Creating an Emergency

With a questionable attitude indicator known before take-off, was it a sense of overconfidence or simply carelessness that compelled this experienced IFR pilot to attempt partial panel IMC?

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Flight instructors often note to the student, early in the training cycle, that there are back-up systems in case the primary equipment fails. However, with respect to the single engine purring away on the nose of the aircraft they will often add, “Don’t worry, they hardly ever fail, and if it does, the airplane will keep flying—it just turns into a glider.” Reassured and confident, our flight training continues.

When we began working towards our instrument rating, back-up systems became even more important. We spent countless hours staring at a critical six pack of gauges in front of our eyes. We learned how to interpret their meaning and how to verify if one had failed, and what to do if it did. We would fly partial panel and adjust our scan. Using these skills we can keep the shiny side up in the clouds. It was more difficult, but doable. Again, we were reassured and confident with our knowledge.

The 72-year-old pilot had been flying for about 40 years. He was a lawyer and a real estate investor with access to larger aircraft flown by professional pilots, but he also owned and enjoyed flying a 1978 Pressurized Cessna 337 Skymaster. In its push-pull engine configuration the aircraft does not have any asymmetrical thrust issues—should one fail. Many multi-engine pilots purchase the Skymaster for this reason alone. The pilot acquired his aircraft in 1980, 28 years before the accident, and he used it for frequent trips between his home in New Jersey and a seasonal place in Maine. The aircraft was also equipped with dual vacuum pumps, one on each engine.

During the accident investigation the pilot’s current logbook was not located, so the NTSB estimated his hours using one from three years prior and from a third class medical application completed a year before. The pilot had approximately 2500 hours of total time and 2000 hours in type. Of these, 250 were in actual instrument conditions and 215 were under the hood. There was nothing to indicate the possibility of the pilot not being current as he had been flying about 175 hours per year.

Homeward Bound

The pilot and his wife arrived at Millinocket Municipal Airport (KMLT) in Millinocket, Maine on a Thursday. The following Sunday morning the pilot called Flight Service for a weather briefing for a return flight to his destination of Caldwell, New Jersey (KCDW). He was advised, by the briefer that VFR flight was not recommended for the intended flight. A low pressure system was moving across the area creating rain showers and instrument conditions interspersed with pockets of VFR. The pilot filed an IFR flight plan with an altitude of 10,000 feet for the 2 hour and 18 minute trip.

At the time of departure Millinocket was reporting clear skies, ten miles visibility with light winds from the north. Further south, Portland, Maine was Marginal VFR in light rain interspersed with IMC. The pilot told the Millinocket FBO manager they would be back in a couple of weeks for the July 4th holiday. Also, almost certainly on the pilot’s mind was the fact his grandson would be getting married the very next weekend.

At 12:28 local the airborne pilot contacted Boston Center and informed the controller of the filed IFR flight plan. The pilot also said “…but we gotta go VFR, I’m having a little trouble with the… uh artificial horizon so we’re going to try and make it VFR…” Fifteen minutes later the pilot contacted Boston Center again and said he wanted to obtain his IFR clearance to Caldwell. An IFR clearance was provided by the controller at 8000 feet.

At 12:50 the pilot was handed off to Naval Air Station Brunswick Approach Control. The pilot reported no problems or concerns to the controller. At around 13:10 he was given a hand off to Portland Approach. Although he acknowledged the radio call and confirmed the frequency, he never checked in with Portland.

The Predictable Occurs

Radar plots obtained from Brunswick indicate that, over the course of a few minutes, the airplane made several alternating turns to the southwest and northwest. The aircraft maintained an altitude between 7900 feet and 8200 feet with the groundspeed varying between 137 and 179 knots. The last recorded altitude was at 7200 feet. The lack of radar data indicating increasing rates of descent and groundspeed, and the loss of contact at the higher altitude may be indicative of an in-flight break-up, possibly caused by pilot induced maneuvers.

At the time of the accident the closest weather reporting airport was 25 miles to the northwest. This station reported the wind was out of the east at six knots; seven miles visibility; few clouds at 500 feet; scattered clouds at 1000 feet and an overcast at 1500 feet. However, weather radar imagery indicated the aircraft was in an area of IMC with light to moderate precipitation.

Small portions of the aircraft’s interior were found floating in an oil slick off the Coast of Maine, in an area where the depth of the ocean is 250 feet. The majority of the aircraft was never recovered. The NTSB ruled the probable cause to be “The pilot’s improper decision to continue the flight in instrument meteorological conditions after experiencing an attitude indicator malfunction.”

Confidence and Knowledge

Pilots in these NTSB reports are typically intelligent individuals with no intentions of flying themselves and their loved ones to the scene of an accident. They make decisions to continue a flight based on confidence in their aircraft, their perceived piloting abilities, and outside influences. This is likely the case here too. The pilot was experienced and he knew his aircraft well. Planning for the upcoming wedding may have entered into the decision.

The above scenario raises the fundamental question, which will never be answered—did the pilot know his Attitude Indicator had failed before he took-off for a flight into IMC? A vacuum system failure is unlikely with two pumps onboard. The probable suspect is a mechanical failure of the Attitude Indicator. Because the pilot had mentioned a problem with the AI, it is possible that it had already failed and he planned to complete his flight home under VFR, or he was confident he could use the partial panel skills he was taught in the past. If the failure was noticed in VMC, it was obviously foolish to continue the flight into IMC.

Yes, partial panel is a back-up solution for gyro failure, but in IMC this is an emergency situation when no other alternative is available—period. Hopefully, instructors make that aspect clear during initial or recurrent flight training. Perhaps this pilot believed that, already knowing he had a bad AI, he was avoiding the initial pitfall of surprise—that flying the needle, ball and airspeed early could bring him through. Continuing into IMC with a known failure of the most critical gauge for instrument flight is creating your own emergency.

Armand Vilches is a commercial pilot, instructor and FAASTeam member. He brings an extensive background in risk management and insurance to aviation and flight instruction.

This article originally appeared in the June 2013 issue of IFR Refreshermagazine.

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