Service difficulty report · Tat Probe · Boeing 737823

Difficulty date
July 31, 2019
Submitted
August 3, 2019
Operation
Air carrier
Aircraft
N807NN
Make and model
Boeing 737823
Aircraft serial
31077
Aircraft time
30,929 hours, 12,356 cycles
Part
Tat Probe
Part number
102LA2AG
Part serial
A94235
Condition
Unreliable
Location
First Officer'S
Stage of operation
CR
How discovered
O
Nature of condition
S
Precautionary procedure
O

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

AIRCRAFT WAS GROUNDED: PILOT REPORTS DURING CRUISE FLIGHT FL 370 IN CLEAR SKIES, F/O ALTIMETER & AIRSPEED BECAME UNRELIABLE. IAS DESAGREE, ALT DISAGREE, EECS WENT INTO SOFT ALTN MODE. RAN AIRSPEED UNRELIABLE AND EEC ALTERNATE MODE QRH. INDICATIONS RETURNED TO NORMAL WHEN DECENDING THRU 25,000 FEET. EEC SWITCHES ARE IN HARD ALTERNATE MODE. MAINTENANCE ACCOMPLISHED DFCS BITE, FOUND MX MSG 22-11822, PERFORMED TASK FIM 22-11-00, REPLACED FO PITOT PROBE IAW AMM 34-11-01, RH ADM IAW AMM 34-21-04, TAT PROBE REPLACED IAW AMM 34-21-06. PERFORMED PITOT SYSTEM FLUSHING IAW AMM 34-11-00. PERFORMED ALL REQUIRED TEST ALSO HUD TEST IAW AMM 34-36-00. ALL CHECKS NORMAL. NO FURTHER FAULTS. (SEE SDR # AALA201908019022 & AALA201908029017)