A lear 35A first officer reports that his captain made an unauthorized takeoff taxiway takeoff.

Attributes
ACN	356786
Time
Date	199612
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mci
State Reference	MO
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	IMC
Light	Dawn
Aircraft 1
Controlling Facilities	tower : mci tower : lax
Operator	common carrier : air taxi
Make Model Name	Learjet 35
Operating Under FAR Part	Part 135
Flight Phase	climbout : takeoff
Route In Use	departure sid : sid
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : first officer
Qualification	pilot : commercial pilot : cfi pilot : instrument
Experience	flight time last 90 days : 100 flight time total : 1450 flight time type : 42
ASRS Report	356786
Person 2
Affiliation	company : air taxi
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	incursion : runway non adherence : clearance other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

The captain began to taxi for a departure on runway 19R. We were on the fourth leg of the trip and fatigue was a problem on the non scheduled overnight flight. As we taxied, the captain was rushing so we could depart with minimum fuel burn (fuel status was not a flight factor -- we had plenty). As we approached A2 on taxiway B, we were cleared for takeoff on runway 19R. I began the copilot duties of doing the various pretkof checklists when we reached A1. The captain turned left onto taxiway a while I was still doing pretkof checks. As we immediately began the takeoff roll, I was roughly halfway through the checklist. My eyes were inside the whole time. As I called V1, we continued to takeoff. After rotation, the captain noticed that we had just taken off on a taxiway.

Original NASA ASRS Text

Title: A LEAR 35A FO RPTS THAT HIS CAPT MADE AN UNAUTH TKOF TXWY TKOF.

Narrative: THE CAPT BEGAN TO TAXI FOR A DEP ON RWY 19R. WE WERE ON THE FOURTH LEG OF THE TRIP AND FATIGUE WAS A PROB ON THE NON SCHEDULED OVERNIGHT FLT. AS WE TAXIED, THE CAPT WAS RUSHING SO WE COULD DEPART WITH MINIMUM FUEL BURN (FUEL STATUS WAS NOT A FLT FACTOR -- WE HAD PLENTY). AS WE APCHED A2 ON TXWY B, WE WERE CLRED FOR TKOF ON RWY 19R. I BEGAN THE COPLT DUTIES OF DOING THE VARIOUS PRETKOF CHKLISTS WHEN WE REACHED A1. THE CAPT TURNED L ONTO TXWY A WHILE I WAS STILL DOING PRETKOF CHKS. AS WE IMMEDIATELY BEGAN THE TKOF ROLL, I WAS ROUGHLY HALFWAY THROUGH THE CHKLIST. MY EYES WERE INSIDE THE WHOLE TIME. AS I CALLED V1, WE CONTINUED TO TKOF. AFTER ROTATION, THE CAPT NOTICED THAT WE HAD JUST TAKEN OFF ON A TXWY.

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.