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AIM 

Section 91.167(b). For example, there are 3 high altitude airports in the U.S. with approved instrument approach 

procedures where all of the MDAs are greater than 2,000 feet and/or the landing visibility minimums are greater 

than 3 miles (Bishop, California; South Lake Tahoe, California; and Aspen

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Pitkin Co./Sardy Field, Colorado). 

In the case of these airports, it is possible for a pilot to elect, on the basis of forecasts, not to carry sufficient fuel 

to get to an alternate when the ceiling and/or visibility is actually lower than that necessary to complete the 

approach. 

2. 

A small number of other airports in mountainous terrain have MDAs which are slightly (100 to 300 feet) 

below 2,000 feet AGL. In situations where there is an option as to whether to plan for an alternate, pilots should 

bear in mind that just a slight worsening of the weather conditions from those forecast could place the airport 

below the published IFR landing minimums. 

3. 

An IFR flight to an airport which requires special equipment; i.e., DME, glide slope, etc., in order to make 

the available approaches to the lowest minimums. Pilots should be aware that all other minimums on the 

approach charts may require weather conditions better than those specified in 14 CFR Section 91.167(b). An 

inflight equipment malfunction could result in the inability to comply with the published approach procedures 

or, again, in the position of having the airport below the published IFR landing minimums for all remaining 

instrument approach alternatives. 

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11.  Flights Outside U.S. Territorial Airspace 

a. 

When conducting flights, particularly extended flights, outside the U.S. and its territories, full account 

should be taken of the amount and quality of air navigation services available in the airspace to be traversed. 

Every effort should be made to secure information on the location and range of navigational aids, availability 

of communications and meteorological services, the provision of air traffic services, including alerting service, 

and the existence of search and rescue services. 

b. 

Pilots should remember that there is a need to continuously guard the VHF emergency frequency 121.5 

MHz when on long over-water flights, except when communications on other VHF channels, equipment 

limitations, or cockpit duties prevent simultaneous guarding of two channels. Guarding of 121.5 MHz is 

particularly critical when operating in proximity to Flight Information Region (FIR) boundaries, for example, 

operations on Route R220 between Anchorage and Tokyo, since it serves to facilitate communications with 

regard to aircraft which may experience in-flight emergencies, communications, or navigational difficulties. 

REFERENCE

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ICAO Annex 10, Vol II, Paras 5.2.2.1.1.1 and 5.2.2.1.1.2. 

c. 

The filing of a flight plan, always good practice, takes on added significance for extended flights outside 

U.S. airspace and is, in fact, usually required by the laws of the countries being visited or overflown. It is also 

particularly important in the case of such flights that pilots leave a complete itinerary and schedule of the flight 

with someone directly concerned and keep that person advised of the flight’s progress. If serious doubt arises 

as to the safety of the flight, that person should first contact the appropriate FSS. Round Robin Flight Plans to 

Canada and Mexico are not accepted. 

d. 

All pilots should review the foreign airspace and entry restrictions published in the appropriate 

Aeronautical Information Publication (AIP) during the flight planning process. Foreign airspace penetration 

without official authorization can involve both danger to the aircraft and the imposition of severe penalties and 

inconvenience to both passengers and crew. A flight plan on file with ATC authorities does not necessarily 

constitute the prior permission required by certain other authorities. The possibility of fatal consequences cannot 

be ignored in some areas of the world. 

e. 

Current NOTAMs for foreign locations must also be reviewed. International Notices regarding specific 

countries may be obtained through the Federal NOTAM System (FNS) NOTAM Search External Links or the 

Air Traffic Plans and Publications website. For additional flight information at foreign locations, pilots should 

also review the FAA’s Prohibitions, Restrictions, and Notices website at 

https://www.faa.gov/air_traffic/publications/us_restrictions/. 

Preflight 

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