pjvr99

Next on the 'to-do' list Moving to reverse is not a problem, torque, ff, rpm normal. Got to be very careful coming back as the torque picks up very quickly. If left long enough the rpm will decrease below 94%, risking flameout. TIT rises some

Vid as promised. Don't worry about the odd movements, it's the way my HTC captures the movement. Sound is not recommended, except to determine up- and downshift. Starts of in NGI then goes to LSGI, back to NGI, and finishes at LSGI. +-1minute, 8MB on Photobucket

Installed one of the last props we ran, engine is perfect. This is the only thing we didn't do because we were out of time - priority engine. We will be doing more troubleshooting in the next few days, then this will be checked also. I did move up close to the engine to see if there was any linkage movement on the controls - nada. Also shutting the engine down from NGI didn't show anything as the blades go back as soon as the engine slows. Will post a vid later today ...... PJ

Done - no change Done - also changed out covers Done - removed all 5 cannon plugs. Ran a purely mechanical prop, no anti-icing, no aux feather motor, no pressure cutout, no low light, no synchrophaser, no feather solenoid Did that - no difference Looking into that Removed from equation by installing a known good prop Thanx for the feedback so far. When/if we find out what it is, I'll get back PJ

Hey HerkyWorld Got an unusual situation here. Engine starts normal, LSGI torque set correctly. When the LSGI button is pulled to upshift to Normal Ground Idle, torque stabilizes for a moment at +-1200"lb ........ then increases to +-6000"lb, rpm decays to 94%, and TIT increases. Also prop noise indicates the engine is labouring. When LSGI button is pushed in, everything returns to normal. Standing on the blade line, you can see the pitch change occurring. Changed out valve housing, pitchlock regulator, and low pitch stop. Also removed all cannon plugs to remove electronic influence - no good! Stays the same ..... Anyone out there seen this before? any ideas, theories ........ anything? Have a great day PJ

Hey HerkyWorld Got an unusual situation here. Engine starts normal, LSGI torque set correctly. When the LSGI button is pulled to upshift to Normal Ground Idle, torque stabilizes for a moment at +-1200"lb ........ then increases to +-6000"lb, rpm decays to 94%, and TIT increases. Also prop noise indicates the engine is labouring. When LSGI button is pushed in, everything returns to normal. Standing on the blade line, you can see the pitch change occurring. Changed out valve housing, pitchlock regulator, and low pitch stop. Also removed all cannon plugs to remove electronic influence - no good! Stays the same ..... Anyone out there seen this before? any ideas, theories ........ anything? Have a great day PJ

Awesome!!!

Hey guys 2 x Propeller specialists needed in Jeddah, Saudi Arabia. PM me for info, CV's to [email protected] Thanx PJ

Also got taken out by the refueling questions - only 57%

C-130F (ex-USN) 410 c/n 3636 411 c/n 3660 412 c/n 3696 Were not flown after arrival in SA due to corrosion and other issues. C-130B (ex-USAF) 408 c/n 3526 409 c/n 3530 These two were upgraded to C130BZ along with the other original SAAF birds

Victorp1, do you have a copy of this CSL available?

Natops, you hit the nail on the head. If the engine is being started with +-80psi instead of 30 to 35psi the spin up time is often markedly shorter. In turn, 50psi fuel pressure to cut off enrichment is also reached quicker. It is thus possible that the window of opportunity to see anything on the gauges is very small. A hot engine starts and spins up somewhat faster than a cold engine. Main tank boost pumps operate at 18 - 24psi, while aux and external at 30 - 40 psi. Basically this is already fuel pressure in the manifold, meaning that the time available to see some- thing before 50psi is reached, is reduced. I know, I'm looking for something highly improbable, but sometimes it's just those little things that trip us up. I honestly do hope it's a bad cockpit switch or broken wire ....... something regular and simple

Another thought: if the starts are being done on the ground, is this engine being started using APU/GTC bleed air, or engine bleed air? And are the tank boost pumps being used, more specifically aux and/or external tanks?

Tstat = thermostat?? Didn't touch it. Load control EGT 620°C, acceleration 610°C

APU came from overhaul, ran through test cell - all good. Installed on aircraft, bleed air on, but no load, there is a 5 - 10psi pressure surge, small EGT and RPM flux. When a load is applied (eg aircon pack), it stabilizes. Removed and sent to test cell, again nothing could be found. Installed on another aircraft, has the same problem. Replaced the load control valve, but still the same. Anyone have any ideas ...??

Had something similar several times in the last few years. In one case #1 would increase rpm to 102% with #3 as master - #3 valve housing change fixed it. The others all got traced back to the synchrophaser rack.

Believe me, it was the last thing I would suspect. However, a bit of a give-away was the 30psi oil pressure at 900° TIT and 75° oil temp. My thoughts were tending to a break/crack in the ADH front cover plate or a failure of the seal between the pressure and scavenge sides of the pump ....... but that's how knowledge and experience is accumulated

Just make sure the aircraft is shored properly, and that the tail supports are in tight

This is the source of my problem in the vid ..... a.k.a. poppet valve in the main oil pump pressure regulator

Had this one too, many, many moons ago .......

... moved ........

Two areas to look at here: 1. left hand harness could have broken wires on the speed switch c/plug. Swap it out, see what happens; 2. a little more difficult to determine, but maybe a bad tower shaft, bearings, or gears. Hook a direct reading gauge to 5th/10th stg bleed valves, and run the engine. Pressure should be same as CDP, but could be as much as 10psi lower. The thing you're looking for is flux exceeding about 5psi. At the same time keep an eye on TIT and fuel flow. excessive or erratic fluctuation would give an idea

No. But if my suspicions are correct, it will be necessary to change them out. We're just debugging a little oil leak at the moment - then our beady eyes will be moving there. Oil problem moved here http://herkybirds.com/forums/showthread.php?p=13985#post13985

On a whim today, I did a TIT calibration. Shooting TIT from the T-block, starting at 50°C and incrementing 50°C up to 1100° all readings within 2°C. Before and after indications of OAT, TIT and fuel temp was 30°C, 31°C and 34°C (fuel was higher because the sun had already gotten to the pump). I hooked up my relay and ran the engine @ 900°C and only had a 1°C change ..... Bob, you you need to tell your FE's to concentrate on the important things:- 1. Wine 2. Women 3. Song :-)

Ah, now that's a different game, Bob. First thing to realize is that no 2 gauges are going to give exactly the same reading. Next thing would be that that low down, there is no guarenteeing the thermocouple's accuracy. Also effect of air movement through the engine, swirling around the fuselage, etc. Sunrise on the left wing? In the test cell, GENERALLY, early morning has TIT, OAT, fuel and oil temps within 1 or 2 degrees. Later in the day, this can change by a substantial amount. Why is the FE concerned about this? The TIT system measures measures combustion temperature, and is set up for an individual engine.