Narrative:

While cruising at 16000' MSL on an IFR flight plan I entered clouds for a brief time and picked up moderate ice. After coming out of clouds I asked ZSE for a block airspace to FL190 and was given that clearance and cleared to FL190. I advised ATC that for the present I would remain at 165000' since I was above the clouds, but might need higher to stay above. The controller cleared me to remain at 16000' and simply advise him when freed higher and it would be granted. Shortly after changing center frequency once again the cloud conditions rose and I called center and requested FL180, at which point the controller responded 'roger aircraft identification.' since all I thought I needed was a response to my request for higher as noted by the previous controller saying simply 'advise when you need higher, no problem,' I proceeded to climb to FL180 to avoid potential serious icing in clouds. As I was climbing the controller called and asked if I was climbing and I advised affirmative. He responded that he had not cleared me but continue to FL190. There was no conflict of any kind, however there was evidently a misunderstanding. The controller did not say he would report this and nothing further was said. I assume there was no report filed. In this situation I clearly understood that the controller understood my desires and asked simply to call and request another altitude and it would be given, so the response of 'roger' meant to me that I could proceed. Evidently the controller did not think so. Possibly this controller was unaware of my conversation with the previous controller and the current controller was simply and only acknowledging my request not familiar with the text of my previous conversation.

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Original NASA ASRS Text

Title: GA SMA ALT DEVIATION EXCURSION FROM CLRNC ALT.

Narrative: WHILE CRUISING AT 16000' MSL ON AN IFR FLT PLAN I ENTERED CLOUDS FOR A BRIEF TIME AND PICKED UP MODERATE ICE. AFTER COMING OUT OF CLOUDS I ASKED ZSE FOR A BLOCK AIRSPACE TO FL190 AND WAS GIVEN THAT CLRNC AND CLRED TO FL190. I ADVISED ATC THAT FOR THE PRESENT I WOULD REMAIN AT 165000' SINCE I WAS ABOVE THE CLOUDS, BUT MIGHT NEED HIGHER TO STAY ABOVE. THE CTLR CLRED ME TO REMAIN AT 16000' AND SIMPLY ADVISE HIM WHEN FREED HIGHER AND IT WOULD BE GRANTED. SHORTLY AFTER CHANGING CENTER FREQ ONCE AGAIN THE CLOUD CONDITIONS ROSE AND I CALLED CENTER AND REQUESTED FL180, AT WHICH POINT THE CTLR RESPONDED 'ROGER ACFT ID.' SINCE ALL I THOUGHT I NEEDED WAS A RESPONSE TO MY REQUEST FOR HIGHER AS NOTED BY THE PREVIOUS CTLR SAYING SIMPLY 'ADVISE WHEN YOU NEED HIGHER, NO PROB,' I PROCEEDED TO CLB TO FL180 TO AVOID POTENTIAL SERIOUS ICING IN CLOUDS. AS I WAS CLBING THE CTLR CALLED AND ASKED IF I WAS CLBING AND I ADVISED AFFIRMATIVE. HE RESPONDED THAT HE HAD NOT CLRED ME BUT CONTINUE TO FL190. THERE WAS NO CONFLICT OF ANY KIND, HOWEVER THERE WAS EVIDENTLY A MISUNDERSTANDING. THE CTLR DID NOT SAY HE WOULD RPT THIS AND NOTHING FURTHER WAS SAID. I ASSUME THERE WAS NO RPT FILED. IN THIS SITUATION I CLEARLY UNDERSTOOD THAT THE CTLR UNDERSTOOD MY DESIRES AND ASKED SIMPLY TO CALL AND REQUEST ANOTHER ALT AND IT WOULD BE GIVEN, SO THE RESPONSE OF 'ROGER' MEANT TO ME THAT I COULD PROCEED. EVIDENTLY THE CTLR DID NOT THINK SO. POSSIBLY THIS CTLR WAS UNAWARE OF MY CONVERSATION WITH THE PREVIOUS CTLR AND THE CURRENT CTLR WAS SIMPLY AND ONLY ACKNOWLEDGING MY REQUEST NOT FAMILIAR WITH THE TEXT OF MY PREVIOUS CONVERSATION.

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.