sharp instrument and was fully removed by flushing with hot water. After removal of the obstruction, the probe was tested and, according to the CMM, it could be re-certified and returned to service. Figure 9: View looking into the pitot probe inlet Source: UTC Aerospace Systems Other recent occurrences B737-8FE VH-VUG 3 April 2014 Brisbane 201402626 During take-off, while accelerating through 90 kt, caution message ALT” annunciated. As “EEC engine thrust was normal, the captain continued the take-off. Once airborne, Disagree” and “IAS Disagree” messages were displayed on the crew’s PFDs and the captain’s stick-shaker “ALT operated intermittently. Comparison between the captain’s, FO’s and standby airspeed indications showed that the captain’s airspeed was under-reading significantly. Control of the aircraft was handed over to the FO and the aircraft levelled at 7,000 ft before returning for landing at Brisbane. Later investigation showed that the inlet of the captain’s pitot probe was partly obstructed by material consistent with a mud-dauber wasp nest.
sharp instrument and was fully removed by flushing with hot water. After removal of the obstruction, the probe was tested and, according to the CMM, it could be re-certified and returned to service. Figure 9: View looking into the pitot probe inlet Source: UTC Aerospace Systems Other recent occurrences B737-8FE VH-VUG 3 April 2014 Brisbane 201402626 During take-off, while accelerating through 90 kt, caution message “EEC ALT” annunciated. As engine thrust was normal, the captain continued the take-off. Once airborne, “IAS Disagree” and “ALT Disagree” messages were displayed on the crew’s PFDs and the captain’s stick-shaker operated intermittently. Comparison between the captain’s, FO’s and standby airspeed indications showed that the captain’s airspeed was under-reading significantly. Control of the aircraft was handed over to the FO and the aircraft levelled at 7,000 ft before returning for landing at Brisbane. Later investigation showed that the inlet of the captain’s pitot probe was partly obstructed by material consistent with a mud-dauber wasp nest.
ao-2013-212-final-report.docx