C130K - Effy Runs

[propersplitbrainme]

A question for Herc sooties that has arisen from a lesson we do here at Cosford on engine performance testing.

During my time on the mighty Albert in the 90's I recall conducting 'efficiency runs' or effy runs as they were known which I believe (correct me if I'm wrong please) are carried out to check the performance of an installed engine. Can someone please refresh my memory as to what these runs involve, i.e. what the general process is, what you are checking for etc.

Cheers

 

[fat lazy techie]

From my memory you are right, it is the efficiency of the engine you are checking for. To do this you have to run the engine to either 19600 lbs torque or 1050 centigrade TIT. You then punce these numbers, along with outside air temp and altitude with the altimeter set at 1013 mb. This should then give you a result of hopefully between, I think as it's been a while, 95 & 104% efficiency.

Hope this helps.

 

[Fu Fu Valve]

Effy's

Effy's

From memory they were usually done before Primary or Primary* so if an engine had a problem the Primary Team (did a year on that too) would pick up the joys of a burner change.
The joys 1 handed blind wirelocking..... bring those days back.DT_Xtremez_30:

 

[fileeth]

As i remember (over 10 years ago!!) it is as FLT stated in post #2 but with the days reading set and not the standard 1013mB - i thinkDT_Xtremez_42:

 

[fat lazy techie]

As i remember (over 10 years ago!!) it is as FLT stated in post #2 but with the days reading set and not the standard 1013mB - i thinkDT_Xtremez_42:

Almost right. The days reading was for the purpose of torque cal, always carried out prior to the effy run (honestDT_Xtremez_42

 

[propersplitbrainme]

From my memory you are right, it is the efficiency of the engine you are checking for. To do this you have to run the engine to either 19600 lbs torque or 1050 centigrade TIT. You then punce these numbers, along with outside air temp and altitude with the altimeter set at 1013 mb. This should then give you a result of hopefully between, I think as it's been a while, 95 & 104% efficiency.

Hope this helps.

Yeah, its filled in a little more detail from my vague memory as I recall gradually advancing the throttles watching the torque and someone else calling out the TIT. Didn't fuel flow feature in there somewhere?

 

[fat lazy techie]

Yeah, its filled in a little more detail from my vague memory as I recall gradually advancing the throttles watching the torque and someone else calling out the TIT. Didn't fuel flow feature in there somewhere?

Not for the effy calculation. IIRC there is a nice little chart in the back of the EGR MP that you can draw lines on to work it all out manually when away from the calculator.

With regards to advancing the throttles, you had to take the matching engines on each wing up together then leave one at about 15000lbs while advancing the other and you are correct about the calling out as well. It has been a while though.

I do miss those days, now I get to drive JPs around for a living.

 

[Pistonbroke]

On my first tour at Lyneham, back in the 70's, 99 times out of 100 the donk would be down on performance so we were told not to carry them out unless instructed by high auth etc. (This was on A line Primary team). If they were down the usual fix was a comp wash with walnut shells. I don't know if it is still done but this involved strapping a hopper on top of the engine with two tubes fed down the side of the panels into the intake. The whole lot was topped up by one of us sitting on top of the engine, keeping the hopper full. It was probably the only job that smelt quite nice. You could get a couple of percentage of performance this way.

 

[Tin basher]

Off TopicThrowing walnut shells down engines to make them work better. Kids today just wouldn't believe itOff Topic

 

[Bikerbill]

Definitive answer

Definitive answer

Gents (and ladies),

There is another open topic about this, to which I have posted a response, but to save you the time looking for it I have done a 'cut-and-paste' in the best traditions of 6442s and 6000's. and I think I have the definitive answer to your question.

To do an effy run you will need the OAT and pressure altitude. You get this by setting the altimeter to 1013mb. Then operate the engines in symetrical pairs, leave the one not being checked at 15,000 lb Tq, then advance to either 19,600 Tq or 1050 deg C, which ever occurs first. Make a note of the other reading as well as this is the one you will need to fill in the chart or calculator. You do not need fuel flow, but must ensure all loads are removed from the engine being tested, so no bleed air, hydraulic or electrical loads. You will also have needed to complete a torque cal (piece of wee-wee with the EIDS guages).

The limits are 96% - 108%. If the engine is low on performance doing a comp wash (or grit wash, we don't use walnut shells any more) will normally get you about 3 or 4% of efficency back.

The graph at the back of MP366 (engine test) is complicated when you first look at it but is really quite good once you know where the lines are meant to go. The calculator must be loaded with the latest software otherwise the info is not correct.

There is also a computer programme 'borrowed' from R-R that is now on some machines that is very simple to use. I have one on my machine in the K-school.

Hope this helps, if not please feel free to contact me in KHeMS.

 

[propersplitbrainme]

Found a copy of the graph Bikerbill, it all came flooding back! The only thing I couldn't remember was the limits which you've given me.
Top stuff, ta DT_Xtremez_30:

 

[wobbly]

We now do a similar thing on the J model called an MGT Verify. We have to turn off the bleeds to all the engines and then take it up to take off power (4750 SHP) and let it settle for a 2 minutes. Then we shut down and use our computer to break the wow micro-switches which will initiate an EMS download. We then take this download and debrief it on our GMS computer in rects control. This will give us a set of MGT figures that are slightly different to our indicated figures. We then use the airfield elevation air pressure and convert it to PSI and then use our performance graph (PSI vs MGT) to give us a max allowable MGT figure. If our figures are below this graph figure then we are good but if not its time to start looking for bleed air leaks etc to sort it out.

Its not too much of a problem in th UK but out here in Kandahar it cripples us as they call for it to be done every 30 days and when your tasking every night it can sometimes prevent you from making the program as you can sometimes take 12-36 hours to get a High powered running bay as there is only one area to do this and its constantly booked up.

If you're reading this and your at HERCJ IPT you need a fooking slap! What engine needs performance checking every 30 days unless there is a major design floor with it? Or have I hit the nail on the head there?

I might just have to start a thread on the J's IPT and there total lack of experience in theatre thus causing us a world of harm with the fooking stupid decisions they're making which have major impact on theatre ops.....

 

[Billy Whizz]

Hey mate - you having a pop at me???

 

[wobbly]

You're not Engine IPT are you mate? If so then when did that happen?

Anyway, I stand by what I said that IPT make decisions that have a major impact on theatre ops which is why it shouldn't be manned by Civilians but instead manned by experienced service personnel who know the impact of their decisions at the sharp end.....

Even more off topic.............

This is reflected by the fact that they made an engine script that could only be ran between the temps of 10 degrees and 30 degrees. We were not allowed to defer the oops code that brought up the running of this script either. This gave me great pleasure to inform them that the temperature out in some of our operating theatres never dropped below 30 degrees rendering the aircraft grounded for 3 months of the year.....great foresight.

Also, during the winter months in the UK the same script meant we had to tow the aircraft into the hangar just to get it warm enough to do the check. Although they have apparently sorted this all out now it just shows the blinkered attitude IPT have shown.

Just a dig at IPT mate, thats all I know they mean well but some of the decisions that are made are done with zero consulatation with the people that matter, the lads and lasses on the shop floor.

Right, back on topic.....K effies.

 

[metimmee]

You're not Engine IPT are you mate? If so then when did that happen?

Anyway, I stand by what I said that IPT make decisions that have a major impact on theatre ops which is why it shouldn't be manned by Civilians but instead manned by experienced service personnel who know the impact of their decisions at the sharp end.....

Even more off topic.............

This is reflected by the fact that they made an engine script that could only be ran between the temps of 10 degrees and 30 degrees. We were not allowed to defer the oops code that brought up the running of this script either. This gave me great pleasure to inform them that the temperature out in some of our operating theatres never dropped below 30 degrees rendering the aircraft grounded for 3 months of the year.....great foresight.

Also, during the winter months in the UK the same script meant we had to tow the aircraft into the hangar just to get it warm enough to do the check. Although they have apparently sorted this all out now it just shows the blinkered attitude IPT have shown.

Just a dig at IPT mate, thats all I know they mean well but some of the decisions that are made are done with zero consulatation with the people that matter, the lads and lasses on the shop floor.

Right, back on topic.....K effies.

On two projects I have been working on, I have lost count the number of times the squadron have refused to turn up to meetings. I explain that they will lose the ability to influence the direction of the projects and will end up with whatever they are given if they dont get involved. Being an aircraft technician myself, I do tend to make decisions that are as friendly for groundcrew as is practical. The aircrew know the value of attendance and always pitch up with representation.

My advice in dealing with PTs is get in their face and make sure they listen. If you want something to change, get your hierarchy on-side and present the PT with a reasoned argument and keep asking and bringing it up in liaison meetings.

I'd be interested in their 30 day frequency. They really ought to be able to explain this, if only to get buy-in from you guys. On one of my projects, for the training package that was being written I asked for a small part to explain why we were making the change which would ultimately result in more work for the maintainers....the 30 days may have been selected on a whim DT_Xtremez_42: do they know this is a problem at the pointy end?

I dont work for Herc PT btw!

 

[Billy Whizz]

You're not Engine IPT are you mate? If so then when did that happen?

When they cross-dressed me at Cosford and binned the Sooty out of here. Officially, I am IPT Mech/AF/Sooty and I've done a grand total of one sooty task in 2 years. As you know, luckily I have RR sit 5 yards away so I know who is getting all the HTPT queries/tasks on engines! DT_Xtremez_30:

 

[sumps]

Stuff it! It’s been two weeks so…Off Topic

They really ought to be able to explain this, if only to get buy-in from you guys....the 30 days may have been selected on a whim do they know this is a problem at the pointy end?

…good point, however, I know that RR (in particular the US side) are very sensitive over the information they give out especially if there is “a reason why” attached to it.

Wobblers, ol' chap! Are you sure that the IPT and LM are trying to remonstrate with RR ba5terdized (Hybird) engine? (given the experience in the HTPT that askes the questions of RR - Billy.W. being the exeption!)

It's well documented that the AE2100 turbine and associated areas/systems have been through a lot of physical design changes since its inception on the Herk "J", hence needs a lot of TLC – including any testing regimes devised this side of the MGT V’ tables turning up!.

I wonder if the turbine liner issues, disk incidents combined with other associated system issues within the engine and with the amount of funding the US Gov’ put in during its development have driven the running and testing of this variant to a point of constriction.

It would be interesting to see if RR are experiencing similar problems on the other variants of the AE2100 or on other variations of the core engine that are installed on the V22’s T406 or the Global Hawk using AE3007 and how their effies are plotted (and how the engines are preforming in general) seeing as they could reasonably be expected to operate within a similar environment to that of the AE2100D3.