Cargo Ramp Rigging

[andrewelsh]

Hey guys,

I have been trying to rig the cargo ramp, and I've run into some issues; I have completed the internal rig and external rig on the ramp. Locks 10 are both raised one shim to keep the load on them, but unfortunately locks l/h 2 and r/h 4 are engaged (raising the ramp by 1/4 -1/2 ") even though they have no vertical shims installed. I realize that simply adding a couple more shims to locks 10 would probably solve the issue,. BUT the ramp has now started to raise the door up.

Can't seem to add any more to 10, and can't take any away.

Maybe I'm missing something simple.

[Ramrod]

Open the cargo door and take a look at the #2 L & R saddles for divots and wear. Check for proper gaps in all the other stations (4 thru 10) Over time this wear will allow the Cargo door to drop lower. The ramp is normally rigged first then the door.

If only one shim is under ramp lock station 10 and the cargo door is being pushed up, that tells me to look at the cargo door rigging. Cargo ramp gap issues at stations 2 & 4 can sometime be traced back to ramp hinge bushings worn and/or not properly installed parallel to the ground. If all this checks out good, contact LMCO for assistance. Also keep an eye on your lock and unlock pressures as stated in the Job guide as this will let you know if you have the proper cargo ramp lock #10 preload.

Check for excessive amounts of sealant on the cargo ramp where the cargo door seal sits. Many times this has to be removed to rig the ramp and cargo door.

One more important step, were the ramp lock saddles removed? If so, you may have to identify if the proper saddle is in the proper position. They all have very slightly different angles and they are not too noticeable to the naked eye. Part numbers have also been known to be wrong in the past. Depot had issues with installing the wrong saddles in the wrong positions in the past. I believe this is also in the job guide and a tool for checking them is either in the 52 series JG or the -OO-GE.

I hope this helps.

Ramrod

[Steve1300]

Sounds like Ramrod has done a few ramp and door rigs.

I have also found the blocks mounted under the forward end of the cargo door to be the incorrect dimension. We had four of them found to be 1/4" too tall, and they contacted the ramp early - lifting the door when they should not have.

I don't have my notes with me now, but LMCO can tell you the top angles of the lock saddles in order to ensure that you do not mix the saddles up. Once they get crossed, you will find the #2 locks tight and pull your hair out trying to get it correct.

Bushings are a big issue, and they are easily missed because they are invisible to us unless we remove the ramp. However, the easiest way to see if anyone installed them vertically instead of horizontally is to check for side-to-side movement of the ramp and the actuator end. Lockheed Service News gives a method of checking for the proper amount of play. If the play is not there, the bushings are installed incorrectly.

[Ramrod]

Sounds like Ramrod has done a few ramp and door rigs.

I have also found the blocks mounted under the forward end of the cargo door to be the incorrect dimension. We had four of them found to be 1/4" too tall, and they contacted the ramp early - lifting the door when they should not have.

I don't have my notes with me now, but LMCO can tell you the top angles of the lock saddles in order to ensure that you do not mix the saddles up. Once they get crossed, you will find the #2 locks tight and pull your hair out trying to get it correct.

Bushings are a big issue, and they are easily missed because they are invisible to us unless we remove the ramp. However, the easiest way to see if anyone installed them vertically instead of horizontally is to check for side-to-side movement of the ramp and the actuator end. Lockheed Service News gives a method of checking for the proper amount of play. If the play is not there, the bushings are installed incorrectly.

Ignore the cargo door until the ramp is rigged completely. Then troubleshoot the cargo door. Make sure your lock/unlock pressures are with in the tolerance specified in the JG. When complete, the cargo ramp, when locking, should NOT shift to one side or another or pull in the sloping longeron's.

On the cargo door, look at the cargo #2 L & R saddles. Check for deep divots or wear. These are the only saddles that should have zero (0) gap. Saddles 4,6,8 & 10 should have a gap, check the JG for the proper clearance. One telltale sign of excessive wear on the #2 cargo door saddle(s) is wear or divot on the cargo door lock saddle.

Steve posted a good check on the phenolic blocks on the cargo door where it meets the ramp. Also I have seen thick sealant across the entire width of the ramp/door seal contact area. Maybe you need to cut out the sealant where the blocks contact the ramp. It has been my experience that a properly rigged ramp and door and a good pressurization seal, there is no need for sealant across the width of the ramp, only the corners need sealant, and normally it is not that thick.