Narrative:

We were cleared to taxi to runway 31C at midway airport. The copilot, having the airport diagram, directed me to the runway. The windshield was slightly fogged up from the moist conditions. Upon reaching the runway, we were cleared for takeoff on runway 31C. The aircraft was taxied onto the runway as the copilot pointed out the centerline lighting. The aircraft was positioned slightly left of the assumed centerline lighting position and held there while the cabin was checked to see if passenger were buckled in and ready to go. The windshield was still slightly fogged up due to the moist atmospheric conditions at the time. Brakes were held as power was increased to takeoff power, allowing for improvement in defogging windshield. Brakes were released as per procedure. Copilot was called to make any adjustments to power. As aircraft headed down runway and accelerated for takeoff, copilot called for airspeed xchk at 60 KTS. Shortly thereafter, we heard a single thump, sounding similar to a tire rolling over a recessed centerline light. Aircraft instruments, annunciator panel were fine, as was the directional control of the aircraft. Thinking an aircraft tire rolled over a centerline light was the cause of the noise, we continued the takeoff and I positioned aircraft between the lights left and right of us to prevent running over the recessed lights again. The rest of the flight proceeded normally to destination. Postflt inspection found a hole on the underside of the inboard right flap, another small hold in right outboard flap. Midway airport was called immediately to inspect the runway we departed on. After inspection of the runway, midway tower called back and indicated a runway light and the top of a sign were knocked down. Upon studying the airport diagram, we found that there wasn't centerline lighting on runway 31C. We concluded that aircraft must have been lined up on right side of runway, which had a paved entrance the entire width of the displaced threshold. The problem was caused by lack of aircraft situational awareness by the crew. Given the complex and confusing environment we were in, a better familiarization of the airport layout should have been understood. Furthermore, I should have crosschecked copilot's directions and paid extra attention due to the slight fatigue of the crew.

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Original NASA ASRS Text

Title: C560 CREW LINED UP ON THE RWY EDGE LIGHTS AND THOUGHT THEY WERE THE RWY CTRLINE LIGHTS. THE RWY DOES NOT HAVE CTRLINE LIGHTS.

Narrative: WE WERE CLRED TO TAXI TO RWY 31C AT MIDWAY ARPT. THE COPLT, HAVING THE ARPT DIAGRAM, DIRECTED ME TO THE RWY. THE WINDSHIELD WAS SLIGHTLY FOGGED UP FROM THE MOIST CONDITIONS. UPON REACHING THE RWY, WE WERE CLRED FOR TKOF ON RWY 31C. THE ACFT WAS TAXIED ONTO THE RWY AS THE COPLT POINTED OUT THE CTRLINE LIGHTING. THE ACFT WAS POSITIONED SLIGHTLY L OF THE ASSUMED CTRLINE LIGHTING POS AND HELD THERE WHILE THE CABIN WAS CHKED TO SEE IF PAX WERE BUCKLED IN AND READY TO GO. THE WINDSHIELD WAS STILL SLIGHTLY FOGGED UP DUE TO THE MOIST ATMOSPHERIC CONDITIONS AT THE TIME. BRAKES WERE HELD AS PWR WAS INCREASED TO TKOF PWR, ALLOWING FOR IMPROVEMENT IN DEFOGGING WINDSHIELD. BRAKES WERE RELEASED AS PER PROC. COPLT WAS CALLED TO MAKE ANY ADJUSTMENTS TO PWR. AS ACFT HEADED DOWN RWY AND ACCELERATED FOR TKOF, COPLT CALLED FOR AIRSPD XCHK AT 60 KTS. SHORTLY THEREAFTER, WE HEARD A SINGLE THUMP, SOUNDING SIMILAR TO A TIRE ROLLING OVER A RECESSED CTRLINE LIGHT. ACFT INSTS, ANNUNCIATOR PANEL WERE FINE, AS WAS THE DIRECTIONAL CTL OF THE ACFT. THINKING AN ACFT TIRE ROLLED OVER A CTRLINE LIGHT WAS THE CAUSE OF THE NOISE, WE CONTINUED THE TKOF AND I POSITIONED ACFT BTWN THE LIGHTS L AND R OF US TO PREVENT RUNNING OVER THE RECESSED LIGHTS AGAIN. THE REST OF THE FLT PROCEEDED NORMALLY TO DEST. POSTFLT INSPECTION FOUND A HOLE ON THE UNDERSIDE OF THE INBOARD R FLAP, ANOTHER SMALL HOLD IN R OUTBOARD FLAP. MIDWAY ARPT WAS CALLED IMMEDIATELY TO INSPECT THE RWY WE DEPARTED ON. AFTER INSPECTION OF THE RWY, MIDWAY TWR CALLED BACK AND INDICATED A RWY LIGHT AND THE TOP OF A SIGN WERE KNOCKED DOWN. UPON STUDYING THE ARPT DIAGRAM, WE FOUND THAT THERE WASN'T CTRLINE LIGHTING ON RWY 31C. WE CONCLUDED THAT ACFT MUST HAVE BEEN LINED UP ON R SIDE OF RWY, WHICH HAD A PAVED ENTRANCE THE ENTIRE WIDTH OF THE DISPLACED THRESHOLD. THE PROB WAS CAUSED BY LACK OF ACFT SITUATIONAL AWARENESS BY THE CREW. GIVEN THE COMPLEX AND CONFUSING ENVIRONMENT WE WERE IN, A BETTER FAMILIARIZATION OF THE ARPT LAYOUT SHOULD HAVE BEEN UNDERSTOOD. FURTHERMORE, I SHOULD HAVE XCHKED COPLT'S DIRECTIONS AND PAID EXTRA ATTN DUE TO THE SLIGHT FATIGUE OF THE CREW.

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.