Industry Insight: An 'icing' accident

The Phenom crash hit close to home to me, literally. I live in Gaithersburg, and my family has kept airplanes at Montgomery County Airpark since 1964. This accident rocked the community and reignited a decades-long feud between the airpark and the residential communities that surround it.

The pilot set an approach reference speed (V_REF) of 92 knots. But as the airplane neared Runway 14 on autopilot, speed bled off as the pilot neglected to add power and the autopilot dutifully kept raising the nose to maintain the glidepath. Only as the indicated airspeed dropped through 92 knots did the pilot add any power. It was too little, too late. The Phenom stalled at 87 knots, rolled partially inverted, and hit two houses.

The NTSB named “the pilot’s conduct of an approach in structural icing conditions without turning on the airplane’s deice system, leading to ice accumulation on those surfaces” as the primary cause of the accident. With anti-ice On, the airplane would have had higher calculated VREF speeds, providing more of a buffer against stall.

Nobody will ever know whether the airplane did in fact have ice on it. The airplane stalled at 16 degrees angle of attack, which more likely indicates the airframe was minimally contaminated or ice free. The NTSB report says a clean Phenom 100 will stall at an angle of attack of 28.4 degrees—an astounding number that is suspiciously higher than any transport jet I’ve seen. But that’s where the NTSB hung its hat.

The NTSB’s choice to largely blame icing, instead of the pilot’s neglect to properly fly the airplane, leads me to believe the NTSB wants to use this accident to push its agenda to amend certification requirements for flight in icing conditions. If the pilot had flown his calculated VREF (icing speeds or no), I wouldn’t even be writing this piece. This isn’t a new thing for the NTSB. Following several icing crashes, it has pushed the FAA for changes in icing certification and equipment. Some accidents confirmed ice accumulation via pilot conversation on the cockpit voice recorder, but the Phenom pilot only made a passing mention of snow far earlier during the descent.

At my airline, we turn the anti-ice equipment on any time the total air temperature is below 10 degrees Celsius in clouds, precipitation, or if visibility is less than one mile. These guidelines are an industry standard. I would wager that we accumulate ice less than 1 percent of the time we fly in these conditions. Ice often comes and goes quickly during climbing or descending flight, with little or no accumulation.

At the time of the Phenom crash, the weather was good, with an overcast at 3,200 feet and 10 miles visibility. There were some pilot reports of ice and, as typical of most winter days, icing conditions were in the forecast. The airplane was not in icing conditions for several minutes prior to the crash. The NTSB assumed the airplane accumulated ice during its descent from the higher altitudes—based on the evidence in the report, that’s a stretch.

If the pilot had used the anti-ice equipment, it would have added 16 knots to VREF and the audible stall warnings would have started several seconds earlier. But the fact that the airplane warned of an impending stall multiple times before the crash tells me that another half-dozen warnings may not have saved the day. After all, if you’re going to ignore one VREF speed, it’s just as easy to ignore another. Finally, even if a pilot forgets to turn on anti-ice equipment before entering ice, he almost certainly will be reminded when he sees it starting to accumulate.

Perhaps the NTSB should focus its attention on the training of pilots of owner-flown jets. Are training providers pressured to give pilots a pass because they just spent millions on their new jets? After a nine-day, 21-hour course of flight instruction in the Phenom, an instructor advised more training for the accident pilot. The pilot then found a local instructor and trained another six days to satisfactorily earn his type rating.

This same pilot wrecked his Daher TBM 700 turboprop at the same airport in 2010 during a landing attempt. How does a pilot who recently wrecked an expensive turboprop airplane get insurance to fly an exponentially more expensive—and higher-performance—jet? Wouldn’t the insurance company mandate a second pilot, at the very least?

Icing may have been a factor in this crash; however, it was clear that the pilot stopped flying the airplane at the worst possible time.