As if 7 strikes were not enough . . .
As I have studied aircraft accidents, a few have really gotten under my skin. The Cessna 525 crash I wrote about last week in Get-Out-Of-Here-Itis is one of those. For that reason, I’m going to break safety investigation rule/tradition/law by speculating about what happened in the 3 minutes from takeoff to impact. Reasonable, although unsupported, assumptions have to be made for this to work. I’m willing to accept the sketchy part here because
where I’ll end up is plausible and instructive. Assumptions:
1) Initial route was SQUAM J49 ALB or Direct ALB. SQUAM is 265 from Augusta State Airport (AUG) and ALB VOR is 261. Both fit the “about 260 degrees” heading reported for the Cessna as it departed AUG. See chart from SkyVector.com
2) Radio frequencies and navigation aids (NavAids) were not preprogrammed into the appropriate equipment.
3) Radio and navigation controls were located on the lower console where they could be easily reached from both seats in the cockpit, if multi-piloted.
After taxiing just about all over the airport, including across the grass and through a ditch, our bored-with-Maine pilot applies takeoff power and roars down Runway 17 in near zero visibility conditions. Caution! Physiology discussion ahead. Think back . . . way back . . . do you remember those lessons on how the human body is not designed for flight? How about that little piece of your vestibular system called the otolith organ? Yes, you remember. It tells you if your nose is up, down, or level, unless you experience a strong accelerating force propelling you forward. Then the otolith is fooled into thinking you are looking up or leaning back.
She reports passing through 1000 feet on her way up to 10,000 as she turns the aircraft from the runway heading of 171 to about 260. This means she switched the radio from Tower to ATC while in the turn. After rolling out on a heading of about 260, she dials ALB into the VOR or Flight Director so she can join the airway.
Caution! More physiology. While the plane is in a right turn, she turns her head down and right to tune the radio located on the lower center console. She turns back to the front to make her call to ATC. The plane remains in a turn until she rolls out on a heading of about 260. Then she looks down and right again to tune in ALB. Are you confused, yet? Think about her semicircular canal signals. They experienced a right turn (plane), right (head for radio), left (head), left (plane), right (head for VOR), left (head). Remember, her otolith is already out of sorts from the takeoff acceleration in near zero visibility. It then gets inputs of up (plane on takeoff), down (head for radio), up (head), down (head for VOR), up (head).
Thirty-eight seconds after passing 1000 feet (The time it took to rollout on heading and dial the VOR.), she declares an emergency at 3500 feet and 267 knots due to attitude indicator failure. If you’re trying to do the math in your head, that’s more than 2000 feet per minute of climb. Thirteen seconds later, radar indicates the Cessna is in a steep descending left turn.
Classic spatial disorientation death spiral. Think back, again. If an attitude or rate of turn is held long enough, our vestibular system can be fooled into thinking something other than straight and level is straight and level. Assuming a standard rate turn, our pilot turned for about 30 seconds in 2000 FPM climb and turned her head down and right in the cockpit to tune a radio. What was her inner ear supposed to tell her brain when she looked back up and rolled out on heading? Then she turned her head down and right again . . .
I won’t rehash the 7 seven strikes that should have kept this pilot on the ground, but I will repeat this: partial panel practice is critical. Aside from crosschecking your attitude indicator, it can help the higher functioning parts of your brain overpower a confused vestibular system and make you a better instrument pilot. Get out there with a friend for safety, put on a hood, and cover up your attitude gyro. It’s an easy addition to a VFR flight to spend 10 minutes each doing basic instrument maneuvers.
How do you prepare for a failed attitude indicator emergency?
Chart and route graphic obtained from SkyVector.com
Vestibular system graphics from
US Army Training Circular 3-04.93
Related:
Weird Winds or Something More Serious?
From Air Facts Journal