MD-80 Series (DC-9-80) Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft
All operations were normal up to the RVSM Check at FL 290. We noticed that the Standby Altimeter was frozen with an off flag and the Airspeed was showing zero. I asked the First Officer to pull out the QRH to see if we have a checklist related to our situation. It turned out that there was no checklist for a Standby Altimeter and or Standby Airspeed failure. We also checked the circuit breaker panel and found no popped circuit breakers.I then gave the controls to the First Officer as it was my leg; and I informed him that I was going to call the Company via SELCAL. I was then linked to Dispatch and Maintenance Control explained my situation. Maintenance Control also agreed that there was no checklist for our situation. Dispatch then informed me to continue the flight to [destination] and they would have Maintenance waiting for us to fix the airplane. I declined to continue to our destination; as I felt it was unsafe to continue with our destination still being close to 3 hours away and it was IFR at our destination. If we were to lose electrical power; we would have no altitude or airspeed on emergency power. Not a situation I wanted to be in. Dispatch then gave us the okay to return to [departure airport]. Return flight was normal. We switched airplanes and we also spoke to the Duty Pilot.
Captain reported returning to departure airport when the standby airspeed indicator and standby altimeter failed.