apexlined Posted July 12, 2011 Share Posted July 12, 2011 What the effect if high cross over cut TIT ( example : 860 degrees) and low cross over cut TIT ( example : 780 degrees). TQ:confused: Quote Link to comment Share on other sites More sharing options...
pjvr99 Posted July 13, 2011 Share Posted July 13, 2011 TIT decrease = torq decrease TIT increase = torq increase What is your real question? As long as x-over TIT is 800° - 840°, no problem Quote Link to comment Share on other sites More sharing options...
Lkuest Posted July 13, 2011 Share Posted July 13, 2011 I think you are asking: Why crossover is 800-840 degrees, and if it is not, why should we correct the problem? Am I correct? There are several reasons why crossover at 860 degrees or 780 degrees is bad. 1. Throttle alignment. The throttles all have to be within 1/2 knob of each other above crossover when aligning all 4 engine TIT signals. Below crossover, we have no temperature controlling, so we don't care about throttle alignment below crossover. 2. If the TD system is tuned properly, crossover will be 800-840 degrees. If it is not 800-840, your TD system is improperly tuned or you have a bad coordinator. 3. If the TD system is tuned properly, and the coordinator is not malfunctioning, then it could be a sign of TIT indicator malfunction, which should be repaired immediately. Quote Link to comment Share on other sites More sharing options...
apexlined Posted July 15, 2011 Author Share Posted July 15, 2011 when advance throttle, the TIT increase until 860 then back to range x over TIT(800 - 840) and the other situation when advance throttle the TIT increase then back to 780 not under range x-over. is it can be problem for our engine performance? Quote Link to comment Share on other sites More sharing options...
pjvr99 Posted July 15, 2011 Share Posted July 15, 2011 As long as the TIT corrects to 800-840 at light-out, there is no problem: it merely indicates the FCU to be rich or lean at that point. A good run with several NULL starts and a rich/lean check will tell you whether there is a problem or not with the FCU fuel scheduling. Performance is not affected by a high or low before-light-out TIT. If the corrected TIT is only 780, it is probably indicating a broken or misrigged coordinator (a good place to start when dealing with TD problems) Quote Link to comment Share on other sites More sharing options...
tusker Posted July 22, 2011 Share Posted July 22, 2011 It's a good brain storming!!!...........if you're not within limits, .....throttle split!!.. Let's light up the stoves and do a high power run. The mother's got to fly!!. Quote Link to comment Share on other sites More sharing options...
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