There is no substitue for Experience......
How much is enough?
Excerpts from a NTSB report
"
As the airplane climbed through 11,700 feet, the captain noted light rime ice accumulating on the windshield wiper blades and about a 1/2-inch-wide area of ice on the left wing. During this time, the crew failed to detect a decaying indicated airspeed due to the ice that was accumulating. As he began to activate the manual deice boot system, he felt a heavy vibration in the airframe and the windscreen immediately turned white with ice. The airplane's nose and left wing dropped and the autopilot disconnected. As he was grabbing the yoke, the clacker sounded (indicating an imminent stall), the stick shaker activated, and the ground proximity warning system emitted a "bank angle" aural warning. Digital Flight Data Recorder (DFDR) data showed that the indicated airspeed went from 144 to 130 KIAS over the 26 seconds before the upset, and that the rate of airspeed decay accelerated in the final 10 seconds before the autopilot disconnected. The airplane departed controlled flight at an indicated airspeed of 130 knots, and before the stall warning activated. The data establishes that the airplane went through a series of roll and pitch excursions, reaching maximum values of 86 degrees left wing down, 140 degrees right wing down, 23 degrees nose up, and 40 degrees nose down before the flight crew recovered control. The data also revealed that about 26 seconds before the stall while the airplane was at a speed of 144 KIAS, the airplane began to experience a likely ice-induced slight rolling anomaly that was counter to the direction of the aileron input. Aileron input from the autopilot arrested this slight rolling motion.
The airplane rolled to 86 degrees left wing down, and then went through a series of roll and pitch
movements. It reached 140 degrees of right roll, and a maximum pitch down angle of 48 degrees. It
rolled to 75 degrees left wing down, and a pitch of 31 degrees nose down. It then rolled to 94
degrees right wing down, followed by a pitch angle to 40 degrees nose down. Starting at 1440, the
altitude and outside air temperature parameters stopped recording valid data for a period of 15
seconds. At 1440:06, the airplane's pitch angle began to increase. It passed through 0 degrees
about 6 seconds later at an airspeed of 219 knots, and a recorded maximum vertical acceleration of
2.5 g's. The pitch reached 23 degrees nose up at 1440:24; the minimum recorded airspeed value of
105 knots occurred 11 seconds later while the airplane was at an altitude of 7,840 feet. The
parameters began to stabilize after this time.
The captain had a total flight time of 6,764.08 hours, with 3,981.87 hours accumulated in Saab 340
airplanes, of which 2,519.46 hours was as the pilot-in-command (PIC). He had a total of 970 hours
of instrument experience and between 1,700 and 1,900 hours of night flight. During the preceding 90
days, 30 days, and 24 hours, he reported that he had flown in both the capacity of PIC and
second-in-command (SIC) approximately 172, 47, and 7 hours, respectively. He added that he had
acquired numerous hours of aerobatic flight time in a Cessna 150 Aerobat airplane."
Anytime, anywhere
