Narrative:

Clearance from reykjavik center was to 'climb FL290, expect to cross 59N at FL410.' this clearance was received during the climb. Original clearance was FL280. Request for higher altitude by crew was made. Center asked if we could make FL410 by 59 north; the answer was yes. We then were given the above clearance. Shortly thereafter contact was lost on VHF, and HF communication was impossible during the entire crossing due to the solar flare that erupted 10/wed-thur/89. One contact was made with shanwick at pm 26Z with a position report, '62030 at XX23 FL390 estimating 57040 at next hour 23, SELCAL xyz,' and was acknowledged by them. Another contact was made with julianehab radio at hour 09Z, and we were asked to climb to FL410. This was past 57M. Temperature had climbed from isa -10 (static air temperature relative to standard) to isa +20, and we were unable to maintain FL410. We advised julianehab radio accordingly and descended back to FL390, since again communication on HF had been lost. Upon contacting gander center on VHF, we were told to call the supervisor upon arrival in gander. We were advised that a violation was being filed because we failed to climb to our assigned altitude of FL410 by 59N. We restated that our clearance said '390 with expect 410 at 59N.' 'expect' is not a clearance to 'climb to,' and since we lost all communications, we maintained our last assigned altitude of FL390, as is stated in the regulations.

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Original NASA ASRS Text

Title: CHANGING TEMPERATURES ALOFT AND POOR COMS DUE TO SUNSPOTS CREATE AN ALT DEVIATION.

Narrative: CLRNC FROM REYKJAVIK CENTER WAS TO 'CLB FL290, EXPECT TO CROSS 59N AT FL410.' THIS CLRNC WAS RECEIVED DURING THE CLB. ORIGINAL CLRNC WAS FL280. REQUEST FOR HIGHER ALT BY CREW WAS MADE. CENTER ASKED IF WE COULD MAKE FL410 BY 59 N; THE ANSWER WAS YES. WE THEN WERE GIVEN THE ABOVE CLRNC. SHORTLY THEREAFTER CONTACT WAS LOST ON VHF, AND HF COM WAS IMPOSSIBLE DURING THE ENTIRE XING DUE TO THE SOLAR FLARE THAT ERUPTED 10/WED-THUR/89. ONE CONTACT WAS MADE WITH SHANWICK AT PM 26Z WITH A POS RPT, '62030 AT XX23 FL390 ESTIMATING 57040 AT NEXT HR 23, SELCAL XYZ,' AND WAS ACKNOWLEDGED BY THEM. ANOTHER CONTACT WAS MADE WITH JULIANEHAB RADIO AT HR 09Z, AND WE WERE ASKED TO CLB TO FL410. THIS WAS PAST 57M. TEMP HAD CLBED FROM ISA -10 (STATIC AIR TEMP RELATIVE TO STD) TO ISA +20, AND WE WERE UNABLE TO MAINTAIN FL410. WE ADVISED JULIANEHAB RADIO ACCORDINGLY AND DSNDED BACK TO FL390, SINCE AGAIN COM ON HF HAD BEEN LOST. UPON CONTACTING GANDER CENTER ON VHF, WE WERE TOLD TO CALL THE SUPVR UPON ARR IN GANDER. WE WERE ADVISED THAT A VIOLATION WAS BEING FILED BECAUSE WE FAILED TO CLB TO OUR ASSIGNED ALT OF FL410 BY 59N. WE RESTATED THAT OUR CLRNC SAID '390 WITH EXPECT 410 AT 59N.' 'EXPECT' IS NOT A CLRNC TO 'CLB TO,' AND SINCE WE LOST ALL COMS, WE MAINTAINED OUR LAST ASSIGNED ALT OF FL390, AS IS STATED IN THE REGS.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.