Definitionen av standard minsta sikt för avgång finns i CFR §91.175 Start och landning enligt IFR.
f) Civil airport takeoff minimums. This paragraph applies to persons operating an aircraft under part 121, 125, 129, or 135 of this chapter.
(1) Unless otherwise authorized by the FAA, no pilot may takeoff from a civil airport under IFR unless the weather conditions at time of takeoff are at or above the weather minimums for IFR takeoff prescribed for that airport under part 97 of this chapter.
(2) If takeoff weather minimums are not prescribed under part 97 of this chapter for a particular airport, the following weather minimums apply to takeoffs under IFR:
(i) For aircraft, other than helicopters, having two engines or less—1 statute mile visibility.
(ii) For aircraft having more than two engines— 1⁄2 statute mile visibility.
(iii) For helicopters— 1⁄2 statute mile visibility.
AIM 5-2-8 bekräftar din intuition om att klättra gradienter.
b. What criteria is used to provide obstruction clearance during departure?
Unless specified otherwise, required obstacle clearance for all departures, including diverse, is based on the pilot crossing the departure end of the runway at least 35 feet above the departure end of runway elevation, climbing to 400 feet above the departure end of runway elevation before making the initial turn, and maintaining a minimum climb gradient of 200 feet per nautical mile (FPNM), unless required to level off by a crossing restriction, until the minimum IFR altitude. A greater climb gradient may be specified in the DP to clear obstacles or to achieve an ATC crossing restriction.
Observera att siktminimum inte gäller för del 91-flygplan. Observera också att miniminivåerna för miniminivåer inte har ett minimitak medan publicerade avgångsprocedurer nästan alltid har ett minimumstak eller en stigningsgrad - och har ofta båda.