Narrative:

In preparing to depart from bna on apr/tue/04, I obtained ATIS and contacted ground control. The controller instructed me to contact the tower (clearance delivery sic) to get departure clearance. After receiving departure instructions from the tower, I returned to the ground frequency and informed the controller that I was ready to taxi. The controller said I was cleared to taxi to runway 20C. When I reached the hold short line at runway 20C, I called the ground controller and informed him that I was ready to depart. He called back and stated 'aircraft X, cleared for departure.' I replied 'aircraft X, cleared for departure,' and then proceeded onto the runway, set my gyro to runway alignment, and departed. Shortly after departure, the ground controller called out to me and asked if I was airborne and I replied that I was. He instructed me to contact the tower. The tower instructed me to turn to a heading of 110 degrees. I immediately began a left hand turn towards 110 degrees, but didn't realize at that point that I had set my gyro to 02 degrees instead of 20 degrees. As I continued my turn, the tower informed that I was turning too far to the north. I then realized what I had done and checked the magnetic compass. Unfortunately, it was unreadable. It is an old fluid type and was alternately turning and sticking. I looked at my LORAN for a heading and it had lost the signal. I reported the gyro problem to the tower and the controller instructed me to head east. I attempted to reset my gyro to 180 degrees opposite of my original setting. The tower contacted me twice more to get me on an easterly course. Once I got the gyro reset, I asked the tower if he could confirm that I was now on a heading of 090 degrees and he did so. Shortly afterward, I received an instruction from the controller to call the tower after landing. After a few mins I had recycled my LORAN and it was showing the correct bearing and heading for my destination. The remainder of the flight was uneventful. When I called the tower, I was completely surprised when the controller stated that I had departed without clearance. It wasn't until I spoke with my CFI that I realized my error in not contacting the tower for departure clearance. Several factors contributed to the events. Primarily, my lack of experience with controled field procedures, combined with a fairly extended hiatus from flying, had left me unprepared for the situation. I had been into several controled fields and had been depending on following each controller's instructions explicitly as the best way to rebuild my familiarity with controled field procedures. In some cases, I had been into smaller fields where a single controller served as ground, tower, and clearance delivery. At all other times, the ground controller had explicitly instructed me to 'contact the tower' when I reached the runway and reported 'ready to depart.' when the ground controller at nashville stated 'cleared for departure,' I should have known to then either contact the tower or ask the controller if I should contact the tower. My inexperience, however, made me believe that 'cleared for departure' and 'cleared for takeoff' were the same. Clearly, they are not. I should never depart a controled field without being in contact with the 'tower' controller. The incorrect gyro setting, combined with a defective compass and a non-operating LORAN, served to exacerbate the problem with the 'unannounced' takeoff. While I feel I recovered fairly quickly from the combination of equipment problems, there is no doubt that those few mins of my inability to accurately and quickly follow ATC's instructions, especially under the circumstances of the uncontrolled departure, created a dangerous situation for both myself and other aircraft in the area.

Related reports:

Google
 

Original NASA ASRS Text

Title: M20F PLT CONFUSES BNA GND CTLR PHRASEOLOGY TO CONTACT TWR FOR DEP AS A DEP CLRNC FOR TKOF.

Narrative: IN PREPARING TO DEPART FROM BNA ON APR/TUE/04, I OBTAINED ATIS AND CONTACTED GND CTL. THE CTLR INSTRUCTED ME TO CONTACT THE TWR (CLRNC DELIVERY SIC) TO GET DEP CLRNC. AFTER RECEIVING DEP INSTRUCTIONS FROM THE TWR, I RETURNED TO THE GND FREQ AND INFORMED THE CTLR THAT I WAS READY TO TAXI. THE CTLR SAID I WAS CLRED TO TAXI TO RWY 20C. WHEN I REACHED THE HOLD SHORT LINE AT RWY 20C, I CALLED THE GND CTLR AND INFORMED HIM THAT I WAS READY TO DEPART. HE CALLED BACK AND STATED 'ACFT X, CLRED FOR DEP.' I REPLIED 'ACFT X, CLRED FOR DEP,' AND THEN PROCEEDED ONTO THE RWY, SET MY GYRO TO RWY ALIGNMENT, AND DEPARTED. SHORTLY AFTER DEP, THE GND CTLR CALLED OUT TO ME AND ASKED IF I WAS AIRBORNE AND I REPLIED THAT I WAS. HE INSTRUCTED ME TO CONTACT THE TWR. THE TWR INSTRUCTED ME TO TURN TO A HDG OF 110 DEGS. I IMMEDIATELY BEGAN A L HAND TURN TOWARDS 110 DEGS, BUT DIDN'T REALIZE AT THAT POINT THAT I HAD SET MY GYRO TO 02 DEGS INSTEAD OF 20 DEGS. AS I CONTINUED MY TURN, THE TWR INFORMED THAT I WAS TURNING TOO FAR TO THE N. I THEN REALIZED WHAT I HAD DONE AND CHKED THE MAGNETIC COMPASS. UNFORTUNATELY, IT WAS UNREADABLE. IT IS AN OLD FLUID TYPE AND WAS ALTERNATELY TURNING AND STICKING. I LOOKED AT MY LORAN FOR A HDG AND IT HAD LOST THE SIGNAL. I RPTED THE GYRO PROB TO THE TWR AND THE CTLR INSTRUCTED ME TO HEAD E. I ATTEMPTED TO RESET MY GYRO TO 180 DEGS OPPOSITE OF MY ORIGINAL SETTING. THE TWR CONTACTED ME TWICE MORE TO GET ME ON AN EASTERLY COURSE. ONCE I GOT THE GYRO RESET, I ASKED THE TWR IF HE COULD CONFIRM THAT I WAS NOW ON A HDG OF 090 DEGS AND HE DID SO. SHORTLY AFTERWARD, I RECEIVED AN INSTRUCTION FROM THE CTLR TO CALL THE TWR AFTER LNDG. AFTER A FEW MINS I HAD RECYCLED MY LORAN AND IT WAS SHOWING THE CORRECT BEARING AND HDG FOR MY DEST. THE REMAINDER OF THE FLT WAS UNEVENTFUL. WHEN I CALLED THE TWR, I WAS COMPLETELY SURPRISED WHEN THE CTLR STATED THAT I HAD DEPARTED WITHOUT CLRNC. IT WASN'T UNTIL I SPOKE WITH MY CFI THAT I REALIZED MY ERROR IN NOT CONTACTING THE TWR FOR DEP CLRNC. SEVERAL FACTORS CONTRIBUTED TO THE EVENTS. PRIMARILY, MY LACK OF EXPERIENCE WITH CTLED FIELD PROCS, COMBINED WITH A FAIRLY EXTENDED HIATUS FROM FLYING, HAD LEFT ME UNPREPARED FOR THE SIT. I HAD BEEN INTO SEVERAL CTLED FIELDS AND HAD BEEN DEPENDING ON FOLLOWING EACH CTLR'S INSTRUCTIONS EXPLICITLY AS THE BEST WAY TO REBUILD MY FAMILIARITY WITH CTLED FIELD PROCS. IN SOME CASES, I HAD BEEN INTO SMALLER FIELDS WHERE A SINGLE CTLR SERVED AS GND, TWR, AND CLRNC DELIVERY. AT ALL OTHER TIMES, THE GND CTLR HAD EXPLICITLY INSTRUCTED ME TO 'CONTACT THE TWR' WHEN I REACHED THE RWY AND RPTED 'READY TO DEPART.' WHEN THE GND CTLR AT NASHVILLE STATED 'CLRED FOR DEP,' I SHOULD HAVE KNOWN TO THEN EITHER CONTACT THE TWR OR ASK THE CTLR IF I SHOULD CONTACT THE TWR. MY INEXPERIENCE, HOWEVER, MADE ME BELIEVE THAT 'CLRED FOR DEP' AND 'CLRED FOR TKOF' WERE THE SAME. CLRLY, THEY ARE NOT. I SHOULD NEVER DEPART A CTLED FIELD WITHOUT BEING IN CONTACT WITH THE 'TWR' CTLR. THE INCORRECT GYRO SETTING, COMBINED WITH A DEFECTIVE COMPASS AND A NON-OPERATING LORAN, SERVED TO EXACERBATE THE PROB WITH THE 'UNANNOUNCED' TKOF. WHILE I FEEL I RECOVERED FAIRLY QUICKLY FROM THE COMBINATION OF EQUIP PROBS, THERE IS NO DOUBT THAT THOSE FEW MINS OF MY INABILITY TO ACCURATELY AND QUICKLY FOLLOW ATC'S INSTRUCTIONS, ESPECIALLY UNDER THE CIRCUMSTANCES OF THE UNCTLED DEP, CREATED A DANGEROUS SIT FOR BOTH MYSELF AND OTHER ACFT IN THE AREA.

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.