ADX Navigation and Route Planning 3 — Questions and Answers
Question 1: What is the primary difference between a Victor airway and a Jet Route (J-Route) in the US National Airspace System?
- Victor airways are from 1,200 ft AGL up to but not including 18,000 ft MSL; Jet Routes are FL180 to FL450 (Correct answer)
- Victor airways are only for VFR; Jet Routes are only for IFR
- Victor airways are for heavy aircraft; Jet Routes are for light aircraft
- Victor airways operate east-west; Jet Routes operate north-south
Correct answer: Victor airways are from 1,200 ft AGL up to but not including 18,000 ft MSL; Jet Routes are FL180 to FL450
Victor airways exist from 1,200 ft AGL up to but not including 18,000 ft MSL, while Jet Routes (J-routes) cover FL180 to FL450 within Class A airspace.
Question 2: A dispatcher is planning a flight that requires crossing the ADIZ (Air Defense Identification Zone). What filing requirement is most important?
- A Defense VFR (DVFR) or IFR flight plan must be filed and a position report made before entering the ADIZ (Correct answer)
- No special filing is required if the aircraft stays above 10,000 feet
- Only military aircraft must file special ADIZ plans
- The pilot must contact NORAD directly 72 hours in advance
Correct answer: A Defense VFR (DVFR) or IFR flight plan must be filed and a position report made before entering the ADIZ
Pilots and dispatchers must file a DVFR or IFR flight plan before entering the ADIZ, and report position to ATC to avoid interception.
Question 3: When selecting an alternate airport on a domestic flight plan, what weather minimum must the forecast show at the alternate during the ETA ±1 hour window (standard alternate minimums)?
- Ceiling 600 ft and visibility 2 SM for precision approach, or ceiling 800 ft and visibility 2 SM for non-precision approach (Correct answer)
- Ceiling 500 ft and visibility 1 SM for any approach
- Ceiling 1,000 ft and visibility 3 SM regardless of approach type
- Ceiling 300 ft and visibility ¾ SM for CAT II/III approaches
Correct answer: Ceiling 600 ft and visibility 2 SM for precision approach, or ceiling 800 ft and visibility 2 SM for non-precision approach
Standard alternate minimums are 600-2 for precision approaches and 800-2 for non-precision approaches during the ETA ±1 hour window.
Question 4: What does 'MEA GAP' indicate on an IFR enroute chart?
- A segment where VOR navigation signal reception is not guaranteed at the MEA, requiring a higher altitude for continuous reception (Correct answer)
- A break in the airway where no altitude is published
- An area where terrain clearance is less than standard
- A gap in radar coverage along the route
Correct answer: A segment where VOR navigation signal reception is not guaranteed at the MEA, requiring a higher altitude for continuous reception
An MEA GAP indicates that on that segment the navigation signal may not be received at the MEA, and pilots/dispatchers must be aware of potential navigation unreliability.
Question 5: How does a dispatcher determine the appropriate cruise altitude for a long-haul flight considering step climbs?
- By analyzing the aircraft weight at various points, optimum altitude charts, and fuel burn tradeoffs as fuel is consumed and weight decreases (Correct answer)
- By always selecting the highest certificated altitude at departure
- By selecting the MEA throughout the entire route
- By choosing the altitude ATC assigns at departure and maintaining it
Correct answer: By analyzing the aircraft weight at various points, optimum altitude charts, and fuel burn tradeoffs as fuel is consumed and weight decreases
Step climbs exploit the aircraft's improving optimum altitude as fuel burns off, and dispatchers plan these by analyzing weight, altitude performance tables, and fuel savings.
Question 6: What is a 'random route' or 'random RNAV route,' and when would a dispatcher use it?
- A direct or non-standard route filed between waypoints not following published airways, used to reduce track miles and fuel burn (Correct answer)
- A route generated randomly by ATC computer systems for traffic management
- An emergency route used only when airways are unusable due to NOTAMs
- A route reserved for unscheduled charter operations
Correct answer: A direct or non-standard route filed between waypoints not following published airways, used to reduce track miles and fuel burn
Random RNAV routes allow dispatchers to file direct or non-airway paths between fixes, reducing distance and fuel when airspace and traffic allow.
Question 7: In route planning, what is the purpose of a Minimum Crossing Altitude (MCA)?
- It specifies the lowest altitude at which an aircraft must cross a certain fix when proceeding on a higher MEA segment ahead (Correct answer)
- It defines the maximum altitude at which an aircraft may cross an intersection
- It is the minimum altitude for crossing an international boundary
- It is an ATC-assigned altitude for crossing active MOAs
Correct answer: It specifies the lowest altitude at which an aircraft must cross a certain fix when proceeding on a higher MEA segment ahead
An MCA ensures the aircraft is at a sufficient altitude before it reaches a fix where the MEA ahead is higher, preventing obstacle or signal coverage issues.
ADX Navigation and Route Planning 3
What is the primary difference between a Victor airway and a Jet Route (J-Route) in the US National Airspace System?