Narrative:

WX conditions were approximately 2600 ft broken, 5 mi visibility, winds 190 degrees at 6 KTS, and moderate rain showers. Flight conditions were IMC with no turbulence. I reduced the thrust levers to flight idle and made a smooth and controled landing at vref on or near the second set of touchdown markings. Knowing that the runway conditions were wet and the length was short, I immediately applied pressure to the brake pedals upon touchdown. Captain immediately extended spoilers on touchdown. Deceleration of the aircraft appeared to be normal. At approximately 3/4 of the way down the runway all appeared to be normal and stopping the aircraft prior to the end of the runway was never questionable. At roughly 200-400 ft prior to the end of the runway the aircraft appeared to stop decelerating as it normally does. There is a strong possibility that the aircraft began to hydroplane. At approximately 100 ft prior to the end of the runway, it was apparent that I would not be able to completely stop the aircraft. I deployed the drag chute, because the grass was wet and I wished to utilize every means available to me to stop the aircraft from sliding through the fence. I would have approximated the aircraft speed to be in the vicinity of 40-50 KTS. Demonstrating that there was no effective braking in the last 200 ft. The drag chute opened fully just as the aircraft nosewheel left the runway surface and made contact with the grass. I maintained directional control accomplishing a left hand turn 100 ft and 80 degrees back towards the runway. Once the aircraft was close to straight, I applied a small amount of power to ensure forward movement as to not become stuck in the soaking wet grass. I taxied the aircraft to re-enter the runway surface. I was cleared to back taxi on the runway to the FBO. There was no damage to airport property or to the airplane. Maintenance did a thorough inspection of the aircraft, its braking and anti-skid system, and its tires prior to initiating return home flight. There were no malfunctions or deficiencies to any system and no flat spots on the tires, which would indicate that hydroplaning did occur.

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Original NASA ASRS Text

Title: A LEAR25 HYDROPLANES OFF THE RWY AT PWK, IL.

Narrative: WX CONDITIONS WERE APPROX 2600 FT BROKEN, 5 MI VISIBILITY, WINDS 190 DEGS AT 6 KTS, AND MODERATE RAIN SHOWERS. FLT CONDITIONS WERE IMC WITH NO TURB. I REDUCED THE THRUST LEVERS TO FLT IDLE AND MADE A SMOOTH AND CTLED LNDG AT VREF ON OR NEAR THE SECOND SET OF TOUCHDOWN MARKINGS. KNOWING THAT THE RWY CONDITIONS WERE WET AND THE LENGTH WAS SHORT, I IMMEDIATELY APPLIED PRESSURE TO THE BRAKE PEDALS UPON TOUCHDOWN. CAPT IMMEDIATELY EXTENDED SPOILERS ON TOUCHDOWN. DECELERATION OF THE ACFT APPEARED TO BE NORMAL. AT APPROX 3/4 OF THE WAY DOWN THE RWY ALL APPEARED TO BE NORMAL AND STOPPING THE ACFT PRIOR TO THE END OF THE RWY WAS NEVER QUESTIONABLE. AT ROUGHLY 200-400 FT PRIOR TO THE END OF THE RWY THE ACFT APPEARED TO STOP DECELERATING AS IT NORMALLY DOES. THERE IS A STRONG POSSIBILITY THAT THE ACFT BEGAN TO HYDROPLANE. AT APPROX 100 FT PRIOR TO THE END OF THE RWY, IT WAS APPARENT THAT I WOULD NOT BE ABLE TO COMPLETELY STOP THE ACFT. I DEPLOYED THE DRAG CHUTE, BECAUSE THE GRASS WAS WET AND I WISHED TO UTILIZE EVERY MEANS AVAILABLE TO ME TO STOP THE ACFT FROM SLIDING THROUGH THE FENCE. I WOULD HAVE APPROXIMATED THE ACFT SPD TO BE IN THE VICINITY OF 40-50 KTS. DEMONSTRATING THAT THERE WAS NO EFFECTIVE BRAKING IN THE LAST 200 FT. THE DRAG CHUTE OPENED FULLY JUST AS THE ACFT NOSEWHEEL LEFT THE RWY SURFACE AND MADE CONTACT WITH THE GRASS. I MAINTAINED DIRECTIONAL CTL ACCOMPLISHING A L HAND TURN 100 FT AND 80 DEGS BACK TOWARDS THE RWY. ONCE THE ACFT WAS CLOSE TO STRAIGHT, I APPLIED A SMALL AMOUNT OF PWR TO ENSURE FORWARD MOVEMENT AS TO NOT BECOME STUCK IN THE SOAKING WET GRASS. I TAXIED THE ACFT TO RE-ENTER THE RWY SURFACE. I WAS CLRED TO BACK TAXI ON THE RWY TO THE FBO. THERE WAS NO DAMAGE TO ARPT PROPERTY OR TO THE AIRPLANE. MAINT DID A THOROUGH INSPECTION OF THE ACFT, ITS BRAKING AND ANTI-SKID SYS, AND ITS TIRES PRIOR TO INITIATING RETURN HOME FLT. THERE WERE NO MALFUNCTIONS OR DEFICIENCIES TO ANY SYS AND NO FLAT SPOTS ON THE TIRES, WHICH WOULD INDICATE THAT HYDROPLANING DID OCCUR.

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.