Jump to content

bdash

Basic Member
  • Posts

    57
  • Joined

  • Last visited

Everything posted by bdash

  1. I'm having a clean-out after selling my M20J a while back. The following items are free to whomever is willing to pick them up from Lampson Field (1O2) in Lakeport, CA. Robotow 28VL Mooney cordless towbar This Robotow was included when I bought my M20J back in 2018. I used it once or twice in 2018 and then it sat in my hangar. It needs new battery and/or charger (Milwaukee M28 or Robotow's re-labeled version of the same). Clarity Aloft Link headset 4qts of AeroShell W100 Plus Miscellaneous cleaning supplies from Aero Cosmetics (Wash All, Wash Wax All, Belly Soap, Bug Scrubber pads and microfiber cloths). All unopened.
  2. To circle back on this: I asked that the cylinder be borescoped before proceeding. That revealed vertical scoring on the cylinder walls, consistent with broken rings, so I ended up replacing the cylinder. I’ve flown around three hours since, and am still waiting on signs that the rings have seated. The weather’s looking rough for the foreseeable future so it’ll be at least another week until I’m truly back up and running.
  3. The sticky exhaust valve was said to be the cause of the EGT drop that led to me taking the aircraft into the shop. The low compression was something additional that the shop reported seeing while investigating the issue. Right, if something went awry very recently I'd have not had time to notice a change in oil consumption. Would something like a broken ring be visible in any form in the engine monitor data?
  4. My understanding is that the sawtooth EGT pattern, as well as the asymmetric pattern on the exhaust valve when looking via a borescope, is due to an exhaust valve that's leaking due to erosion after uneven heating, rather than one that's sticking. I haven't seen any pattern in the EGT data to suggest that uneven heating is the issue. That said, borescoping is what I've requested as the next step to see if there's anything wonky with the valve or if it's just a matter of reaming the valve guide, and to see if the cylinder walls show any signs of ring problems.
  5. The potential extra cost, along with the extra time waiting for the airport to re-open, is part of my dilemma with taking that approach. I'd expect something like a broken piston ring, or any high amount of leakage past the rings, to have resulted in increased oil consumption and blow-by. I've not observed any of those things. That's one reason the reported low compression is so puzzling to me.
  6. Major overhaul was about 750 hours ago. All four cylinders were replaced by the previous owner around 200 hours ago (3.5 years).
  7. Contintental's SB03-3 has very detailed guidance about compression tests on their engines. If the compression test reads below their leakage threshold, boroscope the cylinder, and if all looks normal then fly at 75% power for at least 45 minutes before testing compression again. Lycoming's guidance is much less detailed.
  8. During my last flight in my M20J, I noticed a slight roughness that corresponded to a drop in the EGT of cylinder #4 by around 60º. This lasted for 10-15 minutes, went away for a few minutes, then came back for the remaining 5 minutes until I landed. I downloaded the engine monitor data after flight, and it showed the change in EGT very clearly. Looking back over data for previous flights I haven't seen any similar change, or anything else out of the ordinary. So I took the airplane over to my local shop. They did some investigation, and reported back that the underlying problem is an intermittently sticking exhaust valve. That seems to line up with engine monitor data. From some research, addressing this typically involve cleaning the exhaust valve guides. However, the shop reported that as part of their diagnostic process they performed a compression test and cylinder #4 came back with a very low compression reading (< 20/80) due to leakage past the piston rings, and because of this they're saying the cylinder needs to be removed and either overhauled or replaced. The engine was developing full power during the last flight and, with the exception of the EGT drop in the most recent flight, all other data related to the cylinder looks normal and hasn't changed since the annual inspection (at a different shop) around 3 months ago when the compression was in the 70s. One confounding factor here is that the local airport currently has both runway and taxiway closed due to resurfacing, so any engine warm-up prior to the compression test they performed would have been done via a static run-up. Advice I've seen about low compression numbers has been to fly the airplane until everything is up to operating temperatures and re-test, but that won't be possible until the airport reopens in mid-November. Does this warrant pulling the cylinder and overhauling / replacing it, or is there further investigation that should be performed before going down that path? My inclination would be to clean the exhaust valve guides, fly the airplane for an hour or so, and perform a compression test immediately afterwards, on the assumption that the low reading is an artifact of testing rather than an actual problem. But if the likely outcome of this is that the cylinder comes off anyway, that's just extra cost and time wasted.
  9. Took my wife and daughter down to Nut Tree (KVCB, Vacaville, CA) for brunch at Fenton's Creamery this morning. The little one rode up front for the first time, and had SO MANY questions about the airplane once we were home (What was that black knob for? What does the orange button do (CO alarm)? What are all the other buttons for? On and on and on until bedtime). She's been telling us she's going to be a pilot when she grows up since before I took my discovery flight. The only downside at all about our flight today was that it was 95º out. That made for a sweaty time on the ground while we got loaded in and through the run-up. It might be time to look into one of those ice-chest-based coolers I've seen mentioned.
  10. Would you mind sharing which CFI you fly with out of Lampson? I did all of my primary training over in Ukiah, and have done a little work towards my instrument rating while down in the Bay Area for work, but have never run into a CFI while at Lampson. I’m sure there are some lurking around here somewhere. It’d be nice to have a local option.
  11. Merely renting out an aircraft isn't classified as operating "for hire", so 100 hour inspections and such aren't required unless you were also providing flight instruction in the aircraft, or the renter was being paid to carry passengers.
  12. I had a Tempest fine wire plug lose its center electrode a couple of weeks ago. I initially noticed it only as higher than normal EGT on one cylinder during cruise, but a mag check once on the ground showed the engine running incredibly rough on the right magneto. That narrowed things down. I had a mechanic pull the spark plug in question and we were shocked to discover the center electrode missing. We replaced the plug with a Champion fine wire plug because that's what they had available. Interesting to hear that this seems to be a somewhat common failure mode for the Tempest fine wire spark plugs.
  13. I'm the one who was lucky enough to end up with Bennett's aircraft. Dan at LASAR, the head of parts, is a friend of mine, and he knew I'd been shopping for a M20J for a few months (including sending one to LASAR for a PPI that ended up showing unexpected corrosion). Bennett's Mooney was in at LASAR getting an annual inspection done when he made the decision to part ways with it. He mentioned to Dan that he'd likely be sending it down to All American Aircraft when the annual was complete. I gave Bennett a call, we chatted a while, and put together a deal. He was generous enough to have me come by his hangar after the sale closed to pass on a portable O2 system, spare parts, extra headsets, etc., that he no longer needs. A very kind soul.
  14. The G3X maintenance manual says: Standby attitude, airspeed, and altitude instruments are required if a G3X display unit is installed as the primary flight display (PFD) in IFR installations. The standby instruments may be a Garmin G5 or existing pneumatic instruments.
  15. You’re correct. It’s specifically the GDL88 that the installation manual calls out as being incompatible. It does note that a GDL 88 can continue to provide weather and traffic to GTN units, it just won’t appear on the G3X.
  16. Two limitations I see with the G3X vs the G500 as it currently stands: The GAD43 autopilot adapter does not appear to be supported by the G3X, meaning that folks with attitude-based autopilots such as the KFC 150 will need to keep their vacuum-driven attitude indicator to drive their autopilot. The GDL88 is not supported by the G3X, meaning traffic and weather will not be displayed on the G3X.
  17. The way I read it (specifically the Streamlined Cockpit Management section on the G3X product page), the G3X simply provides an interface for controlling the frequencies on a separate nav / comm device, rather than acting as the nav / comm radio itself.
  18. It can be intimidating the first couple of times. The airspace boundaries are complex, there’s terrain to contend with under some of the Bravo shelves, and there’s a large volume of GA traffic mostly confined to the areas under the Bravo. Geo-referenced charts are a great confidence booster with respect to being sure you’re clear of the Bravo and other airspace. Flight following, and keeping your head on a swivel, are a must due to the amount of traffic. The NorCal controllers are professional and very accommodating. The SFO Terminal Area Chart contains some transition routes and flyways that are commonly used to get through or around the Bravo. Since they were only recently introduced, they’re not often requested by name, but the general routes are useful for guidance of where transitions will be approved. I’ve found that it’s important to be aware of local landmarks, which can be challenging if you’ve not spent time in the area. Beyond the visual reporting points that are prevalent on the TAC, NorCal likes to give instructions in terms of freeways. They sometimes even refer to them only by names which aren’t ever mentioned on the chart (101 is the Bayshore Freeway, and I880 is the Nimitz Freeway, for instance). The Bay Area GA airports are even worse about this, using names for landmarks that can’t be identified without existing knowledge. Thankfully I’ve found that both NorCal and the tower controllers have been very accommodating when I’ve stated I’m unfamiliar with whatever landmark they’ve chosen to reference.
  19. To close the loop on this: LASAR took a look and found that the spark plugs in cylinder 4 were oily. They didn't observe any other abnormalities in the cylinder. They cleaned, gapped, and reinstalled them. We'll be keeping an eye on this going forwards. While they were looking into this, they noticed that the engine monitor was not correctly grounded. JPI believes this may explain some of the erratic readings I'd seen. Since we had a few weeks of very wet weather here in Northern California, LASAR took that opportunity to pull the engine monitor and send it to JPI to be updated to the latest software. It was then reinstalled, with the incorrectly-wired ground addressed. Everything has looked good since then, and I've been able to download and analyze the engine data from my recent flights. In the event that I notice any more engine abnormalities we'll now have data to look at.
  20. Yesterday I clocked my 100th hour in my M20J since I bought it in July last year! My parents are visiting from New Zealand, so I decided to take them up for some sightseeing and lunch. We left Lakeport and flew down the Marin coastline, past the Golden Gate Bridge and San Francisco's Ocean Beach, and into San Carlos for a late lunch at the airport restaurant, Sky Kitchen. We parked in transient alongside a very pretty Canadian-registered Bravo, C-GNMM. After lunch we departed over Oakland, and flew a brief tour along the north side of the Bay Bridge, around Alcatraz, along the San Francisco shoreline, before getting a great view of the Golden Gate Bridge from 2,000ft. We then headed back up to Lakeport and did a lap around Clear Lake, taking in the scope of the damage that the Mendocino Complex Fires brought to Lake County last summer, before landing not long before the sun dropped behind the hills.
  21. I spoke with LASAR and the immediate reaction after I described the symptoms was also that it sounded like an intake leak. Since my aircraft is conveniently based at Lampson Field, they're taking a look at it now.
  22. Yep, I'm aware of the need to do the two step update from old versions of the firmware (pre-v3.44 upgrade, then the normal upgrade). For whatever reason the update to the intermediate version never completes. JPI support said that they don't have any suggestions besides sending it in.
  23. The manual for the EDM 830 has instructions for downloading the data to a USB drive. I've confirmed that everything is correct with the USB drive (the EDM 830 can see a firmware update if I copy one onto the same drive, but for whatever reason the updater doesn't permit updating from the firmware version I presently have). The EDM 830 manual does not mention any other mechanism for retrieving data, nor do the system diagrams suggest there is any other means to do so. As I mentioned in my original post, the firmware version that the EDM 830 has installed is an older version that is reported to have issues with data logging, including the "DATALOG ERR" that I often see. I'm doubtful that it's even logging any data. I understand the value of an engine monitor for troubleshooting. It's also invaluable for managing the engine while flying the aircraft. Given that I fly frequently and have little downtime between flights, I've not yet found a good time to remove the engine monitor and ship it to the manufacturer to be updated or repaired. I'd rather not be flying for weeks with nothing but an analog CHT and EGT gauge on a single cylinder to go by. I was expecting that I'd be able to wait until another maintenance event such as my annual inspection when the airplane will otherwise be unusable to deal with that.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.