Air Facts IFR Challenge

At the APINE intersection along V573, 3,000' is BELOW the published minimum enroute altitude (MEA) of 5,500' (note the minimum crossing altitude at MARKI when flying southwest is 5,500'). Given that 3,000' is below the MEA, the navigation signals from HOT may be unreliable.

Pilots, often in haste, select 2,700 at MARKI which is the published minimum obstruction clearance altitude (MOCA) for this route segment; however, by definition, the MOCA  does meet obstancle clearance requriemtns AND assures acceptable navigational signal coveraerge within 22nm of a VOR. Given the MARKI interection is only 21nm from the HOT VOR, navigation signal coverage will be satisfactory.

The FAA issues information on the status of GPS through NOTAMs. Operators may find information on GPS satellite outages, GPS testing, and GPS anomalies by specifically searching for GPS NOTAMS prior to flight.

The terms UNRELIABLE (UNREL), MAY NOT BE AVAILABLE (AVBL), and NOT AVAILABLE (AVBL) when describing the status of GPS. UNREL indicates the expected level of service of the GPS and/or WAAS may not be available. Pilots must then determine the adequacy of the signal for desired use.

This question is difficult in that often pilots assume that use of the term "unreliable" indicates that GPS shouldn't be used, but it only indicates the possibility of unreliable service. It's ultimately up to the pilot to determine whether GPS service is available for primary navigation. It is certianly prudent to have additional navigation equipment for the intended route with the presence of this GPS NOTAM.

This clearance only allows you to follow the lateral navigation guidance on the arrival and does not authorize you to descend to any altitudes published at any of the waypoints. Several waypoints include a crossing altitude with the word “EXPECT”, which is only for planning purposes and still requires a specific ATC clearance to these altitudes at ATC’s discretion.

Pilots will often select the answer choice that they are cleared to descend to the specified altitudes on the arrival given the arrival clearance; however, the instructions “Descend Via…” would have to be included in order for this to be the case.

Most pilots understand that the jet stream shifts north during the summer; however, the jet stream is stronger in the winter because there is a greater temperature difference between the poles and the equator.

Pilots who miss this question will often select that the jet stream is stronger in the summer perhaps becuase the US typically sees more active weather patterns during this season, but it is, in fact, weaker due to the difference in temperature between the tropics and North America being less extreme in the summer.

The term “CRUISE” may be used instead of “MAINTAIN” to assign a block of airspace to a pilot from the minimum IFR altitude up to and including the altitude specified in the cruise clearance. The pilot may level off at any intermediate altitude within this block of airspace. Climb/descent within the block can be made at the discretion of the pilot. However, once the pilot starts descent and verbally reports leaving an altitude in the block, the pilot may not return to that altitude without additional ATC clearance.

A cruise clearance is often used in non-radar environments or lower-traffic areas to allow pilots greater autonomy in their altitude selection.

This question is frequently missed because a) cruise clearances are not used often and b) pilots often assume (for good reason) that it is a requirement to report when leaving a particular altitude; however, it is optional for the pilot to report leaving an altitude at which point the altitude is surrendered. AIM 4-4-3 (d)