SF340 flight crew reports standby altimeter and airspeed severely off in cruise. Post flight reveals...

Attributes
ACN	809477
Time
Date	200810
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	SF 340B
Operating Under FAR Part	Part 121
Flight Phase	ground : preflight ground : maintenance
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial
ASRS Report	809477
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	809478
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : anomaly accepted
Consequence	other other
Factors
Maintenance	performance deficiency : fault isolation performance deficiency : repair
Supplementary
Problem Areas	Maintenance Human Performance Aircraft Company
Primary Problem	Ambiguous

Narrative:

During our first flight of the day; the captain and I noticed that the standby altimeter was off by about 400 ft; and the standby airspeed indicator was off by about 20 KTS at the worst. During the captain's postflt; he noticed that the standby pitot tube was bent slightly outward. The crew that flew the aircraft previous to us wrote up the standby altimeter; as well as the rudder limiter. Because of these previous write-ups; I believe that the damage occurred before the aircraft got to ZZZ. On my preflight in ZZZ I made sure that the pitot covers were off; and that the intakes were clear of debris. I believe that the skirt of the jetbridge; while not actually touching the pitot tubes; was in a position that would have made it difficult to detect such a discrepancy.

Original NASA ASRS Text

Title: SF340 FLT CREW REPORTS STANDBY ALTIMETER AND AIRSPEED SEVERELY OFF IN CRUISE. POST FLIGHT REVEALS BENT PITOT TUBE.

Narrative: DURING OUR FIRST FLT OF THE DAY; THE CAPT AND I NOTICED THAT THE STANDBY ALTIMETER WAS OFF BY ABOUT 400 FT; AND THE STANDBY AIRSPD INDICATOR WAS OFF BY ABOUT 20 KTS AT THE WORST. DURING THE CAPT'S POSTFLT; HE NOTICED THAT THE STANDBY PITOT TUBE WAS BENT SLIGHTLY OUTWARD. THE CREW THAT FLEW THE ACFT PREVIOUS TO US WROTE UP THE STANDBY ALTIMETER; AS WELL AS THE RUDDER LIMITER. BECAUSE OF THESE PREVIOUS WRITE-UPS; I BELIEVE THAT THE DAMAGE OCCURRED BEFORE THE ACFT GOT TO ZZZ. ON MY PREFLT IN ZZZ I MADE SURE THAT THE PITOT COVERS WERE OFF; AND THAT THE INTAKES WERE CLR OF DEBRIS. I BELIEVE THAT THE SKIRT OF THE JETBRIDGE; WHILE NOT ACTUALLY TOUCHING THE PITOT TUBES; WAS IN A POS THAT WOULD HAVE MADE IT DIFFICULT TO DETECT SUCH A DISCREPANCY.

Data retrieved from NASA's ASRS site as of May 2009 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.

SF340 flight crew reports standby altimeter and airspeed severely off in cruise. Post flight reveals bent pitot tube.