Narrative:

I was instructing a private pilot student in a complex airplane (C-172RG). After completing training maneuvers, we flew to btl for stop and goes. We were using runway 31 left traffic. Our first approach was high and ended with a go around. Our second approach, we landed long, and were unable to takeoff because of a lack of runway in front of us. We told the tower that we needed to taxi back. They told us to do a 180 degree turn on the runway and hold short of runway 5, which we did. A king air departed runway 5. The tower told us that we could takeoff on runway 5 from the intersection of the runways, and that 2700 ft would be available for takeoff. From my experience, the airplane would need about 1700 ft for takeoff. So, I concluded that we could depart from the intersection. What I failed to realize was that we were on runway 31. We took off from that runway. After takeoff, the tower informed us that we took off from the wrong runway. We flew back to our home base without incident. I believe this incident occurred from lack of sleep clouding my judgement. The night before I flew on a 4 hour IFR cross country. We landed after midnight (local time). I awoke early (local time) that morning. I flew twice that morning for about 2 hours, and once that afternoon. I felt tired, but had no idea how bad my judgement had become. In the future, I will not schedule flts for late at night and early the next morning. I realize that the 67 hour minimum may not be enough after a tough, long flight.

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Original NASA ASRS Text

Title: INSTRUCTOR WITH STUDENT DEPARTS WRONG RWY.

Narrative: I WAS INSTRUCTING A PVT PLT STUDENT IN A COMPLEX AIRPLANE (C-172RG). AFTER COMPLETING TRAINING MANEUVERS, WE FLEW TO BTL FOR STOP AND GOES. WE WERE USING RWY 31 L TFC. OUR FIRST APCH WAS HIGH AND ENDED WITH A GAR. OUR SECOND APCH, WE LANDED LONG, AND WERE UNABLE TO TKOF BECAUSE OF A LACK OF RWY IN FRONT OF US. WE TOLD THE TWR THAT WE NEEDED TO TAXI BACK. THEY TOLD US TO DO A 180 DEG TURN ON THE RWY AND HOLD SHORT OF RWY 5, WHICH WE DID. A KING AIR DEPARTED RWY 5. THE TWR TOLD US THAT WE COULD TKOF ON RWY 5 FROM THE INTXN OF THE RWYS, AND THAT 2700 FT WOULD BE AVAILABLE FOR TKOF. FROM MY EXPERIENCE, THE AIRPLANE WOULD NEED ABOUT 1700 FT FOR TKOF. SO, I CONCLUDED THAT WE COULD DEPART FROM THE INTXN. WHAT I FAILED TO REALIZE WAS THAT WE WERE ON RWY 31. WE TOOK OFF FROM THAT RWY. AFTER TKOF, THE TWR INFORMED US THAT WE TOOK OFF FROM THE WRONG RWY. WE FLEW BACK TO OUR HOME BASE WITHOUT INCIDENT. I BELIEVE THIS INCIDENT OCCURRED FROM LACK OF SLEEP CLOUDING MY JUDGEMENT. THE NIGHT BEFORE I FLEW ON A 4 HR IFR XCOUNTRY. WE LANDED AFTER MIDNIGHT (LCL TIME). I AWOKE EARLY (LCL TIME) THAT MORNING. I FLEW TWICE THAT MORNING FOR ABOUT 2 HRS, AND ONCE THAT AFTERNOON. I FELT TIRED, BUT HAD NO IDEA HOW BAD MY JUDGEMENT HAD BECOME. IN THE FUTURE, I WILL NOT SCHEDULE FLTS FOR LATE AT NIGHT AND EARLY THE NEXT MORNING. I REALIZE THAT THE 67 HR MINIMUM MAY NOT BE ENOUGH AFTER A TOUGH, LONG FLT.

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.