An F100 accumulates ice formed in the pitot but receives no warning of pitot heat failure.

Attributes
ACN	427142
Time
Date	199901
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : roc
State Reference	NY
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Fokker 100
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	ground : parked
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	427142
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : unable none taken : detected after the fact
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

XA35Z, 118.3, 4000 ft. Roc approach and tower. Upon arrival at roc, our new hire first officer did the walkaround and then approached me with a chunk of ice about 1/2 inch in diameter he had removed from the front of the #1 pitot tube. It had a pin-size hole which still allowed air into the pitot tube. I do not know how much longer this hole would have remained open. Maintenance determined the pitot heat to the captain's pitot tube failed. What concerns me is that there was no indication this element had failed. I believe we should have gotten a level 2 alert and a fault light on pitot #1. If the pitot had closed off air flow completely, our arrival and approach would have been much more exciting. Callback conversation with reporter revealed the following information: reporter stated that the ice pulled from the pitot tube was impressive. He thought for certain it would have plugged the tube, preventing enough air to give proper airspeed indications. Reporter was concerned about the lack of warning of pitot tube heat failure. The flight crew didn't notice any difference in airspeed indication among the 3 airspeed indicators. Reporter was unable to find out any further details about the heat failure or how the heat system indications operated.

Original NASA ASRS Text

Title: AN F100 ACCUMULATES ICE FORMED IN THE PITOT BUT RECEIVES NO WARNING OF PITOT HEAT FAILURE.

Narrative: XA35Z, 118.3, 4000 FT. ROC APCH AND TWR. UPON ARR AT ROC, OUR NEW HIRE FO DID THE WALKAROUND AND THEN APCHED ME WITH A CHUNK OF ICE ABOUT 1/2 INCH IN DIAMETER HE HAD REMOVED FROM THE FRONT OF THE #1 PITOT TUBE. IT HAD A PIN-SIZE HOLE WHICH STILL ALLOWED AIR INTO THE PITOT TUBE. I DO NOT KNOW HOW MUCH LONGER THIS HOLE WOULD HAVE REMAINED OPEN. MAINT DETERMINED THE PITOT HEAT TO THE CAPT'S PITOT TUBE FAILED. WHAT CONCERNS ME IS THAT THERE WAS NO INDICATION THIS ELEMENT HAD FAILED. I BELIEVE WE SHOULD HAVE GOTTEN A LEVEL 2 ALERT AND A FAULT LIGHT ON PITOT #1. IF THE PITOT HAD CLOSED OFF AIR FLOW COMPLETELY, OUR ARR AND APCH WOULD HAVE BEEN MUCH MORE EXCITING. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT THE ICE PULLED FROM THE PITOT TUBE WAS IMPRESSIVE. HE THOUGHT FOR CERTAIN IT WOULD HAVE PLUGGED THE TUBE, PREVENTING ENOUGH AIR TO GIVE PROPER AIRSPD INDICATIONS. RPTR WAS CONCERNED ABOUT THE LACK OF WARNING OF PITOT TUBE HEAT FAILURE. THE FLC DIDN'T NOTICE ANY DIFFERENCE IN AIRSPD INDICATION AMONG THE 3 AIRSPD INDICATORS. RPTR WAS UNABLE TO FIND OUT ANY FURTHER DETAILS ABOUT THE HEAT FAILURE OR HOW THE HEAT SYS INDICATIONS OPERATED.

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.