Is it Ever Sunny in Philadelphia?

Grab Bag

My latest adventure in Warrior 481 had a little bit of everything. A long overdue meetup with an old friend, some significant IMC time ending with an instrument approach into an unfamiliar urban airport, high altitude lunch, a teachable moment from my avionics, sharing the frequency with one of the most recognizable call signs ever created, a scientific conference, an aerial sighting that became yet another aviation history rabbit hole, and an example of how truly weird physics can be. It all culminated with a glorious foray through a fantastical sky and an arrival home in time for dinner.

Science!

At least once a year, I attend a niche scientific conference dedicated to my subject matter expertise. I usually attend as a presenter, but in 2024 I was able to be lazy and merely attend while doing my best impression of a sponge.

The two day conference was held in downtown Philadelphia. The last time I attended, I drove myself and three other colleagues from Rochester to Philly in a rented SUV. It is not a bad drive, roughly five hours each way, but when we returned to Rochester around 11:00 pm after the conference ended, I was exhausted.

This year, a promising weather forecast featuring high freezing levels (expected to be 9,000+ feet) led to a decision to fly myself. Though this did not set me up to be reimbursed for the cost of travel (for both FAR and business reasons), I became very enamored with swapping a five hour return drive for a two hour flight that would deliver me at home in time for dinner rather than well after bedtime. While I have always been a fan of dinnertime, the value of bedtime is on the rise as I get older. My only other colleague attending, John, was combining the trip with an opportunity for his wife to visit her sister near Philadelphia and planned to drive his own car. Thus, I was not leaving anyone in the lurch by choosing to fly.

I planned my trip, reserved a shockingly affordable room at the very fancy Windsor Suites using the corporate booking tool, and put dibs on a backup car from Enterprise just in case. 

April 17: High Altitude Lunch

Date	Aircraft	Route of Flight	Time (hrs)	Total (hrs)
17 Apr 2024	N21481	SDC (Sodus, NY) - PNE (Philadelphia, PA)	2.6	2802.6

The day before departure, satisfied that days of consistent weather forecasts reasonably assured a successful flight, I cancelled the rental car reservation. On Wednesday, April 17, I broke ground exactly at 11:00 am as planned. I expected to manage some cloud layers during the New York portion of the flight, but the forecast called for a high ceiling at Northeast Philadelphia Airport. I expected minimal IMC time and the need for an approach appeared beyond remote. (Famous last words.)

However, there was a presidential TFR (temporary flight restriction) around Scranton that lay on a direct line between Sodus and Philly. Even though I was likely to be cleared through the outer ring by ATC (air traffic control) while on an instrument flight plan, I filed a route from Sodus to the Williamsport VOR (FQM) that circumvented the TFR entirely. It added less than 10 minutes to the overall flight time.

Seneca and Cayuga Lakes in the gloom.

After a recent partial engine failure, I was very attuned to the smoothness of my engine and the indications on the JPI engine monitor after take off. However, the Warrior had no surprises in store for me and the 4.5 hours I had already put on the airplane since the repair increased my confidence that the issue was suitably managed. As I proceeded over the Finger Lakes at 7,000 feet, I was eventually engulfed by the cloud bases. While the horizontal 360° view around me featured zero visibility, I could nonetheless look straight down at the farmland passing below and identify airports in places like Seneca Falls and Elmira as I crossed over them. Spotty precipitation was light to moderate.

Thirty minutes into the flight and at my normal lunchtime, I broke out the DiBella's turkey sandwich and chips that I bought en route to the airport that morning. In a nod to airplane cleanliness, I shunned my preferred "everything" sub roll for a plain one that was guaranteed to shed less debris. (Even though that debris is undeniably delicious.) I enjoyed a relaxed lunch, happy to be away from the insanity of the interstate, and contentedly watched light rain visualize aerodynamic streamlines over my blue wingtips.

Dances with TFRs

While rounding the TFR encompassing Scranton, the bold red ring superimposed on the chart displayed by my iPad vanished. This signified that the restriction had ended. Shortly after noticing the TFR expiration, a new voice joined the Wilkes-Barre departure frequency. The newcomer expressed himself in a competently seasoned voice tinged with a subtle Yeageresque drawl.

"Wilkes-Barre Departure, Air Force One..."

The airplane spent something like a nanosecond in Wilkes-Barre airspace before being handed off to Center. Wilkes-Barre had to deal with my slower ship for quite a while longer after that.

The very next day, Philadelphia was under a VIP TFR that included my destination airport, but this did not affect me because I was busy at the conference all day. On the day after that, another TFR was scheduled over Wilmington, DE starting at 5:30 pm with an outer area extending over Philadelphia. However, it ended about five nautical miles southwest of Northeast Philadelphia Airport. It seemed that I dodged presidential TFRs throughout the entire trip.

Where presidential TFRs are concerned, I don't care who is president or which of the two clubs they belong to; TFRs are truly bipartisan headaches. I am grateful that I live in a place that is not repeatedly subjected to them, I think they are a ridiculous bit of security theater that add little practical value, and I question the strategy of painting bullseyes directly on aeronautical charts that publicly forecast exactly where the president is going to be. But they have become a grudgingly acknowledged facet of pilot life.

Still, it was pretty cool to share the frequency with Air Force One for a moment.

The Inevitable Reroute

Allentown Approach: "Cherokee Four Eight One, I have an amendment to your routing, advise ready to copy."

Of course. How dare I file a direct route into class bravo territory? Foolish mortal.

The reroute was minimal, an insertion of Yardley VOR (ARD) into my flight plan. On departure from Northeast Philadelphia two days later, I was also routed outbound via Yardley. Note to self: file via Yardley if ever returning to Northeast Philadelphia.

This is where I encountered a learning opportunity. I inserted Yardley into the flight plan running on the GNS 430W. My autopilot, HAL, immediately responded by swinging the Warrior's nose far more eastbound than it should have for a direct course to Yardley. 

That's not right...

Perplexed, I studied the avionics and realized that the navigator was setting me up for a 30° intercept of a newly created leg between my previous waypoint (the Williamsport VOR) and Yardley rather than navigating directly to Yardley as instructed by Allentown. I entered the flight plan page, rolled the cursor down to Yardley, and pressed [Direct]. HAL swung the nose of the Warrior back to the southeast on a direct course to Yardley.

Midway through my correction, Allentown noticed the deviation. "Cherokee Four Eight One, I show you turning eastbound rather than direct Yardley."

I explained that I had caught the issue and was already turning direct Yardley, satisfying the controller.

This was a valuable learning experience because it can happen any time a reroute affects the current leg being flown. One way to prevent future occurrences of this would be to temporarily set HAL to continue tracking the previous magnetic heading until getting the GPS flight plan properly programmed into the navigator. Is there a more efficient way to manage this scenario?

Phantom City

Initially, I believed that the original forecast claiming high ceilings around Philadelphia would come to pass. In the vicinity of Allentown, I emerged from the clouds into clear air. But a wall of haze ahead did not bode well for the arrival to Northeast Philadelphia and the airport ATIS (automatic terminal information service) indicated that arrivals were using the RNAV instrument approach procedure to runway 6. 

Allentown stepped me down to a lower altitude and, by the time I was talking to Philadelphia Approach, I was back in the clouds and explicitly instructed to expect the RNAV 6 approach procedure.

Display from ForeFlight as I entered the Philadelphia metro area. There was a lot going on.

As I penetrated deeper into Philadelphia class bravo airspace, Approach continued to step me down while providing vectors for the approach procedure. I was fully in the clouds and flying through rain. At one point, a cluster of tall, ghostly radio towers gradually emerged from the mist -- reaching to approximately 1,000 feet below my altitude -- then seemed to dissolve back into gray obscurity. It was eerie, but this is why ATC and instrument flight rules exist: to prevent instrument pilots from colliding with obstructions, terrain, and other airplanes.

A hint of movement beyond the Plexiglas pulled my eyes from the instruments again. The skyscrapers of Philadelphia emerged from the clouds directly off my nose. I was both awestruck and stunned by the sudden appearance of the central city in my windscreen. Right after I saw the city, I was vectored away from it to the northeast and cleared for the approach.

Bases of Philadelphia's downtown skyscrapers discernible through the haze as I turned to the northeast.

Rain was forecast for Northeast Philadelphia Airport all along. My clever plan was to beat it, but the rain was faster and arrived early. I intercepted the approach course and after a few moments, reached the final approach fix at JUNIA. I pulled the power back and set a notch of flaps to establish a 90 knot, 500 foot/minute descent. Immediately after establishing myself on the glidepath, Warrior 481 descended from the belly of the clouds and emerged over a congested metropolitan area with the airport visible just over four miles away. I barely met my criterion for logging an instrument approach, but I did meet it.

Runway and raindrops.

Still in the rain, I landed on runway 6 and followed taxi instructions to the Atlantic ramp. Line staff seemed confused about where to park me, initially gesturing to the left then, after a moment of dithering, directing me to the right. To be fair, it was raining vigorously and I am sure that the line staff was miserable standing around outside.

I felt their discomfort. Once parked, I wrangled the cabin cover onto the Warrior for the first time in a steady rain and hoofed it across the large ramp with my bags. I was completely soaked by the time I reached the FBO where Lee was waiting for me.

Old Friends

My graduate studies at Indiana University seem like they occurred four lifetimes ago. Nonetheless, as I looked at Lee through my water-spotted glasses, it was like he had not changed at all. (The air was so full of pollen that I could barely see through the residue remaining on my glasses once the rain evaporated.)

I gestured at my sopping hair and clothing and greeted him by saying, "What do you think of my glamorous lifestyle?" 

I have a fond memory of Lee going to dinner with me on the evening before I defended my dissertation, his friendship helping to calm an anxious and exhausted mind. Even though I last saw him as recently as 2010, when we sat down to talk he said, "Catch me up. Start with grad school."

We spent about eight hours together, right on through dinner with my colleague John and his wife. (Ah! Worlds colliding!) It was great to reconnect after all these years.

April 18-19: Extracting Knowledge

From the archive: a photo of me presenting at the 2022 conference in Philadelphia.

The conference was terrific. These conferences always are. When John and I arrived on the morning of April 18th, the first person we encountered was Kim, CEO of the company that runs the conference. I've known her for over ten years.

"Chris! Thanks for coming again this year and for presenting!"

"Oh, I'm not presenting this year," I responded, puzzled.

Kim frowned. "You're not? Why not?"

"No one asked me to."

I watched her mind work quickly and she vowed to fix that oversight for the next one. I found that I was not the only regular speaker in attendance who was not speaking. It was all fine with me. Sometimes it is nice to just learn. One downside of not presenting is that I am not good at small talk during conference mixers. When I attend as a speaker, people usually want to talk with me about what I presented. Presentations make better conversation starters than idle observations on the weather.

I learned about the latest updates in my field, made a few notes whenever someone said something that gave me an "ah ha!" moment, and learned that I was slated to author a national standard focused on my niche expertise -- and that, even though I had not been fully vetted through the onboarding process, could I please get started on that right away?

For lunch on the second day, John saved a seat for me at a table with a group of toxicologists that had just presented in the prior session. As I joined them, their heads all turned to peer up at me expectantly. John explained, "I was just telling them about how you flew yourself here."

"And we're curious why you did not bring John with you!" finished one of the toxicologists.

"Uh..." I stammered, feeling more than a little put on the spot. I usually don't talk about aviation or being a pilot at professional meetings and John had just outed me. I never wanted to be the guy from the joke, the one that goes, "How do you know if you meet a pilot at a party?" with the not-at-all subtle punchline of, "He'll tell you."  In fact, during the cocktail mixer at the conclusion of the previous day, I was talking to Mike whom I have known for seventeen years. I mentioned that I had flown myself to the conference and he immediately looked confused.

"What do you mean by that?" Mike asked. In seventeen years of friendship, I had not once mentioned to him that I was a pilot.

Recovering my bearings with the toxicologists, I said to John, "Hey! You had separate plans with your wife that required you to drive yourself." Thus called out, John laughed and conceded the point. 

That night, John and I had dinner with a new friend, Sam, and his sales associate, Paris. We found an Irish pub with great atmosphere, great food, and deafening live music that constantly got in the way of conversation. In addition to being loud, we found the singer to be significantly lacking in range, particularly compared to the ambitious repertoire he attempted.

Also from the archive: Liberty Bell and Independence Hall, Philadelphia, taken 2022 (it was never this sunny in 2024).

Database Dilemma

As most instrument pilots are well aware, the FAA navigational database turns over every 28 days. In order to be legally compliant while flying on an IFR flight plan, the database in my navigation system needs to be current, especially if any instrument approach procedures are to be flown. Unfortunately, a new cycle began on April 18, meaning that I needed to update the database after arriving in Philadelphia on April 17 if I wanted to be legal to file IFR for the flight home on the 19th. From the weather forecast, I definitely anticipated the need to file.

Although I have a corporate laptop, I do not have administrative privileges on it to install any software. So that was of no help to me. The ultimate solution was to borrow an old Mac Book from Kristy to do the update. Fortunately, I remembered to pull the GNS 430W data card out of the panel when I arrived at Northeast Philly. I performed the update from my hotel room on the evening of the 18th and congratulated myself on being so well prepared.

April 19: Excessive Clearance

At the conclusion of the conference, John and I walked back to the Windsor Suites, retrieved our bags ("That bag is so cute!" enthused the young woman at the counter on seeing my Flight Outfitters flight bag), and called two Ubers. One took John out of the city to reunite with his wife and the other dropped me at Northeast Philadelphia Airport.

Date	Aircraft	Route of Flight	Time (hrs)	Total (hrs)
19 Apr 2024	N21481	PNE (Philadelphia, PA) - SDC (Sodus, NY)	2.6	2805.2

I found Warrior 481 exactly where I left her, though the line crew had at least chocked the wheels. Her skin was yellow with pollen. Between a quantity of fuel bought at $8.26/gallon, plus fees for landing  and parking, and with a $40 handling fee waived for fuel purchased, I escaped Atlantic with a $200 invoice. Not bad for a towered field in a major metropolitan area. At $20/night, overnight parking was less than what John paid at the hotel for his car.

With a preflight completed, I listened to the ATIS that included a reminder of the TFR over Wilmington going live in 30 minutes. Ending five miles southwest of Northeast Philly, it would not affect my route of flight.

By now, instead of displaying the normal boot-up screen, the GNS 430W displayed "Aviation database integrity error." Well, that was a first in 12 years. I checked to ensure that the card was well-seated in the panel. It was. Evidently, the database update I performed at the hotel did not take.

Dammit.

Fearing that I might be stuck in Philadelphia, I shut the airplane down and schlepped the Mac Book, data card, and Garmin USB card reader back to the FBO. "Hi, it's me again," I quipped to the surprised Atlantic staffer who did not expect to see me return. I struggled a bit with the unfamiliar Mac OS, but eventually installed the update. The second time was the charm.

Northeast Ground did not like that I had filed direct to home and notified me that a full route clearance was coming. It was: "Fly runway heading, then radar vectors to Yardley (ARD), Allentown (FJC) Tango 455, WLKES, Tango 440, Elmira (ULW), Buffalo (BUF), direct."

Oof. Dammit.

This was the third time that I was assigned a clearance out of this part of the world that tacked an extra 1.5 hours on to the route by taking me past Sodus all the way to Buffalo, then backtracking east again to Sodus. But I knew the drill. The route was reasonable as far as Elmira and I was sure that I could get someone to send me direct home before I reached Elmira. I swallowed my objection and read the clearance back to the controller.

Historical Failure

Northeast Philadelphia Airport.

Climbing through ragged clouds roughly ten miles north of Northeast Philadelphia Airport I saw what looked like the end of a massive closed runway.

After a doubletake, I confirmed it. The remains of an enormous runway lay below. I was looking at Warminster Community Park and all that was left of the 8,000 foot long runway of the defunct Warminster Naval Air Warfare Center (NAWC). The field was originally home to the Brewster Aircraft Company, makers of the poorly-received Brewster Buffalo single engine fighter that was ultimately canceled by the Navy in favor of the Grumman Wildcat in 1940. During World War II, the company license-built F3A Corsairs that were withdrawn from front-line duty during WWII because the wings fell off a few of them. The Navy eventually assumed control of the field, where it was home to a research center boasting a large centrifuge for high G training of pilots and astronauts. The centrifuge facility is now an event center known as The Fuge. The airfield was closed around 1995 and NAWC operations moved to Patuxent River NAS. It is now a park with some of the former runway having been converted to basketball courts. (Lots and lots of basketball courts.)

Cloudscapes

Although I logged about 0.6 hours in the clouds on the way home, most of the flight was between layers and, as I continued north, the sun began to reassert dominance.

While exiting the conference, I snagged a free bag of chips to snack on during the flight home. At 8,000 feet, my munchies resembled a gorged tick ready to burst. I did not want the bag to pop and make a mess, so I clearly needed to open it in a controlled manner and deal appropriately with the contents. It was a tough job, but I was duty-bound to take care of it as a responsible aircraft owner.

As forecast, icing levels remained greater than 9,000 feet. No convection was in evidence. It was an easy flight home. Even the occasional rain was minor and did a better job of streaking the pollen coating Warrior 481 than removing any of it. With HAL manning the helm, I blasted through the smooth air and marveled at the fantastical creations painted in water vapor across the azure canvas of sky.

Much to my surprise, I was cleared direct to Buffalo while still over Allentown. Fortunately, I was able to negotiate a route direct to Sodus from Wilkes-Barre Approach before taking too great a detour toward Buffalo. My intended two hour flight home -- and the whole reason I chose to fly in the first place -- was preserved.

Passive Intermodulation

On 118.6 MHz with Binghamton Approach, my #1 radio started popping, indicating a weak signal periodically breaking the squelch. I opened the squelch and found myself listening to a DJ promoting a personal appearance somewhere in the area. (Which area? I have no idea.) Moments later, I was treated to Annie Lennox of the Eurythmics performing the 1980s classic "Sweet Dreams (Are Made of This)".

WTF?

FM radio broadcasts are transmitted over a separate range of frequencies (88 - 108 MHz) from the block reserved for civil VHF aviation communications (108 - 107 MHz). It should not be possible to hear FM broadcasts on 118.6 MHz.

Puzzled, I took advantage of the minimal radio traffic to query Binghamton if anyone had reported hearing FM radio on the approach frequency. Being at a higher altitude, I was better positioned to receive the weak signal than Binghamton's ground receiver.

"Negative," came the dismissive response. But I must have piqued the controller's interest, because she called another aircraft she was working to inquire if they heard it too.

"Negative," came the response.

But then a third pilot on frequency chimed in. "I hear it, too." So I wasn't crazy.

"November Four Eight One, let me know if that signal disrupts our communications." I acknowledged, but then moments later, she switched me to Elmira Approach and the issue became moot for me.

After the fact, I posed this scenario to my friend and fellow club member Jamie, an electrical engineer and ham radio enthusiast who knows far more about these things than I do. He named a phenomenon called passive intermodulation (also known less elegantly as the "rusty bolt effect") that effectively results from the mixing of frequencies in metal objects containing dissimilar metal corrosion (Jamie used an example of a gutter) and giving rise to non-linear effects that can result in emission of a signal on a wholly different frequency. It is a form of radio interference that can disrupt critical frequencies (police, fire, aviation) and may necessitate a search for the offending structure creating the interference.

Physics is weird. I wondered if my interference report to Binghamton would result in any follow-up investigation.

Did Anyone See That?

I popped out of the clouds (again) in time to see Cayuga Lake below my right wing while passing Ithaca. I was in the home stretch. In communication with Rochester Approach, I opted for the RNAV-28 approach to the Williamson Sodus Airport.

Crossing the Erie Canal near Clyde, NY.

Inbound to WALCO on the RNAV-28 approach with Sodus Bay in sight.

Sodus Bay.

The Williamson Sodus Airport was VFR when I arrived, but the descent through multiple layers of clouds validated the decision to fly an instrument approach, even if I broke out in the descent to the final approach fix and could not officially log it. As usual, the field AWOS (automated weather observation system) lied its nonexistent ass off with a declaration of five knot winds. Lined up on runway 28 at the usual 90 knot approach speed, I was buffeted by such strong mechanical turbulence that the stall horn complained, suggesting just shy of 50 knots of wind shear in that moment. An earlier National Weather Service warning for low level wind shear had already moved eastward out of the area, but the effects obviously still lingered. I rode chaotic air currents all the way to the ground and the landing was not one of my best. At least there were no witnesses.

Recap

Overall, I logged 5.2 hours on the round trip, 1.9 hours in the clouds, and one instrument approach. I added one new airport to my map (Northeast Philadelphia), experienced (and mitigated and learned from) a gotcha with my avionics, was inspired to learn some new history about a failed aircraft manufacturer, enjoyed an excellent conference, reconnected with terrific old friends, exercised my instrument flying chops, shared the frequency with Air Force One and Annie Lennox, and bore witness to nature's grand artistry.

I have been flying for over twenty years, but I am still amazed that I have the good fortune to experience the wonderful things that aviation has to offer. Best of all, at the end of the day, I found myself sitting at home having dinner with Kristy and The Bear instead of arriving to a slumbering household, handily satisfying my original goal in flying.

Honey, I Think We've Lost Our Spark

Expect the Unexpected

By design, $100 hamburger runs rarely involve much adventure beyond the expected aviating. Sometimes, additional adventure -- perhaps "excessive adventure" -- finds you anyway.

Keen(e) to Explore

Date	Aircraft	Route of Flight	Time (hrs)	Total (hrs)
09 Apr 2024	N21481	SDC (Sodus, NY) - RME (Rome, NY) - EEN (Keene, NH) - SDC	5.0	2795.7

Aloft on a rare weekday off from work, I proceeded eastward toward New Hampshire through smooth air devoid of clouds. I set Keene as my destination, finally making good on a months-long goal to try out Mama McDonough's Irish Pub located in the airport terminal. I made a quick stop at Griffiss International (RME) for fuel before proceeding to Keene. At $5.24/gal, they were practically giving their fuel away. (Well, not actually true, but many places are $6+/gal right now.) Aside from some of the typical glitches in communication between air traffic control and other pilots, including my participation in a relay from Syracuse Approach to another aircraft, nothing noteworthy occurred on the outbound flight. Crises are often preceded by the mundane.

Crossing the "Green" Mountains of Vermont

Closer to Keene (more properly, "Dillant-Hopkins", #273), I was surprised by the amount of activity buzzing around the airport. I sequenced myself into the traffic flow for Keene's 6200 foot long runway 2 where multiple aircraft were holding short waiting for airborne traffic to land. One aircraft scooted out while I was on final and, though I was dubious about this choice, the pilot expedited his departure and was airborne well before I touched down.

Keene's terminal is located on the far north ramp, requiring a significant taxi relative to most uncontrolled fields I frequent. Other transient airplanes parked on the ramp indicated that I was not the only Tuesday arrival for lunch.

Mama McDonough's occupies the eastern end of the terminal building that is shared with the local FBO, Monadnock Aviation. Beyond the pub's unassuming entrance, a line of patrons were waiting to be seated. It was obviously a popular place.

As I waited, I noticed that the day's special was buy one / get one burgers. Should have brought a friend. Regardless, I was at an Irish pub and that usually inspires me to order fish and chips.

Two waitresses worked the room. While busy, they were friendly and efficient. From my seat, I had an excellent view of the ramp and the comings and going of piston and turbine aircraft alike. Partway through lunch, a large turbine aircraft taxied onto the ramp and swung its rear end around to point at the little airplane tied down at the opposite end of the row of parked aircraft that included Warrior 481. Caught in jet blast, the small two seater danced and swayed to the extent that its tie down ropes permitted. It was a demonstration of poor manners from the jet crew and I was grateful that it was not my airplane on the receiving end of the jet wash.

My fish and chips were delicious; my Scottish grandmother would have been pleased. When I cut into the lightly breaded deep fried haddock, I found the fish inside to be perfectly cooked and remarkably moist. Onion rings included among the chips were a nice touch. Excellent food, great service, and a view of the airport ramp made for a terrific lunch experience.

When I returned to the ramp, the piston aircraft had completely turned over since my arrival. Not bad business for an airport diner on a Tuesday.

Taxi Slog

The north ramp at Keene was quite a bit more "turbiney" than most uncontrolled airports I visit.

Though I saw no notifications of this in official FAA sources, a sign near the terminal proclaimed runway 2 as the preferred calm wind runway. In resignation, I made the long taxi from the north ramp back to the departure end of runway 2. I have taxied shorter distances at much larger commercial international airports. 

Drafty

Warrior 481's power plant ran up normally and I departed Keene satisfied with another successful visit to a new airport. Climbing northbound off runway 2 with the town of Keene directly below, I turned westbound as soon as I judged myself well positioned to outclimb the foothills of the mountains immediately west of the airport.

It was unusually breezy in the cockpit, but I focused on flying the airplane until I turned on course and pitched the nose down a few degrees to enter a cruise climb. My troubleshooting was brief. The top latch on the door had come undone. My last experience with this was in a rental Cherokee 180 (N3470R) back in Michigan. Reduced static pressure in the slipstream pulled the door outward just enough that I could not engage the latch. I had two options. I could return to Keene and latch it on the ground or I could wait until I leveled off and put the airplane into a slip (fly it slightly sideways) to push the door closed so that I could latch it in flight. I have never tried the latter and had no practical experience with the technique, only that it should work in principle.

Amusingly, I told the story about Seven Zero Romeo's top latch popping open with Kristy on board recently over dinner with friends. I had bragged to that audience that Warrior 481's door has never popped open in flight during twenty years of ownership. While I guess that boast is still true, I had to eat a little crow with Kristy when I returned home and told her about the incident at Keene.

Crossing through 2,500 feet with the foothills now passing beneath my wings, I was considering my options for dealing with the door when the entire airplane began shuddering as though trying to tear itself apart. Thoughts of the door were promptly relegated to the back burner.

Shake, Rattle, and Roll

The only time I had ever observed such rough engine operation was the one time I experienced carburetor icing in the Warrior. Without even thinking about it, I turned on the carb heat and waited a moment, but nothing changed. I pushed the nose down to a level flight attitude and pulled the throttle back. The roughness ceased below 1300 rpm. I pulled the throttle to idle, pushed the nose down to maintain airspeed, and rolled the airplane back toward Keene. In the turn, I noticed that the JPI engine monitor showed zero temperature reading on cylinder #1. This meant that it was not generating any power.

That explains the roughness. Four cylinder engines don't like running on just three.

"Keene traffic, Cherokee Four Eight One is two miles west and returning to the airport with a rough engine." 

A Mooney inbound for the pattern immediately yielded the right of way to me. I glided back to the runway without any difficulty and actually had excess altitude that I needed to bleed off with a massive forward slip prior to touching down. 

Foreflight ground track showing the departure and immediate return to Keene.

At taxi power, the engine ran smoothly and I vacated the runway. Once on a taxiway, I tried to run the engine up again, but the airplane shook violently when I advanced the throttle above 1300 rpm. In taxiing from the terminal to the departure end of runway 2 just a few minutes earlier, I noticed Monadnock Aviation's maintenance hangar on the northeast ramp. I shut down there and called Ray. He was concerned that I had a stuck valve, but we decided that I would consult with the on field mechanics to see what they could discover.

Benchmark for Customer Service

I wandered into the tidy shop and met Tim and Warren of Monadnock Aviation who listened to my story. Warren explained that, before they could look at my plane, I needed to work out an arrangement with management back at the main terminal building. I called over there and was eventually connected with Beth, a Rochester Institute of Technology grad who was in charge. At her prompting, I described the incident again.

"OK. But first, how are you?" she asked.

"I'm fine." My heart rate wasn't even up.

"Pilots react differently to these situations, so I just want to make sure that you're OK."

"Thanks for asking, but I'm OK." It was thoughtful of her to ask. Once that was out of the way, Beth was all business.

"They're pretty busy right now, but they can probably do some troubleshooting. I cannot guarantee that they will be able to fix whatever is wrong today." 

I understood completely. How could she make any promises without knowing what the problem was? Once she verified my understanding, she asked to talk to one of the guys in the shop. I handed my phone over to Warren so that she could speak with him.

After some additional bureaucratic steps, Tim pulled the Warrior into their hangar. He immediately removed the valve cover on cylinder #1 to check for a stuck valve, but as he turned the prop, the valves moved as expected. It was not a valve problem.

Next, Tim pulled the bottom spark plug out of the affected cylinder. "Well, I found a problem," he declared and handed the spark plug to me.

Broken spark plug.

The ceramic insulator near the electrode was in pieces. When he checked the top spark plug in cylinder #1, it was badly fouled. Despite the redundancy of two spark plugs per cylinder, both plugs in the same cylinder had failed in different ways. What are the odds of that?

Tim replaced the broken spark plug and asked if I wanted him to clean up the other one or replace it as well. I suggested cleaning it first. Tim retreated to the rear of the shop to work on the plug. When he returned, he commented, "It makes a spark now, but it's not a great spark. Keep an eye on it, you might want to replace this one, too."

Tim wrapping up the spark plug replacement on cylinder #1.

With the repair complete, I taxied the Warrior to the edge of the ramp and performed a run-up. The engine ran smoothly regardless of whether I ran on both ignition systems or either individual. Tim printed up a log book sticker for me and sent me back to the main terminal to settle my bill. "They don't let me handle any money," he indicated with a shrug. The total came to $160, not bad for some time and materials. My experience with Monadnock Aviation was the exact opposite from my experience at Columbia County Airport in 2012 when I suffered a carb fire and was presented with a four-figure invoice for essentially no real work. Huge thanks to Tim, Warren, and Beth for their prompt, professional assistance. As a friend of mine later summarized about the entire incident, "It was the best worst thing that could have happened."

After paying my bill, I was taxiing back to runway 2 when another aircraft on frequency called me. "Hey, Four Eight One, what happened to your engine?" I explained the dual spark plug failure and thanked the unknown pilot on the other end of the radio for his concern.

Aftermath

Warrior 481 underwent another successful run-up as I worked through my departure check list. Not forgetting the contemporaneous door issue, I double checked the door latch before throttling up to take the runway.

The engine ran well. The cabin remained free of drafts. I climbed back over foothills of the mountains and ultimately to 6,500 feet for the ride home.

JPI EDM-700 display showing high EGT on cylinder #1.

While the engine ran palpably well, the engine monitor still indicated an issue in cylinder #1. Normally, my exhaust gas temperatures (EGTs) run close to the same value. But EGT on cylinder #1 was running hotter than the others by 170-200 degrees. High EGT usually indicates an inefficient burning of the air/fuel mixture causing a delay in combustion that means less energy is used on the power stroke and more energy is lost through the exhaust valve. EGTs increase during magneto checks for the same reason with each cylinder performing less efficiently on a single spark plug than it normally does on both. Cylinder head temperature (CHT) on #1 was commensurately low.

Tim's comment about the cleaned spark plug not yielding a great spark came back to me. I had that spark plug replaced the next day and in subsequent flights, EGT on #1 has been in line with the others.

So, What Happened?

I am puzzled by the fouled plug. I am very rigorous about leaning my engine, even during taxi, to avoid loading up the plugs with carbon. Did I do so during the long slow taxi from the terminal ramp to the departure end of runway 2 at Keene that day? I could not recall. When I expressed my surprise about the fouling to Tim, he concurred. "Beyond that plug, it looks really clean in there," he noted.

As for the broken spark plug, I only know of two possible root causes for that. Either plugs get dropped / damaged during maintenance and fail later in flight or they experience a detonation event.  Given the successful engine run-up and initial smooth climb away from Keene, it is obvious that the plug failed in flight. I am reasonably certain that no detonation occurred while operating with a full rich mixture in the climb. In real time, I saw no evidence of the whopping temperature spike that would have accompanied detonation and the JPI did not squawk any temperature alerts as it is programmed to do. (And has previously). The most impartial arbiter of what really happened before that cylinder went cold would be temperature data logged by the JPI engine monitor. After multiple download attempts and a consultation with JP Instruments, it appears that the device stopped logging data at some point. I am in the process of working through a fix with JP Instruments, but frustratingly, those data from Keene are lost forever.

Regardless, I put 4.5 hours in local flying on the engine prior to my next trip and observed completely normal operation that provided confidence for the next adventure. In the end, even though it was "buy one / get one burger day" at Mama McDonough's, I am glad that I did not bring a friend with me on the flight to Keene. Sometimes, we get a little more adventure than we need.