Narrative:

Aircraft X; an LJ35/G negative rvsm; requested FL430. ZJX approved entering airspace level at FL430. Traffic was moderate to heavy at both xferring and receiving sectors. Southeast of the orl VOR aircraft reduced rate of climb to less than 500 FPM. ZJX controller called requesting aircraft to increase rate of climb so as to be level at FL430 at the boundary. I advised the aircraft to do so; at which time the pilot of aircraft X stated he could not. I initiated a radar vector to allow the aircraft more time to climb and advised the ZJX controller. Shortly after; the aircraft appeared to have reduced the rate of climb even further. I notified the front line manager that I may have a situation developing and was concerned that the aircraft may stall. The flm contacted ZJX who agreed to accept the aircraft. I observed the aircraft level at FL420 for a minimum of 35 mi. It is my professional opinion that the aircraft was not able to reach FL430 and filed the altitude as a means to utilize rvsm airspace when not properly certified to do so. As a result; the aircraft ended up having to level at an altitude that is not assignable in any instance (FL420).

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Original NASA ASRS Text

Title: ZMA CTLR DESCRIBED EVENT WHEN ACFT FILED FOR FL430 BUT WAS UNABLE TO REACH ALT; ALLEGING FLT CREW FILED INAPPROPRIATE ALT.

Narrative: ACFT X; AN LJ35/G NEGATIVE RVSM; REQUESTED FL430. ZJX APPROVED ENTERING AIRSPACE LEVEL AT FL430. TFC WAS MODERATE TO HVY AT BOTH XFERRING AND RECEIVING SECTORS. SE OF THE ORL VOR ACFT REDUCED RATE OF CLB TO LESS THAN 500 FPM. ZJX CTLR CALLED REQUESTING ACFT TO INCREASE RATE OF CLB SO AS TO BE LEVEL AT FL430 AT THE BOUNDARY. I ADVISED THE ACFT TO DO SO; AT WHICH TIME THE PLT OF ACFT X STATED HE COULD NOT. I INITIATED A RADAR VECTOR TO ALLOW THE ACFT MORE TIME TO CLB AND ADVISED THE ZJX CTLR. SHORTLY AFTER; THE ACFT APPEARED TO HAVE REDUCED THE RATE OF CLB EVEN FURTHER. I NOTIFIED THE FRONT LINE MGR THAT I MAY HAVE A SITUATION DEVELOPING AND WAS CONCERNED THAT THE ACFT MAY STALL. THE FLM CONTACTED ZJX WHO AGREED TO ACCEPT THE ACFT. I OBSERVED THE ACFT LEVEL AT FL420 FOR A MINIMUM OF 35 MI. IT IS MY PROFESSIONAL OPINION THAT THE ACFT WAS NOT ABLE TO REACH FL430 AND FILED THE ALT AS A MEANS TO UTILIZE RVSM AIRSPACE WHEN NOT PROPERLY CERTIFIED TO DO SO. AS A RESULT; THE ACFT ENDED UP HAVING TO LEVEL AT AN ALT THAT IS NOT ASSIGNABLE IN ANY INSTANCE (FL420).

Data retrieved from NASA's ASRS site as of May 2009 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.