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C-130 pulls to the left.


joemontyb
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Many things can cause that. If the aircraft is not leaning left wing low, and your MLG tires are not underinflated on the left side, and your torque indicators are correctly calibrated and even as you are taxiing, and your nose wheel steering is rigged to the center position correctly, then check for dragging brakes on the left MLG.

Would it be a silly question to ask if you are having a constant strong crosswind?

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Also, do you know what parts have been changed? NLG tires the same type? Also, one of the culprits I see alot if the persone rigging is new to it, they might overtighten or under tighten the steering valve plunger bolt. make sure it spins freely.

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Here is a little off the cuff solution we were given to try. I can't say if it really was the problem the but it did go away.

We had an aircraft pull left, we tried all the solutions listed in this page and then some also changed the NWS control valve (swapped to another aircraft it worked fine in that one). However, before we could ops check the control valve we accomplished (sort of) the other solution. We we were told to swap the #1 an #4 props. We started doing that, however; they both we leaking so we put two new props on and the problem is gone and has not returned.

Your guess is as good as mine! And yes all engine power and torque checks were accomplishd prior to moving the props!:confused:

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Cal your torque gages (use the actual cal number in the logbook vice 29850), dip your tanks make sure they are even across, put your flaps up, inflate your tires equally, check your struts for proper servicing and extension.

After all that make sure you set the aircraft up correctly... Torque symmetrical, fuel flow within 50 lbs of each other. Then see if the aircraft will track strait. (Our books say a correction to maintain a strait track "outside of the white" is excessive") so while you can correct it is limited in the amount. Not sure if you are setting the pointer straight and not touching the steering or correct "outside the white" to maintian your track...

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Get your FCF checklist out if you are dealing with the USAF. There is a procedure for downspeeding and shutting down the utility sytem seperately to determine if the problem is rigging. There is more to it but the FCF checklist will help troubleshooting

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we had an aircraft pulling to left,after all rectification c/out.like engine torque adjustment,tire pressure adjusted,steering checked still the same,chock strut pressure equalized,the proplem still the same,at last it solved by increasing the left strut pressure more than the right one,but within limit,and the proplm was solved.

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The is an interesting solution.

Did you use the same gauge to measure strut pressures in all the struts or different gauges?

I like to use hoses that are "Y'd" together and equalize pressure between the left and right struts at the same time, and those hoses go to only one gauge so that the pressure is equalized between the left and right struts. Unfortunately, with the pressures that we deal with and the inherent inaccuracy of gauges (the standard being one increment as a tolerance when calibrating gauges) it is possible to have 200 psi difference between the left and right side if one uses a cheaper gauge to do the work. It is expensive to have a strut pressure gauge with has increments of only 10 PSI in that range. In short, the possibility of error is built in to the system by the quality of the gauges we use.

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Explain to me how a low strut (leaning aircraft, they lean all the time) will cause a aircraft pull?? I think it is the same fix as swapping the propeller from one side to other fixed the problem. Most of the time it's someone in the seat :P that says hey this aircraft pulls and everyone else feels the same thing UNTIL maintenance does something to make it feel better:).

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Explain to me how a low strut (leaning aircraft, they lean all the time) will cause a aircraft pull?? I think it is the same fix as swapping the propeller from one side to other fixed the problem. Most of the time it's someone in the seat :P that says hey this aircraft pulls and everyone else feels the same thing UNTIL maintenance does something to make it feel better:).

Have you ever tried to back an aircraft that was leaning out of a hangar? Try it some day and you won't have to ask the question - it will turn itself toward the leaning side. When towing one forward, it won't be able to force a turn because of the tug. If you taxi one that is leaning, you'll find yourself having to correct for the pull to the low side constantly. The more the lean, the harder the tendency to turn.

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Currently, I am also having “one†reported pulling towards left during taxing; and during the landing roll when shifting throttle from F/I to G/I left wing sharply tends to go down. (Engine torque indicated equal in all positions).

Left legs found weak re-serviced with hyd and nitrogen, the lifting of wing solved but the pulling to left during taxi remained reported by captains, Rigging and adjustment on the steering c/out, nose tires changed, all wheels re-torqued, steering control valve changed…etc; No improvement in stopping the write-up .

The last action was the change of steering actuators accompanied with a cup of coffee to the pilot in charged to perform the taxi check during his waiting to prepare airplane for taxi check.

This time I was with them during the taxi-check; there was no pulling tension when pilot hold the steering on the white mark but when leaving the steering free the airplane moving slowly toward left, this act repeated upwind and downwind, with inboard engines alone or outboard alone, with low or normal RPM, finally captain looked at me, asking me to comment; I told him I never been on left seat to evaluate, but is it recommended to leave the steering wheel free? I added, was the coffee offered to you not enough to keep hand in touch with the steering.

Defect cleared by the captain. What solved the defect, Coffee or actuators?? No idea.

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