Background Information is available: HERE.

PREFACE
=======
I describe four possible scenarios for an eclipse flight from Punta Arenas.
Option number 4 permits a post-eclipse overflight of the South Pole and a
duration of totality of only 9 seconds shorter than the possibly achievable
maximum.  This is at a mid-eclipse intercept of 23:06:02 UT, which is at a
point that is the shortest distance along the path of totality from the South
Pole.  The cost of doing this is an additional 522 nautical miles (total)
"extra" flying distance over a near-minimum distance intercept at 23:10UT, an
increase of appx. 10% in flight distance.
 

OPTION SUMMARY
===============
At this point, is seems to me, that a decision between four "basic"
flight options needs to be made - then the flight can be offered
as the specific details are worked out.

1) Near shortest distance.
2) Near maximum eclipse.
3) Near maximum eclipse with South Pole overflight.
4) Eclipse intercept with shortest distance to South Pole.

I suspect - though Kelly and Rick are seeing this particular
"suggestion" from me for the first time, they may have interest
in pursuing #4, as it might provide the best "cost/benefit"
trade.

OPTION DESCRIPTION
=================
Below I outline a few of those details of  these four possible flight
scenarios. In all cases I am presuming that the  "totality run",
i.e. aircraft positioning and heading realignments, will be
completed eight minutes before mid-eclipse.  I am also assuming
the "totality run" will continue for three minutes past mid-eclipse
(i.e., allowing almost two minutes of post-totality viewing of
the first stages of the egress phase of the partial eclipse).
We can "tune" these relative times later, but they are a good
starting point.

I have indicated flight/segment distance and estimated times exclusive
of ascent/decent, alignment maneuver, and operations
in and around Punta Arenas. At  full cruise (assuming Mach 0.87?),
presumably something on the order of 40 minutes needs to be added
to this for take-off/landing, ascent/decent, and in-flight maneuvers,
but LanChile needs to evaluate that (I'm assuming there appx.
a 2000 ft/min rate of climb).

Additionally time-critical nature of the eclipse is such that
entry onto the totality run needs to be as un-constrained as possible.
Above, I have "built in" a window ahead of totality by allowing
eight minutes of flight on  an intercept course (with a little less
than seven minutes before totality).  This may be insufficient
to allow for windage or other in-flight or take-off delays.  The
aircraft cannot arrive "late" as it can not overtake the moon's
shadow.  Indeed, additional time may (likely should) be budgeted
to arrive at the entry point of the totality run "early" and either:
(a) perform "station keeping" maneuvers until a release time to
fly along the track, or (b) define a possibly earlier start-time for
the centerline run.  If the later, totality would be experienced
"earlier" than pre-planned if the aircraft were no arriving late,
but that would actually be of little consequence.

The four flight option considered are as follows:

Option #1:  Near Shortest-Distance to/from Punta Arenas
A flight to observe mid-eclipse at or near 23:10 UT.  This has the
benefit of a nearly minimized flight distance while still yielding
a duration of totality of 2m 21s.  This is only shorter from the
theoretical maximum duration (using an aircraft with a ground
speed of 470 nM/hr) of 2m35s by 14s which would occur with
an intercept at appx 22:48UT.  This flight would reduce the
travel distance and time (and hence cost) over a flight from
Punta Arenas to reach the point of maximum eclipse duration.

Option #2: Near Maximum-Duration
A flight to observe mid-eclipse at a point to nearly maximize
the eclipse duration.  For this I would SUGGEST an intercept at
22:55UT for two reasons. The difference between a 22:48UT
intercept and one at 22:55, in terms of the duration of totality
is only 1 second (with the Sun only 0.3 degrees lower in the sky,
both at very close to 15 degree elevation) - but shortens the flying
distance significantly.  Also, there will be at least one other
aircraft operating in the area near maximum eclipse (a QANTAS
B747-400), and it would be best to keep the two aircraft out
of "close" proximity.

Option  #3: Near Maximum Duration with South Pole Overflight
This is a variant of option #2, but would involve an overflight
(at low altitude?) of the Amundsen-Scott South Pole station.
Kelly Beatty and Rick Feinberg suggested this possibility to
foster possible additional interest in the flight.  If this is viable
it COULD be done either before or after the eclipse.  In what follows,
I consider it AFTER only to get the ball rolling.

Option #4: Near Shortest-Distance To/From South Pole
Option #3 raises the idea of  an mid-eclipse intercept at the
shortest distance of travel from the South Pole.  This would
allow both eclipse observing and a  South Pole overflight without
the full distance/time (cost) as reaching for maximum eclipse.
I hadn't discussed that previously with Kelly/Rick but outline that
here as well.
 
 

The choice between these four options will depend upon:

(a): Technical viability given any operating restrictions and
constraints with the A340 aircraft, and

(b): Cost/benefit trade of a longer flight to gain a small amount
of totality - and possibly a South Pole overflight.

Issue (a) needs to be assess by Lan Chile flight operations, in
particular Cpt. Fucslocher.

Issue (b) needs to be decided upon by Kelly Beatty and Rick Feinberg
subject to (a).

Note: I in computing distances to/from Punt Arenas I am using
the following co-ordinates Latitude = 53d 09'S, Longitude = 70d 55'W.
*** PLEASE ADVISE if these are not the coordinates of the
airport runway at Punta Arenas.
 

OPTION HIGH-LEVEL DETAILS:
=======================
1) Option #1 - 23:10 UT intercept
    TOTALITY = 2m 20.9s, SOLAR ALTITUDE (mid eclipse) = 9.6 degrees

Note, this was detailed previously on:
http://nicmosis.as.arizona.edu:8000/ECLIPSE_WEB/ECLIPSE_03/2310.html

(a) Totality run to begin at 23:02 UT with the aircraft at a position
of Latitude = 77.5245S, Longitude = 40.3610E.  This would entail a great
circle flying distance of 4681 km from Punta Arenas (forward azimuth =
162d 27' 45").

(b) The aircraft at (a) would fly a heading of 244.53 degrees (ground
track of 240.27 degrees) With a ground speed of 470 nM/hr the
lunar umbra will overtake the aircraft at 23:08:49.6 UT with the
aircraft at latitude = -77d 56' 30.2"S, Longitude = 36d 39' 24.6"E.

(c) Mid-eclipse will occur, with the aircraft co-axially located in the
center of the moon's shadow at Lat=78.0079S, Long = 35.9997E,
 at 23:10UT after flying 62.7 nautical miles from the start of the "totality
run".  At mid eclipse the Sun will be at an azimuth of 154.5 degrees
(instantaneous ground track of 245.27 degrees, i.e., "straight out" the sunside
cabin windows) and 9.6 degrees above the astronomical horizon.

(d) The trailing edge of the lunar umbra will pass over the aircraft
at 23:11:10.5 UT, with the aircraft at Latitude = -78d 04' 29.2"S,
Longitude = 35d 19' 59.9"E.

(e) After flying 23.6 nautical miles in three minutes from the point of
mid-eclipse, at 23:13 UT the aircraft will execute a heading alignment
maneuver to 240d 47' 57" deg (forward azimuth)
while at Lat = 78.1820S, Long = 34.3153E to return to Punta Arenas.
This would entail a great circle flying distance of  4522km to Punta
Arenas.

The flight distance from Punta Arenas to point (a) is 4681 km
The flight distance along the centerline run is 160 km
The flight distance from (d) to Punta Arenas is 4522 km

Total flight distance = 5056 nM
Estimated Flight Time = 10.76 hours (plus and estimated 45m)

QUESTION: Is there sufficient line-of-site clearance to the
wing-tips from all sunside window, with the sun at 9.6 degree
elevation for an unobscured view?
 
 

2) Option #2 - 22:55 UT intercept ("Near" mid-eclipse)
    TOTALITY = 2m 34.5s, SOLAR ALTITUDE (mid eclipse) = 14.9 degrees

(a) Totality run to begin at 22:47 UT with the aircraft at a position
of Latitude = 74.6854S, Longitude = 84.0050E.  This would entail a great
circle flying distance of 5607 km  from Punta Arenas (forward azimuth =
171d 37' 21").

(b) The aircraft at (a) would fly a heading of 204.69 degrees (ground
track of 203.10 degrees) With a ground speed of 470 nM/hr the
lunar umbra will overtake the aircraft at 22:53:42.8 UT with the
aircraft at latitude = 75d 29' 11.9"S, Longitude = 82d 40' 46.7"E.

(c) Mid-eclipse will occur, with the aircraft co-axially located in the
center of the moon's shadow at Lat=76.6388S, Long = 82.4008E,
 at 22:55UT after flying 62.7 nautical miles from the start of the "totality
run".  At mid eclipse the Sun will be at an azimuth of 114.7 degrees
(instantaneous ground track of 205.03 degrees, i.e., "straight out" the sunside
cabin windows) and 14.9 degrees above the astronomical horzon.

(d) The trailing edge of the lunar umbra will pass over the aircraft
at 22:56:17.3 UT, with the aircraft at Latitude = 75d 47' 34.3"S,
Longitude = 82d 07' 06.5"E

(e) After flying 23.6 nautical miles in three minutes from the point of

mid-eclipse, at 23:58 UT the aircraft will execute a heading alignment
maneuver to 201d 00' 41" deg (forward azimuth)
while at Lat = 75.9969S, Long = 81.7545E to return to Punta Arenas.
This would entail a great circle flying distance of 5448 km to Punta
Arenas.

The flight distance from Punta Arenas to point (a) is 5607 km
The flight distance along the centerline run is 160 km
The flight distance from (d) to Punta Arenas is 5448 km

Total flight distance = 6056 nM
Estimated Flight Time = 12.89 hours (plus and estimated 45m)
 
 

3) Option #3 - 22:55 UT intercept ("Near" mid-eclipse) with SP Overflight
    TOTALITY = 2m 34.5s, SOLAR ALTITUDE (mid eclipse) = 14.9 degrees

(a-d same as above)
 

(e) After flying 23.6 nautical miles in three minutes from the point of

mid-eclipse, at 23:58 UT the aircraft will execute a heading alignment
maneuver to 180d 0' 0" deg (forward azimuth)
while at Lat = 75.9969S, Long = 81.7545E to fly to South Pole.
This would entail a great circle flying distance of  1564 km to the South
Pole.

(f) Flight from South Pole to Punta Arenas.  Distance = 4018 km (forward
azimuth = 289d 05' 00"
 

The flight distance from Punta Arenas to point (a) is 5607 km
The flight distance along the centerline run is 160 km
The flight distance from (d) to south Pole is 1564 km
The flight distance from South Pole to Punta Arenas is 4018

Total flight distance = 6128 nM
Estimated Flight Time = 13.04 hours (plus and estimated 45m)
 
 

4) Option #4 - 23:06:02UT intercept (Closest to South Pole)
    TOTALITY = 2m 26.5s, SOLAR ALTITUDE (mid eclipse) = 11.8 degrees

(a) Totality run to begin at 23:58:02 UT with the aircraft at a position
of Latitude = 78.0158S, Longitude = 55.8088E.  This would entail a great
circle flying distance of 4920 km from Punta Arenas (forward azimuth =
166d 09' 04").

(b) The aircraft at (a) would fly a heading of 230.29 degrees (ground
track of 226.51 degrees) With a ground speed of 470 nM/hr the
lunar umbra will overtake the aircraft at 23:04:48.8 UT with the
aircraft at latitude = 78d 36' 23.3"S, Longitude = 52d 33' 38.5"E.

(c) Mid-eclipse will occur, with the aircraft co-axially located in the
center of the moon's shadow at Lat=78.7084S, Long = 51.9432E,
at 23:06:02UT, where the axis of the umbral cone is closest to the South
Pole, after flying 62.7 nautical miles from the start of the "totality
run".  At mid eclipse the Sun will be at an azimuth of 140.3 degrees
(instantaneous ground track of 230.94 degrees, i.e., "straight out" the
sunside cabin windows) and 11.8 degrees above the astronomical horzon.

(d) The trailing edge of the lunar umbra will pass over the aircraft
at 23:07:15.3 UT, with the aircraft at Latitude = 78d 48' 42.3"S,
Longitude = 51d 19' 02.2"E

(e) After flying 23.6 nautical miles in three minutes from the point of
mid-eclipse, at 23:09:02 UT the aircraft will execute a heading alignment
maneuver to 180d 00' 00" deg (forward azimuth)
while at Lat = 78.9635S, Long = 50.4320E to fly to South Pole.
This would entail a great circle flying distance of  1233 km to the South
Pole.

(f) Flight from South Pole to Punta Arenas.  Distance = 4018 km  (forward
azimuth = 289d 05' 00")

The flight distance from Punta Arenas to point (a) is 4920 km
The flight distance along the centerline run is 160 km
The flight distance from (d) to south Pole is 1233 km
The flight distance from South Pole to Punta Arenas is 4018

Total flight distance = 5578 nM
Estimated Flight Time = 11.87 hours (plus and estimated 45m)

NOTE: The UT intercept of 23:06:02 gives the shortest flying distance
from the end-of-totality run break-off to the South Pole "on the way"
back to Punta Arenas.  With this intercept the duration of totality is
only 9 seconds less than the theoretically achievable maximum under
equal flight conditions (i.e., 94.2% of the air-extended maximum
duration of totality), and is 478 nautical miles shorter in total
flying distance (i.e., then compared to option #2).  Option #4
is 522 nM longer than option #1, but the South Pole overflight might
provide sufficient "value added" that it should be seriously considered
instead of option #1.

See: CHART-A  CHART-B

Notes on Charts:
1) The three intercepts at mid-eclipse times 22:50, 23:06:02 and 23:10 UT
are annotated as the blue circles with black dots on centerline.

2) The track of the aircraft is in green for -8 minutes and + 3 minutes
before and after mid eclipse.

3) The red outlines aroun the blue circles indicate, across the
diameter cut by the aircraft track, where the aircraft is in
totality (I did not draw the shadow ellipses for the three points
and the contats for each one, as the graph got muct too "busy).

4) The orange lines are the segments from Punta Arenas to the
start of the totality run at mid-eclipse minus 8 minutes.

5) The purple lines are the segments from the end of the totality
run at mid eclipse plus 3 minutes to either Punta Arenas or to
South Pole.

(4) and (5) are schematic representations, I did not do a
map projection of the great circle tracks.

Glenn Schneider, 10 Feb 2003