Alternate visibility must be at least 1 statute mile and not less than the approach minimum visibility.
Category A helicopter reduced visibility cannot be below ¼ mile or 1,200 feet RVR.
An ILS with an inoperative MALSR is permitted only when the applicable minimum visibility is increased by ¼ mile, if allowed by the Inoperative Components Table.
ARTCC controllers do not use the LIGHT precipitation category; when intensity is unknown, they state “INTENSITY UNKNOWN.”
Pilots may deviate without ATC clearance under emergency authority when weather threatens safety.
A higher-than-standard climb gradient must be provided when obstacles require more than 200 feet per nautical mile.
A tailplane stall can occur without obvious wing-stall symptoms.
Exceeding \(V_{FE}\) with ice contamination can lead to an unrecoverable tailplane stall.
Cold-temperature corrections apply to charted IFR altitudes, but altitudes specifically assigned by ATC must not be corrected.
MSA provides 1,000 feet of obstruction clearance but is not the same as an airway altitude.
MOCA provides navigation signal coverage only within 22 NM of the nearest NAVAID.
MRA identifies the lowest altitude at which an intersection can be identified from an off-course NAVAID.
MCA applies when approaching steep terrain and must be reached before crossing the intersection.
MAA is the highest altitude at which the airway can be flown with adequate navigation signal.
A 45° procedure turn is normally 10 NM, but the outline specifies 5 NM for Category A or helicopters and up to 15 NM for high-performance aircraft.
Minimums are based on 1.3 times stall speed in the landing configuration at maximum certificated gross weight.
If the aircraft exceeds its category speed limit, use the next higher category’s minimums.
RVR values are expressed in hundreds of feet; for example, “24” means 2,400 feet.
A standard TAA “T” structure eliminates the need for a procedure turn when the NoPT indication applies.