IFR Alternate Airports (1-2-3 Rule)

When filing an IFR flight plan, you must include an alternate destination airport when the weather forecast at your original destination predicts conditions below those specified in CFR 91.169. To help remember those conditions, you can use the 1-2-3 rule.

1 - During the time 1 hour before to 1 hour after the estimated arrival time
2 - Ceiling less than 2,000 feet
3 - Visibility less than 3 miles

If the above conditions exist, an alternate airport must be filed.

The alternate airport also has requirements that it must meet.

• If the airport has an instrument approach published, the weather must be forecast to be (at the ETA) better than the alternate airport minima specified in that approach or the following standard conditions:


• Precision Approach: 600ft ceiling and 2SM visibility


• Non-Precision Approach: 800ft ceiling and 2SM visibility

Instrument/Equipment for IFR Operations

Those required for VFR day and night flight plus:

G - Generator or alternator
R - Radios
A - Altimeter
B - Ball (slip/skid indicator)
C - Clock (seconds)
A - Attitude Indicator
R - Rate of turn (turn coordinator)
D - Directional Gyro

Aircraft Airworthiness

These are the required checks for an aircraft to be legal to fly...

A - Annual
V - VOR Check (for IFR)
1 - 100hr (If used for hire)
A - Altimeter (Altimeter/Pitot Static System)
T - Transponder
E - ELT Battery

These are the things that must be present on board for the aircraft to be legal to fly...

A - Airworthiness Certificate
R - Registration
R - Radio Operators License (Mainly for International flights)
O - Operators Manual (POH)
W - Weight and Balance

Systems Requirements for Day/Night VFR

For Day VFR…

M - Magnetic Compass
A - Airspeed Indicator
T - Tachometer
F - Fuel Quantity Gauges
O - Oil Pressure Guage
O - Oil Temperature Guage
L - Landing Gear Position Indicator (If applicable)
M - Manifold Pressure Gauge
A - Altimeter
T - Temperature Guage (Liquid Cooled Engines)

And for Night VFR…

F - Fuses
L - Landing Light (For hire only)
A - Anticollision Light
P - Position Lights
S - Source of Electrical Power

Instrument Checks

The five T’s are a quick instrument checklist that’s used when setting up for an instrument approach.

1. Turn
2. Time
3. Twist
4. Throttle
5. Talk

There's also the WIRE checklist for other quick reminders

W - Weather (ATIS/ASOS etc)
I - Instruments (VOR OBS set, DG aligned etc)
R - Radios (ILS/LOC/VOR/DME/ADF/COMM)
E - Everything else (Flaps, Gear, Engine power etc)