The last positive position of Aircraft 768 was obtained at 0150 AST
by celestial means. It can be assumed that this position was accurate.
At this position the airplane was left of course and Lt. Cowan altered
heading to get back on course. Dead reckoning was carried on from this
point throughout the rest of the mission until land was first encountered at
approximately 0500 AST.
It is of interest to note that only two
celestial fixes were obtained during the entire mission, the first at
2008 ½ AST and the second at 0150 AST. It was possible to get celestial
fixes at various times during the flight as is evidenced by Lt. Lesman’s
ability to get true headings by celestial means right up until 0240 AST.
There were several factors which aggravated the situation in which
the crew found themselves at 0501 AST:
(1) The C-1 autopilot had been retrimmed and reset after the climb
to 24,000 feet at 0420 AST. A precession rate on the auto-
pilot gyro had been determined on the previous autopilot
setting, and the navigators were forced to use the past pre-
cession with the new setting.
(2) The navigators, before take-off, had got the maps on which
their course was plotted until they covered only that area
adjacent to the path of expected flight. They had neglected
to take the emergency map kit provided by Project 5. This
emergency map kit contains all available maps of Siberia,
Alaska, Canada, Greenland, and the Canadian Archipelago.
Consequently, they had map coverage extending east as far
only as the eastern shores of Borden and Melville Islands,
west as far as 180 degrees, and south as far as 74 degrees on
a VSO-XPE, and a strip map extending from Fairbanks to
Point Barrow.
(3) Perhaps if they had climbed instead of continuing on
for one hour and forty minutes under the overcast it would
have been possible to obtain one or more celestial fixes and
get a further check on gyro precessions.
Regardless of these facts, the navigators, upon finding themselves
over land, should have immediately eliminated certain possible land
masses and accepted the plausibility of others, for example:
Siberia:
(1) Too far from the lst known position.
(2) The sun could not be seen at all if the airplane were
over Siberia. Since Siberia would be in total darkness
at that time. The navigators had celestial tables with
them which would give this information.
Alaska:
(1) Point Barrow and a vicinity within several hundred miles
could be eliminated because it is a flat, level region. It was
stated in reports, both verbal and written, that the land
encountered had mountains which ran into the water. These
were seen on the radar scope and visually. Northwestern
Alaska could be eliminated because of its distance from
the last known position. All of the territory of Alaska
could be excluded because the sun would not yet have
risen.
(2) The sun would not rise at this hour along the Canadian
coastline unless the airplane had been east of 110 degree
West longitude,
This leaves the Canadian Archipelago as the only possible area in
which the airplane could have been. Moreover, it has been stated both
in written reports and verbal accounts by the crew members that the land
first encountered looked to be some sort of intermittent land and water
area and within an hour and a half it was fairly definitely established
that they seemed to be flying over island formations. Yet from a digest
of the reports it can be assumed that the DR navigator, and perhaps other
members of the crew, thought they were somewhere west of Ladd Field, Siberia as
a possibility not excluded. Otherwise, why was the decision
made to fly into the sun as a last resort? This direction would be roughly
southeast. Certainly, a navigator would not fly in a southwesterly direction
if destination were believed to be west or southwest of his position. At
this point it is worthwhile to note that Lt. Lesman eliminated many of the
possibilities of probable position as outlined above and expressed the opinion
that the aircraft was somewhere in the Canadian Archipelago. He also
expressed the desire to fly in a generally southwest direction in relation
to the sun’s position. Evidently these theories were given no weight.
Once the crew had determined to some extent their general locality,
it seems they could have done only two things which would have been of
some practical value:
(1) The sun could be seen on the horizon and, consequently, a
general southwest heading could be flown. Flying different
headings for brief periods of time or a circling motion is
not generally regarded as a sensible action to be initiated
when lost.
(2) Remain on that heading until a sunline could be obtained for
a line of position or until a definite checkpoint was picked
up by visual means.
Since the return of the crew of airplane 768 to Ladd Field it has
been quite definitely established that the airplane first made landfall
at Ellesmere Island. They stated that they saw mountains with cliffs
extending directly out of the sun. This fact was substantiated first
by radar means and later visually when the airplane passed over this
point. Ellesmere is the only island in the Archipelago which has
mountains which extend into the sea, are 10,000 feet or more in height,
and run in a series of ranges parallel to the coast. The general shape,
features, and heading of the northern cost of this island have been
identified by Lt. Adams, the radar operator, as being similar to what was
seen on the radar scope.
After the airplane climbed to the altitude of 24,000 feet at 0420
AST to get on top of the overcast the C-1 autopilot was reset. The
navigator continued to correct the airplane approximately 10 degrees to
the left every 20 minutes on the basis of the previous 30 degree per hour
precession. Evidently the precession of the autopilot gyro had changed
at the time of resetting from a high rate of precession to the right to a
lesser amount of precession to the left. On addition, the wind was out of
the northwest quadrant and continued to give an increasing drift to the
left which accounts for the airplane making a half circle to the left and
ending up at Ellesmere Island.
WAYLAND W. WILLIAMS
1st Lt., Air Corps
Squadron Navigator
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