B737-400
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Air Traffic Control Issued Advisory / Alert; Flight Crew Diverted; Flight Crew Landed As Precaution; General Declared Emergency; General Maintenance Action
Aircraft
On climbout; autothrottle failed at approximately 10;000 FT. While running checklist; ATC notified us of no transponder being received. Received ACARS from Dispatch saying our times where erroneous. While checking that; GND PROX Fail light illuminated. Decided to stop climb at FL280 to remain clear of RVSM airspace. While continuing checklists; Cabin Altitude Warning Horn went off at cabin altitude of about 10;000 FT (10;500 FT cabin altitude was the maximum we got to and no masks deployed). Ran CABIN ALT WARNING QRH and were unable to control cabin altitude in STBY and switched to manual. Commenced descent to 10;000 FT after declaring an emergency. ENG Master Caution illuminated (LOW IDLE) on descent. Contacted Dispatch and coordinated for a divert. Remained in continuous contact with ATC throughout flight. Landed uneventfully at our divert airport with no assistance required. No passengers required assistance upon landing. Maintenance discovered plastic bags and insulation in the Pressurization Outflow Valve after shutdown. Malfunction could not be duplicated. Possible Air/Ground Sensor. Still being reviewed by Maintenance.
B737-400 Captain experiences numerous anomalies during climb including loss of cabin pressurization; possibly caused by a faulty ground/air sensor. Plastic bags were found in the outflow valve on post flight.