Narrative:

Our assignment was a continuous duty trip from cvg to btv and back that reported at XA00 and would release almost 14 hours later with approximately 4 hours of sleep at the hotel in btv. Upon reporting to the aircraft in cvg, I found maintenance performing a check of the pitot/static system. After completion, we pushed back from the gate and prepared to taxi when 6 probe heat inoperative caution messages appeared. About an hour later maintenance completed replacement of a computer control box, reset the system, and we flew to btv with no further anomalies. Upon reporting to the aircraft in btv, we started the APU and established AC power then received caution messages for inoperative right angle of attack heat and right static heat. After pulling and resetting circuit breakers, the messages cleared and the aircraft was signed-off as fit for flight. However, immediately after takeoff we received caution messages for inoperative total air temperature probe heat and right static heat. We reset the appropriate probe heat switches as directed by the abnormal procedures section of our quick reference handbook. Both messages persisted, and the only additional guidance from the QRH was as follows: tat probe heat caution message persists: do not rely on air temperature indications. Left static heat caution message persists: do not rely on affected side instruments: 1) standby altimeter/airspeed indicator and, 2) cabin pressure acquisition module. This portion caused confusion because I believed it said we had lost both the first officer's and the stby instruments while the chief pilot thought only the stby's were unreliable and maintenance said only the first officer's instruments were affected. My questions were: 1) should we remain clear of icing conditions, 2) should the air data source select be set to norm on air data computer #1 (in norm, air data computer 1 sends data to captain's pfd and the now unreliable air data computer 2 sends information to first officer's pfd. In air data computer 1, both captain and first officer pfd's would show reliable air data computer 1 data.) initial company guidance was to proceed through icing conditions, but avoid accumulation, and leave the source select in norm. Subsequent company guidance was to avoid icing conditions, and leave the source select in norm. When I explained that with my air temperature indications also considered unreliable, the only way to positively avoid icing conditions would be to remain clear of clouds and clouds were along my route to cvg, the company decided it would be ok to fly through icing conditions. I again asked about the air data source select and was told to select air data computer 1. But that caused a loss of both flight directors, the autoplt, and the mach trim. (This is when the altitude/heading wandered a bit.) it was subsequently decided to return the source select to norm. We proceeded to cvg without further difficulty.

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Original NASA ASRS Text

Title: CL-65. CHIEF PLT ORDERED THE CREW TO FLY INTO ICING CONDITIONS WITH CHRONIC MULTIPLE PROBE HEAT PROBS IN NON COMPLIANCE WITH THE MEL OR COMMON SENSE.

Narrative: OUR ASSIGNMENT WAS A CONTINUOUS DUTY TRIP FROM CVG TO BTV AND BACK THAT RPTED AT XA00 AND WOULD RELEASE ALMOST 14 HRS LATER WITH APPROX 4 HRS OF SLEEP AT THE HOTEL IN BTV. UPON RPTING TO THE ACFT IN CVG, I FOUND MAINT PERFORMING A CHK OF THE PITOT/STATIC SYS. AFTER COMPLETION, WE PUSHED BACK FROM THE GATE AND PREPARED TO TAXI WHEN 6 PROBE HEAT INOP CAUTION MESSAGES APPEARED. ABOUT AN HR LATER MAINT COMPLETED REPLACEMENT OF A COMPUTER CTL BOX, RESET THE SYS, AND WE FLEW TO BTV WITH NO FURTHER ANOMALIES. UPON RPTING TO THE ACFT IN BTV, WE STARTED THE APU AND ESTABLISHED AC POWER THEN RECEIVED CAUTION MESSAGES FOR INOP RIGHT ANGLE OF ATTACK HEAT AND RIGHT STATIC HEAT. AFTER PULLING AND RESETTING CIRCUIT BREAKERS, THE MESSAGES CLRED AND THE ACFT WAS SIGNED-OFF AS FIT FOR FLT. HOWEVER, IMMEDIATELY AFTER TKOF WE RECEIVED CAUTION MESSAGES FOR INOP TOTAL AIR TEMP PROBE HEAT AND RIGHT STATIC HEAT. WE RESET THE APPROPRIATE PROBE HEAT SWITCHES AS DIRECTED BY THE ABNORMAL PROCEDURES SECTION OF OUR QUICK REFERENCE HANDBOOK. BOTH MESSAGES PERSISTED, AND THE ONLY ADDITIONAL GUIDANCE FROM THE QRH WAS AS FOLLOWS: TAT PROBE HEAT CAUTION MESSAGE PERSISTS: DO NOT RELY ON AIR TEMP INDICATIONS. L STATIC HEAT CAUTION MESSAGE PERSISTS: DO NOT RELY ON AFFECTED SIDE INSTS: 1) STANDBY ALTIMETER/AIRSPD INDICATOR AND, 2) CABIN PRESSURE ACQUISITION MODULE. THIS PORTION CAUSED CONFUSION BECAUSE I BELIEVED IT SAID WE HAD LOST BOTH THE FO'S AND THE STBY INSTS WHILE THE CHIEF PLT THOUGHT ONLY THE STBY'S WERE UNRELIABLE AND MAINT SAID ONLY THE FO'S INSTS WERE AFFECTED. MY QUESTIONS WERE: 1) SHOULD WE REMAIN CLR OF ICING CONDITIONS, 2) SHOULD THE AIR DATA SOURCE SELECT BE SET TO NORM ON AIR DATA COMPUTER #1 (IN NORM, ADC 1 SENDS DATA TO CAPT'S PFD AND THE NOW UNRELIABLE ADC 2 SENDS INFO TO FO'S PFD. IN ADC 1, BOTH CAPT AND FO PFD'S WOULD SHOW RELIABLE ADC 1 DATA.) INITIAL COMPANY GUIDANCE WAS TO PROCEED THROUGH ICING CONDITIONS, BUT AVOID ACCUMULATION, AND LEAVE THE SOURCE SELECT IN NORM. SUBSEQUENT COMPANY GUIDANCE WAS TO AVOID ICING CONDITIONS, AND LEAVE THE SOURCE SELECT IN NORM. WHEN I EXPLAINED THAT WITH MY AIR TEMP INDICATIONS ALSO CONSIDERED UNRELIABLE, THE ONLY WAY TO POSITIVELY AVOID ICING CONDITIONS WOULD BE TO REMAIN CLR OF CLOUDS AND CLOUDS WERE ALONG MY RTE TO CVG, THE COMPANY DECIDED IT WOULD BE OK TO FLY THROUGH ICING CONDITIONS. I AGAIN ASKED ABOUT THE AIR DATA SOURCE SELECT AND WAS TOLD TO SELECT ADC 1. BUT THAT CAUSED A LOSS OF BOTH FLT DIRECTORS, THE AUTOPLT, AND THE MACH TRIM. (THIS IS WHEN THE ALT/HDG WANDERED A BIT.) IT WAS SUBSEQUENTLY DECIDED TO RETURN THE SOURCE SELECT TO NORM. WE PROCEEDED TO CVG WITHOUT FURTHER DIFFICULTY.

Data retrieved from NASA's ASRS site as of July 2007 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.