A LR35 departed the runway after weathervaning on a runway poorly drained following a passing thunde...

Attributes
ACN	842031
Time
Date	200906
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Make Model Name	Learjet 35
Operating Under FAR Part	Part 91
Flight Phase	Landing
Route In Use	Visual Approach
Flight Plan	IFR
Component
Aircraft Component	Wheels/Tires/Brakes
Person 1
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Commercial
Experience	Flight Crew Last 90 Days 55 Flight Crew Total 1328 Flight Crew Type 1014
Person 2
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 150 Flight Crew Total 19700 Flight Crew Type 4200
Events
Anomaly	Ground Excursion Runway Inflight Event / Encounter Loss Of Aircraft Control Inflight Event / Encounter Weather / Turbulence

Narrative:

Upon landing at a reference speed of 115 KTS; on centerline; and on the numbers; the aircraft appeared to be operating normally until the first brake application was attempted. Brakes appeared to be non-effective; aircraft began to weathervane into the wind (wind; 200/10kts. On runway xx); and drift to the right. At approximately 100 KTS; the pilot flying called for the 'chute;' I deployed the drag chute; which straightened the plane out again. However; the plane began to weathervane into the wind again and continued to drift right. Brakes were still completely ineffective. At approximately 70 KTS aircraft departed the right side of the runway with about a 30-degree left crab angle. Aircraft continued for about 100 yards before coming to a stop back on taxiway golf. Official cause of the incident was hydroplaning. Although weather at the time of landing was light rain; a severe thunderstorm had just passed through the area. The runway surface was flat with no easy way for water to run off. I recommend the airport re-surface the runway with a surface shape (including grooving) that allows for better water run off. No injuries occurred; and no major aircraft damage seen.

Original NASA ASRS Text

Title: A LR35 departed the runway after weathervaning on a runway poorly drained following a passing thunderstorm and continued light rain. The aircraft's drag chute was deployed and momentarily helped direction control.

Narrative: Upon landing at a REF speed of 115 KTS; on centerline; and on the numbers; the aircraft appeared to be operating normally until the first brake application was attempted. Brakes appeared to be non-effective; aircraft began to weathervane into the wind (wind; 200/10kts. on Runway XX); and drift to the right. At approximately 100 KTS; the pilot flying called for the 'chute;' I deployed the drag chute; which straightened the plane out again. However; the plane began to weathervane into the wind again and continued to drift right. Brakes were still completely ineffective. At approximately 70 KTS aircraft departed the right side of the runway with about a 30-degree left crab angle. Aircraft continued for about 100 yards before coming to a stop back on taxiway Golf. Official cause of the incident was hydroplaning. Although weather at the time of landing was light rain; a severe thunderstorm had just passed through the area. The runway surface was flat with no easy way for water to run off. I recommend the airport re-surface the runway with a surface shape (including grooving) that allows for better water run off. No injuries occurred; and no major aircraft damage seen.

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.