Page 26 - Feb 20 TNT

Jet Journal
The Compliance Spectrum
by Thomas P. Turner
It’s a phrase found frequently in NTSB reports: “The pilot’s failure to....” An (admittedly old) NTSB survey
of accidents from 1978 through 1990 revealed that procedural noncompliance was a factor in 78 percent of all crashes. It’s one thing to say the pilot failed to comply with a procedure. It’s another thing entirely to understand why even good and well-meaning pilots are sometimes noncompliant and to develop strategies for making sure the pilot does things right.
There are five uniquely different types of noncompliance, each with its mitigations – and unfortunately, acci- dent histories. What might cause you to forget to do something or to do some- thing wrong? How can you recognize where you currently fall on the compli- ance spectrum?
Untrained (or Ignorant) Noncompliance
From the NTSB:
The pilot advised ATC he was descend- ing. However, the airplane climbed brief ly,
followed by a series of descents and climbs with varying airspeeds that continued for about five minutes. The pilot informed the controller he could not disengage the auto- pilot and requested radar vectors to return to the departure airport. While returning, the pilot said it took full forward and back control pressure to descend and climb, respectively, and he solicited and received assistance from another pilot on how to turn off the autopilot. The advice included pulling the autopilot circuit breaker, which the pilot said he did. The pilot apparently did not consult the emergency procedures for an autopilot pitch trim malfunction, which included a step to manually ret- rim the airplane. As the airplane turned to final witnesses saw it enter a vertical descent and impact a lake. Performance studies showed that, during the turn, the airplane was just two knots above its stall speed. It is likely the airplane experienced an aerodynamic stall.
The NTSB probable cause:
The pilot’s failure to maintain adequate airspeed which resulted in an aerodynamic stall. Contributing were the pilot’s misuse of the forward elevator flight control input
with the autopilot engaged, which resulted in the full airplane-nose-up trim; his failure to recognize and correct the mis-trimmed airplane per the emergency procedures; and the excessive control forces required to maintain control in the mis-trimmed condition, which resulted in pilot fatigue.
One end of the compliance spectrum is what I call untrained or ignorant non- compliance. The pilot doesn’t do some- thing or does something wrong because he/she does not know the checklist or procedure exists.
The bulk of your training, and virtu- ally all of your recurrent instruction, probably focused on stalls, steep turns, ILS approaches, takeoffs and landings, and similar skills. These are all vital, and history shows we need to train on them even more. But very little instruc- tion and even transition training covers the design and operation of airplane systems – how the fuel system works, or dealing with electrical faults or the normal, abnormal and emergency op- eration of optional equipment like au- topilots and electric trim. As we move into more complex airplanes, it takes
24 • TWIN & TURBINE / February 2020 Jet Journal
PHOTO COURTESY OF PAUL BOWEN PHOTOGRAPHY