This December 2008 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Diamond DA-20C1. Injuries: 1 Fatal. Location: Alamo Lake State Park, Ariz. Aircraft damage: Destroyed.
What reportedly happened: The 18-year-old pilot obtained his private pilot certificate a month before the accident. He earned his certificate in 90 days through a Part 141 professional pilot program. By the accident date, his total flight time was about 94 hours. Total pilot-in-command time was about 52 hours, and his total pilot-in-command time in the accident model of airplane was about 34 hours.
In the school’s “Training Course Outline” booklet, under the “Safety Procedures and Practices” section, the following rule is published: “Spins will only be practiced when an instructor is on board.” The accident pilot’s instructor had provided his student with spin awareness training, including actual spins. This training was repeated on more occasions than listed in the FAA-approved training curriculum.
Pursuant to the flight school’s curriculum, the pilot filed a round robin flight plan for a solo instructional cross-country flight principally intended to further his expertise in navigation. Airwork was not supposed to be performed. After takeoff, he did not open his flight plan, which included a cruising en route altitude of 6,500 feet MSL. However, he climbed to 14,000 feet. At the halfway point he landed and refueled, then departed for the return flight. On the way back he climbed to about 9,400 feet. After flying about 30 minutes, the pilot reversed course and began performing air work between 6,700 and 7,300 feet MSL. Two witnesses in a boat observed the airplane in a spinning descent. One of the witnesses said the airplane completed eight turns before disappearing behind a hill. Radar showed the airplane descending at 6,000 feet per minute before it disappeared from radar.
An examination of the airframe and engine revealed no anomalies that would have precluded normal operation. The reason that the pilot failed to recover from the spin was not determined.
Probable cause: The pilot’s failure to maintain control during the performance of a maneuver and his failure to recover from the subsequent aerodynamic stall and spin.
For more information: NTSB.gov
Forgot to add that the “typical” profile of fatal stall/spin accidents involve pilots who:
1. Hold a private or commercial certificate
2. Are on a daytime, pleasure flight in good weather
3. Have logged fewer than 1,000 hours
4. Are in or near the traffic pattern
5. Are in the process of turning and/or climbing
From this standpoint, a lot of pilots will routinely operate in the danger zone where typical stall/spins are likely to occur for quite a long time in their flying careers. Consequently, we all need to exercise good judgment and maintain good stall/spin awareness skills at all times.
Although I disagree that there were any brilliant aeronautical equations used in the presentation of rates of descent during spins (a stopwatch, a prominent road, an accurate count, and a simple rate calculation were all that were needed), I do agree that teaching good aeronautical decision making to avoid unsafe conditions is a critical (and unfortunately, sometimes overlooked) aspect of flight training.
Thanks for the real numbers Rich, I stand corrected – you are after all the recognized “Spin Master”. I’d love to take one of your classes sometime in the near future, time and money allowing.
I think B. McDonald stated the primary cause of the accident correctly. This should remind us Flight Instructors that we have a responsibility to teach good aeronautical decision making too and to recognize unsafe attitudes.
Great! All you engineers so well versed in the aerodynamics of spinning an airplane have totally impressed us all! Now think about these two numbers for a short moment. 52(hrs)18(yrs). Suppose this might some how fit into your brilliant aeronautical equations?
Airplanes in spins do so at relatively “low and constant” airspeeds, typically on the order of 60 mph or so in a vertical descent.
60 mph times 5280 ft/mile divided by 60 minutes/hour = 5,280 fpm.
It is not at all uncommon for airplanes in spins to have descent rates between 4,000 fpm and 8,000 fpm. While timing 3-turn spins in six different airplanes, I found the rates of descent to vary from 4,300 fpm in the Piper Tomahawk to 5,700 fpm in the T-34.
Bottom line: a 6,000 fpm descent would certainly be consistent with a stall/spin.
I agree with. R Miller, the aircraft was in a spiral not a spin.
I think you’re correct. I don’t believe that the plane would be descending that fast in a spin.
If he was decending at 6,000 feet per minute, it was a spiral, not a “stall and spin”.