What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23)The pilot of N996TD misunderstood a clearance to climb to a higher altitude. He read back the clearance to ATC with no response. After receiving traffic information the pilot was concerned that his altitude assignment may have been in error. He queried ATC and was instructed to maintain his previously assigned altitude. Loss of vertical separation occurred during his climb and subsequent descent. This incident has a dual responsibility for the error. The incident report from ATC clearly states that the controller was "off line" so to speak during the pilot's read back. There is dual responsibility of ATC and the pilot to understand the clearance. ATC should have confirmed the clearance if there was confusinon on the frequency. The pilot, not receiving any other responce, began his climb. Therefore, this incident is closed with no further action.
As the FAA filed it
(-23)THE PILOT OF N996TD MISUNDERSTOOD A CLEARANCE TO CLIMB TO A HIGHER ALTITUDE. HE READ BACK THE CLEARANCE TO ATC WITH NO RESPONSE. AFTER RECEIVING TRAFFIC INFORMATION THE PILOT WAS CONCERNED THAT HIS ALTITUDE ASSIGNMENT MAY HAVE BEEN IN ERROR. HE QUERIED ATC AND WAS INSTRUCTED TO MAINTAIN HIS PREVIOUSLY ASSIGNED ALTITUDE. LOSS OF VERTICAL SEPARATION OCCURRED DURING HIS CLIMB AND SUBSEQUENT DESCENT. THIS INCIDENT HAS A DUAL RESPONSIBILITY FOR THE ERROR. THE INCIDENT REPORT FROM ATC CLEARLY STATES THAT THE CONTROLLER WAS "OFF LINE" SO TO SPEAK DURING THE PILOT'S READ BACK. THERE IS DUAL RESPONSIBILITY OF ATC AND THE PILOT TO UNDERSTAND THE CLEARANCE. ATC SHOULD HAVE CONFIRMED THE CLEARANCE IF THERE WAS CONFUSINON ON THE FREQUENCY. THE PILOT, NOT RECEIVING ANY OTHER RESPONCE, BEGAN HIS CLIMB. THEREFORE, THIS INCIDENT IS CLOSED WITH NO FURTHER ACTION.