Sooner or later all pilots experience bouts of spatial disorientation. The episode can last a second or two, or can persist long enough to present real problems up to and including the loss of the aircraft and all on board.

An old friend — long retired — told me of piloting a U.S. Air Force C-54 (Douglas DC-4) one night on the North Atlantic Blue Spruce routes between layers over a sloping stratus cloud deck — the higher cirrus layer was thin enough to allow moonlight to illuminate the cloud layer below. Circumstance required the crew to hand-fly. The constant effort to keep the wings level — aircraft were fitted with spinning metal gyros in those days — with the sloping cloud deck in their outside visual field caused both pilots to suffer bouts of spatial disorientation, vertigo and nausea. After an hour or so they found the only solution was to lower their seats to the bottom positions and block the cockpit windshields with charts. They had to get rid of the confusing visual stimulus.

The electro-mechanical-chemical system in our bodies that enables us to establish our positions in space is unfathomably complex. Sensors in this system include our eyes and the visual cortex; the vestibular organs in our ears; the kinesthetic receptors in our muscles, tendons and joints; and the neuron synapses in our brains. All of those things working together enable us to tell up from down, acceleration rates in all axes and dozens of other things that that we need for survival on this planet in two dimensions — let alone when piloting an aircraft in three.

The brain is continually processing the information from these sensors. And when the input is missing or distorted, we lose our built-in orientation system and must rely on other inputs. In the case of pilots, these other inputs, of course, are the aircraft instruments. Remember Lesson 1 on Day 1 of your initial instrument flight training: When the instruments and your body disagree, trust the instruments.

Believing aircraft instruments when they are at odds with our bodily sensations is difficult. After all, the brain is taking in thousands of inputs a second from the body’s sensors, but information from the aircraft instruments only enters the computations when we attend to them. It all boils down to developing a rapid, analytical scan. That takes plenty of experience and practice. (And for most business pilots in FAR Part 23 airplanes, that doesn’t mean simply managing the automation. Rather, it means hand-flying the aircraft while you are dealing with navigation, communication, system configuration, dropped pencils, and all the rest.)

Sadly, there is nothing uncommon about the accident we’ll discuss this month. Similar incidents befall pilots in high-performance singles and light/medium twins dozens of times each year. It seems to me that only the N-numbers and locations change. The circumstances and the NTSB findings of probable cause remain grimly similar.

The Accident

Those probable cause findings usually go like this: “The pilot’s failure to maintain airplane control during a missed approach in night instrument meteorological conditions due to spatial disorientation and a lack of instrument proficiency.”

That is precisely what the NTSB had to say about the loss of a Cessna 310R, N98BT. It crashed into a pond during a missed approach at Jacksonville Executive Airport (CRG) in Florida on Dec. 8, 2013, about 1821 EST, killing its pilot and two passengers. The pilot was operating on an IFR flight plan from St. Lucie County Airport, 200 mi. to the south.

Here’s what the investigators were able to learn about the pilot and the accident:

The airplane was in radio and radar contact with Jacksonville Approach after a routine IMC flight from Fort Pierce, Florida. The flight was at 5,000 ft. At 1806, the controller advised the pilot of ATIS information, which included visibility 1.5 mi. with mist and ceiling overcast at 400 ft.

Between 1809 and 1812, the controller cleared the flight to descend to 3,000 ft. and then 2,000 ft., which the pilot acknowledged and complied with.

At 1814, the controller informed the pilot that his position was 7 mi. from ADERR intersection, the final approach fix, and instructed him to fly a heading of 350 deg. and to maintain 2,000 ft. until established on the localizer. The pilot acknowledged the instruction.

At 1815, the pilot was instructed to contact the CRG tower. The CRG controller cleared the flight to land on Runway 32 and provided a PIREP from a flight that landed 30 min. prior. That report, which included an observation that lights were visible at 300 ft. AGL and the runway was in sight at 200 ft. AGL, was acknowledged by the pilot.

At 1817, a low-altitude alert was generated in the tower and the controller instructed the pilot to check his altitude. The pilot acknowledged the instruction and stated he was at 600 ft., which was the altitude indicated by ATC radar.

At 1819, the pilot advised that he was performing a missed approach.

The published missed approach procedure was a climb to 700 ft. then a climbing right turn to 1,900 ft. on a 180-deg. heading. The tower controller instructed the pilot to fly a heading of 280 deg., which would be a left turn, and the pilot acknowledged. The controller did not provide an altitude and told the pilot to contact Jacksonville Departure, to which the pilot did not reply. No further communications were received from the accident airplane.

The crossing altitude for ADERR was 1,900 ft. MSL. FAA radar data revealed that the airplane passed ADERR about 1 mi. right of localizer course and about 900 ft. below the published crossing altitude. It then descended and leveled off at about 600 ft., while twice proceeding left of localizer course and re-intercepting. During the third intercept, it descended to about 300 ft. and then began a climbing left turn to 900 ft. MSL, before radar contact was lost.

The wreckage subsequently was located about 1 mi. south of CRG, submerged in a pond of a residential development. The wreckage was upright, intact and oriented about a southerly heading. The leading edges of both wings and the nosecone exhibited impact damage. The fuel tanks on each wing were breeched. The flaps were extended 15 deg. and the landing gear were retracted.

Control continuity was established. The elevator had been trimmed to the 5-deg. nose-up position and the rudder trim actuator corresponded to a 5-deg. tab left (nose right) position. Aileron trim was neutral. The cockpit area was crushed. All four seats were ejected and the lap belts and shoulder harnesses remained intact. The lap belts in seats No. 1, 2 and 3 were buckled.

The pilot’s side of the instrument panel was equipped with an electronic flight instrument system (EFIS) with backup attitude indicator. The pilot’s attitude indicator and turn and bank coordinator were removed and disassembled for inspection. The disassembly of both instruments revealed that their respective gyros exhibited rotational scoring. The throttle, propeller and mixture controls were full forward. The altimeter indicated 200 ft. with 30.19 displayed in the Kollsman window. The airspeed indicator needle displayed 130 kt.

The engine, propeller and vacuum systems were examined by specialists who found nothing that would have prevented normal operation before impact.

The Pilot

The investigation turned to the pilot. An autopsy determined he had died of multiple blunt force traumas. Blood tests were negative for carbon monoxide, alcohol and drugs.

The pilot held a private pilot certificate with ratings for airplane single-engine land, airplane multiengine land and instrument airplane. His most recent FAA third-class medical certificate had been issued on Aug. 2, 2013. At that time, he reported a total flight experience of 1,600 hr. The pilot obtained his instrument rating in 2002 and his multiengine rating in 2007.

Investigators did not recover the pilot’s logbook. Review of an insurance application, dated July 30, 2012, revealed that the pilot reported 1,550 total hours, of which 800 hr. were in multiengine airplanes and 30 of those hours in the same make and model as the accident airplane. The application did not list instrument experience.

The review of a flight instructor’s logbook revealed that he had provided the pilot a biannual flight review on June 30, 2012; however, no record of an instrument proficiency check or instrument experience was located.

Finally, the investigators turned to the pilot’s flight planning and the weather. At 1611, the pilot telephoned flight service and filed an IFR flight plan for the flight. After filing the flight plan, the flight service specialist asked if he could check any weather for the pilot and the pilot replied no, that the weather “looked good.” At that time, the recorded weather at CRG included visibility 2 mi. in mist and overcast ceiling 400 ft..

The recorded weather at CRG at 1833 was: wind, 060 deg. at 4 kt.; visibility, 2.5 mi. in mist; overcast ceiling at 200 ft.; temperature, 18C; dew point 17C; altimeter, 30.20 in. Hg.

In the End

Although the tower controller’s issuance of nonstandard missed approach instructions without specifying an altitude might have added to the pilot’s workload, radar data show an initial turn consistent with the instructions and an associated climb indicating that the nonstandard instructions were not a factor in the accident.

The Safety Board said, “Given the night instrument meteorological conditions with restricted visibility and the sustained left turn and climb, it is likely the pilot experienced spatial disorientation. The investigation could not determine the pilot’s overall and recent experience in actual IMC; however, his inability to align the airplane with both the final approach fix’s lateral and vertical constraints is consistent with a lack of instrument proficiency.”

Spatial disorientation claims far too many airmen and their passengers. Here in Cause & Circumstance, we’ve reviewed reports of airliners, business jets and turboprops, and all manner of smaller machines that have descended uncontrolled to the ground because their pilots became disoriented.

While airline and business aviation training centers are at work enhancing their simulators and training syllabuses to help crews avoid spatial disorientation, or to recover from an upset, the pilots of most smaller general aviation aircraft are on their own to assure that they get and maintain the skills needed for proficient, comfortable instrument flight. It’s really a matter of life or death. BCA

This article appears in the October issue of Business & Commercial Aviation with the title "Disorientation Deja Vu."