Forum: F-16 Procedures

had a jet yesterday come down with an ITADs fault 83 with a 1-dnf message. no perfomance data was downloaded and we could not duplicate the problem. i am looking for some black and white to explain how the fan speed would be effected by the landing gear being down on takeoff.

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You mean O doesn't know ???

One word. AFETS.

Best Regards,

I agree with Joe … I believe there are some messages out for the ITADS fault which are benign and a software issue. But your tech/LM rep would know. We kept the message traffic in the forms of one jet that used to spit out that fault regularly.

VarkVet wrote:

I agree with Joe … I believe there are some messages out for the ITADS fault which are benign and a software issue. But your tech/LM rep would know. We kept the message traffic in the forms of one jet that used to spit out that fault regularly.

I agree with VarkVet my jet had the exact same issue about 4 years back and we did the same thing the engine troops received a message saying it's ok and we also put it in the forms. So every time a pilot showed up I had him read it. Stayed in my forms until the phase guys pulled the engine for phase over a 100hrs later. Then it went to other planes with that same message in their forms.

Agree; many ITADS fault codes are anything but reliable. Most are simply nuisance faults that indicate 'waiver' versus any true 'fault' in the motor. All need to be checked though as a few of them will indicate an engine issue. (Consult your applicable AFETS/Tech Rep/Depot Manager)

As for information concerning engine idle and the gear handle; look in the -1 Flight Manual. Explains how the various motors (-220/-229/-100/129) adjust between ground/flight idle based on the handle position. Search for 'ground idle' or 'idle area'. The various GS books should also detail ground idle function of the respective motors.

Keep 'em flyin' Thumb

TEG

Macmoe1, the fault is for Delta Fan Speed Scheduling being off, not necessarily fan speed. Of course, all of your ITADS faults occour during take off when WOW indicates airborne and that is when the DEC takes the 4 scan snapshot due to that is theoretically when the engine is running is hardest. That is when the ACL's, ACH's, DNF's and all your addictional messages for the 83 kick. Check your 70FI-1-1 (or 11-1 on blk 40's) becuase the fault is not validated until in CETADS. Working with your AFETS, 83 DNF's can be code 2's until u can verify that is in CETADS. If CETADS does not confirm, automatic return to service. The DEC cannot legitimately diagnose trend faults, thats why there's CETADS. And unless you can take WOW during and engine run, you cannot dupe on the ground.

The DNF issue is usually 90% the result of slow core/turbine deterioration and the other 10% to faulty fuel scheduling due to the MEC or the T4B limiter. The F110 community is starting to see this more often now and depending on location, more often than other places. But this problem was a very hot topic in the F101 community in the last 5 years. CETADS logic on that was called the Lo Thrust 82, 84, 86 fault.

I have a copy of the engine managment reference book in storage i need to find that has a lot of the answers that are not addressed in the F110 books (and surprising the F110 side and the F101 side don't talk). In a nutshell, the DNF is a unit which is the result of Fan Inlet Temp (T2) x Fan Speed (NF) divided by some crazy number. Now here's where the deteriation comes into play. The gases off the HPT drive the LPT which in turns gives you fan speed. When the HPT starts deteriorating, it puts out less, fan speed goes down. The DEC will have the MEC correct this by means of supplying a lil more fuel at a time to keep the fan up to speed. But eventually, the T4B limiter will kick on (@1665F on F101's) and the fuel increase will stop to keep the HPT from over temping. When that happens, the DNF will roll back and start popping the fault. And I tell you, a B-1 with a legitimate DNF (Lo Thrust) problem in the desert will take the hole runway just to barely get off the ground and will have the crew with all 4 engines in min aug to keep up with a tanker. Thats what happens when production doesnt listen. Lol

If your AFETS guy is lost, have him call Mr. George Kanno in kunsan, when had that issue before i got there, and I worked with them guys for the waiver for the DNF fault. Tell em Mitch sent you. The current 70Fi will have you change parts that have nothing to do with it. Even the F101s are ETAR'd (Engineer Technical Assistance Requested) so the fault is disregaurded until the DT4B hits 200 then the engine is waivered until -6 DNF. Once it hits that limit, it goes to backshop, core cleaned, HPT replacee and back on the line. Currently G.E. is working a water wash but of course funding is an issue and the DNF increase is not much.

I just PCS'd to McGuire so I need to search my books and get more figures out. But PM me if you had any more questions about it. I can save you the pointless DEC or MEC changes at the end of the tree if the Fuel Flow is above /or below 1700PH when u snap back out of intermmediate. Lol.

TEG long time bruh!!

You are like a broken record with that response Joe. In my twenty years, I only found a couple of AFETS that were worth a damn. They were the ones that would actually roll up their sleeves and go out on the line with TO in hand to help work a problem. The rest of them would just sit in their office and give you something to go try. I would much rather pick the brain trust on this site then count on one of them. So next time, instead of taking the time with your standard response, either contribute something useful or just say nothing.

sgtskull wrote:

You are like a broken record with that response Joe. In my twenty years, I only found a couple of AFETS that were worth a damn. They were the ones that would actually roll up their sleeves and go out on the line with TO in hand to help work a problem. The rest of them would just sit in their office and give you something to go try. I would much rather pick the brain trust on this site then count on one of them. So next time, instead of taking the time with your standard response, either contribute something useful or just say nothing.

If you read all the posts, you'll note that Joe isn't the only one who is properly saying that there are official channels for getting technical support.

Exfltsafety, true, we all know there are proper channels for that . But we all know there is usually a day or two wait for a response since at times the AFETS guy you get some times winds up being new to the system and they end up sending out an email to find out too. And we all know AFETS and Tinker are never in @ night time when you need them after the flying day's over and your doing end of day downloads. Very Happy

With that being said, that is why it seems everybody comes here for some kind of "reference only" guidance.

Macmoe1, I'm digging through my email to to find the message from GE regarding the DNF issue that sheds more light on it. But like I said earlier, your EMB section should actually have the Engine Trending Analysis manual that will discuss how the WOW plays into the engine trending, there is your black and white. Our 70GS does not break down trending.

I only reply with the most useful advice that I can: TECH DATA, TECH DATA, TECH DATA or AFETS/CETS. That advice will get you there 99% of the time.

As far as seeking troubleshooting information on this site, I agree that there are a few knowledgeable folks here, but very few have access to the latest and greatest information (many are retired or no longer work the F-16) but are you telling me there is no one at your location who can answer these types of questions?

Seeking improper guidance and circumventing TO procedures gets people HURT or KILLED. Your AFETS or CETS are there to help you out. If they don't know the answer right away, how can you fault them for it? You can't expect someone to know everything about this airplane, but your AFETS and CETS reps know where to find the answer. After thirty years on this airplane, I still learn something new every day.

Asking questions on F-16.net will not get your airplane fixed. Ever heard of the Falcon Hotline? How can you skip all of the resources available to you and use a public forum to discuss combat aircraft discrepancies?

Best Regards,

From what it seems like, he's at Osan, and that issue is fairly new over there. I was in Kunsan 11-12 (so I am very current on the tech data) and just so happen the AFETS rep that arrived was a Pratt guy, so they were cluseless and still trying to learn the GE. It ended up being me having to spool him up on the situation, but that's also our job to pass on info to inform them. But then again, I ran the flightline trending program at Dyess. So when I arrive to Kunsan day and our AFETS guy wanted to change a MEC. After I explained everything, he was still in doubt, until he called Tinker and spoke to the engineers and he was shocked. Lets just say, Kunsan now has the new waiver that updated the DNF limits to new limits.

As far as the CETS rep? Thats funny, the CETS rep in the ROK is some inbound SrA that gets thrown in there cause they wanna keep the experience on the line. All the CETS rep in the ROK due is make sure the daily downloads are done. Our CETS guy was a C-130 guy!!

But if you are truely still in Osan and doubt it, call the Kunsan AFETS office and ask to speak to Mr. Kanno. Tell him Mitchell directed you to him. He call put ya'll (Osan) on the same page with the issue just like we're are just like we're finally on the same page with the Oracle program not reconciling on the whole ROK!

By CETS I mean Lockheed. Unfortunately, there are not as many Lockheed Tech Reps as there used to be.

Best Regards,

Surprisingly Joe, all the CETS reps I seen were at times AFETS but mainly the GE guy assigned to that base. Never really seen any Lockheed guys for that program ever during time on 16's on a few bases nor any Boeing guys for CETS issues on the B-1. Those guys were always wrapped more around avionics stuff (sniper pods, system upgrades). Just my Two Cents

Quick primer for those who aren't familiar with the acronyms:

CETS = Contractor Engineering and Technical Services = L,ockheed Tech Reps, or GE, or P&W, or NGC, or Boeing, or Sikorsky...you get the idea.

AFETS = Air Force Engineering and Technical Services = Military civilians who perform the same function as a Lockheed Tech Rep.

You will NOT see a Lockheed guy as an Engine Tech Rep; but you can see an AFETS guy as an Engine Tech Rep. Big difference between Lockheed CETS and USAF AFETS is that the Lockheed guy gets his engineering dispositions from Lockheed, while the AFETS guy gets his from OO-ALC, WR-ALC, or OC-ALC.

Many moons ago you saw a million GD Tech Reps at F-16 bases, usually four or five guys at each base, sometimes with a Pratt or GE CETS. Times have changed however, and with most of the F-16 engineering responsibility shifting from Lockheed to Ogden, you see fewer Lockheed guys. Actually, the way the regulation is written (AFI 21-110 if I recall correctly) the CETS guys are supposed to be interim in nature, training up the AFETS guys and effectively working themselves out of a job.

If you are fortunate enough to have both CETS and AFETS at your location and they have a good working relationship, it is the best of both worlds.

The reason that I continue to push both CETS and AFETS is that these are the guys who are going to help you get your problem solved, and get the solution into the books. AFETS represents your brain trust and continuity, and they can help you with your 107s and if you don't have a Lockheed guy on site, AFETS can also write FSRs.

I urge all to use Tech Data and your CETS and AFETS to make the system work the way it should.

Forum: F-16 Procedures

engine faults with l/g malfunction