Narrative:

On climb out we entered a layer of ice. As soon as the anti ice came on the bleed temps went to the red scale within thiry seconds. Anti icing failed soon after. We were able to climb out of the layer and stay on top the rest of the trip to our first destination. Maintenance control said the problem was a plugged orifice and filter. We were told to do an ice test and that would prove it to be fixed. I heard the maintenance tech ask control if there was another way to test the bleed and apparently control said no. On the subsequent climb out we entered ice; anti-ice came on and bleeds went into the red scale again. We coordinated with dispatch to avoid icing conditions and were able to make it into the next destination. The rest of the day we worked with contract maintenance trouble shooting the problem with the bleeds. One procedure had us run the engines at 90% N2 for two minutes while testing the bleed system. Each time we ran this test the bleeds went into the red scale immediately; exactly same way as we experienced in the air in icing conditions. Maintenance control sent two company maintenance guys who arrived monday morning. At midmorning they told us the plane was fixed: 'it passed our test no problem'. Also they cleaned some filters and replaced a heat sensor. I told the guys we have had two bleed over temps in icing conditions and one was after maintenance said they had cleaned filters and fixed the problem. I also told them I would not fly this plane into known icing again until I see the bleed system pass the test we ran the previous night. They said they would set up the plane for the test and to come back in about thirty minutes. Four hours later; dispatch called and said the plane was fixed and ready for a ferry flight to a maintenance station. The ferry flight was to fix heat damage from excessive hot bleed air to the leading edge of the wings. I told control to have the maintenance guys bring the plane back to the gate and pick us up. Since no icing was reported on our route; I figured it to be safe to complete the ferry flight. I believed the bleed system was not fixed even though maintenance had signed it off as being fixed. During the climb out I switched the deice override knob to all and immediately the bleed temps went to the red scale. Three times I wrote this bleed problem up. It wasn't until we brought the plane to the maintenance hangar that I felt anyone wanted to listen to what we had to say about the problem. A lot of additional problems could have been prevented had maintenance control not repeatedly conducted an easy fix; including the heat damage to the wings leading edge and the multiple cancellations. The event occurred due to pressure from maintenance control to keep an aircraft in service with quick fixes and failing to do thorough investigations. Maintenance also repeatedly said the aircraft passed operational checks only to subsequently have the same bleed over temperature in flight; possibly damaging the leading edge of the wings.

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Original NASA ASRS Text

Title: The flight crew of an unidentified 'commuter type aircraft' reports multiple failures by Maintenance to repair overheating wing anti-ice bleeds.

Narrative: On climb out we entered a layer of ice. As soon as the anti ice came on the bleed temps went to the red scale within thiry seconds. Anti icing failed soon after. We were able to climb out of the layer and stay on top the rest of the trip to our first destination. Maintenance Control said the problem was a plugged orifice and filter. We were told to do an ice test and that would prove it to be fixed. I heard the Maintenance Tech ask control if there was another way to test the bleed and apparently Control said no. On the subsequent climb out we entered ice; anti-ice came on and bleeds went into the red scale again. We coordinated with Dispatch to avoid icing conditions and were able to make it into the next destination. The rest of the day we worked with Contract Maintenance trouble shooting the problem with the bleeds. One procedure had us run the engines at 90% N2 for two minutes while testing the bleed system. Each time we ran this test the bleeds went into the red scale immediately; exactly same way as we experienced in the air in icing conditions. Maintenance Control sent two Company Maintenance guys who arrived Monday morning. At midmorning they told us the plane was fixed: 'It passed our test no problem'. Also they cleaned some filters and replaced a heat sensor. I told the guys we have had two bleed over temps in icing conditions and one was after Maintenance said they had cleaned filters and fixed the problem. I also told them I would not fly this plane into known icing again until I see the bleed system pass the test we ran the previous night. They said they would set up the plane for the test and to come back in about thirty minutes. Four hours later; Dispatch called and said the plane was fixed and ready for a ferry flight to a maintenance station. The ferry flight was to fix heat damage from excessive hot bleed air to the leading edge of the wings. I told Control to have the Maintenance guys bring the plane back to the gate and pick us up. Since no icing was reported on our route; I figured it to be safe to complete the ferry flight. I believed the bleed system was not fixed even though Maintenance had signed it off as being fixed. During the climb out I switched the deice override knob to all and immediately the bleed temps went to the red scale. Three times I wrote this bleed problem up. It wasn't until we brought the plane to the Maintenance hangar that I felt anyone wanted to listen to what we had to say about the problem. A lot of additional problems could have been prevented had Maintenance Control not repeatedly conducted an easy fix; including the heat damage to the wings leading edge and the multiple cancellations. The event occurred due to pressure from Maintenance Control to keep an aircraft in service with quick fixes and failing to do thorough investigations. Maintenance also repeatedly said the aircraft passed operational checks only to subsequently have the same bleed over temperature in flight; possibly damaging the leading edge of the wings.

Data retrieved from NASA's ASRS site as of April 2012 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.