We Help You Pass
Our free online study guide really works. You can study for your FAA private pilot ground school exam right now. For more info about the 4VFR.COM project, click here. You can find a daily update log here.

Live ATC Audio Streams
Tune into live air traffic control frequencies from North America. This feature requires Real player. Start listening to ATC now!

Reference Library
Our glossary lists and databases have grown quickly. I am working to create an on-line reference library to tie together all the loose ends. You can check out what is currently available in the library

FAA Practice Exam - New!
Introducing our newly enhanced practice exam. Now with figures!. Take a test a day for a week, and I guarantee you will do better on your exam.

Get Started Now

Show your support for 4VFR.COM - Link us. Bookmark us. Tell your mother about us. Press CTRL-D to bookmark this site now!. Check out one of our proposed T-Shirt Designs.

Exams Taken 992,072

Feature Article: Engine Failure Accidents

  • 22% of all accidents
  • 4% only partial failure
  • 30% undetermined reasons

Probable causes
  • Carburetor icing
  • 30% of which occurred during T/O or cruise
  • Pilot corrected cause after crash
  • Mysterious event

Engine Failure Statistics

  • 28 percent of engine failures are for unknown reasons where fuel, air or spark are responsible.
  • 2 percent are internal failures sometimes detectable by oil analysis
  • 2 percent are oil problems related to pumps, filters or lines.
  • 3 percent are induction problems related to hoses, clogging or alternate air doors
  • 5 percent are spark problems related to spark plugs, magnetos, wiring harness, or switches.
  • 6 percent are related to poor maintenance
  • 7 percent are due to cylinder/valve problems due to improper leaning
  • 8 percent are fuel related problems of selectors, carburetors, primers, or pumps.
  • 8 percent are carburetor ice related where application of heat occurs too late to be effective.
  • 11 percent are from contaminated fuel
  • 20 percent are from starvation, exhaustion or other failure to deliver problems.
  • Pilots are in the main most likely to be responsible for an engine failure.

Engine component failure accidents:
    1.Lycoming engines fail twice as often as Continental
    2. Engine size has no effect of frequency of failure
    3. 43% mechanical
    4. 1 in 5 accidents during cruise. Cruise flight accidents due to weather and fuel.
    5. 1 in 3 engine/prop
    6. 1 in 4 due to gear or brakes
    7. 1 in 6 due to fuel
  • Fuel exhaustion is most common factor.
    8. 18% of engine type accidents caused by engine failure unrelated to pilot induced failure.
    9. 1.296 per 100,000 flight hours
    10. Pneumatic system is 1:40,000 IFR flight plans filed.
    11. 25% of all accident occur after partial or total loss of engine power.
    12. When planes switched from piston-powered engines to jet engines in the 1960s, they immediately became more reliable by a factor of 10.


Last Modified May 27, ©2026 TAGE.COM

Related Links
Featured Articles
  • Teaching Memory
  • Before Takeoff Check
  • Power-off Stalls
  • ATC Problems in Decending Order
  • Fuel/Electric accidents
  • About Students
  • Teaching Memory
  • Abnormal Situation Training
  • Crosswind Takeoff
  • Airworthiness Directive
  • Runway Incursions
  • Private Pilot Sharing of Expenses
  • Wind and Groundspeed
  • Landings on Final
  • The Plotter

    More Flight Training Articles...

  • Student Kudos
    "Thank you for your free exam prep site. As a self-study student pilot, I greatly appreciate such help. On Sunday, Dec 2, I successfully completed the Private Pilot Knowledge exam with a score of 60/60 for 100%. You site contributed to this success. "
    - Herb Martin