13-Nov-2003 -- For several months I had planned to overfly the North Pole. The primary reason was to operationally test, in a realistic environment, new ring laser gyro inertial navigation units and avionics control units (computers) as part of an avionics upgrade to our aircraft. High latitude flight places unique demands on navigational systems and the singularity at the North Pole would be exceptionally challenging.
This attempt would be complementary to my overflight of 0n-180w that ensured this same system performed well during multiple transitions between the north/south/east/west hemispheres. Program delays slipped my planned visit date from Sep to Oct then again until Nov. I had hoped to still have daylight over the Pole but, on 13 Nov, there was not even astronomical twilight.
My flight plan would have us track north along the 142w meridian (we would overfly all the 142w confluences north of the 65th parallel) and then make a left turn before starting a clockwise orbit around the world at 89 deg 45 min north and cross over the pole on the 180w-0w meridians. We would then turn left to fly counterclockwise around the world in a similar manner, crossing over the pole again along the 90e-90w meridians. Finally, a cloverleaf over the pole (for additional crossings) would be accomplished before heading south on the 112w meridian towards the magnetic north pole for a 30nm diameter orbit around it before returning home.
Picture 1 shows the northern portion of our route we would fly to the North Pole. Picture 2 displays the southern portion of the same route. Picture 3 shows the routing around and over the North Pole. In this picture, 90e is at the top, 0w is at the right side, 90w is at the bottom and, 180w is at the left side. Picture 4 shows our planned orbit around the Magnetic North Pole.
Most narratives speak of the adventure along the way to a particular confluence. Our story would be no different...
Crew show was extremely early. Due to the length of our crew duty-day, a preflight crew would preflight and start engines for us. After a promising weather briefing and checking the last minute details, we went out to the jet. Walking out, I pointed out Polaris in the sky only about 35 degrees above the horizon and noted that in less than 9 hours, it would be directly overhead. When we got to our jet, I could not help but sense that it was alive and ready for the adventure upon which we were about to embark. Even with my helmet on, the characteristic pure tone of the engines was still very loud. With the dark sky and stadium lights, the cool temperatures and noise, it was almost surreal. A quick change of seats with the preflight crew, accomplishing the remaining checklist items, wheel chalks removed, clearance to taxi, a sharp salute to the crew chief, and we were on our way.
Weighing nearly a half million pounds, we took off into the dark early morning sky. Sunrise occurred off the Oregon coast and we would continue to chase the suns terminator until we finally caught and then passed it at the northern edge of Alaska. Twilight quickly turned to complete darkness where we would remain for the rest of the flight. In-flight refueling east of Fairbanks ensured all of our mission objectives would be met.
A waning circumpolar moon provided illumination and a get-well reference to help us head south into the correct hemisphere should our inertial systems and new processors decide to fail near the Pole. The lunar illumination and high albedo from the surface were insufficient for any pictures outside the aircraft or of the surface. As we flew, a large solar storm was underway and was creating some active northern lights - just as predicted by the space weather team. We were disappointed that the moon somewhat attenuated what otherwise would have been a great show. We also discovered that it is possible to look *south* from the vicinity of the Pole and to see northern lights - even when within the center of the auroral oval maximum. Cool charts that depict this phenomenon are located at http://www.sec.noaa.gov/pmap/.
One of the multiple "truth" sources onboard was an Ashtech Z-12 reference receiver that would be used along with other special instrumentation to determine the errors between where our inertial system thought it was and where the Ashetch GPS and other reference instrumentation thought it was. Our aircrafts built-in GPS system was intentionally not used or turned on so that our system under test would navigate using only Doppler and Deflection of Vertical gravity data to update in order to measure the absolute performance of our system. GPS and radar fixes were not used to update our navigational model. We followed steering cues from our inertial systems in a free inertial mode only for the entire flight.
Anticipation of our arrival at the top of the world was high among the crew. As we started our clockwise orbit, we were transiting time zones in less than a minute each! Watching our longitude change so fast was truly an amazing experience! We planned to straddle the 180w line during the polar crossing and transition to the counterclockwise orbit. Conceptually, this would allow half the crew to be in Friday while the other half remained in Thursday. Actual execution of this proved impossible since the slightest "S" turn made quite a difference in our longitude as we neared the pole (but we had to try it!).
Since it was nearing Christmas, we read letters to Santa from our kids and, with the help of the cabin pressure differential at the sextant port, "delivered" their handwritten requests directly over the pole.
We had our personal GPS's onboard as well. Stuck to our windows using R-A-M mounts were my reliable Garmin eMap and a GPS-35 connected to a serial data logger. An additional eTrex was connected to a laptop PC for a real time moving map. We found their position data to be extremely close to the Ashtech costing orders of magnitude more. Handheld GPS units placed in our aircraft windows tends to limit their view of the sky to one hemisphere (left/right/front) instead of the omni directional view from an installed system. This would cause some momentary reductions in the number of satellites we were tracking – immediately after turns and especially during the cloverleaf over the pole. Although predicted visibility never went below 8 satellites and the geometry was excellent, we did notice that re-acquisition of satellites was markedly slower than at lower latitudes on our Garmin receivers following a loss of signal.
Looking though one of our overhead windows, Polaris was clearly visible directly overhead - the celestial events we observed throughout the flight were amazing – from the circumpolar moon, to the northern lights, to the apparent change in the night sky from a 55 degree change in latitude! Wow!
Proceeding south to the magnetic north pole was also a rather noteworthy event. Onboard magnetic heading systems showed our heading to be 330 while proceeding on a 180 true track. Magnetic variations in excess of 160 degrees were experienced along our route of flight! We flew a 30nm complete arc around the estimated location (82 18n, 113 24w) of the magnetic north pole because it moves throughout the day. The Natural Resources Canada Geologic Survey has a tremendous amount of information on the magnetic pole at http://www.geolab.nrcan.gc.ca/geomag/northpole_e.shtml.
Pictures 5&6 are flash photos of my eMap approaching the pole. We were making a short video of the GPS and stopped it to try getting a still shot crossing the pole. I discovered that we should just have let the video continue and capture a frame from that – Rats! We could have gotten a much closer shot had we just let the video continue! Picture 5 shows us just 0.105 degree away from 90N – about 195 meters! Capturing a GPS position picture of my eMap (that only updates at 1Hz) this close to the pole when you are moving at 215 m/s is pretty good!
This attempt to visit 90N would not have counted as an actual visit even if I had been able to take a picture within 100 meters horizontally since we were 28000 feet above it. Unfortunately, post flight analysis and data reduction revealed that we did not fly within 100m horizontally of 90 north however; we were considerably closer than depicted on my eMap in Picture 5. This is outstanding performance from a navigational system operating in a free inertial mode for almost 10 hours!
As I try to do with my other visit narratives, I'll include some numbers for future visitors that will hopefully be of use in their planning: Total distance flown was over 8300 nautical miles. Total time for this attempt was 18.8 hours with 64,615 gallons (about 420,000 lbs) of jet fuel consumed. I will also concede that the first visitors from the Navy (as well as the Brits) have me beat from their visit - both their trip duration (weeks?) and fuel consumed (would that be measured in grams?) are numbers that I simply can’t match.
A journey and attempted confluence visit to be remembered!