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Is there whiskey in your compass? 5 things your CFI isn't telling you

The nickname "whiskey compass" has been around since the early days of flying. The liquid that the compass card moves around in needs to be non-freezing. So before compasses held kerosene in them they carried alcohol, hence the name. Pilots often joke that the whiskey is put there just in case you have to ditch in the back country and wait long hours for a rescue. In reality, the "whiskey" or any alcoholic fluid you'll find in modern compasses, degrades the mechanism causing some unfortunate errors like the magnetic dip you may be familiar with, giving us the memory aid UNOS (undershoot North, overshoot South).


Many flight students are familiar with magnetic dip, but may not be aware that their difficulty in holding a proper heading while referencing instruments is caused in part by whiskey in the compass. Here are some other things your CFI isn't telling you about flying: Sláinte!


ADS-B Was Implemented to Counter Pilots Removing their Transponders

ADS-B transmitters allow an aircraft's position as determined from GPS satellites to be communicated to Air Traffic Control and other aircraft. This is to overcome the limitations of the old radar-based surveillance system. As any student pilot knows, aircraft are invisible to radar when their transponders are removed, and the FAA, DEA, and CIA were fed up with the number of pilots flying incognito over US airspace. Hence, ADS-B was mandated for most flights.



Private Pilots are Prohibited from Receiving any form of Compensation for Carrying Passengers, Monetary or Otherwise

Many of us know that Private Pilots must pay at least their pro rata share of operating expenses when carrying passengers. Not as well known are several FAA interpretations designating as "non-monetary compensation" certain things such as a "warm smile from a grateful passenger", or "fond memories of a day well spent with friends."


Viewing Objects at Nighttime is Aided by Off-center Viewing, Because Fixating Directly on Objects Causes them to Move Around

Students are taught not to look directly at objects at night but to view them off-center. This is due to a phenomenon called autokinesis, which causes objects to bounce around the sky when looked at directly by other pilots. One of the courtesies you can show other pilots at night is to avoid staring directly at their aircraft so as not to affect flight paths.


There is No Class F Airspace in the United States, but the FAA is Working to Implement Introducing it Over the Next 10 Years

While Class F is not currently designated in US airspace, it will be phased in throughout the 2020s. Class F airspace will only be accessible by flying outbound on a Victor Airway known as "The Highway" to the Sea of A Thousand Islands. Time will freeze as soon as you arrive in Class F and children will never grow old.


If you enjoyed these 5 highly factual pieces of information about flight training, please continue your training by signing up for Online Ground School today! Have a great April!


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