Wherever I moved the throttle, the engine maintained a flight idle
state with no response.
SOCATA also encourages pilots to take advantage of one of theTBM850's other tricks: It will descend like a box of hammers if the power is pulled to flight idle
and the nose is pushed over to VMO, which is 266 knots indicated.
Once begun, it's a continuous descent at around 200 knots and flight idle
power to the FAF, with a standard descent gradient of 250 feet/nm, slowing to approach speed and [less than or equal to] 150 feet/nm before reaching the FAF without a level-off.
During the last 60 seconds of the accident flight, both engines were operating at a "typical approach power setting." About six seconds before the end of the data stream, the power levers were commanded back from an approach power setting to flight idle
. The power levers reached idle stop about two seconds later and remained there for approximately two seconds before being advanced about one second prior to the end of the data.
The pilot cycled the bleed-air knob, clearing the caution, but it returned every time he increased power from flight idle
In a lot less time than it's taken you to read the last paragraph, the A/C abruptly pulled both throttles to flight idle
, extended the speedbrake, turned our squawk to "emergency," and commenced a rather aggressive descent.
The previous proposal would have superseded an existing AD that currently requires repetitive visual inspections or checks to verify that the flight idle
stop system circuit breakers are closed, as well as repetitive functional tests to determine if the backup flight idle
stop system is operative.
Fearing an unresponsive engine at this point, I immediately brought the collective full-down, took the twist grip back to flight idle
and then back to full-open in the hope that something would reset and the engine would spool up.
Chop the power to flight idle
, point the nose over and down you go at 1500 FPM.
With power reduced to flight idle
for approach, it got low and slow and then wouldn't spool back up, winding up as an very expensive lawn dart 100 feet short.
The pilot reported then setting the parking brake and positioning the throttles back to flight idle
before placing the propeller levers in the feather position.