While cruising at FL240 and 330 knots indicated; A319 captain experiences onset of vibration that in...

Narrative:

Flying faster than normal in order to get back on schedule; after an intermediate level off during the climb; fl 240; we were indicating 330K. Well below vmo/mmo. After a few minutes aircraft experienced an onset of vibration increasing in intensity. Immediately reducing speed; it was moderate by the time aircraft slowed and then finally dissipated. Engine vibration indicators were absolutely normal. We continued the flight at a much lower cruise altitude than filed (FL290) and slower speed . . . M.74. Even at .74 the vibration was very slight but still noticeable.high speed buffet? Maybe but again we were well below the indicated vmo/mmo 'redline'. Possible inaccurate airspeed indicators aka thales airbus 330 problems? I know the aircraft will be flight tested but suggest investigation into the accuracy of the airspeed indicators.

Original NASA ASRS Text

Title: While cruising at FL240 and 330 knots indicated; A319 captain experiences onset of vibration that increases in intensity. Slowing to Mach .74 greatly reduces the vibration and the flight continues to destination.

Narrative: Flying faster than normal in order to get back on schedule; after an intermediate level off during the climb; FL 240; we were indicating 330K. Well below Vmo/Mmo. After a few minutes aircraft experienced an onset of vibration increasing in intensity. Immediately reducing speed; it was moderate by the time aircraft slowed and then finally dissipated. Engine vibration indicators were absolutely normal. We continued the flight at a much lower cruise altitude than filed (FL290) and slower speed . . . M.74. Even at .74 the vibration was very slight but still noticeable.High speed buffet? Maybe but again we were well below the indicated Vmo/Mmo 'redline'. Possible inaccurate airspeed indicators AKA Thales Airbus 330 problems? I know the aircraft will be flight tested but suggest investigation into the accuracy of the airspeed indicators.

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	847454
Time
Date	200908
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	A319
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Airframe
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe

While cruising at FL240 and 330 knots indicated; A319 captain experiences onset of vibration that increases in intensity. Slowing to mach .74 greatly reduces the vibration and the flight continues to destination.