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Aero Precision provides military aviation aftermarket solutions for c-130


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Everything posted by pjvr99

  1. Hey guys Wondering if anyone can help me with info on the N prefix on the blade serial numbers. We have just gotten a TCTO covering a number of blades. Some of the serials are N8xxxxx others are just 8xxxxx. What does the N refer to ..... Tnx in advance PJ
  2. pjvr99

    Stalled start on -15

    speed valve stuck closed, bleed valves not opening
  3. pjvr99

    Xover cut tit

    Cutback is a misleading term, as the TIT before correction may be lower than corrected TIT. For example, TIT before light out may be 790°C and 835°C after light out. There was an increase rather than a cutback. AGAIN, there is NO limit for TIT before light out, only 800 to 840 after light out.
  4. pjvr99

    Crossover TIT Correction

    As a follow-up to this, we had one a few weeks back that actually went over a 1000°C before cutting back to 830 or so. Found the fcu schedule had shifted rich, adjusted CIT, and everything went back to where we expected it .....
  5. For several weeks flight and ground crews have been pecking away at a problem where engine torque, fuel flow and TIT increase when engine anti-icing is turned on. We're not talking 100"lbs of torque here, its over 4000"lb and/or 300 to 500 pph of fuel. Every conceivable component from FCU, speed valve, anti-icing side valves, and the whole TD system has been replaced at least once with no change. Last week the engine was finally removed and sent to test cell. Engine was started, runs great, makes good power, but when anti-icing is turned on there is a massive surge of torq and fuel which the TD barely contains. I had the to see what happens in NULL - instant soil-the-underwear moment as torq jumps from 12500"lb to almost 18000"lb, fuel goes 1600pph to 2000pph, and TIT from 900°C to 1040° ...... I have a small flapper installed over the inlet duct anti-icing vent so we can see when the anti-icing valve opens. This device was working as intended, meaning a/icing on flapper flaps, but ...... massive torq, TIT and FF increases. We eventually shut down the engine without any real idea of how to proceed with troubleshooting. Then I started thinking: what if, somehow, a/icing air is getting into the FCU CIT or CIP lines .... Some examination of diagrams led me to the CIP inlet in the compressor inlet housing. A/icing air is pumped into the same strut as the CIP fitting. If the fitting is corrode, cracked or loose, you'd be dumping 100psi air onto the CIP bellows. Long story short, a really skinny guy was sent up the 'S'-duct and CIP fitting was replaced. VOILA! A/icing no longer causes massive increases in torq, ff, and TIT
  6. pjvr99

    Bleed effect on max power

    Looks like the old 1C-130H-2-4 manual. It has some really interresting graphs, although i dont remember anything to do with bleed air in it
  7. pjvr99

    Throttle Quadrant

  8. https://www.ilsmart.com/Aviation/part/6798233.htm Part number 6798233
  9. pjvr99

    Allison 501-D22A Engine

    2 things will happen here: 1- you will lose the commercial (civilian) certification for the D22 2- you will have no fuel flow indication. The T56 engine uses a 28v DC power supply for the ff transmitter and indicators, while the D22 uses a 115v 400hz power supply. The wiring and connectors are completely different. In my opinion this would be a completely wasted excercise, not to mention the expense of recertifying the D22 again
  10. pjvr99

    Allison 501-D22A Engine

    engine core or complete QEC?
  11. pjvr99


    Probably want to keep APU shut down when taxing on dirt or unprepared strips. Having said that, the intake screen holes are big enough to let in small gravel and stones which can and will damage the compressor when it is started again ....
  12. Hey guys My topic is a follow on of this discussion. Over the last several months we have had a large number of TD related problems. Some have been fixed by the usual TD am or valve change, or just a careful yellow box. Many have either been sent to me in the test cell, or I have spotted enough of a disparity to warrent further investigation. The most common failing is a high take off TIT in AUTO, with a lean fuel control. I like to set SLOPE and NORMAL at 1075°C and take things from there. As long as TIT doesnt exceed 1083°C we're good to go. Normally a new amp or a bit of careful tweeking of the NULL orifice and the CIT can bring everything in line. Recently these things just had no effect. Chatting to a test cell operator in the US, he told me that he had installed another TIT guage in his cab connected to the AMP terminals on the T-block. I did the same and damn near had heart failure - with 1080°C showing on the IND side, I was only getting 1060 or so on the AMP side. Changed thermocouples and harnesses - voila! problem solved. I have now made this a fixed check on all engine runs when we do the TD system checks. Referance for this check can be found in 2J-T56-56 SWP 058 03 Sect 15
  13. pjvr99

    Oil lose inflight

    no problem, this is how we all learn
  14. pjvr99

    Oil lose inflight

    Another thought, pull off the compressor rear bearing vent lines and check for oil - the lines are normally dry
  15. pjvr99

    Oil lose inflight

    OK. big scavenge problem. How is oil temperature? Pull off lower E-duct from 14th stage. check the #2 & #3 bearing lines visible for oil staining. After that check #2 & #3 bearing lines to the external scavenge pump that they are not blocked. Heve you changed main oil pump yet?
  16. pjvr99

    Oil lose inflight

    What is the difference in indicated oil quantity with engine running at 100% rpm and indicated oil qty immediately when engine is shut down (no rotation)? During ascent/descent are the oil pressures steady, or is there a fluctuation? Is there any fluctuation on the ground? Did the engine go across test cell before going back to aircraft?
  17. pjvr99

    Oil lose inflight

    Lockheed Service News V18 #3 contains a brilliant explanation of causes and troubleshooting of oil dumping. It was later made into a service bulletin. I suspect you may be looking at RGB scavenge failure
  18. check gimbal assembly - something is worn out
  19. pjvr99

    Xover cut tit

    I will say there is nothing wrong, nothing to do, nothing to fix - system is operating within specification. mechanical fuel schedule and electronic fuel schedule are perfectly matched
  20. pjvr99

    Xover cut tit

    There is no wrong TIT before correction
  21. pjvr99

    Xover cut tit

    Do you mean a rise from 'before light out', meaning less than 800 and correcting to 800 to 840 after light out: yes, it is good. The ONLY, let me repeat that, ONLY requirement is a correction of 800 to 840. There is the rare occasion when the mechanical and electronic schedules are the same and no correction occurs. If this happens you need to do a proper TD system check.
  22. pjvr99

    Bird FOD

    Not much to be done there. Airfield safety should be taking care of birds thru keeping grass verges short, falcons, etc. Nothing a crew can do once they're committed to land or take off
  23. pjvr99


    Ok cool
  24. pjvr99


    So did you get it fixed?
  25. pjvr99


    Thank you. based on this and your previous mentioning the shift to another engine, it sounds like you have a rollback, a problem with the synchrophaser. Check out synchrophaser, sych rack, and also run synch box tester. sometimes the problem can be a false signal generated by a seemingly good valve housing. also check all 4 prop pulse generators.