“I purchased this airplane a few months ago,” Mitch posted to his initial ticket after enrolling his 1969 Mooney M20C in the SavvyQA maintenance consulting program, “and took it to a maintenance shop this week for its annual inspection. This shop had just opened its doors, and I chose it because it was offering owner-assisted annuals and had immediate openings.”
As he was reading Mitch’s post, Savvy account manager Brandon Thompson A&P/IA felt the hair on his arms start to stand up. Virtually all the competent shops Savvy works with have their annual inspection schedules booked solid for at least weeks and often months in advance.
Mitch went on to explain that he’d been having no issues with the airplane during the 30 hours of operation since he’d purchased it. The engine used very little oil, and the compression readings were quite good when the IA took them while Mitch watched. Two days into the inspection with no major issues identified, the IA said he would call when the parts Mitch approved came in.
“The next day, I got a call from the IA saying he needed to overhaul the engine because he had found metal on the oil screen. He’s trying to contact Lycoming to see if they’ll allow him to sign it off requiring another inspection after two hours of flight to see if the engine is making metal.”
That sounded fishy to Brandon, who knew that Lycoming had no authority to tell an IA whether or not to sign off an annual as airworthy. Brandon also knew that Lycoming offered very detailed published guidance about “what to do if metal is found in the screens or filter.”
“I’m new to this,” Mitch told Brandon, “but I already have several reasons not to trust this shop to do an engine overhaul.”
OMG, Brandon thought, this just-opened shop is proposing to overhaul the engine THEMSELVES? Although it is legal for an A&P mechanic to perform an engine major overhaul, it’s very risky business for an aircraft owner to entrust anyone other than an FAA-certified engine repair station with a long track record and sterling reputation to do such critical work.
“I’m hoping the IA will sign off the plane so I can fly it to a more established shop for a borescope and a second opinion,” posted Mitch, showing excellent instincts for a first-time aircraft owner. “Alternatively, I’m hoping he’ll complete the annual and sign it off as unairworthy with a list of discrepancies that include ‘engine making metal’ so I can get a ferry permit and fly it elsewhere.”
It struck Brandon that the IA probably had other ideas, especially after Mitch told him that the IA had taken possession of the airplane’s maintenance logbooks and refused to permit Mitch to take them home until after the annual inspection was complete. Brandon knew that no IA has the authority to hold an owner’s logbooks (or airplane) hostage in this fashion. In fact, such bad acts are precisely why Savvy advises its clients NEVER to allow their original aircraft logbooks out of their custody and control, and to make available only digital scans or other copies to shops and mechanics who work on their aircraft. There is no legitimate reason that any mechanic (or even an FAA inspector) requires access to the originals.
SavvyQA is a consulting service that allows aircraft owners to pose questions and obtain advice from members of Savvy’s team of maintenance experts. Mitch’s initial questions for Brandon were these:
- Should I be concerned about the IA making a logbook entry requiring reinspection in two hours?
- If possible, I would like to have Advanced Aircraft Services LLC in Troutdale, Oregon do a borescope inspection and, if needed, the overhaul. Have you had any experience with them? Are there other options you would recommend?
Brandon explained that (1) no IA has the authority to require any sort of inspection at any particular time—nor does Lycoming—only the FAA has that authority; and (2) Advanced Aircraft Services LLC is not an FAA-certified engine repair station, and it’s not a good idea to have an engine overhauled by a mechanic in the field.
Brandon then posted a few questions for Mitch…
- Did you get a prebuy examination before you purchased the Mooney?
- At what airport is the aircraft presently?
- The photo of the screen shows a LOT of debris, but the angle of the photo is strange. Please collect the debris on a clean paper towel or coffee filter, and use a magnet to see whether or not it’s ferrous metal. Also rub a pinch of the debris between your fingers to determine whether it’s metal or just carbon granules (which will crush between your fingertips). If it’s mostly ferrous metal, you shouldn’t fly the airplane.
…and offered Mitch a few items of unsolicited advice…
- Do not authorize this shop to perform any more work on your aircraft until the inspection is complete and they have given you a complete discrepancy list and repair estimate. It’s time to tell this IA to dial it back.
- The logbooks are your property, not the shop’s. Even if you refuse to pay the shop’s bill, they must return them to you. The shop is obligated by regulation to make signed maintenance record entries for the inspection and any repairs it performed, but you should require those entries to be made on self-adhesive stickers. The shop is also entitled to ask you to pay a reasonable deposit covering the inspection and any repair work you’ve already approved, that’s fair. The shop has no right to hold your logbooks hostage. If you wind up in a dispute over the shop’s bill, the shop is entitled to go to court and obtain a mechanic’s lien on your aircraft, but in the absence of such a lien the shop cannot hold your aircraft hostage.
- Your IA doesn’t need permission from Lycoming to do anything. Any mechanic has access to Lycoming’s guidance on this subject. This is also covered by Lycoming SI 1492D.
- I suggest you be present for the oil screen reinstallation (make sure it’s clean) and servicing the engine with fresh oil, and then perform a 20- to 30-minute ground run. Afterwards, be present when the screen is removed and inspected. Save any particles that come out.
The Plot Thickens
In response to Brandon’s question about whether a prebuy was performed, Mitch responded…
Sort of. The seller was an IA and it was his dad’s plane. He was doing an annual on it when his dad died. He flew it 15 minutes back to its hangar where it sat for almost two years before he sold it to me. The plane was not insured, and he would not allow it to leave the hangar. It was in the middle of nowhere with no maintenance on the field.
I found an A&P that was willing to fly out with me and look at it. While the seller did a quick 90-minute annual inspection, the A&P I brought removed access panels and looked for corrosion, and poked around at the engine a bit.
The oil screen came up in conversation. The seller said he had just cleaned it and it had only flown 15 minutes since then. My A&P said that since we were about to fly it 4 hours back home, checking the screen would introduce a risk of oil leak. Since everything else about the plane looked great, my A&P recommended that I leave it alone.
“I’ll go easy on you for the prebuy,” Brandon told Mitch. “The annual was pencil-whipped by the seller, and I’m guessing that if you had pulled the screen you likely would have found metal. Mistakes were made but here we are.”
Mitch posed a couple more questions:
There are two things that I was thinking about last night…
- The plane came with a multigrade oil in it, which I flew with for about 6 hours and saw no noticeable oil consumption. I drained it and replaced it with Aeroshell W100 Plus and during the next 10 hours it consumed two quarts of oil. The next 6-8 hours after that it used only 1/4 quart. Is there anything about changing oil types that could cause issues?
- The morning I started the plane to fly it to shop for the annual inspection, it was very difficult to start, and the fuel pump was making grinding noises until it warmed up. The aircraft sat outdoors overnight, and again the next morning was hard to start and the fuel pump made grinding noises. Is it possible that the fuel pump could be making metal that is getting into the oil?
- Changes in oil type won’t matter. When you changed the oil, did you check the screen? Has the screen been inspected since the last time the seller inspected it?
- You said “the fuel pump was making grinding noises until it warmed up.” Are you talking about the electric boost pump or the engine-driven fuel pump? I’m assuming the latter, and I can’t imagine how you could possibly tell that a grinding noise was coming from the fuel pump rather than somewhere else in the engine. In any case, any metal from the fuel system would be caught by the fuel strainer and wouldn’t make it into the oil system.
Dialing It Back
“Did you get down to the airplane today?” Brandon asked Mitch. “Did you collect the debris and determine whether it’s ferrous metal, non-ferrous metal, or carbon?”
“I did make it out to the airport yesterday,” Mitch reported. “The metal is non-ferrous.” He continued…
The IA talked to Lycoming on the phone, and they said to remove the suction screen. I did, and it contained mostly carbon with a small amount of metal. We bagged up the debris samples and are mailing them to Lycoming for analysis.
As for the fuel pump noises, it was the electric boost pump and the noises occurred when I was priming the engine before cranking it. It had been in the 20s the night before so everything was cold-soaked. Once the engine warmed up and I turned the pump back on for takeoff, it sounded fine.
As things stand now, the IA is finishing up the annual, verifying AD compliance, and waiting on a response from Lycoming on the metal samples. I’ve told him not to do any additional work.
If an overhaul is needed, I’ve heard I can purchase an overhauled engine online for around $25k that would come with a full warranty, and that I might get around $8k back when I send in my old engine. I still have a lot of research to do, but I’m curious if you have any recommendations for or against doing that.
“We shouldn’t talk about overhaul yet,” Brandon said. “We can discuss your options if we get to that point, but let’s not jump the gun. And please never trust any A&P to tear down your engine; that should be done only by a professional engine builder in a certified engine repair station.”
“Can you have the IA borescope the cylinders?” Brandon asked. “The most common source of aluminum in a Lycoming is from the piston pin caps scuffing on the cylinder walls. If this is what’s happening, the borescope will reveal one-inch streaks of aluminum up and down the cylinder wall at the 3- or 9-o’clock position. Sometimes this problem simply resolves itself. If it doesn’t, you may need to remove one cylinder to free the stuck piston pin. That’s a whole lot less expensive than a major overhaul.”
“If your IA doesn’t have a borescope, you can get a good one for less than $200 and you might want to purchase one for yourself. Also, whether now or later, I recommend purchasing an Airwolf remote-mounted oil filter. Filters do a much better job of cleaning the oil, and you’ll catch fine metal particles that would be undetectable if you just have screens.”
“I asked the IA about doing a borescope inspection,” Mitch reported, “and he has an old scope that cannot take pictures. I guess another $200 isn’t the end of the world when compared to what I’m already spending.”
“If it’s $200 for a borescope or $25,000 for an overhaul, I would roll the dice on a scope. If you make it out of this mess in one piece, that scope will be your best diagnostic tool for years to come.”
The next day, Mitch posted:
Got a call from the mechanic today. Lycoming will run their analysis on the metal fragments on Friday.
The IA borescoped the cylinders with his old scope and says they all “”look pretty rough.” Now he’s pushing for a top overhaul. He wants to remove all the cylinders and send them to Premier Aircraft Engines in Troutdale, and also said something about “getting a look at the bottom end once the cylinders are off.”
I have not approved anything.
“Overhauling your 38-year-old cylinders would be crazy,” Brandon opined, “given that brand new Superior Millennium cylinders are $1,100 each. Let’s not discuss removing cylinders unless we determine that this is really necessary.”
“I’m going to go to the shop next Wednesday with the new borescope I just ordered,” said Mitch, “and try to get some images of the cylinders to attach to this ticket for you to look at. By then, Lycoming should have analyzed the metal fragments too.”
Brandon offered Mitch some guidance about what he should do with his new borescope:
- Organize the borescope images in a way that we know what cylinder each one came from.
- Keep the light on the scope at max brilliance, and move the tip of the scope around until the sensitivity self-adjusts to obtain the clearest image.
- Piston pin cap wear will show up as streaks in the 3- and 9-o’clock positions. Capture images of any such streaks that you see.
- Be sure to get good images of the exhaust valves.
- If the cylinder wall is developing corrosion pitting, it will usually start developing at the top of the barrel because that’s where the oil film is lost first.
- Oil control issues will cause puddling of oil at the bottom of the barrel.
A Week Later…
“I got some borescope images today,” Mitch finally reported, posting a link to a Google photo album to which he’d uploaded his images. The image quality was exceptional. All four exhaust valves looked perfect. The #3 cylinder barrel exhibited some scratches, but none of the cylinders had evidence of aluminum smearing in the 3- or 9-o’clock positions.
“Lycoming said the metal was likely from a piston pin cap, same thing you told me a week ago” Mitch continued. “My IA still wants to replace all four cylinders. He’s claiming that the exhaust valves look ‘dangerous’ to him, even though they looked okay to me.”
“I don’t see anything wrong with those valves,” replied Brandon. “What on earth does your IA think is so dangerous about them?” Brandon attached a copy of the AOPA Air Safety Institute “Anatomy of a Valve Failure” poster that gives examples of what good and bad exhaust valves look like. He also attached a photo of what piston pin cap scuffing looks like under the borescope.
Mitch said the IA was reacting to some dark-colored “splotches” on the outer edge of some of the valves. Brandon explained that those “splotches” were simply oil droplets, not evidence of burned valves.
At this point, Brandon’s advice to Mitch (following Lycoming’s guidance) was to clean and replace the screens, service the engine with fresh oil, then do a 20- to 30-minute ground run and then pull and inspect the screen again to see if additional debris was found in the screen. If the screen was clean, then the next step would be to fly the engine for an hour or two and reinspect. If the screen was still clean, then fly for 10 hours and reinspect.
Mitch’s IA would hear none of this. He cited Lycoming’s guidance that if ½ teaspoon of metal or more was found in the screen or filter, the engine must be torn down. The IA was unwilling to consider anything short of removing all four cylinders and “getting a look at the bottom end.”
At this point, Jeff Iskierka A&P/IA—Savvy’s technical director and Brandon’s manager—felt compelled to jump into the conversation:
I do not like the fear mongering this IA is laying on Mitch. What he’s proposing to do is serious overkill. He started off spring-loaded to the “major overhaul” position, now he’s wanting to do a top overhaul even though the borescope inspection shows conclusively that there’s nothing wrong with the top end. Makes no sense.
I am not at all happy with the thinking process of this IA. The exhaust valves look pristine, but this guy says they look “dangerous.” Obviously he has no clue.
There’s no way this engine has “made” anywhere near ½ teaspoon of metal. Remove all the carbon from the debris in the screens and there’s not much left. What is left is aluminum, not ferrous metal or bearing material. Even Lycoming’s metallurgy lab agrees with this. From what I can tell, this IA has no valid evidence for determining the engine to be unairworthy.
What Brandon has recommended (reinspect the screen after a ground run, etc.) comports precisely with Lycoming’s written guidance. What the IA is insisting on is just shooting from the hip.
So what do you do at this point, Mitch?
First, you need to get your airplane out of this shop. That has to be your top priority. Let the shop finish its inspection and create a list of airworthiness discrepancies. Brandon can help you make sure that only genuine airworthiness items are on this list.
Do not let this IA touch your engine other than to add oil and inspect the screens. Do not let him remove any cylinders. Do not let him overhaul anything. We’ve seen no evidence that such actions are needed. You should insist upon scrupulously following Lycoming’s published guidance. The guidance calls for reinspecting the screen after progressively longer periods of ground running and flying, and that’s what you need to do.
Hopefully this inexperienced IA will ultimately see the light and agree. If he does, have him sign off your annual as airworthy and then fly away and never return. Otherwise, you should require him to sign off the annual as unairworthy with a discrepancy list, pay his invoice, get your plane and logbooks out of his hangar and clutches as soon as you can, and we’ll help you get the airplane ferried to a competent shop.
Regardless of how you get the plane out of this place, you should plan to take it to an experienced and competent shop (we’ll help you find one) and set up a cautious program of frequent flying and reinspection of the screens (or preferably the oil filter that you should have retrofitted) until such time as we feel confident about the condition of your engine.
I can’t promise you that an engine overhaul won’t ultimately prove necessary. What I can promise is that we will do our best to make sure that your decision to overhaul (and it is yours to make) won’t be made without clear and convincing evidence that such a drastic step is necessary.
The saga of Mitch’s annual inspection is still ongoing. We don’t yet know the punch line. Will his IA see the light, relent, and agree to follow Lycoming’s thoughtful and reasonable published guidance? Or will he continue to try to strongarm Mitch with scare tactics? (If he does, we’ll do our level best to help Mitch resist them.) Will Mitch manage to get his airplane home without a ferry permit?
Sorry, we don’t know yet—but we thought Mitch’s unfinished story was too interesting and instructive not to share.
When dealing with your own aircraft maintenance decisions, wouldn’t you feel more confident knowing experts like Brandon and Jeff were in your corner? Learn more about SavvyQA,
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