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Manually draining refuel manifold

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I have heard many reasons why the manual says to drain the SPR manifold manually. I just wanted to throw this out there and find out why after you have already accomplished draining the roughly 200lbs of fuel with the drain pump the manual says to drain the residual into a container.

It seems to me that the mere half gallon of fuel left in the manifold would be far fetch to call it a weight and balance issue. And the old a rock might burst the manifold open on t/o or landing is not actually going to get that small amount to spill anywhere. In reality the JP-8 we use would be much more volatile in a vapor form in that manifold to cause an explosion or fire of the sort.

Of course I know after EVERY refuel this manifold gets drained . :laugh: Especially when aircraft are fueled off station and no suitable draining method or container is available.:silly: In the history of the Herk I am not aware of any catastrophic event that not manually draining the manifold has caused to require this step. Of course im not Mr Lockheed either. Any insight or light that could be shed with a logical reason would be greatly accepted.

My gut tells me its a step that should in actuality only be performed if you have a bad drain pump and have to fly the aircraft to another location in order to make the repairs. Good ole Herk and her redundant systems!

Tell me what you all think! For that matter you guys in the civilian industry what does your guidance say. Any inputs from experiences on other airframes and instances of the like would be good to hear also.

Regards

Max

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Actually you don\'t do it because of a rock.

You drain the sump for the probable chance of a blown tire.

I have seen several tires blown in my time and some did nothing but others did major damage, including tearing out the whole SPR area piping.

So yes, you drain it for a very real reason.

Dan

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:huh: I honestly can say that i have never heard of doing a manual drain on the SPR manifold as a routine operation.

I was never trained that way nor did i ever see the manual drain method used excluding a failure in the drain pump which occured once. Maybe it was something that the RAAF ommitted from our tech manuals?

Interesting.

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I agree with dagebow. In my 7 years with Transafrik in Angola & other s**t-holes of the world, I can\'t remember ever draining the SPR manifold -- & we blew A LOT of tires. (Of course, the tire always seemed to blow on a rainy night on a dirt runwway.)

Don R.

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Dan Wilson wrote:

Actually you don\'t do it because of a rock.

You drain the sump for the probable chance of a blown tire.

I have seen several tires blown in my time and some did nothing but others did major damage, including tearing out the whole SPR area piping.

So yes, you drain it for a very real reason.

Dan

I agree a blown tire is another scenario, i didnt want to list every scenario. But im asking about manually drained on top of using the drain pump. Just as everyone else has responded. Whats the harm the small amount...(less than half a gal)...of residual fuel left in the manifold going to cause. Not to mention it is almost impossible to 100% completely drain the manifold by using the manual drain valve. And any fuels technician can verify that when they have to replace or remove the coupling. There is always fuel still in there.

Even if the tire blows out and tears all the SPR area apart. In your experience have you always manually drained the manifold into a bucket or suitable container after you have completed a refuel? The real question would be what difference would it make.

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dagebow wrote:

:huh: I honestly can say that i have never heard of doing a manual drain on the SPR manifold as a routine operation.

I was never trained that way nor did i ever see the manual drain method used excluding a failure in the drain pump which occured once. Maybe it was something that the RAAF ommitted from our tech manuals?

Interesting.

Very! Maybe the RAAF used common sense and decided it wasnt intended to be drained manually and some how in the USAF we have established that there is a manual drain there so we should use it.....everytime! Of course i could go on my soapbox on how things get changed by people who really dont know what they are doing. But, alas ill just hash this up to an experience issue and say that over time the actual use for certain components on this aircraft get lost. Over time the intent gets twisted and all of a sudden we are doing things and we really dont know why we do them other than...somebody said so....instead of the why\'s and how\'s something work.

Thanks for the resposes!

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I refueled many \"A\" models, and I don\'t remember draining the manifold.

I been out for 41 years so my CRS is really acting up.

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South African Air Force always drained residue (used it to wipe down engine cowls, etc), SAFAIR always drained, and Saudi Air Force drains. Reason given - to reduce fire hazard

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Max,

Man I agree totally with what you are saying on this one! There are many scenarios as to why this gets drained after each refuel. The main one I have heard is the one Dan mentioned earlier with the blown tire. I agree and think this is very senseless with the little amount that is in there. I have seen many times when they actually do drain the thing you may only get a couple of drips and then there are times you might actually get a sufficient amount (1/4 gallon or so). So maybe they put it in the 1C-130H-2-12JG-10-1 for the reason you may have a weak drain pump and it may not suck all that fuel up and put it back in #3?

I have seen a few times you get those older engineers and they will pop the SPR cap on a -1 and push the valve in. More times then many they end up getting wet and mad at the same time. Then you see the Crew Chief dragging the bucket because now he has to drain the thing.

Good topic though and it will be good to see everyones responses on this one!

Do you know Danny White or Matt Stiles? Good people! I hope to get Dyess as my next assignment.

DaveB)

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It does sound senseless until you have to put out a fire in that area for whatever reason. What little fuel may be left over may make a big difference.

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Correct me if I am wrong here:

What about UARSSI equipped aircraft? After an inflight refuel the SPR drain pump is used to drain the manifold. When you flip the switch to line drain you automatically open the offload valve to use this feature. What about the fuel once again that is puddled at the bottom of the SPR after that?

DaveB)

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On UARRSI birds the FE also can control the \"manual drain\" valve, now controlled electronically as well as able to be manually opened. At the end of the drain time with the drain pump, residue fuel is dumped overboard where it evaporates. Note: don\'t drain unless you are pressurized since the fuel often runs along the fuselage and comes in through the rt paratroop door or ramp hinge. Now you have fuel fumes in the cargo comp.

Mike

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1685FCC wrote:

Correct me if I am wrong here:

What about UARSSI equipped aircraft? After an inflight refuel the SPR drain pump is used to drain the manifold. When you flip the switch to line drain you automatically open the offload valve to use this feature. What about the fuel once again that is puddled at the bottom of the SPR after that?

DaveB)

I Love it...that is a very good point! Ive been doing more digging and reading at work, and it turns out this is not unique to 130\'s. pretty much all heavy USAF acft have this in there manual.

Anywho, i appreciate everyones inputs and concerns in what they believe the hazards are, but one of the things we have to take into consideration here is the fact that we can say with almost absolute certainty that this step does not get accomplished regularly. Im not saying that is ok because it very much so is a blatant disregard for tech data. I do know however that if a very real hazard does exist why do we not have a warning note or caution stating this hazard in the manual.

Also, everyone is aware of the relatively high flashpoint of Jp-8. And once again we know that the vapor is more hazardous than the liquid. So are we not creating a greater hazard by draining it period with that logic? And once again even after performing this step there is still fuel in the manifold because you can not get it 100% empty with out disconnecting the coupling. We VENT and dump more fuel from out fuel vents and dumpmast on a regular basis than you can get out of this manifold after a refuel.

My 2 cents.

BTW, yes i know Dan white and stiles...stiles is becoming a FE currently and i believe he is up at Little Rock in class....Dan is a Pro Super on graves.

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L382fe wrote:

On UARRSI birds the FE also can control the \"manual drain\" valve, now controlled electronically as well as able to be manually opened. At the end of the drain time with the drain pump, residue fuel is dumped overboard where it evaporates. Note: don\'t drain unless you are pressurized since the fuel often runs along the fuselage and comes in through the rt paratroop door or ramp hinge. Now you have fuel fumes in the cargo comp.

Mike

Thats interesting, so they made it to where you can vent whats in the manifold in flight. Does there happen to be a reason why they would go that extra mile to include that option. Or is it just another its done just because? Heck with that option the crew chief has no reason to drain it on the ground. Fe can just drain after take off. :)

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Maybe the reason that the RAAF does not drain, is the difference in fuel grade (or at least it used to be) in Australia we always used AVTUR which is a civilian grade and is equivelant to JP1.

Makes also for slightly lower black smoke.

Regards

Col

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herkman wrote:

Maybe the reason that the RAAF does not drain, is the difference in fuel grade (or at least it used to be) in Australia we always used AVTUR which is a civilian grade and is equivelant to JP1.

Makes also for slightly lower black smoke.

Regards

Col

Yeah Col i was thinking that as well, AVTUR is less volitile than the old JP-4 fuel used in the US which would have been when the manuals were written.

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you get those older engineers and they will pop the SPR cap on a -1 and push the valve in. More times then many they end up getting wet and mad at the same time

HAH, I have had more than one good laugh at the idiots that do that.

In over twenty years as an FE I never did that and couldn\'t understand those that did. \"but what if you have fuel in there\" Well I guess theres fuel in there and I don\'t know it - oh well!

Roger that on the UARRSI drain, procedure was

\"Line Drain - ON\" you selected this for 8-10 minutes to run the regular drain pump.

\"Sump Drain - ON\" for 1-2 minutes. this is the sump drain.

And yes it is a fire hazard to have fuel back there if you blow a tire BUT I really never worried too much about it, its just been a procedure as long as I was on the Herk. Could they do away with it and be reasonably safe - YES

Maybe someone should submit a change to eliminate the step, even if its denied maybe they will give you an \"Official\" reason for keeping the step in.

Dan

th_Chuckmovieshort.jpg

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Love the site and have been following for the last year through all the changes without responding because I have forgotten so much. However this topic reminded me of a personal experience and spurred my earlier response. From what I have noticed on this site most responses are based on personal experiences and even though there are disagreements they are normally constructive. Therefore I figured that I would share this one even though it may not be completely on point.

I was a very young mechanic on AC-130\'s on my first TDY and a crew came out to do a -1 just as we finished refueling. They were in a hurry so the crew split up the inspection duties. The old (at least what I thought at the time) IO (LM) asked me why I did not drain the SPR manifold. Of course I sat there with the deer in the headlights look. He let me know in no uncertain terms that I screwed up and that he was the one that would have to put out any fire that may occur and if he ever came out for a -1 and got wet from the poppet valve he would kick my a__. I got a bucket pretty quick.

Needless to say I drained the manifold after the next refuel but much to my dismay there was a good bit of fuel that came out during the next -1. After the 2nd chewing out I learned to do it right before the crew showed so there was nothing but a drip when checked.

Before the flight home the IO pulled me aside and asked if I drained the manifold. When I said yes he explained the reason that he was so hard on me was that he believed if you took care of all the \"little\" things that the big things would take care of themselves. He did not check the poppet valve then and never did again but it was a running joke for years between us.

I learned two things from him on that trip:

1. If you are supposed to do it - do it.

2. If you don\'t do it - let those that it may affect know it.

Those two lessons have served me well over the years. Unfortunately the person that taught me those lessons is no longer with us. His name is Roy Duncan and perished on Jockey 14.

On the lighter side of things, it does not matter if you drain the manifold on UARRSI aircraft or not because the flight engineer will not like how you configured it and is going to transfer on taxi so he will drain it before takeoff:woohoo: (Had to get a litle poke at the eng.)

Jody

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Hey this is a pretty good post!

On the lighter side of things, it does not matter if you drain the manifold on UARRSI aircraft or not because the flight engineer will not like how you configured it and is going to transfer on taxi so he will drain it before takeoff (Had to get a litle poke at the eng.)

The offload valve should prevent fuel from getting back down the SPR line after that happens, but valves do fail!

Dan, I was waiting for your post to see what you had to say about the UARRSI system. I am fairly new to UARSSI since I have been on slicks my whole career (except for 64-14859 aka franken slick, half EC-130, half HC-130 and now a slick!). When you go to \"SUMP DRAIN\" the remaining fuel goes out the UARRSI vent line behind the w/w, correct? Where you still in when they added the rubber hose to this line to prevent the vacuum affect? (Damn that was some funny s!@# on the flick up there!)

Thanks for sharing your story 696574CC, and godspeed to your friend and everyone on Jockey 14.

Have a good one fellas I have to get ready for an MSET/UCI inspection this week. AFSOC is taking a look at my W&B program. :ohmy:

DaveB)

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Dan Wilson wrote:

HAH, I have had more than one good laugh at the idiots that do that.

In over twenty years as an FE I never did that and couldn\'t understand those that did. \"but what if you have fuel in there\" Well I guess theres fuel in there and I don\'t know it - oh well!

Roger that on the UARRSI drain, procedure was

\"Line Drain - ON\" you selected this for 8-10 minutes to run the regular drain pump.

\"Sump Drain - ON\" for 1-2 minutes. this is the sump drain.

And yes it is a fire hazard to have fuel back there if you blow a tire BUT I really never worried too much about it, its just been a procedure as long as I was on the Herk. Could they do away with it and be reasonably safe - YES

Maybe someone should submit a change to eliminate the step, even if its denied maybe they will give you an \"Official\" reason for keeping the step in.

Dan

th_Chuckmovieshort.jpg

I am going to submit the change and see what happens.

Its kind of like grounding aircraft, in the late 80\'s they did a study that determined the actual grounding of aircraft has no significant impact on static electricity generated. Even the 00-25-172 states aircraft are only required to be statically \"dissipated\" once after flight. But the MDS specific JG says to ground with two ground wires one fwd and one aft. Fortunately, if you have no means to ground the aircraft there is a note that allows you to statically bond to the refueling source.

As far as the manual drain goes, Im curious if since we are using less volatile JP-8 now if this step is no longer necessary unless your drain pump has failed. Ill report back with the results of what I find. Thanks for the many inputs and experiences! There truly is a wealth of knowledge here!

v/r

Max

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When you go to \"SUMP DRAIN\" the remaining fuel goes out the UARRSI vent line behind the w/w, correct?

It still drains out the old sump drain line. What they did was just run a bypass around the manual sump drain valve and stuck a solenoid valve in there that is controlled on the overhead.

Yep, know all about the rubber hoses. When I first came to shadows they were pretty new at the UARRSI thing so never knew about it, just kept coming in IFE with fuel fumes. Told em to look at the gunships, the hose just moves the drain out far enough so the airflow doesn\'t take it right back in thru the paratroop doors LOL.

Guess I had a leg up on them doing the UARRSI thing when I first crosstrained on the EC-E\'s so was just four years non-current when I got to the 9th. Didn\'t take much to dust it off.

Dan

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Hey, the hazard may be more than a blown tire. The picture below shows the result of an in-flight fire initiated by a small arms hit on the surge supressor behind the SPR panel. The resulting in-flight fire continued for several minutes while the residual fuel in the refueling manifold drained into the damaged (burning) area.....

[img size=600]http://herkybirds.com/images/fbfiles/images/785_Fire_600X400.jpg

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Interesting, incident with the small arms fire.

Ironically that is not the response that was cited when i contacted Warner Robins on this matter. Matter of fact i was given no reason other than to remove as much residual fuel as possible.

Here is another interesting fact, in the old -2 MM there is a Note that states Manual drain of SPR manifold is not required if the drain pump is operational. Id give you the Pg and ref if i had it in front of me. Thats what sparked my interest into calling the engineer/SPO at WR.

He said at this time they do not have a reason to change the task to include such guidance. Hmmmm, SO. :blink:

I was also educated on the fact that this has come up in the past and was discussed in detail at the 2003 Product Improvement Working Group PIWG conference. So i dug up that report, it is amazing that this was discussed and the hazard was deemed negligible and improbable for leving the residual fuel in the manifold after an approipriate drain from the pump. It goes on to say text would be added to the JG to clarify this and allow only the pump drain as long as the pump drain is functioning. Well my friends that was 2003, checked to see if anything in the following PIWG yrs for follow up, and in 2005 it stated that the JG would remain the same and the hazard was upgraded to marginal but acceptable with SPO review. 2008 is right around the corner and we still dont have a solid answer on this. I would think with all the theories that have been specualted about this would be opened closed if it very well were a hazard. Side note, i also checked the -1 and there is nothing related to this also.

Here is the bottom line. It very well cannont be a FAA saftey concern if this only applies to USAF aircraft. I believe this one very well may have just slipped through the cracks and since aircraft mechanics as a whole do not observe this step and we successfully complete our mission day to day and seem to get on just fine. The next step is defining the real hazard and waste we are creating by transfering a hazardous fuel/contaimanant and causing uneccessary exposure to out personnel and the cost of HAZMAT disposal by EPA standards (which we know are becoming stricter and stricter) Which is a more acceptable risk, people exposure,excess cost, enviromental waste. Or performing a step just because no one want to make a call while we raise the BS flag.

If i seem a little agravated, it because im actually losing sleep over this, i think i have OCD. I have actually dreamt about this, i think i need some time off and a vacation. Im not quite finished with this yet and once i compile the data on the time money and personell we endanger maybe ill have a sgnificant leg to stand on. I guess ill have to see how it goes.

MADmax

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Here\'s another view, same airplane. Noteworthy is the obvious heat damage to the ALE-40 flare dispensers---fortunately, the flares did not launch. The crew inside the airplane was trying to fight the flames that were coming from outside through the opening in the fuselage, and the fire was being fed by the residual fuel...

[img size=407]http://herkybirds.com/images/fbfiles/images/New_Picture.png

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we are creating by transfering a hazardous fuel/contaimanant and causing uneccessary exposure to out personnel and the cost of HAZMAT disposal by EPA standards (which we know are becoming stricter and stricter)

While I cannot not and will not address the issue of when to drain, let me comment on the above, We simply used to pour any GOOD fuel we drained into a piece of SE that ran on diesel. That eliminated the disposal problem.

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