If you read my previous post just a few days ago, you’d know that I was just out to Pittsburgh for a jet trip that ended up canceled. I got home in time to see the July 1st fire works display in Chesapeake City, and prepared for the next opportunity to use my airplane to do jet trips on Monday. I’m using my airplane quite a bit, and even have another vacation flight planned for Florida when I get back from this next mission.

N833DF was ready to go again, or so I thought as I launched out to Pittsburgh Monday around 2pm. The plan was to do a flight Tuesday; go see the Flight 93 Memorial on Wednesday; do another flight on Thursday; and then head home before dark if the weather permitted. Thunderstorms have been the order of the day, and I usually see them building if I’m not dodging them this time of year.

Something happened on the way to Pittsburgh that I didn’t notice what at the time. The JPI data revealed the timing, and gave me the benefit of hindsight in this story telling. In the graph below, notice the change in EFT on left engine cylinder #4 at approximately 1 hour and 10 minutes into the flight. You can see a drop in EGT of about 100 degrees that shows something odd was beginning to happen. Actually, the damage was already done at this point, but I didn’t see it.

At this point I landed and the ground crews put my airplane away. I grab a crew car, and check into the hotel to prepare for the next few days of flying the G280, unaware that a challenge lay ahead on the return flight.

Fun Flying the G280: The flight plans for the jet will take me to Charleston, Naples Florida, and other stops, so this will be fun. I didn’t get any landings on this trip, and the trip scheduled changed constantly, but I still enjoyed the experience. I’m going to ride this train awhile longer, and see how it goes.

Go Home Day: It is the 7th of July. We’d just completed a return flight from Charleston in the jet, and it’s time to pull my airplane out and fly myself home. The developing issue with my airplane reveals itself to me as I level off in cruise. At least this is when I first become aware of it.

The JPI EDM 760 starts flashing with a DIFF warning and my eyes are finally focused on the problem. The alarm was because the EGTs were so out of whack, and now I see that left side #4 EFT is 500 degrees below everyone else. The airplane has been talking to me for a few days now, but I haven’t been listening.

Looking back, the left engine has been starting differently for the last few trips. I could be wrong, but I think I missed several opportunities to look more closely and find it. I think I will need to do a more thorough pre-flight occasionally. We’ll see why as I continue this story.

Now that I’m in cruise with nobody else to talk to, I start thinking through the problem. EGT is low on one probe, and I consider that I’ve had issues with probes during the initial installation. It could be just a bad probe. The engine is running fine; CHTs are normal; no differential power issues; and the props are remaining synced. Oil pressure and temperatures are also good and comparable side to side. In other words, there are no outward signs that the information being presented is valid. I must be a bad probe or bad information, so I decide to continue for the remaining hour until I get home.

The JPI graph below shows you the information I had, including fuel flow.

The storms are building: I’m getting home relatively early and flying through weather that is juicy and prime for thunderstorm development. I needed to do an instrument approach into KILG. Immediately after being handed off to Philly, they gave me a vectors for sequence direction as if I’d been handed off late. I complied and was number three for the approach. The controller never told me WHAT APPROACH I would actually be flying, and I initially assumed it was runway 01. The engines both perform flawlessly during the maneuver, and I thought nothing more about them.

The next thing I knew, Philly gives me a final vector to intercept the final approach course, but still fails to say what approach I was flying. ‘Philly – turn right heading 060 and intercept the final approach course, but for which approach?’ I replay. He admits he never told me, and I’m very happy about all the work I’ve done with the Avidyne IFD550. Just a few moments before this exchange I heard one of the planes in front of me call out a fix, and from that loaded up the RNAV 09 approach. He confirmed that approach, I activated the VTF, and intercepted with plenty of time.

Everything continued as normal after a short landing, 180 deg turn on the runway, and taxi back to my hangar. Not until I brought the throttles to idle did I realize that something else was actually happening. the left engine backfires just before it shuts down. That ain’t right.

It is now Thursday afternoon, and I’m supposed to fly my wife to Florida this Sunday. I decide to call my A&P, Paul Phillips, and talk about what I should do. I’m ready to drive to Florida again, and I tell Paul there is no pressure here unless it is something simple. Last year I had broken my left knee and had to drive instead of fly. Bev and I still saw some cool places and had a great time together. Neither of was overly concerned about driving.

Paul and I convinced ourselves that this is most likely lead fouling on one of the plugs in that cylinder. He asks me to meet him at his hangar, but I decide not to fly the airplane further for fear that I could harm the engine. I also didn’t like taking off with a known issue, so I demurred and offered to just drive and do this work later.

Paul insisted that he could to come to my hangar on Saturday and just bring a plug with him. I reminded him that the Electro-Air system on my engines requires a unique plug, in case both are affected. I liked the idea that Paul would do a detailed inspection with me when he arrives, and I wanted that insurance before I put Beverly in the airplane. The weather was going to be challenging, and this all had to be right.

I STILL didn’t pull the engine panels: I was hot and tired after all the flying I’d done, so after the plan was in place and I believed I understood the problem, I went home. What I should have done is inspected my engine thoroughly before going home.

Saturday Morning Maintenance: Arriving an hour or so before Paul on Saturday morning, I finally pull the panel off of the left engine outboard. The exhaust break is immediately obvious, and I see soot patterns in the compartment. I start looking around for heat damage, but don’t see anything obvious after I clean off the soot. I’d have seen this early and could have done better repair planning earlier had I not been lazy and pulled this panel Thursday afternoon. Check it out below.

Holy hole in my exhaust BatMan! Obviously, I called Paul immediately and caught him at his shop, where he had stopped on the way up from his beach house. That was luck I didn’t expect or deserve. It was Saturday morning and the first time I’d taken off the left cowl. My trip was tomorrow and I was convinced now that we were driving. This system would have to be sent off for repairs.

Paul saves the day. When he saw the pictures, he stunned me by telling me he had an airplane there with a new system on it. He’d remove that one and bring it up for me. So that is what he did.

Paul arrived and removed the old exhaust piece that had failed. Only then did I notice that the hangar had failed (the probable cause of all this), and we both then realized that we didn’t have one. Still not to be defeated, Paul got in his truck and fought traffic down and back from Dover to get a hangar for me. That meant 40 minutes in beach traffic each way. We finally wrapped it all up by 3pm Saturday, and I called Bev to inform her we were flying and I’d be home to pack.

Paul Phillips – PhillAir, completing the repairs and inspection on my left engine.

Lessons Learned: I need to improve my pre and post flight inspections. It takes a few minutes pull the four panels and look at the engines, fuel lines, exhaust systems, and exhaust hangars specifically. I’ll start doing this before contract trips and trips I take my wife on. When I have a problem after a flight, I’ll look into it more thoroughly right then, so as to better prepare for appropriate maintenance. Finally, I’ll look at the JPI data with new knowledge, and scan it more frequently in flight. I got lazy and could have caught this much earlier. The JPI did a wonderful job of talking to me, but I missed what it was saying in this case. I didn’t hear it.

Paul was awesome in this case. I’m so glad I overhauled my engines and updated my avionics before I retired. My goal now is to wear this airplane out by using it, and I’m on my way with 300 hours on the engines as of this writing.

I accepted two trips after we get home from Florida, so I’ll be with Paul again before or right after that trip for oil change and AD updates. Then it’s off to Jekyll Island again in September.

Bev and I are doing retirement well.

Fly safe.


By fdorrin

Fully retired now, unless something interesting comes along. I’ve enjoyed a lucrative career as an Electrical Engineer, Certified Software Solutions Developer, and Project Manager. An excellent and fun career that I’m very proud of. I began flying commercially in Dash-8 aircraft for Piedmont Airlines, and moved on to instruct in the Gulfstream 280; WestWind; and Astra jet aircraft. I’ve also been blessed with a type rating in the B-25 bomber in a fortunate turn of events. My wife, Beverly, and I currently own and operate a beautifully restored PA30 Twin Comanche, which we use to explore the CONUS.