TBM 700 control lost abruptly
Pilot killed, occupant escaped burning home
By the time the air traffic controller finished delivering a low altitude alert, the TBM 700 flown by a Minnesota bank executive returning home from Florida was already through the roof of a Brooklyn Park home.
While icing could have played a role, the accident may also be another example of a TBM 700 loss of control at low speed.
With an NTSB preliminary report still pending, details including ADS-B data; ATC audio recorded by LiveATC.net; and footage captured by a doorbell camera showing the TBM in a near-vertical, rotating dive suggest that the flight ended with a stall and spin soon after passing the final approach fix for the GPS Runway 9 approach to Anoka County/Blaine (Janes Field) in Minneapolis.
Dolan checked in with the tower just before 12:18 p.m. local time and was cleared to land on Runway 9. The tower reported wind at 10 knots from 50 degrees, and Dolan, in his final recorded transmission, confirmed he had the latest weather information.
The last METAR recorded before the accident (at 11:49 a.m.) reported overcast skies at 900 feet, 10 miles visibility, a ground temperature of 37 degrees Fahrenheit (3 degrees Celsius), a dewpoint of 36 degrees Fahrenheit (2 degrees Celsius), and a relative humidity of 93 percent. While there were no active advisories for icing in the area at the time, it appears likely the TBM 700 was in instrument conditions during the approach: A pilot departing Minneapolis-St. Paul International/Wold-Chamberlain Airport at 11:36 a.m. reported cloud tops at 6,000 feet. About two hours before the accident, a Cirrus SR22 pilot reported light rime icing at 5,500 feet, 20 nautical miles west of the accident location.
The TBM 700 is certified for flight into known icing, and while conditions may have been conducive to structural ice accretion at 3,000 feet msl, it is unclear whether icing was actually a factor. The GPS groundspeed was 110 knots as the aircraft completed a right turn and began tracking the final approach course, around the time Dolan checked in with the tower controller. Adding about 10 knots to account for the quartering headwind still leaves the airspeed short of the landing gear and initial flap extension speeds of 178 knots indicated listed in the TBM 700 pilot’s operating handbook before-landing checklist.
Four ADS-B transmissions were recorded in the final two minutes as the aircraft began to descend from 3,000 feet, and the groundspeed dropped further, from 87 knots to 77 knots.
Data recorded by ADS-B Exchange shows the aircraft making a sharp left turn and a rapid descent at 12:21 p.m. The tower controller issued an altitude alert around the same time a Ring camera captured the TBM 700 in a near-vertical, twisting dive. Homeowner Ken Tobacman told Good Morning America there was a "big boom" as the TBM 700 struck his home, which he escaped as it was quickly engulfed in flames.
Even without ice accumulation, the TBM 700 has known characteristics that may have contributed to the accident. Aviation Week reported in 2023 on a 2019 accident involving the same model aircraft that lost control during an attempted go-around. Daher engineers determined the stall speed of that accident aircraft with takeoff flaps was 74.2 knots, without taking bank angle into account. Stall speed increases 6 knots with a bank angle up to 30 degrees, and by 15 knots at 45 degrees of bank.
The Pratt & Whitney Canada PT6A-64 engine produces considerable torque at full power, which was also a factor in other accidents involving this aircraft, Aviation Week noted. If Dolan's aircraft was flown behind the power curve, it would have been more vulnerable to this torque roll effect that the French accident investigation agency documented in a 2014 study of 19 TBM 700 accidents involving loss of control in flight between 1990 and 2010.
One common thread in these accidents was loss of control while banking left during final approach. Another was that none of the pilots involved in these accidents was a full-time professional pilot.
Pilots who flew a British TBM 700 demonstration in 2003, deliberately exploring low speeds at high power settings, noted the aircraft has a tendency to roll left during a stall, which becomes more pronounced at lower speeds. The pilots found the roll was controllable at speeds above 70 knots.
