TIT

[rami]

During flight no.2 engine read higher TQ & F.F with same TIT

i adjust all throttels to set same F.F ,ifound no.2 engine TIT read lower by 20c(above cross over)

the maintenance crew check and replaced all thermocouples ,the problem still

[Lkuest]

I would recommend installing the TD Amp Test Set on to the Firewall TIT harness and checking the indication that way. The indicator should read within 6 degrees of what the TD Amp Test Set is set to, but to be safe, I'd change a low-reading gauge until you get one that reads right on, or slightly high, but within limits. Also, Ohm out the T-block and check the Y-lead. Then, do a good Torque Calibration. If you don't have specialized equipment, or can't afford to start swapping parts out, you can just swap TIT indicators and fuel flow indicators between motors, as well as swap the Y-Lead leads between the AMP side and IND side of the T-block for troubleshooting only.

Technically though, there is no limitation on Fuel Flow alignment, just a blurp in the -1 that says it could indicate a malfunction. That is why I would recommend calibrating the torque indicators. You should also check how old the engine is. If the engine is newer than the other three, it will by nature pull more torque.

Every situation is different, but I believe it is an indication problem in the TIT indication system somewhere.

[NATOPS1]

What is your NULL start temp? Where is your TD valve NULL setting? (full increase/ decrease?)

What is your correction at crossover? Increase or decrease in TIT?

If you place ALL the TD's to NULL and match FF as before what are your readings?

[pjvr99]

What NATOPS1 says. Null/auto TIT, before/after light out TIT at X-over, and rich/lean TIT

TO 2J-T56-56 SWP 060 00 Troubleshooting Table 57: Replace thermocouples.

If this doesn't work, do an OHM's check on the coordinator potentiometer.

Last, if this is an ABB or other solid state TD amp, have a go at swapping it out

[Dan Wilson]

You sound like an FE, if so I would recommend getting ahold of a 6cf-1 TO for your particular aircraft.

This will give you all the goodie numbers you need to know about power differences between the engines.,

Torque indicators are your PRIMARY power indicators, so when you line up engines you really need to either line up torque or line up TIT (most common) but not fuel flow.

Back when we had to use them for fuel usage logs we had to go by them (FF indicator) but for some reason I never really trusted the FF indicator as much as the other indicators or accurate numbers.

Some difference is normal, all four of your engines are going to have much different hours and cycles on them (sometimes tens of thousands of hours) giving you much different wear patterns and % efficiency on all four.

In the end the 6CF-1 for your aircraft will give you all the specific numbers and notes.

Dan

[Steve1300]

There is so much that affects the torque readings on the engines, but so many people just ignore torque indication and treat it as a meaningless gauge. Of course, if you don't bother to ensure that it is accute, it becomes a meaningless gauge. the same goes with verifying the accuracy of the TIT indicators. None of those excuses help when trying to discuss the apparent problem with your engineer who just got out of the simulator.

If we maintain our systems correctly, it can save many hours of chasing a problem that never existed.

[325X1]

Hmmm, this is 3 weeks old. Problem solved? If not, does anyone use a H261 series temperature tester anymore? That tester is easy to use and has verified indication and wiring on many a plane some good some bad.