Inbound on the approach, the round-gauge instrument trainer’s pilot was piqued to see the course deviation indicator creeping left of center. Determined to keep the approach stabilized, he corrected 10 degrees right to reverse the trend.
Yes, to the right—as appropriate to fly the LOC BC RWY 23 approach to the New Bedford (Mass.) Regional Airport.
Without the latest graphic displays, the reverse sensing by which pilots tracked localizer back courses demanded special mental acrobatics. Methods vary, but flying a back course was raw-data IFR at its most uncooked—foreign territory to glass-age pilots for whom raw data suggests something primitive whether used to navigate a front course or its recalcitrant reciprocal. Back course errors were the forerunners of today’s mode confusion—the bane of glass-cockpit pilots confronting more information than the know-how to use it.
Raw-data aviation remains relevant in one respect: No one ever said that pilots flying raw-data approaches had sacrificed their airmanship on the altar of technology. Does that suggest a refresher mission for glass pilots?
"Globally, the requirements to use the highest levels of automation and maintain electronic glideslope when available has degraded large airline commercial pilots' basic airmanship abilities from VFR maneuvering to raw data instrument navigation," wrote an air-carrier pilot in an Aviation Safety Reporting System narrative, venting displeasure at a first officer going "heads down" to enter keystrokes in a black box "instead of quickly complying with ATC instructions."
But wait: Don’t great graphics produce great situational awareness (SA)?
Not if the aircraft does something unexpected, when great confusion may arise, as another pilot reported after a nav system turned an aircraft left to enter a hold, rather than right, as expected.
"Our SA quickly moved from green (thinking we had the information needed to perform the task) to yellow (trying to quickly figure why the aircraft continued to turn in the wrong direction and how to best correct this error)."
Next time, "I will be set up and ready to downgrade to raw data (VOR tuned, radial dialed in) just in case our automation does not move the aircraft as expected, and use this raw data until SA is fully regained."
Would your raw-data instrument skills stand up to the challenge of a low-tech instrument proficiency check? From preflight prep to parking, finding out makes a meaningful mission for your next practice flight.