Those VFR Weather Minimums

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Pilots’ world is full of acronyms and sayings to help memorizing critical facts, procedures and flows. Some of them are neutral and even make sense in the usage context like IMSAFE self check:

Illness, Medication, Stress, Alcohol, Fatigue, External Pressure

Some lack much sense, like pre landing check list:

Brakes off
Undercarriage (down and locked)
Mixture rich

Propeller pitch
Fuel pump on and sufficient
Instruments (D.I, altimeter)
Switches (carb heat, landing light, etc.)
Harnesses and hatches secure

Some are just funny, like TOMATO FLAMES (required VFR equipment list):

           Tachometer for each engine
           Oil Temperature for each air-cooled engine
           Magnetic Compass with Deviation Card
           Airspeed Indicator
           Temperature gauge 
           Oil Pressure gauge 
           Fuel gauge for each fuel tank
           Landing gear position indicator
           Altimeter
           Manifold pressure gauge
           ELT, if required
           Safety belts and harnesses

While preparing for the FAA written exam I found it’s difficult to remember VFR weather minimums. See yourself, this table is not memory friendly http://www.faa.gov/ATPubs/AIM/Chap3/aim0301.html#tbB190ROBE. So I decided to come up with the way to memorize all those numbers by classifying and creating a smaller table.

First, we have three levels of visibility and three levels of clouds clearance.

Visibility (odd numbers):

-         Low: 1 mile

-         Medium: 3 miles (Low + 2)

-         High: 5 miles (Medium + 2)

Clouds clearance:

-         Low: Clear of Clouds

-         Medium: 500, 1000, 2000 (progression: 500, 500*2, 500*2*2)

-         High: 1000, 1000, 1 mile (three ones)

There are total 5 different combinations of these requirements:

Essentially, we have four levels of weather minimums with two variations of Relaxed. To avoid confusion with “Relaxed” levels think that it’s important to see the traffic and ground in Bravo airspace (medium visibility over the low cloud clearance) as it is more congested than Golf (low visibility and medium cloud clearance).

Although it does not look as simple as GUMPS after making this table I remembered those numbers well. I guess working on your own mnemonic system (even a lousy one) is the best way to memorize things. J