OFFICE OF THE PRESIDENT

December 10, 1999

Dear Dr. Ebbs:

This is a follow-up to my November 1, 1999 teleconference with Mr. Jack Haun, Mr. Lyle Sunderland, and Mr. Grant Brophy, concerning my discovery of an apparent design flaw with the integral fuel tank equipped aircraft. I contacted the individuals on your staff, after learning of the recurrent problems with engine hesitations and power interruptions that you have experienced, and the potential threat to instructors, students and staff flying your fleet of 53 172Rs, 3 172RGs, and 38 172S.

The attached documents, including digital pictures taken by the local FAA, provide evidence of the testing that I conducted, in the presence of the FAA, demonstrating that water is being trapped in the integral wing tank, never making it to any of the 13 sumps.

This documentation was forwarded by the local FAA office to Mr. Jeff Gorney at AAI-200, Washington, DC and Mr. Jeff Janusz at ACE-116, Wichita, Kansas.

I believe the "corrective action" that you propose in response to your situation will only mask the true problem, and increase the likelihood of a potential threat.

Increasing your engines’ horsepower will provide 100 lbs. more useful load, allowing the plane to carry an observer without de-fueling. However, I recognize that it will also allow you to top off the tanks at night, which may decrease the frequency of power interruptions caused by overnight condensate forming in the tanks that never makes it to any of the aircraft’s 13 sumps.

No increase in horsepower, or topping off of the tanks will address the source of the problem. The cause is the integral wing tank and the design that allows water to be trapped never making it to any of the 13 sumps.

I have tried repeatedly to convince Cessna of the seriousness of this problem. Not only have officials of Cessna failed to acknowledge the problem, but they have also provided explanations that are contradictory and irresponsible. The FAA is all too aware of the impact of this finding, however I hold out little hope that officials in Washington will take expedient action.

As I continue to pursue this matter with other Cessna owners and interested parties, I sincerely hope you will carefully review the documentation with the members of your staff. I am available to discuss this further with you or others, and provide additional details.

Dr. Ebbs, as a pilot of 33 years, and a Cessna owner, my love of aviation is exceeded only by my sense of what is right. I am sure you share these feelings, and I look forward to further contact with you concerning this matter. Please feel free to contact me at.

Sincerely,

Robert E. Scovill Jr.