February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 1 Cowl Thermal Anti-ice Valve Reliability February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 2 Amber NCTAI Light on During Takeoff and Climb Customer/Fleet Concern • Several operators have reported amber COWL ANTI-ICE light coming on during takeoff and climb The amber COWL ANTI-ICE light comes on when the duct pressure down stream of the NCTAI valve is too high • Valve repair facility has reported a significant number of NCTAI valves being returned for COWL ANTI-ICE light on Cowl Thermal Anti-ice Valve Reliability February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 3 Engine Nose Cowl Thermal Anti-ice System Cowl Thermal Anti-ice Valve Reliability February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 4 NCTAI Valve Regulator Worn • Repair facility found that over pressure was caused by a worn reference regulator in the NCTAI valve • Wear caused by dynamic instability in the regulator • Instability caused continuous regulator poppet cycling at 250 - 300 Hz. This cycling also causes the valve to “buzz” • The regulator poppet and seat wears until they will not seat causing the NCTAI valve to regulate too high Cowl Thermal Anti-ice Valve Reliability February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 5 NCTAI Valve Regulator Worn Wear Wear Wear Wear Very Heavy Deep Wear Virtually No Wear Wear Different views of poppet. The poppet is worn all around Housing split in two to expose the bore. One half has very heavy wear, the other half has virtually no wear. February 2002 WTT face to face CFMI / Boeing Proprietary Information - Unauthorized Disclosure, Use, or Export are Prohibited 6 Reference Regulator Will be Replaced Corrective Action • Honeywell has tested the NCTAI valve with the reference regulator used on the pre-cooler valve, bleed air regulator and high stage regulator for 737-300-900 airplanes Valves that buzzed with the original regulator would not buzz with the new regulator • Honeywell and Boeing are processing a change to use the reference regulator from the bleed air regulators and pre-cooler valve • Using standard flow, service bulletin is scheduled for release in August 2002. We will expedite introduction of the improved valve as much as possible Cowl Thermal Anti-ice Valve Reliability作者: 979199501 时间: 2011-4-12 00:31:49 标题: 回复 1# 航空 的帖子
CFM56-7B TRAINING MANUAL ENGINE FAN TRIM BALANCE作者: kinran 时间: 2011-6-4 23:40:50
