Saturday, September 2, 2017

Bad Attitude

Milk Run

Date Aircraft Route of Flight Time (hrs) Total (hrs)
02 Sep 2017 N21481 SDC (Sodus, NY) - PTK (Waterford, MI) 2.5 1702.8

Cool air supported our aluminum wings at 6,000 feet and a tailwind hastened our passage over the Earth. We were filed direct to Oakland County International Airport, a flight we have made so many times that it has become routine. Unlike our last several cross country flights, the sky was absolutely clear of clouds. An advisory for moderate turbulence in the vicinity of Detroit was the only potential weather risk ahead.



Typical of any direct flight between Sodus and Oakland County, we passed north of Niagara Falls.

Ho-hum. 

When something as spectacular as Niagara Falls evokes a nonchalant reaction, that something has officially become old hat.

FlightAware ground track from KSDC to KPTK

In the vicinity of London, Ontario, we were assigned a new squawk code and given a revised clearance. "Cleared present position direct AXXIS, then SWWAN TWO arrival." Interesting. Usually, our flights to Oakland County are direct and it is only on departure that we are assigned a specific routing. I put us on course to AXXIS and studied the arrival procedure as the Warrior cruised approximately one mile over Ontario farmland.

We were established on the SWANN TWO arrival procedure while still over Canada, but this was a temporary state. Detroit Approach vectored us off the procedure before we passed Lake St Clair. I suspect that the vector was to move us south of the skydiving drop zone near Romeo, MI.

Oakland County International was rather busy that morning. We were number three to land on runway 9 Right with additional traffic alongside us for runway 9 Left. The Bear gave a traffic alert for the Piper Arrow on approach to the parallel runway slightly aft of our left wingtip. Parallel runway operations can be uncomfortable for those of us that do not regularly conduct them and The Bear was no exception.

As for the forecast turbulence, that did not come to pass. It was the easiest cross country flight we have experienced as a family in a long time (no clouds, no weather, no customs, no exploding water bottles, etc.)



After landing, we negotiated the recently renamed taxiways to the Michigan Aviation ramp. Once parked, I gawked as Michigan Aviation line service tugged a T-28 Trojan (post WWII military trainer) out to the ramp.

Visitation

Surgery and a hospital stay for Mom inspired this hastily planned day trip to southeast Michigan. Michigan Aviation was kind enough to lend us a crew car for the duration of the afternoon so that we could visit her at "St. Joe's" in Pontiac. For someone who spent several hours in surgery just two days before, Mom looked fantastic.

After a great visit with Mom, we returned to the airport by 4:00 that afternoon for the journey home. For the first time in years, the expected routing email I received prior to launch was "radar vectors / direct". There was no need to negotiate with ATC for a route that did not cross Lake Erie.

Stratus Versus Cumulus

Date Aircraft Route of Flight Time (hrs) Total (hrs)
02 Sep 2017 N21481 PTK (Waterford, MI) - SDC (Sodus, NY) 2.9 1705.7

As we climbed toward our filed 7,000 foot cruise altitude, we penetrated the cloud deck and smoothly passed through several stratus layers before emerging on top. As I suspected she would, Kristy decided that she preferred stratus clouds over cumulus.




Ontario lay below, invisible beneath layers of cloud. Generally, we were either in the clouds or between layers. Passing through areas of precipitation, we watched water streaming over the wings. Though she is not a fan of flying in the rain, even Kristy admitted that it was an interesting visual.


The Bear simply conked-out for most of the ride over Canada.

Check Your Attitude

Occasionally, we encountered mild updrafts and I would push the nose down to hold altitude. After a while, I realized that the attitude indicator (AI, a gyroscopic instrument displaying an artificial horizon) showed a greater pitch downward than was realistically possible.

Over several minutes, the displayed pitch increased and developed into an apparent rightward roll as the AI gradually failed.


The vacuum pump was producing adequate suction and the directional gyro, also vacuum driven, was functioning normally relative to the magnetic compass. All other indications, including the pitot-static instruments (airspeed, altimeter, and vertical speed indicator) and the turn coordinator (an electrically driven gyroscopic instrument) provided consistent data. There was something wrong with the AI gyro.

As the AI rolled into a patently ridiculous indication, I covered it and opened the electronic attitude display in ForeFlight fed by AHRS data from the Stratus 2. This equipment is not certified for instrument use, but it does provide useful backup information in a pinch and I specifically bought it for that purpose. Fortunately, I have practiced partial panel flight enough times this year to feel comfortable and proficient flying in instrument meteorological conditions (IMC) with the AI covered.



We continued eastbound in between layers. As we crossed the international border after checking in with Buffalo Approach, we entered dense IMC and I could feel my workload increasing. The weather in Buffalo indicated a ceiling around 4500 feet. I informed ATC that my AI had failed (per FAA regulations, equipment failures on IFR flights need to be reported to ATC) and requested a descent into VFR conditions.

"Cherokee Four Eight One, descend and maintain 5,000. If that's not low enough, we'll get you lower." The controller checked with another aircraft in the vicinity to confirm that the new assigned altitude would work.

"Cherokee Four Eight One, do you want to declare an emergency?"

Emergency?

Many pilots attach a stigma to declaring an emergency, fearing a mountain of paperwork combined with unholy retribution from the FAA. Most sources indicate that this is not really the case. In fact, declaring an emergency confers upon the pilot advantages of preferred handling and allows the pilot to do what he or she needs to do in the name of safety, even if it results in breaking some rules. Declaring an emergency is a useful tool available to pilots in need of additional help.

With this understanding firmly in mind, this did not feel like an emergency. I was calm, in control, and proficient on partial panel operations. I had already been granted clearance to a lower altitude in visual conditions to reduce my workload. Thus, I was already getting what I wanted. What more did I need?

I told Buffalo that I did not want to declare an emergency at that time.

What would have pushed it over the line for me? Had the ceiling been much lower necessitating an instrument approach to land, I think that would have constituted an emergency. In that case, additional hand-holding from ATC would have been welcome.

We emerged from the cloud bases over gloomy western New York terrain shortly before leveling at 5,000 feet. My workload instantly dropped to normal.

Buffalo passed me to Rochester Approach, where I informed them of my intent to fly a visual approach into Sodus. A few minutes later, we entered IMC again and I asked for a lower altitude.


Rochester cleared us down to 2,500 feet, an altitude that we held for the remainder of the flight home.



Somewhere between Rochester and Sodus, the cover fell off my AI. It was now displaying a normal indication and continued to do so as I maneuvered into the pattern and landed. The contraption may have reverted to good behavior, but I have officially branded it as untrustworthy.

FlightAware ground track from KPTK to KSDC.

Oh, Deer...

After clearing the runway, I brought the Warrior to a stop. Three deer were congregated ahead near the side of the taxiway. If any of them ran into the propeller, it would mean a lousy day for everyone involved. We looked at them. They looked at us. The ears of the closest deer flipped up and, moments later, those of her two comrades did as well. We continued to stare at each other.

We had a standoff.

In hopes of breaking the stalemate, I locked the brakes and ran the engine up to 2,000 RPM. At the roar of the engine, all three deer bolted for the woods and cleared the way for us. "It's not like I have a horn to use," I explained to Kristy as we continued on to our hangar.

It was just one more thing to manage in the life of a pilot.

Next Steps

Mike Busch once wrote in a 1995 article that, "The accident database and university research seem to agree: if your attitude gyro quits while you're in thick soup, you're probably gonna die." Having a backup, even a non-certified backup like the Stratus 2, made a big difference. However, my fundamental take-away from the experience with an AI failure is that practiced proficiency can make the difference between an emergency and a challenge. This is why we practice. I am grateful to the other pilots who have ridden right seat in Warrior 481 with me this year while I practiced partial panel operations under the hood. I think that made all the difference in the world.

Warrior 481 is officially banned from IMC until I resolve the issue with the AI. Options include overhauling the mechanical SigmaTek AI already in the panel or replacing it with something else. The AI has been overhauled twice since I purchased Warrior 481, once in 2005 and again in 2011. Another six years later, it's starting to go again.

I am intrigued by the Garmin G5, a solid state electronic replacement AI with a four hour battery backup. It is reasonably affordable (a relative term in the realm of avionics) and would eliminate my dependence on two balky mechanical systems: the mechanical AI gyro itself and the vacuum pump that powers it. This setup would still require a vacuum pump for the directional gyro, but that gyro is less critical to the safety of flight than the AI. With 630 hours since install, the current vacuum pump is also due for replacement.

Sometimes, even milk runs come with their challenges.

2 comments:

  1. A valuable lesson in "things I need to do when I get my IR" as well! Clearly all your partial panel practice (say that 5 times fast) paid off; it's undeniably a necessary skill, especially when flying family in actual when you never quite know what may break at an inopportune time.

    One club I'm considering joining is considering the G5 themselves, I think. Seems like a nice little unit, AMUs aside. In this day and age it really seems like solid state is the way to go.

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    1. My thoughts exactly. The AI was a genius invention in its time, but it has liabilities. The solid state stuff seems so much more reliable.

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