gulti

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Anybody have idea about the wiring config behind the Engine Fire & turbine overheat T-handle? There are six ports if you open the upper portion of the t-handle like below:

O O O

O O O

Where, 1st and last port of upper part are shorted, same as for the lower part. There are 4 colored wires there - Red, Blue, Brown and White. I want to know where those wire are connected? Because all the connection has been torn in our aircraft (C-130B).

I need to know it urgently. Plz if anybody knows it gimme an idea.

We are using Combined Altitude Radar Altimeter (CARA), model: AN/APN-232(V). After switching it on 'FAIL' indication shows on ground in both the indicators (Pilot side & Nav side) for about 30-45 sec. After that period it become normal.

In air, above 1000 ft both the indicators fluctuate with all indications (RT FAIL). But, at the same time TCAS system operation remain normal.

For this prob, we have done the fol troubleshooting:

a. CARA R/T, Height Indicators, Antennas are changed.

b. Continuity of wiring was measured.

But still we are facing the same problem.:confused:

It will be appreciated if anybody is having any other solution.

Those numbers are for the bad engine. Air pressure could not be recorded.

For good engine, time 45 sec and Max rpm 35%.

Yes, we have changed it earlier. Effect was the same.

duplication....

An easy thing to do would be to shove a borescope into the left and right hand bleed collectors and inspect all of the 5th and 10th bleed valves all the way around. If you have one stuck in the closed position, that could easily cause your problem. So could indication problems between the thermocouples and the flight deck indicator.

The engine is obviously getting enough air since the engine winds up in 45 seconds. Unless fuel is being bypassed through the fuel enrichment valve, all other fuel causes should have been eliminated by now through changing all the components, including the TD system with starting in Null and changing the TD Valve.

At this point, you might as well flow test the fuel nozzles and check that the thermocouples haven't been burned up. Do all 4 engines read the same TIT after the aircraft has been shut down for 12 hours or more?

Borescope test carr out, all the valves are ok. Indicators are good.

fuel enrichment valve has been changed with a new one. Prob still exists.

Fuel nozzles and thermocouples are also changed. No 2 eng (problem) shows less TIT than others.

Time 45 with other eng, 65 with GTC.

Max RPM 22% with GTC. 32% without GTC.

Yes rpm was 35% when the TIT goes 850+.

Fuel flow was 350pph at 16% until light-off.

On behalf of rsd653 I m replying all the ques u asked. We r still facing the same problem.

starter control valve not opening fully, bleed air shut off valve not opening fully, starter

turbine damaged, compressor worn out/FOD'ed, cracked bleed air duct, blown bleed

duct gasket, speed sensitive valve porting air to bleed valves below 94%, TD amp

driving TD valve to PUT condition

starter control vale is ok, bleed air shut off valve operating good, starter turbine is ok, compressor checked, found ok. bleed air duck found in good condition, speed sensitive valve replaced with a new one,TD amp replaced with a new one. But still problem is there. I mean Start TIT is 856'C.

let us assume the starting time is ok!....props blade angle is in ground idle range ok...You've tried it in null!!........rigging is ok!!......could have to deal with an FCU change..What else could it be. ......................the bad John.......................................................I think if I recall.....had that kind of problem many sun arounds!!............Cheers to you guys!!

Yes starting time we get 45 sec to reach 60% for starting at first. prop angle at grd idle is 4'. yes we've tried in null. Rigging also correct. Yes we Have changed the FCU also. But still result was same.

I agree with NATOPS1 about the acceleration bleed valves. Disconnect the high pressure out line at the speed sensitive valve which goes to the acceleration bleed valves and see if it starts OK.

I had a bad speed sensitive valve one time which would close the valves at 45% and the TIT would increase rapidly. After shutdown a visual of the acceleration bleed valves revealed they were open because when the RPM droped below 45%.

We have changed the speed sensitive valve with a new serviceable one. But we've not tried the high pressure out line at speed sensitive valve. Tomorrow we are going to do that. The result we get, I'll let u know.

Well, lets see FCU change or something 100000000% easier... HUM.... There are so many things that can cause this, so to not do all the easy (cheaper) things first is not the best way to go about it.

It looks like rsd653 has done most of them so...

rsd653 when you say "Starting tit high more than 850'c" how high?

Have you tried to use high pressure air from an engine or just you GTC?

Pj brings up a good point the starter may turn the prop and engine but may bog down due to failure or the starter control valve may be "regulating" the air to the starter at a lower pressure.

When you start the engine how "low" does the air pressure go? At 16% what is the air pressure reading?

22 psi + I would guess as you continue the start until the overtemp.

What RPM do you get to befor the temp goes up? 30 40 or 60%?

We got some times 856, sometime 860'C also.

Yes we have tried high pr air also.

35psi+ with GTC.

we got 35% approx.

So friends, thanks all of u for all the replies u have given. We r really suffering a lot. Plz help us, how can we get rid of this high TIT prob. If u have any more queries plz ask. I'll answer as soon as possible. Our herculies is on ground for a long time. And we deadly want to see it air. Plz send your precious thinking and suggestions about the problem.

I m Waiting for your replies.