Home       Features       Site Map      Français

Image is not available

btn videos engbtn articles engbtn courses eng

Attitude Indicator

Dear Editor,

I would like to respond to the essay on Kennedy’s fatal spiral dive accident, published in Aviation Safety Letter 4/99. Developing a new attitude indicator that combines a moving horizon and miniature aircraft would make little difference to whether a pilot would be able to recover from a spiral dive. The fact is that, typically, the pilot misinterprets its indication (no matter what the design) and fails to cross-check with other instruments — this is a question of training and proficiency. If the pilot gets more comfort from seeing the little airplane in a banked attitude, he or she can look at the turn co-ordinator.

If the accident was indeed a result of a spiral dive as a result of disorientation, the emphasis of the investigation should be on the human aspects so others can learn how to break the chain of events that led to the tragedy. This means recognizing the pressure to get to a destination, especially when behind schedule. Often we do not want to disappoint our passengers and this self-imposed pressure can push us to fly into adverse conditions; this is known as "get-home itis." We also need to recognize the environment we are getting into, including the weather and the type of aircraft; recognizing our own limits against this backdrop of pressure and environment may be the key to prevent such occurrences. Let’s get the training to enhance our abilities or be prepared to say "no" if conditions exceed them.

James Greenhill
Montreal, Quebec

Thank you Mr. Greenhill. Indeed your comments about self-imposed pressure, environment (night VFR among others), and the pilot’s own abilities are crucially important, and likely responsible, in some part, for that accident. We can learn a lot from your letter alone. However, I do not believe the article by Dr. Roscoe meant to ignore those issues, rather to discuss a very specific instrument and how it could be improved. It’s like "thinking outside the box" and it probably deserves more scrutiny. In fairness to all, here are the main points of Aero Innovation’s response to your letter. - Ed.

Dear Mr. Greenhill,

Your comments on the decision to go flying or not are relevant but do not address the reasons pilots, despite their level of experience, risk calculation, and flight planning, fail to recognize spirals when they occur, and why pilots hold full ailerons in the direction of turn all the way to ground impact (a fact known when flight data recorders (FDR) are present). In the U.S. alone, this happens more than twice a week, sometimes to highly experienced and current pilots.

It is not only reasonable but also a duty to improve poorly engineered instruments if the improvements prevent pilots from inadvertently entering spiral dives and/or ease the recognition of a dive and/or suggest proper recovery procedures. This is more than just a training issue, as all of us eventually meet a level of mental saturation triggering instinctively humane reactions not always in accordance with good airmanship or past (sometimes distant) training. This is what human factors are all about. Thank you for sharing your views with us.

Jean LaRoche
President of Aero Innovation

SmartPilot proudly works with.

aopa logocopa logoeaa logo

sar logo

We would like to acknowledge the financial support of the Government of Canada for this initiative through the Search and Rescue New Initiative Fund (SAR NIF).