B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 119
Human-Machine Interface; Confusion
Aircraft Equipment Problem Less Severe
Flight Crew Returned To Clearance; General Maintenance Action
We were climbing through FL295 when we received a VNAV disconnect message. I looked at my flight instruments and noticed my airspeed was falling and crosschecked with my First Officer's instruments; which were normal. While performing the memory items and checklist for Airspeed Unreliable; we received an aural 'airspeed low' message; an IAS Disagree flag; and the EEC's transitioned to soft alternate mode. We completed the EEC Alternate Mode Checklist and the EEC's were transitioned to Hard Mode. We then completed the ALT Disagree Checklist.When we leveled off; I notified ATC of our reduced altimeter and airspeed indicator abilities. After consulting with Dispatch and Maintenance Control; Maintenance recommended a return to our departure airport. We joined the STAR back to the airport where landed without event. My flight instruments returned to normal at about FL180. This aircraft had history of pitot static problems within the previous week. I did perform a thorough review of the logbook prior to flight and was aware of its history. A phone call to Dispatch and Maintenance Control might have given me more insight to the problem at hand.
A B737-700 flight crew consulted with Maintenance and opted to return to their departure airport following receipt of multiple pitot static related anomalies.