Narrative:

While in the right seat, acting as copilot, handling the radio communications, I discovered that myself and the pilot at the controls were lacking some information needed at our destination. I proceeded to contact company aircraft on a UHF frequency while the pilot at the controls continued to monitor VHF frequency, talking to ZDC. I had difficulty hearing company aircraft and therefore was concentrating on my conversation with that aircraft, along with writing the information down. Center had cleared us to climb to FL230 (we had filed for final altitude of FL240). Pilot at the controls thought we had been cleared to FL240. At approximately FL235 center contacted pilot at the controls and inquired aircraft altitude. When pilot at the controls was informed that we had only been cleared to FL230 he immediately descended down to FL230. Lack of communication, and distraction were the causes for this event. I allowed my attention to be concentrated on one single task (copying information from other aircraft). The necessary corrective action to prevent such an event from occurring again is twofold: first, make certain that all flight crewmembers are aware of all clrncs. Secondly, don't let one problem cause you to be distracted. I have certainly learned these lessons through this event.

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Original NASA ASRS Text

Title: MTR ALT DEVIATION OVERSHOT CRUISE ALT.

Narrative: WHILE IN THE RIGHT SEAT, ACTING AS COPLT, HANDLING THE RADIO COMS, I DISCOVERED THAT MYSELF AND THE PLT AT THE CTLS WERE LACKING SOME INFO NEEDED AT OUR DEST. I PROCEEDED TO CONTACT COMPANY ACFT ON A UHF FREQ WHILE THE PLT AT THE CONTROLS CONTINUED TO MONITOR VHF FREQ, TALKING TO ZDC. I HAD DIFFICULTY HEARING COMPANY ACFT AND THEREFORE WAS CONCENTRATING ON MY CONVERSATION WITH THAT ACFT, ALONG WITH WRITING THE INFO DOWN. CENTER HAD CLRED US TO CLB TO FL230 (WE HAD FILED FOR FINAL ALT OF FL240). PLT AT THE CONTROLS THOUGHT WE HAD BEEN CLRED TO FL240. AT APPROX FL235 CENTER CONTACTED PLT AT THE CONTROLS AND INQUIRED ACFT ALT. WHEN PLT AT THE CONTROLS WAS INFORMED THAT WE HAD ONLY BEEN CLRED TO FL230 HE IMMEDIATELY DSNDED DOWN TO FL230. LACK OF COM, AND DISTR WERE THE CAUSES FOR THIS EVENT. I ALLOWED MY ATTN TO BE CONCENTRATED ON ONE SINGLE TASK (COPYING INFO FROM OTHER ACFT). THE NECESSARY CORRECTIVE ACTION TO PREVENT SUCH AN EVENT FROM OCCURRING AGAIN IS TWOFOLD: FIRST, MAKE CERTAIN THAT ALL FLT CREWMEMBERS ARE AWARE OF ALL CLRNCS. SECONDLY, DON'T LET ONE PROB CAUSE YOU TO BE DISTRACTED. I HAVE CERTAINLY LEARNED THESE LESSONS THROUGH THIS EVENT.

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.