pjvr99

We have 2 types of oil coolers in operation: the older type has the full oval frontal

area cooling; and a newer type where the face is square.

Older type cools very well, but has a tendency to high back pressure

Newer type doesn't cool very well, but has great back pressure

My biggest problem is trying to decide which is the greatest evil: oil dumping in

flight, or high oil temp during ground operation ...........

http://www.aerojetwash.com/

Seems like a pretty good setup. When I contacted them about other

configurations, they had no problem.

... depending on the HF you have installed it could be putting out several hundred watts of power. (One of ours puts out 400 watts peak.)

Good old HF radios - I'd forgotten about these. Yes, 120 watts AM, and 400watts on sidebands. I remember them causing some strife for me many years ago ......

PJ, the canon plug removed.... aint it the same as null operation?

what is the influence in the power settings? ok there is no input of the TD Ampli no more!

very curious!

greetz bob

Bob

I've had a few instances where the TD valve was being driven to a PUT or TAKE position, even

with the TD switch in NULL. The solid state amps have been the sinners in these cases.

A long time ago I had something similar. The only thing I found

out of the ordinary, was the t/m housing was filled with oil. The

t/m was replaced and the problem went away.

More recently, a break in the insulation between the reference

coil wires in the QEC kit also gave a fluctuation

T/m indicator power supply problem would be my first guess.

Hi Bob

Are these occurences while on deployment or at home?

What are NULL and AUTO take-off TIT on affected engines?

Solid state TD amps - have you tried starts with TD valve cannon plugs disconnected?

PJ

I agree with doing it 'by the book', but also remember my apprentice days where we were taught

to do this. Seem to remember a servicing sticker on the strut of a light fighter actually requiring

you to tap the strut to free up air bubbles ............

I agree with Steve 1300. Shoot TIT to guage from the T-block (if you can), verify indication system

is working properly. Then take a look at the coordinator.

Agree, sounds like a bad relay box . . . . .

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

Picked up this story yesterday on News24.com .....

Wellington - A New Zealand aircraft engineer died after he was sucked into an aircraft engine while carrying out maintenance work, it was reported on Monday.

Air New Zealand subsidiary Safe Air said the 51-year-old man died during a routine maintenance operation on Monday morning at its base in the South Island town of Blenheim.

Safe Air did not detail how the man died but Fairfax Media said sources had informed it he was sucked into the engine of a C-130 Hercules that had been removed from the aircraft and installed in the airline's testing bay.

The man had apparently walked into the testing bay while the engine was running, Fairfax reported.

Safe said police and labour department officials were investigating the death.

It said Air New Zealand chief executive Rob Fyfe was travelling to Blenheim to support the man's family and colleagues.

Condolences to family and friends

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)

TIT decrease = torq decrease

TIT increase = torq increase

What is your real question? As long as x-over TIT is 800° - 840°, no problem

No pressure after pump change, sounds like accessory drive failure ............

My feeling is a screwy solid state thermostat - had a number

of similar over the years . . . .

To get back to the origional problem, my feeling is a wiring problem. Maybe a

dry joint in a cannon plug at a pressure break, firewall, in a lead. Having reread

the original post, he does says at all power settings ...... torq should not be

used as a comparative reference as a 98% engine wil have much less torq than

a 108% engine, especially once throttle is above x-over. If the TD systems on

symmetrical engines are good, TIT should be near identical with throttles above

x-over lined up. Fuel flows on engines should be very close, but may differ for

a number of reasons. RPM should be 99.75% to 100.25%

Haha, that's an easy one. Check your bleed valves. Close your engine bleed then check the engine anti-ice to see if you get a 24 degree rise. If you get less than 24 degrees TIT rise, lets say it only rises 18 degrees you have a stuck bleed valve, if you get no rise at all your anti-ice valve is stuck open or your bleeds are just stuck open.

Check it in null too.

Does it have oil cooler augmentation?

Not true: bleed valves will not affect TIT rise at LSGI and NGI, below X-over, or in NULL. The

24°C rise is created when scoop anti-icing and inlet anti-icing are functioning correctly. A lesser

rise will indicate one or both a/icing side valves, and/or a/icing solenoid valve inop and/or scoop

valve inop.

Now: the only way to figure out what's happening is to do man-on-stand. Start engine, and at

NGI, lightly touch fingers to side valve(s) and feel if they're hot: if so, valve(s) are open. If cool

have cockpit open engine a/icing for a minute, and touch again. If still cool, valve(s) are closed.

In either case the problem may lie with the side valves stuck open/closed, or with the solenoid

valve which controls them being inop.

A hand held over the scoop vent on the RHS of the inlet duct will tell you whether the scoop valve

is functioning as required.

I have very similar results in the test cell, and on the odd run I sit

in on the aircraft. The only setting where it is out of the range is

at LSGI. I have a suspicion that its cause is the way the fuel flow

transmitter works, and the accuracy of the gauge.

I do not believe this to be a crisis, as my indication is consistant in

all engines with similar performance at similar atmospheric conditions

A little new to these engines then? Okay, T-block is located on the upper left side of

the combustion case - used to connect the two thermocouple harnesses together. Next,

the Y-lead - takes the signal from the T-block through the fireseal, and then splits to connect

to the TD amp, and back to the firewall for the indicator signal.

T-block part no: 6840004

Y-lead part no: 6847718

By the way, what is an 'ECTM converter' .......?? Another question: are the throttles lined

up above X-over?

What about T-block and Y-lead? I realize this is a long

shot (and difficult), try swapping the indicator and amp

wires around on the T-block - only allowed 6·C difference

at same throttle position. Also try disconnecting at firewall,

gauge, and T-block, then do resistance checks between the

chromel-alumel wires and also to ground. In all cases there

should NOT be any continuity . . . .

Something else to try, use your TD tester to shoot TIT signal

to cockpit

Good luck, let us know what you find

Turbine blades missing .........

2J-T56-56 SWP 058 03 gives a table for starting times vs air temp. These times are commonly

referred to as "on-speed", i.e. the time taken from starter button pressed, until RPM is stabilized

at LSGI

Torq, rpm, TIT, fuel flow stabilized at 72% ............

Couple of things still have me puzzled: in the first post was stated problem occurred during

descent. That would mean a pretty serious yaw when then miscreant engine suddenly increased

power. The second thing that worries me is the 80% - bleed valves would have opened, and

flameout would be the result

This is really wacky .............