A be-60 on a high speed runway taxi for airspeed indicator maintenance overran the runway's end when...

Attributes
ACN	843035
Time
Date	200907
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Aircraft 1
Make Model Name	Duke 60
Operating Under FAR Part	Part 91
Flight Phase	Takeoff
Route In Use	None
Flight Plan	None
Component
Aircraft Component	Brake System
Person 1
Function	Single Pilot
Qualification	Flight Crew Commercial Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 50 Flight Crew Total 2500 Flight Crew Type 300
Events
Anomaly	Aircraft Equipment Problem Less Severe Ground Event / Encounter Loss Of Aircraft Control Ground Excursion Runway

Narrative:

There appeared to be a discrepancy between the pilot and co-pilot's airspeed indicator. To verify this we initiated a high-speed taxi on the runway. The runway was sufficiently long according to the poh for accelerate and stop for the current conditions. Upon conclusion of the test phase (reaching rotation speed); the power was retarded and brakes applied. Braking occurred but was insufficient to stop the aircraft before running off the end of the runway approximately 20 ft. The brakes had been tested prior to beginning the run; but not to emergency braking capability. When brakes were applied the wheels continued to spin ie; there was insufficient braking to comply with the poh standard for emergency braking as would occur in an aborted takeoff. Since this sort of braking is; by definition; only used in emergencies; the brakes' inability to perform was unknown. If there had been a warning mechanism or a policy to test such hard braking; the over-run would not have occurred.

Original NASA ASRS Text

Title: A BE-60 on a high speed runway taxi for airspeed indicator maintenance overran the runway's end when the emergency braking did not stop the aircraft as aircraft performance manual indicated.

Narrative: There appeared to be a discrepancy between the pilot and co-pilot's airspeed indicator. To verify this we initiated a high-speed taxi on the runway. The runway was sufficiently long according to the POH for accelerate and stop for the current conditions. Upon conclusion of the test phase (reaching rotation speed); the power was retarded and brakes applied. Braking occurred but was insufficient to stop the aircraft before running off the end of the runway approximately 20 FT. The brakes had been tested prior to beginning the run; but not to emergency braking capability. When brakes were applied the wheels continued to spin ie; there was insufficient braking to comply with the POH standard for emergency braking as would occur in an aborted takeoff. Since this sort of braking is; by definition; only used in emergencies; the brakes' inability to perform was unknown. If there had been a warning mechanism or a policy to test such hard braking; the over-run would not have occurred.

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.

A be-60 on a high speed runway taxi for airspeed indicator maintenance overran the runway's end when the emergency braking did not stop the aircraft as aircraft performance manual indicated.