EFLIGHT 2015 – 20 March 2015 Total Solar Eclipse

An Amazing Flight into The Darkness of the Lunar Umbral Shadow
From the Pristine, Dark, Cloud-Free Free Skies > 37,000 feet AMSL

Dr. Glenn Schneider
Astronomer and EXCEDE Project Principal Investigator
Steward Observatory and the Department of Astronomy
933 North Cherry Avenue
The University of Arizona
Tucson, Arizona 85721 USA
Telephone: 520-621-5865
email: gschneider@as.arizona,edu
URL: http://nicmosis.as.arizona.edu:8000

~ 3m 45s ± ~ 10s of prolonged Greatest-Eclipse Totality @ 63.4° N Latitude


Launched from Dusseldorf, Germany to the point of "Maximum Eclipse"

A COLLABORATIVE ADVENTURE OFFERED BY:

Dr. Glenn Schneider (Steward Observatory, University of Arizona) Eclipse Flight Technical Planning/Implementation

Airberlin Airlines Aircraft Provider Aircraft Operator

Deutsche Polarflug / AirEvents, Ltd. Air Charter Flight Logistical Arrangements

TravelQuest International --> CONTACT for <-- Flight Bookings

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THE TSE 2015 PATH OF TOTALITY

The TSE 2015 path of totality (left: blue arc, right: gray arc) with our planned point of "to the max" mid-eclipse intercept indicated (red markers).
(Maps: left - adapted from Espenak and Meeus 2006, 5MCSE; right - adapted from HMNO)

For TSE 2015 we have planned a spectacular airborne eclipse expedition to simultaneously satisfy the goals and objectives of umbraphiles called by the siren's song of "duration, duration, duration" while obviating concerns of very high-probability cloudy weather miles below on the Earth's surface.  EFLIGHT 2015 MAX will stretch the duration of totality to ~ 3m 45s, with our aircraft immersed centrally in the lunar umbra at mid-eclipse from a sky-high venue > 11 km above the surface of the Earth.  EFLIGHT 2015 MAX will launch from Dusseldorf, Germany with optimal eclipse viewing as the driving requirement for defining all details of the flight plan of our Air Berlin Boeing 737-800 aircraft.  During totality, the eclipsed Sun will be positioned "straight out" the main cabin passenger windows for optimum viewing of the corona enshrouded Sun and umbral shadow on the sea/ice below and eclipse-darkened sky above from an altitude of > 37,000 ft AMSL where we will be above any obscuring clouds and otherwise disturbing weather below.

Stunning stratospheric views (and photographs) of the 01 August 2008 Total Solar Eclipse, at 82° N latitude, 11 km above the Arctic Ocean, were uniquely obtained on board our then-chartered AirBerlin (LTU) A330-200 EFLIGHT 2008 aircraft (above by Dan McGlaun, Bill Kraemer, Glenn Schneider).  In planning EFLIGHT 2015 MAX we drew significantly in detail upon the successes of this historical predecessor implemented also in partnership with AirEvents/Deutsche Polarflug under the experienced guidance and technical leadership of Dr. Glenn Schneider (Steward Observatory, The University of Arizona) and in collaboration with TraveQuest International.

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THE "WEATHER" (acuna matata)

At |latitudes| > 60°, such as our MAX point of mid-eclipse intercept, the tropopausal boundary between the troposphere below (where "weather occurs") and the stratosphere has typical equinoctial heights of < 9–10 km. Polar stratospheric (nacrecous) clouds are extremely rare and only form at very low temperatures (< -78° C) during the deep polar winter, making the probability of cloud-free eclipse viewing nearly 100% at our equinoctial flight altitude of 37,000 ft (~11.3 km) at our chosen observing location.  Of course, we will have flexibility for in situ retargeting (with a small trade in totality duration) of our viewing locations if that is required for any reason, however unlikely. 

THE AIRCRAFT and ON-BOARD ECLIPSE-VIEWING

The passenger cabin windows on the right side of the aircraft will be used for eclipse viewing and photography. Seat offerings, and on-board operations during the eclipse-viewing phase of the flight, have been designed to provide an optimal eclipse observing experience.  All rows offer at least one window suitable for eclipse viewing* with those numbered in green as annotated on the figure below fully unobscured with seat backs in upright positions.  (*Row 11 with one window, and Row 13 with two, have window edges marginally obscured as shown).

The locations of the windows on the cabin wall with respect to each of the passenger seat rows are illustrated in the figure below.  To maximize the utility of all windows accessible to any seat row without interference to adjacent rows, seat backs in some specific rows may be tilted backwards to provide partial to full access to the window nearest the adjacent passenger seat (those identified in light blue) without compromising the useful window(s) in the seat row behind.


(1) Early Preparations: Detailed photographs and measurements of all seat rows and windows will be made available to eclipse viewers far ahead of the flight, to allow informed preparations by photographers, those using optical aides, and or planning window-sharing with a seat-row partner (see above).

(2) At Dusseldorf International Airport:  our flight will be given first priority by Air Berlin's handling, ground operations, flight planning and in-flight will also be communicated as priority 1 towards Air Traffic Control and for inter-flight coordination.

(3) Our Outbound Flight Plan: is baselined for a 45 minute earlier than critically required take-off time, providing built-in contingency time against the possibility of a take-off delay or strongly unfavorable outbound head-winds.

(4) Windows Quality/Frost Risk Mitigation: The specific Air Berlin B737-800 we will use will be one of the very newest in their aircraft fleet with very fresh windows with minimal scratches or sleeks that could otherwise act as frost-formation centers.  Cabin air will be pre-conditioned to reduce the potential and minimize the (unlikely) risk of frosting, and the aircraft will then remain at high altitude prior to totality (no descents for "flightseeing") to keep the relative humidity on potential frost-forming surfaces low. Additionally, not all available seat-rows with eclipse viewing windows will be offered to keep several in reserve for viewing position exchange, in the unlikely event of individual anomalous window frosting elsewhere in the aircraft.

(5) No Extraneous Passengers: This is a dedicated eclipse-viewing flight.  No seats will be offered on the anti-sun side of the aircraft for others to "fill" the aircraft.  No potential over-crowding, no unintentional interference or distractions during the totality run to eclipse-viewers.

(6) During the Totality Run: Eclipse observing will be conducted without any intra-eclipse "seat swapping/rotation" of positions with excess passengers (obviated by (5)) otherwise disturbing/interfering with same, or adjacent row eclipse-viewers.  This "exclusive" or pre-planned partner-shared use only of the windows will enable an atmosphere much more conducive to concentrated and uninterrupted eclipse viewing.

(7) Throughout All Flight Planning and in situ until CIII on the Aircraft: Dr. Glenn Schneider will act actively as the consulting expert with the mission planners and flight crew to assure the smooth execution of the totality run and mid-eclipse intercept per the baseline plan and in response to any in-flight deviations.

(8)  Post-Totality: Upgraded catering and celebratory imbibement after collecting solar coronal photons to revel in our successes.

EFLIGHT 2015 MID-ECLIPSE (ME) INTERCEPT FOR MAXIMUM DURATION

WHY THIS LOCATION?

For EFLIGHT 2015 baseline planning purposes, here we adopt  a flight altitude for the eclipse-observing phase of the flight (and nominal out/inbound cruise phases) of 37,000 ft AMSL. Here (for initial planning), a no-wind condition is assumed and a TAS of Mach 0.78 (i.e., ground speed equals airspeed) during at-altitude cruise.  We designate a "Totality Run" as that portion of the flight devoted to the observation of the total phase of the eclipse. The Totality Run is planned so the aircraft has assumed straight-and-level flight (nominally) at constant speed at and throughout the totality and during pre/post flanking intervals closely prior to and after totality. 

The point (time correlated location and UTC) of "mid eclipse" (ME) intercept is the instant at which the aircraft is concentrically located in the Moon's umbral shadow.  The totality run is planned so the aircraft heading is the solar azimuth at ME minus 90 degrees, so the Sun will present itself "straight out" the sun-side passenger windows.  This is the right (starboard) side of the aircraft, so enabling an aircraft velocity vector component in (not against) the velocity vector of the Moon's shadow with a resulting increase in the duration of totality as seen from the moving aircraft.

In practice, small compensating adjustments to the derived totality run (and pre-totality run flight plan) based upon:

(a) TBD (Phase 2) statistically most-likely, and/or in situ actual winds-aloft,
(b) different (faster is better for longer totality) TAS during the totality run within operating limits, and
(c) different (higher is better for sky clarity) flight level to the limit of the service ceiling with trade of achievable ground speed. 

Such parametrically defined variations to the baseline flight plan, subject to aircraft operational and performance constraints, will be reviewed and discussed with the aircraft flight operations and planning personnel, and are readily (re)-computatble as needed. (See here an overview of the EFLIGHT planning S/W [20 MB PDF file], developed and used by G. Schneider for many prior successful EFLIGHTs.

The baseline flight plan presented here is of sufficient fidelity for the (presumed nominal) parametric conditions assumed that, if rigorously followed, will successfully result in a highly viewing-optimized and geometrically precise time-correlated mid-eclipse intercept with the aircraft concentrically located along the apex of the lunar umbral shadow cone.

N.B.: All timings and correlated locations, and maps presented here are (in detail) valid ONLY for the specific set of baseline assumptions used here.  Later recomputation of the eclipse observation plan (and thus to a small degree end-to-end) flight plan, based upon parameterization a-c above, is expected and anticipated.

The totality run (TR) is entered (nominally) at the completion of a heading re-alignment maneuver (with a constant-radius turn onto the TR track) at the requisite UTC, location, altitude, TAS, and heading.  Once on the TR track, before the start of totality (C2 = "second contact"), small adjustments to the aircraft speed may be made to compensate for winds-aloft or turn-exit navigation errors to maintain the desired mid-eclipse flight profile.

N.B.: The specific pointg of mid-eclipse intercept results in a totality duration appx 0.05s (insignificantly) shorter than the absolute theoretical maximum (for this set of flight parameters) for this eclipse.  This was arrived at from a cost/benefit trade to reduce the overall flight distance R/T from Dusseldorf while retaining in-flight contingency margins,

BASELINE EFLIGHT and ECLIPSE-OBSERVATION ("Totality Run") PLANNING

TIME-CORRELATED WAYPOINTS and ECLIPSE CIRCUMSTANCES FOR EFLIGHT 2015 MAX
Flight scenario: FL 370, Mach 0.78 (TAS 447.4 nm/hr).  No statistical winds assumed.
(Details Subject to Change)

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