I am shortly to complete an instrument rating course and "Stalled warning" (Flight International, 24-30 August) made interesting reading. It seems to me that a lack of basic instrument scan has been a major factor in the accidents the piece discussed.
During the instrument rating test the student is required to recover from various stalls while flying under instruments. The basic scan pattern of instrument flying is attitude indicator (AI)-vertical speed indicator (VSI)-target instrument. So in the case of a stall it should be AI-VSI-airspeed indicator (ASI), with the altimeter brought in occasionally to bake up the VSI.
When you couple this basic scan pattern with the old "power plus pitch equals performance" adage it should be possible to safely climb away from the ground when presented with a false stall warning. But greater use of automation, as has been suggested in other articles recently, is no doubt leading to a breakdown in basic instrument flying skills - all three accidents discussed happened at night.
T G GRIFFITHS
BENFLEET, ESSEX, UK
Source: Flight International
