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pjvr99

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Posts posted by pjvr99

  1. grade 1010 oil is used for preserving engine fuel system if engine is in storage over 45days. I have had the dubious honour of starting and running both an APU and an engine on 1010, having forgotten to switch over the fuel supply .....

  2. The -60 GPU has a variable controller on the fuel cluster to keep rpm steady ..... sometimes

    causes more problems than just a drop in rpm would. The RPM on the run sheet is corrected

    for the tach generator and rpm indicator on the test cell. Once APU is installed on aircraft,

    it runs at indicated 100% and 400Hz. These figures can be checked in 2G-GTCP85-41-1

     

  3. even with max bleed load, electrical system requirements are still 380 to 420Hz/ Keeping this in mind, if the RPM drops

    below 95% the bleed air load control valve will be closed. Normal RPM drop when going from no load (100%) to

    full load (97.5%)

     

     

  4. Available now ......

     

    1x slightly battered T56/501 engine technician. Paint peeling but still fully functional.

     

    Well guys, the arabian adventure is over and i'm in the market for a job. Anyone know of anything, or hear of

    something, email me on pjvr99(at)gmail.com

     

    Tnx

    PJ

  5. I can never remember which one it is, bur one of the starters requires the misting plug removed at the

    bottom of the pad - check TO's

     

    Vibration can be a bitch - couple years back the line guys came in with big eyes accusing each other of

    not installing starter nuts properly as it had come adrift after replacement a few days before. It was tightened

    tested and released to service. 2 days later it was dangling again. i stepped in and had the engine removed

    and sent to test cell. During my hook-up I found all the control linkages to be excessively worn, and had to 

    replace gimble assy before continuing. During start i found fuel flow to be unstable and 16% micro-switch

    operating around 23%. Once the engine was on-speed RGB and compressor vibration were noted 

    at 1.8mils. Once we got to cross-over both were running at about 2,5 mils with the turbine joining the party

    at around 2mils. We changed out vibration transducers and even a known good propeller to see if the 

    vibration numbers would change, but to no avail. Engine was torn down and sent to overhaul

     

  6. 6 hours ago, NATOPS1 said:

    Aircrew in regards to Pitchlock prop operations and engine shutdown shutdown at a speed where you cannot maintain 96% or 150KTAS...

    What does your book actually say?

    Ours says "Attain a speed"

    Do you slow to determine blade angle and then shutdown at 96% or 150KTAS or at any given speed above 150KTAS?

    96% of what, NATOPS ....

     

     

  7. No i do not believe engine vibration to be the cause of the ignition system problem - that is a problem all on its own.

     

    Having said that, i had an engine on the stand for vibration evaluation and found speed valve, speed switch, coordinator, gimbal assy all malfunctioning or worn out. A couple days after failing engine for out of limits vibration including turbine and RGB,  I canned the excitor box for another engine. Once it was removed and I could inspect it, I found the screws holding the internal mechanism in place to have vibrated out, leaving several holes in the casing.

     

    Bottom line: vibration is NOT your friend

  8. If oil gets into the fly-weights it would most likely only affect the speed at which the switches operate; not the electrical functioning of the ignition system itself. At your next HSC, ISO or engine removal I would suggest replacing the speed switch garloc seal

    You would only pull the ignition cb if you had continuous ignition after engine stabilized at LSGI or NGI

     

  9. Hi Bob, prosperous 2016 to you also.

     

    Engine (power package) on test stand or aircraft match up within 1%, i.e. 98% on test stand will be around 97% on

    the wing.

     

    As to running on a dynamometer, we had some engines from RollsRoyce that came with dyno sheets. I was

    pleasantly surprized when the performances came in within 2%

     

    As to atmospheric effects: engines on cold wet days may be awesome, but the same older worn compressor

    on a hot humid day looks like it has emphysema

  10. 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

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