Variations and Training
Since there are no Flight Data Recorders required by Regulations to be installed in Light Twin Engine Airplanes, Air Operators of these types of airplanes are not require to monitor and record altitude and airspeed during flight. However, the majority of light airplanes today are GPS equipped where flight parameters are available.
Common Cause variations is Normal Operations and Special Cause variations is Emergency Operations.
Departure airport elevation is 3500ft, mountainous area with peaks to 10000ft and destination airport elevation is 3500ft.
The climb up to cruising altitude of 12000ft is normal. At 12000 the pilot levels off, maintaining airspeed of 165kts.
Shortly thereafter the airplane descends with a slight increase in airspeed. At 11700ft the airplane climbs back to 12000ft.
Next thing is another increase in airspeed, climb to 15000ft, with a sudden drop in speed to 55kts and drop in altitude from 15000ft to 11000ft. Shortly thereafter operations are back to normal with cruising altitude of 12000ft and 165kts.
A final blow to the flight is when a severe gust causes one wing to stall at 55kts and the airplane enters into a spin.
SMS is to use tools available and to be moving forward.
SMS is not to get stuck in the past with old Systems
Altitude and speed variations beyond acceptable limits due to thunderstorm are Special Cause variations and require different training than Common Cause. Variable cause training is training for Emergency Operations.
By applying GPS parameters Air Operators have an SMS tool available to collect and analyze data, apply this knowledge in developing Training Programs, to increase Safety Margins and to elevate level of Customer Service.