Narrative:

We were repositioning the aircraft from den to apa for XD30 charter. We were pressed for time because we could not start out duty time till XC30, since yesterday's trip ended at XS30. We needed to show 10 hours of rest for far 135.261. This cut us short on our usual 1 hour of preflight preparation and 1 hour in position prior to departure. We taxied out on 1 engine and started the other engine during the taxi. During the second start, tower called us with instructions and the copilot answered. After taxiing to the runway, we finished the before takeoff checklist and I said, 'taxi into position and hold.' the copilot said, 'no, we're cleared for takeoff.' I assumed he was correct because it was a week of 14 hour days and XA30 wake-ups for myself. If anyone was not at his peak it was myself, not the copilot. So we taxied onto the runway and departed. After takeoff, tower called us and said we did not have takeoff clearance. The copilot still believes we did have the clearance. There are several factors involved here as to the cause. One is the far requiring 10 hours of rest in the last 14 hours. Is this really a sufficient amount of time? I have never found it to be. Another point is a practice I have found common at den. If it is not busy, you will be on the tower frequency for taxi instructions and you will receive a takeoff clearance long before you get to the end of the runway and before you solicit them for a takeoff clearance. Naturally, we do not have to accept it, but when you're already in a hurry it becomes very enticing to accept it before you are really ready. And finally the breaking of a cardinal rule--that if there is any doubt, ask again. It would have saved a lot of grief.

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Original NASA ASRS Text

Title: TKOF WITHOUT CLRNC.

Narrative: WE WERE REPOSITIONING THE ACFT FROM DEN TO APA FOR XD30 CHARTER. WE WERE PRESSED FOR TIME BECAUSE WE COULD NOT START OUT DUTY TIME TILL XC30, SINCE YESTERDAY'S TRIP ENDED AT XS30. WE NEEDED TO SHOW 10 HRS OF REST FOR FAR 135.261. THIS CUT US SHORT ON OUR USUAL 1 HR OF PREFLT PREPARATION AND 1 HR IN POS PRIOR TO DEP. WE TAXIED OUT ON 1 ENG AND STARTED THE OTHER ENG DURING THE TAXI. DURING THE SECOND START, TWR CALLED US WITH INSTRUCTIONS AND THE COPLT ANSWERED. AFTER TAXIING TO THE RWY, WE FINISHED THE BEFORE TKOF CHKLIST AND I SAID, 'TAXI INTO POS AND HOLD.' THE COPLT SAID, 'NO, WE'RE CLRED FOR TKOF.' I ASSUMED HE WAS CORRECT BECAUSE IT WAS A WK OF 14 HR DAYS AND XA30 WAKE-UPS FOR MYSELF. IF ANYONE WAS NOT AT HIS PEAK IT WAS MYSELF, NOT THE COPLT. SO WE TAXIED ONTO THE RWY AND DEPARTED. AFTER TKOF, TWR CALLED US AND SAID WE DID NOT HAVE TKOF CLRNC. THE COPLT STILL BELIEVES WE DID HAVE THE CLRNC. THERE ARE SEVERAL FACTORS INVOLVED HERE AS TO THE CAUSE. ONE IS THE FAR REQUIRING 10 HRS OF REST IN THE LAST 14 HRS. IS THIS REALLY A SUFFICIENT AMOUNT OF TIME? I HAVE NEVER FOUND IT TO BE. ANOTHER POINT IS A PRACTICE I HAVE FOUND COMMON AT DEN. IF IT IS NOT BUSY, YOU WILL BE ON THE TWR FREQ FOR TAXI INSTRUCTIONS AND YOU WILL RECEIVE A TKOF CLRNC LONG BEFORE YOU GET TO THE END OF THE RWY AND BEFORE YOU SOLICIT THEM FOR A TKOF CLRNC. NATURALLY, WE DO NOT HAVE TO ACCEPT IT, BUT WHEN YOU'RE ALREADY IN A HURRY IT BECOMES VERY ENTICING TO ACCEPT IT BEFORE YOU ARE REALLY READY. AND FINALLY THE BREAKING OF A CARDINAL RULE--THAT IF THERE IS ANY DOUBT, ASK AGAIN. IT WOULD HAVE SAVED A LOT OF GRIEF.

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.