did the second object appear to 'move' left. Can't remember now exactly when the second object appeared but probably 5 miles NNE of ORTAC on the 207 radial from Southampton. At the time I made a comment to Jersey ATC so this should be recorded on the audio tape.
   
8. Can you remember at which position/time you disengaged the autopilot? (At about 1412:30, just after passing ORTAC, the radar plot of the Trislander appears to show a gradual turn from 207deg onto a course of about 212deg, towards the objects, followed at around 1418 by a correction back on to ~190deg for the approach to Alderney.)
   The autopilot was engaged throughout the flight until a very short final, sat 1 mile from Alderney airport. Work load was high. I don't remember turning towards the objects specifically but this is probably due to the central wind screen divider being quite large on a Trislander and may have obscured the view of the closest of the objects.
   
9. Did you notice any afterimages when looking away from the objects after viewing with binoculars or naked eye?
   No after-images were visible after removal of the binoculars.