Narrative:

Bottom line: captain violated by gander radio center for exercising command and not step climbing. Gander center, gander radio never confirmed a required clearance to step climb. ACARS message not complete -- 200 NM southwest of torbay, received ACARS oceanic clearance to 'expect FL350 and expect clearance to climb to reach FL370 by XX15Z.' (no begin climb time was ever issued.) all FMS parameters checked. FMS initial altitudes selected FL330, FL350, FL370. FMS computed step climbs were used to accept higher altitudes. At XX15Z the winds were 20-30 KTS higher than forecast, and we stayed ahead of flight plan. We were accurate on all waypoint position reports based on actual winds which we updated in the FMS. The temperature at FL290 was isa -8 degrees (colder than isa). The temperature at FL330 was approximately isa. We were later cleared to FL350, but the expected clearance to FL370 was not issued. The winds continued to increase to 120-130 KTS tailwind. The temperature at FL350 was now isa +12 degrees. The FMS now did not provide safe buffet margin to climb to FL370. The cruise N1 was only 4% below the cruise limit. The low speed foot was still too close to our cruise mach. I checked our weight and the flight manual and decided not to climb due to not enough buffet protection. At XY07Z I called gander radio (HF) approximately 200 mi west of 30W longitude and advised them 'unable to climb to FL370 due to buffet restrs.' the FMS maximum altitude was 37.8. I advised shanwick radio (gander would not respond or answer my calls) that I could descend to a lower altitude. Gander radio came back and said, 'you are in violation of your clearance, I am issuing an infraction of a nat's clearance.' note #1: because of the increase in temperature our true airspeed (TAS) at FL370 (which we reached 50 mins later) was higher by 2 KTS than our TAS at FL290 at the same mach .83. Note #2: I spoke directly with gander center over the telephone and they withdrew the violation. They admitted their error. Note #3: the ACARS message (clearance) was not correct. Note #4: gander radio center did not follow their own radio readback and clearance procedures for issuing step climbs. The north atlantic mnps requires better technology than HF radios. All aircraft should be required to have TCASII and position reporting via ACARS/satcom link.

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Original NASA ASRS Text

Title: AN ACR FLYING OVER THE ATLANTIC IS UNABLE TO ACCEPT HIGHER ALT AS ASSIGNED. ACR IS A WDB CARRYING FREIGHT.

Narrative: BOTTOM LINE: CAPT VIOLATED BY GANDER RADIO CTR FOR EXERCISING COMMAND AND NOT STEP CLBING. GANDER CTR, GANDER RADIO NEVER CONFIRMED A REQUIRED CLRNC TO STEP CLB. ACARS MESSAGE NOT COMPLETE -- 200 NM SW OF TORBAY, RECEIVED ACARS OCEANIC CLRNC TO 'EXPECT FL350 AND EXPECT CLRNC TO CLB TO REACH FL370 BY XX15Z.' (NO BEGIN CLB TIME WAS EVER ISSUED.) ALL FMS PARAMETERS CHKED. FMS INITIAL ALTS SELECTED FL330, FL350, FL370. FMS COMPUTED STEP CLBS WERE USED TO ACCEPT HIGHER ALTS. AT XX15Z THE WINDS WERE 20-30 KTS HIGHER THAN FORECAST, AND WE STAYED AHEAD OF FLT PLAN. WE WERE ACCURATE ON ALL WAYPOINT POS RPTS BASED ON ACTUAL WINDS WHICH WE UPDATED IN THE FMS. THE TEMP AT FL290 WAS ISA -8 DEGS (COLDER THAN ISA). THE TEMP AT FL330 WAS APPROX ISA. WE WERE LATER CLRED TO FL350, BUT THE EXPECTED CLRNC TO FL370 WAS NOT ISSUED. THE WINDS CONTINUED TO INCREASE TO 120-130 KTS TAILWIND. THE TEMP AT FL350 WAS NOW ISA +12 DEGS. THE FMS NOW DID NOT PROVIDE SAFE BUFFET MARGIN TO CLB TO FL370. THE CRUISE N1 WAS ONLY 4% BELOW THE CRUISE LIMIT. THE LOW SPD FOOT WAS STILL TOO CLOSE TO OUR CRUISE MACH. I CHKED OUR WT AND THE FLT MANUAL AND DECIDED NOT TO CLB DUE TO NOT ENOUGH BUFFET PROTECTION. AT XY07Z I CALLED GANDER RADIO (HF) APPROX 200 MI W OF 30W LONGITUDE AND ADVISED THEM 'UNABLE TO CLB TO FL370 DUE TO BUFFET RESTRS.' THE FMS MAX ALT WAS 37.8. I ADVISED SHANWICK RADIO (GANDER WOULD NOT RESPOND OR ANSWER MY CALLS) THAT I COULD DSND TO A LOWER ALT. GANDER RADIO CAME BACK AND SAID, 'YOU ARE IN VIOLATION OF YOUR CLRNC, I AM ISSUING AN INFRACTION OF A NAT'S CLRNC.' NOTE #1: BECAUSE OF THE INCREASE IN TEMP OUR TRUE AIRSPD (TAS) AT FL370 (WHICH WE REACHED 50 MINS LATER) WAS HIGHER BY 2 KTS THAN OUR TAS AT FL290 AT THE SAME MACH .83. NOTE #2: I SPOKE DIRECTLY WITH GANDER CTR OVER THE TELEPHONE AND THEY WITHDREW THE VIOLATION. THEY ADMITTED THEIR ERROR. NOTE #3: THE ACARS MESSAGE (CLRNC) WAS NOT CORRECT. NOTE #4: GANDER RADIO CTR DID NOT FOLLOW THEIR OWN RADIO READBACK AND CLRNC PROCS FOR ISSUING STEP CLBS. THE NORTH ATLANTIC MNPS REQUIRES BETTER TECHNOLOGY THAN HF RADIOS. ALL ACFT SHOULD BE REQUIRED TO HAVE TCASII AND POS RPTING VIA ACARS/SATCOM LINK.

Data retrieved from NASA's ASRS site as of July 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.