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hehe

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Everything posted by hehe

  1. Fuselage station. There were versions of the C-130 that went well past the nose radome. MC-130H had a longer nose radome, HC-130H and MC-130E had yokes that extended way forward of the nose, other models such as AC-130 had a massive pitot that extended well past the nose radome. If there is a pitot probe attached to the nose of a plane during design or initial testing, it defines where the fuselage station starts. They wouldnt use negative fuselage stations if they already know there will be a reference point that far forward. Most forward point defines 0 and it gives room for modification of extension of the nose.
  2. It keeps the aux pump from cavitating at high altitude. Used to have issues with not being able to open the ramp and door at high altitude because the aux pump would cavitate. High altitude ramp and door mod was to fix that issue. It mostly did
  3. I've always 100% disconnected scissors when towing as well. There is zero gain by towing with them connected. You might be hunting a self induced problem by towing with scissors connected. If you really want to go down the rabbit hole though, I would 100% ensure your strut is serviced properly (meets and exceeds minimum X dimensions) and you can pull the flow reducers out of the steering actuators to ensure they are in good shape. There are plugs on the aft side of the steering actuators, under that plug there is a flow reducer with a spring. That limits how fast the actuators can move fluid through them. The steering control valve doesn't do much when it's not being powered, the reduction in flow really resides in the actuator end caps. You could also check the bearings on the forward steering actuator trunnions, those bearings are finicky and bind up quite often if not properly maintained and lubricated often. Again, you are probably chasing a problem that is self induced though, no need to tow with scissors connected, it's all risk with no reward. Chris
  4. Why would you ever tow with it connected? I've never heard of any manuals that state to tow with it connected
  5. When you tow, you have to disconnect the NLG scissor. The top and bottom are not linked. Are you towing with the scissors connected? You should never have any reason to even talk bout the steering control valve because it's not in play when the upper scissor is disconnected from the lower scissor. Im very confident when I say you might be towing incorrectly,
  6. I would suspect a MLG motor or utility relief valve to create that low of a pressure drop on both engines when isolated. Assuming you are isolating everything correctly, but do this: 1. Turn off all 3 boost packs (red guarded shutoffs). Is pressure the same? If it changes, isolate boost pack 1 at a time. 2. Run the system up and let it run for a good 15 minutes. Does the utility relief valve get hot? Can you hear it bypassing? Possible that it is dumping your pressure back to return 3. Remove the hydraulic lines and cap the outlet ports from the landing gear selector valve. Run the system up, does it still have the low pressure?
  7. hehe

    Placard

    This is just a marking for the ring segment at fuselage station 165. The fuselage is essentially just a bunch of beefed up rings connected together.
  8. hehe

    Struts

    It's not a bad idea to do it and hydromite is by far the best strut servicing tool available. As far as hydromite, If you aren't using hydromite or aware of how to use it, you are shorting yourself. If someone told me to go leak check a strut, service a strut, R2 a strut, deflate a strut, etc, etc. I'm asking for a hydromite. Hydromite is awesome for fixing strut leaks and servicing. Take the time to learn about it.
  9. hehe

    Struts

    The struts are a time change item so you don't change the fluid out, the entire strut gets replaced. Short of moisture in the hydraulic fluid and it not meeting the water content limits, the fluid doesn't really break down in struts like it does in the system. Sometimes you can drain a reservoir and the fluid is visibly darker or dirty looking. Struts, in my experience, don't really have this same problem because there aren't moving parts in the strut short of o-rings. The fluid doesnt really come in contact with wear items like an engine pump or motor produces for example. This is just my opinion since I've drained a lot of struts and never really came across one with dirty fluid.
  10. Elevator boost pack is what bleeds down pressure in both systems. If you pressurize booster and utility, and shut off the elevator boost pack shutoff valves, the systems will hold pressure after shutting down engines. Not forever but noticeably longer than without the elevator boost packs shutoff. If you also hold the elevators neutral, the pressure will not deplete. If the elevators are on the stops (yoke forward) the 3.8 GPM bypass will quickly deplete pressure Long story short, I would look at the elevator boost pack in relation to booster side. Bypass not bypassing when elevator is forward on the stops, elevator booster shutoff valve partially closed, booster return filters clogged
  11. Not sure what you are doing to troubleshoot this but it's pretty easy to start. 1. Start diagnosing the tripped open ECB IAW 24FI for tripped ECB. 2. Swap/R2 APU relays and check all power connections. I would caution resetting the ECB multiple times until you figure out what is causing it to trip.
  12. If the handle locks up at 40% it is almost always because someone pulled the UP lock lever while lowering flaps. The lock and flap lever interfere with each other in this state and lock the handle up. What model of C-130 was this?
  13. So they went from zero to 40% flaps and the handle stopped or flaps stopped? If the handle stopped moving, I know exactly what caused it. If flaps stopped, the handle would be at 100% but flaps would only be at 40%.
  14. When you say you had flaps stuck at 40%............ Handle could still move from full up to 100%? Utility pressure was solid around 3k when trying to move flaps? Did it trip when flaps were going up or down? Did you find water in the asymmetry brake switches? Reason I ask these things is because 40% is a very specific range where a lot of crews induce their own "flap failure" issue that is just operator error.
  15. the note about changing oil when it exceeds this temp is in the instrument limits area of the 00GV if I remember correctly. Completely random place but I did read it a few years back
  16. Have you checked the PPDU/LVPS circuit breakers?
  17. You still have the briefing available to show? Is it the one that floated because the tanks were empty and it floated like 50 hours before being sunk
  18. First thing would be to make sure it passes a cabin decay check. Not by a second or two but a good pass. The ability of the cabin the hold a pressure is important Next I would check the Jet Pump and check valve under desk in aft right of cockpit. Check for cleanliness and corrosion. Both have been known issues Check outflow, safety valves. Make sure the outside static ports on right side of forward fuselage arent clogged or painted over. Those are the sensing ports for pack and safety valve
  19. First question is what year/model? Yes it matters if its a B-model verse a mid 80s H-model. Ground test valve commonly considered bad for transfers and to be honest it almost never is. Check the rigging to the ground test valve. It should be tighter on one cable verse the other so that the valve wants to pull to the closed position. The incorrect rigging of the cable is much more common than a valve itself. Check the brake shuttle valves. These can transfer aux to utility and utility to aux when brakes are used. They should not allow fluid to flow through them once they shift to other side of shuttle. A strange one that I have seen is one of the brake selector valves not receiving power to close so both valves were open and causing util/aux brake pressure to fight at the shuttle valves. Its easy to check. They are powered close so when energency is selected, you should have 28 vdc on normal selector and opposited when normal is selected. Nose landing gear uplock, NLG actuator and nose gear emergency selector valve can also cause this. Not too common but I have seen it. Do you have UARRSI, refuel pods or weapons systems? If so, all of those can be points of transfer. Emergency brake and normal brake accumulators should be checked for internal leakage as well. Most common of all is a person not fully depleting brake pressure on BOTH normal/emergency before moving the ground test. There is always some avionics or electrics guy that wants to help but doesnt know the details of running hydraulics. I have seen people chase this ghost and come to find out the new guy was improperly trained on tying ground test.
  20. I have a library full of C-130 books, odds are I have the book. Was it hard/soft back? , kind of a small/thin book or large/thick book? Color images/black-white? Describe it the best you can to help me limit my search. I have too many books to just go page by page
  21. The Ejected pressure from the engine should never indicate exactly in the flight deck for quite a few reasons. 1. Pressure drops across distance. In order to get 125 psi in the flight deck, the engine would need to be making 150-ish psi at the engine (just an estimate). Pressure drops across distance because flow and volume is required to get that pressure across a distance. 2. The system has allowable and normal leaks. Every valve in the system is bleeding off or leaking a small amount. Some are calibrated to leak a certain amount and others just leak as a result of their design. Very few pneumatic systems are perfectly leak proof. For example, if you have 20 valves in a system and they are all leaking small amounts of air, your 125 psi becomes more like 70 after the bleed offs. This is why the system has a bleed down time. The drop from 30 to 15 psi in 22 seconds or more is a indication a satisfactory level of "normal" leakage. If there were no leaks in the system at all, your bleed air pressure would never drop. 3. Almost all systems are like this. Hydraulics, fuel, electrical, oxygen, etc. The system is designed to provide a higher amount than is required so that it can "bleed off" some for normal system losses and still provide a set amount. Hope that helps.
  22. Here is a C-130 flight manual for reference. This sequence started on A models because the GTC door had to be manually closed and the engine generators were split between inboard/outboard. So they would start #3 and #4 and then shut down GTC, manually close the door and then start left wing. Some pubs mention starting engines in a different sequence than 3/4/2/1 to spread the wear and tear on engine starters. The first engine started off of GTC/APU Bleed air will wear faster than the others with engine bleed air because of the higher flow/pressure from the engines. Generally speaking, if you 100% always start #3 first, data/trends say that you will replace the #3 engine starter before the other engines.
  23. It is in the Aircrew's starting engines checklist of the flight manual. It says something like "normal starting sequence is 3 / 4 / 2 / 1" depending on which flight manual you read
  24. 1. I will have to double check but I think the 3k RPM is low speed ground idle and 3.6K RPM is normal ground idle (engine at 100% rpm) Why would you ever need to figure out the GPM at low speed ground idle? You would never fly at that engine RPM 2. Pressure equals out. If you had 3K and 3.1K you would probably see a little bit above 3K by the time the pressure equalized and got to the pressure transmitter at the utility or booster panels. Pressure drop is roughly 100 psi every 50 feet (not written down anywhere just what I have seen)
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