An air carrier crew departed lit runway 4R at intersection Y believing that was the runway's takeoff...

Narrative:

Taxiing to runway 4R we were given a takeoff clearance passing south which is several hundred feet prior to the next intersection Y. At first we thought it was strange to receive a takeoff clearance so early. We both looked at the runway at 4R-Y and noticed the threshold markings. We commented that this looks like the end of the runway. The taxiway continued; but it took a jog to the right and sloped downward quite a bit; again leading us to believe that the intersection and the threshold we were looking at was the takeoff point. As we entered the runway I looked to the right and noticed that the runway did go farther back but it sloped downward. We discussed that we thought this was the takeoff power point of the runway and the part of the runway farther back appeared to be unusable and proceeded to takeoff. Once airborne after further discussion we realized that we had taken off from an intersection and not the end of the runway. We referenced the performance data and saw that we 2500 ft of stopping margin from the intersection of departure. The thing that was most misleading in this event was the point at which we received the takeoff clearance. In hindsight a quick call to the tower to confirm the departure point was something that should have been done.

Original NASA ASRS Text

Title: An Air Carrier Crew departed LIT Runway 4R at Intersection Y believing that was the Runway's takeoff position point.

Narrative: Taxiing to Runway 4R we were given a takeoff clearance passing S which is several hundred feet prior to the next intersection Y. At first we thought it was strange to receive a takeoff clearance so early. We both looked at the runway at 4R-Y and noticed the threshold markings. We commented that this looks like the end of the runway. The taxiway continued; but it took a jog to the right and sloped downward quite a bit; again leading us to believe that the intersection and the threshold we were looking at was the takeoff point. As we entered the runway I looked to the right and noticed that the runway did go farther back but it sloped downward. We discussed that we thought this was the takeoff power point of the runway and the part of the runway farther back appeared to be unusable and proceeded to takeoff. Once airborne after further discussion we realized that we had taken off from an intersection and not the end of the runway. We referenced the performance data and saw that we 2500 ft of stopping margin from the intersection of departure. The thing that was most misleading in this event was the point at which we received the takeoff clearance. In hindsight a quick call to the Tower to confirm the departure point was something that should have been done.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	861836
Time
Date	200911
Local Time Of Day	0601-1200
Place
Locale Reference	LIT.Airport
State Reference	AR
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Large Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Takeoff Taxi
Flight Plan	IFR
Person 1
Function	First Officer
Person 2
Function	Captain
Experience	Flight Crew Last 90 Days 184
Events
Anomaly	Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy

An air carrier crew departed lit runway 4R at intersection Y believing that was the runway's takeoff position point.