Narrative:

While operating in rvsm airspace. We were in level flight at FL360; moderate turbulence; dodging thunderstorms and received numerous aircraft alerts along with an intermittent stick shaker (indicated airspeed was greater than 30 KTS above the lower foot). One of the alerts was the autopilot disconnecting along with the autothrottles. As the pilot flying I maintained altitude and airspeed while the first officer (pilot not flying) referenced the QRH for the associated alerts. The QRH drove us to the md-11; airspeed: lost; suspect; or erratic checklist. This checklist calls for the aircraft to get stabilized in altitude and airspeed and then compare airspeeds from both pilots stations along with the standby to determine the faulty system. We determined that the first officer's airspeed was off by -15 KTS. During this entire portion of the checklist I was hand flying the aircraft in rvsm airspace due to neither autopilot being available. I'm aware that this isn't in compliance with the far's; but in our situation of running the checklist requirements and the turbulence along with the inoperative equipment it was the only choice we had. During this entire situation; our altitude never varied by more than +/- 150 ft from FL360; which was our cleared altitude. Both the first officer and I felt that our actions were the best choice for the bad situation. Thanks to my first officer for his systems knowledge and proficiency; it truly helped to prevented this situation from getting out of hand.

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Original NASA ASRS Text

Title: An MD-11 First Officer's airspeed indicated fifteen knots less than the Captain's indications during moderate turbulence at FL360. The Captain hand flew the aircraft in RVSM airspace because the autopilots were inoperative along with an intermittent stick shaker.

Narrative: While operating in RVSM airspace. We were in level flight at FL360; moderate turbulence; dodging thunderstorms and received numerous aircraft alerts along with an intermittent stick shaker (indicated airspeed was greater than 30 KTS above the lower foot). One of the alerts was the autopilot disconnecting along with the autothrottles. As the pilot flying I maintained altitude and airspeed while the First Officer (pilot not flying) referenced the QRH for the associated alerts. The QRH drove us to the MD-11; Airspeed: Lost; Suspect; or Erratic Checklist. This checklist calls for the aircraft to get stabilized in altitude and airspeed and then compare airspeeds from both pilots stations along with the standby to determine the faulty system. We determined that the First Officer's airspeed was off by -15 KTS. During this entire portion of the checklist I was hand flying the aircraft in RVSM airspace due to neither autopilot being available. I'm aware that this isn't in compliance with the FAR's; but in our situation of running the checklist requirements and the turbulence along with the inoperative equipment it was the only choice we had. During this entire situation; our altitude never varied by more than +/- 150 FT from FL360; which was our cleared altitude. Both the First Officer and I felt that our actions were the best choice for the bad situation. Thanks to my First Officer for his systems knowledge and proficiency; it truly helped to prevented this situation from getting out of hand.

Data retrieved from NASA's ASRS site as of July 2013 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.