Chapter 3

CHAPTER 3
EN ROUTE

MEA – Minimum En route Altitude; the lowest published altitude between radio fixes which ensures acceptable navigational signal coverage and meets obstacle clearance requirements.

MOCA – Minimum Obstacle Clearance Altitude; the lowest published altitude between radio fixes on VOR airways, off-airway routes, or route segments which meet obstacle clearance requirements. It also ensures acceptable navigational signal coverage only within 25 statute (22 nautical) miles of a VOR.

MCA – Minimum Crossing Altitude; the lowest altitude at certain fixes at which aircraft must cross when proceeding in the direction of a higher MEA.

MRA – Minimum Reception Altitude; the lowest altitude at which an intersection can be determined.

MAA – Maximum Authorized Altitude; the maximum altitude usable for a route segment that ensures signal reception without interference from another signal on the same frequency.

OROCA – Off-Route Obstruction Clearance Altitude; this provides obstruction clearance with a 1,000-foot buffer in non mountainous terrain areas and a 2,000-foot buffer is designated mountainous area within the United States. This altitude might not provide signal overage from ground-based navigational aids, Air Traffic Control radar, or communications coverage.

2. If no applicable minimum altitude is prescribed (no MEA or MOCA), what minimum altitudes apply for IFR operations? (14 CFR §91.177)

Minimum altitudes are:
a. Mountainous terrain – at least 2,000 feet above the highest obstacle within a horizontal distance of 4 NM from the course to be flown.
b. Other than mountainous terrain – at least 1,000 feet above the highest obstacle within horizontal distance of 4 NM from the course to be flown.

3. What cruising altitudes shall be maintained while operating under IFR in controlled airspace (Class A, B, C, D, or E)? In uncontrolled airspace (Class G)? (14 CFR §91.179)

IFR flights within controlled airspace (Class A, B, C, D, or E) shall maintain the altitude or flight level assigned by ATC. In uncontrolled airspace (Class G), altitude is selected based magnetic course flown:

Below 18,000 feet MSL :
0 to 179° odd thousand MSL
180 to 359° even thousand MSL

18,000 feet up to but not including 29,000 feet MSL :
0 to 179° odd flight levels
180 to 359° even flight levels

4. What procedures are applicable concerning courses to be flown when operating IFR? (14 CFR §91.181)

Except when maneuvering an aircraft to pass well clear of other air traffic, or the maneuvering of an aircraft in VFR conditions to clear the intended flight path (both before and during climb and descent), the following applies:
a. Maintain the centerline of a federal airway
b. Maintain a direct route between navigational aids or fixes defining the route.

5. On a direct flight not flown on radials or courses of established airways or routes, what points serve as compulsory reporting points? (AIM 5-3-2)

Along direct routes, reports are required of all IFR flights over each point used to define the route of flight.

B. En route Procedures

1. What reports should be made to ATC at all times without a specific request? (AIM 5-3-3)

The pilot must report:
a. When vacating any previously assigned altitude or flight level for a newly assigned altitude or flight level.
b. When an altitude change will be made if operating on a clearance specifying VFR-On-Top.
c. When unable to climb / descend at a rate of at least 500 feet per minute.
d. When approach has been missed (request clearance for specific action; i.e., to alternate airport, another approach, etc.).
e. Change in the average true speed (at cruising altitude) when it varies by 5 percent or 10 knots *whichever is greater) from that filed in the flight plan.
f. The time and altitude or flight level upon reaching a holding fix or point that the pilot is cleared to.
g. When leaving any assigned holding fix or point.
h. Any loss, in controlled airspace, of VOR, TACAN, ADF, low-frequency navigation receiver capability, GPS anomalies while using installed IFR-certified GPS/GNSS receivers, complete or partial loss of ILS receiver capability or impairment of air / ground communications capability.
i. Any information relating to the safety of flight.
j. Upon encountering weather or hazardous conditions not forecast.

2. What reporting requirements are required by ATC when not in radar contact? (AIM 5-3-3)

a. When leaving final approach fix inbound on the final (non-precision) approach, or when leaving the outer marker (or fix used in lieu of the outer marker) inbound on final (precision) approach.
b. A corrected estimate at anytime it becomes apparent that an estimate as previously submitted is in error in excess of 3 minutes.

3. What items of information should be included in every position report? (AIM 5-3-2)

a. Identification
b. Position
c. Time
d. Altitude or flight level
e. Type of flight plan (no required in IFR position reports made directly to ARTCCs or approach control)
f. ETA and name of next reporting point
g. The name only of the next succeeding reporting point along the route of flight, and
h. Pertinent remarks

4. Are you required to report un-forecast weather encountered en route? (AIM 5-3-3)

Yes; pilots encountering weather conditions which have not been forecast, or hazardous conditions which have been forecast, are expected to forward a report of such weather to ATC.

5. Explain the terms “maintain” and “cruise” as they pertain to an IFR altitude assignment. (AIM 4-4-3)

Maintain – Self-explanatory: maintain last altitude assigned.
Cruise – Used instead of “maintain” to assign a block of airspace to a pilot, from minimum IFR altitude up to and including the altitude specified in the cruise clearance. The pilot may level off at any intermediate altitude, and climb / descent may be made at the discretion of the pilot. However, once the pilot starts a descent, and verbally reports leaving an altitude in the block, he may not return to the altitude without additional ATC clearance.

6. When will ATC issue a “cruise clearance”?

ATC will usually issue a cruise clearance when:
a. Conditions permit a pilot to proceed to, descend, make an approach and land at an airport that is either within / below / outside controlled airspace and without a standard instrument approach procedure.
b. Conditions such as bad weather or turbulence call for more flexibility for the pilot to avoid weather turbulence.
A cruise clearance can be used in conjunction with an airport clearance limit when it is to allow the pilot the capability to proceed to the destination airport, descend and land in accordance with applicable regulations.

7. Why would a pilot request a VFR-On-Top clearance? (AIM 4-4-7)

A pilot on an IFR flight plan operating in VFR weather conditions, my request VFR-On-Top in lieu of an assigned altitude. For reasons such as turbulence, more favorable winds aloft, etc., the pilot has the flexibility to select an altitude or flight level of his/her choice (subject to any ATC restrictions). Pilots desiring to climb through a cloud, haze, smoke, or other meteorological formation and then either cancel their IFR flight plan or operate VFR-On-Top may request a climb to VFR-On-Top.

8. Is a VFR-On-Top clearance a VFR clearance or an IFR clearance? (AIM 4-4-7)

A VFR-On-Top clearance is an IFR clearance.

9. Which airspace prohibits VFR-On-Top clearances? (AIM 4-4-7)

Class A airspace.

10. What operational procedures must pilots on IFR flight plan adhere to when operating VFR-On-Top? (AIM 4-4-7)

They must:
a. Fly at the appropriate VFR altitude.
b. Comply with the VFR visibility and distance from cloud criteria
c. Comply with instrument flight rules that are applicable to this flight; i.e., minimum IFR altitudes, position reporting, radio communications, course to be flown, adhere to ATC clearance, etc.

11. What is a “clearance limit” and when is it received? (AIM 4-4-3)

A traffic clearance issued prior to departure will normally authorize flight to the airport of intended landing. Under certain conditions, at some locations. A short-range clearance procedure is used, where by a clearance is issued to a fix within or just outside of the terminal area, and pilots are advised of the frequency on which they will receive the long-range clearance direct from the center controller.

12. What information will ATC provide when they request a hold at a fix where the holding pattern is not charted? (AIM 5-3-7)

An ATC clearance requiring an aircraft to hold at a fix where the pattern is not charted will include the following information.
a. Direction of holding from the fix, in reference to the eight cardinal compass points (i.e. N, NE, E, SE, etc.).
b. Holding fix (the fix may be omitted if included at the beginning of the transmission as the clearance limit).
c. Radial, course, bearing, airway or route on which the aircraft is to hold.
d. Leg length in miles if DME or RNAV is to be used (leg length will be specified in minutes on pilot request or if the controller considers it necessary).
e. Direction of turns, if holding pattern ins non standard (left turns), the pilot requests, direction of turns, or the controller considers it necessary to state direction of turns.
f. Time to expect further clearance and any pertinent additional delay information.

13. What are the maximum airspeeds permitted for aircraft while holding? (AIM 5-3-7)

MHA – 6,000 ft 200 KIAS
6,001 – 14,000 ft 230 KIAS
14,001 – and above 265 KIAS
Note: Holding patterns at all altitudes may be restricted to a maximum speed of 175 KIAS. Holding patterns from 6,001 to 14,000 feet may be restricted to a maximum airspeed of 210 KIAS. These non standard patterns will be depicted by an icon.

14. What is a non standard versus a standard holding pattern? (AIM 5-3-7)

In a standard pattern, all turns are to the right. In a non standard pattern, all turns are to the left.

15. Describe the procedure for crosswind correction in a holding pattern. (AIM 5-3-7)

Compensate for wind effect primarily by drift correction on the inbound and outbound legs. When outbound, triple the inbound drift correction to avoid major turning adjustments.

16. What action is appropriate when approaching a holding fix at an airspeed in excess of maximum holding speed? (AIM 5-3-7)

Start a speed reduction when 3 minutes or less from the fix. Speed may be reduced earlier, but ATC must be advised of the change.

17. Why is it important for the pilot to receive an EFC time with initial holding instructions? (AIM 5-3-7)

In case of lost communications, the pilot will know when to depart the holding pattern.

18. Describe the different recommended entry methods for holding. (AIM 5-3-7)

The three types of entry are :
a. Parallel
b. Teardrop
c. Direct

19. What is the leg length for a standard holding pattern? (AIM 5-3-7)

The standard leg length is:
a. 1 minute inbound at or below 14,000 feet MSL, and
b. 1 ½ minutes inbound above 14,000 feet MSL.

20. If assigned a DME hold, what procedures should be utilized? (AIM 5-3-7)

The same entry and holding procedures apply to DME holding, except distances (nautical miles) are used instead of time values. The outbound course of the DME holding pattern is called the outbound leg of the pattern. The length of the outbound leg will be specified by the controller, and the end of this leg is determined by the DME readout.

21. When does the timing for the outbound leg in a holding pattern begin? (AIM 5-3-7)

Outbound leg timing begins over / abeam the fix, whichever occurs later. If the abeam position cannot be determined, start timing when turn to outbound is completed.

C. Oxygen Requirements

1. What regulations apply concerning supplemental oxygen? (14 CFR §91.211)

a. At cabin pressure altitudes above 12,500 MSL up to and including 14,000 MSL, the minimum flight crew must use oxygen after 30 minutes.
b. Above 14,000 MSL up to and including 15,000 MSL, the minimum flight crew must continuously use oxygen.
c. Above 15,000 MSL, each passenger must be provided with supplemental oxygen and the minimum flight crew must continuously use oxygen.

D. Emergencies

1. When may the pilot-in-command of an aircraft deviate from an ATC clearance? (14CFR §91.123)

Except in an emergency, no person may, in an area in which air traffic control is exercised, operate an aircraft contrary to an ATC instruction.

2. If an emergency action required deviation from 14 CFR Part 91, must a pilot submit a written report, and if so, to whom? (14 CFR §91.123)

Each pilot-in-command who is given priority by ATC in an emergency shall, if requested by ATC, submit a detailed report of that emergency within 48 hours to the manager of that ATC facility.

3. Concerning two-way radio communications failure in VFR and IFR conditions, what is the procedure for altitude, route, leaving holding fix, descent for approach, and approach selection? (14 CFR §91.185)

In VFR conditions : If the failure occurs in VFR, or if VFR is encountered after the failure, each pilot shall continue the flight under VFR and land as soon as practicable.

In IFR conditions : If the failure occurs in IFR conditions, or if VFR conditions are not within range, each pilot shall continue the flight according to the following:
a. Route:
Assigned by route assigned in last ATC clearance.
Vectored go direct from point of radio failure to fix, route, airway in vector clearance
Expected by route that ATC has advised may be expected
Filed by the route filed in flight plan

b. Altitude (highest of following altitudes for the route segment being flown):
Minimum minimum altitude for IFR operations
Expected altitude / flight level ATC has advised to expect in a further clearance
Assigned altitude / flight level assigned in the last ATC clearance

c. Leave Clearance limit:
• When the clearance limit is a fix from which the approach begins, commence descent or descent and approach as close as possible to the except-further-clearance time if one has been received; or if one has not been received, as close as possible to the estimated time of arrival as calculated from the filed or amended time en route.
• If the clearance limit is not a fix from which the approach begins, leave the clearance limit at the expect-further-clearance time if one has been received; or if none has been received, upon arrival over the clearance limit, and proceed to a fix from which an approach as close as possible to the estimated time of arrival as calculated from the filed or amended (with ATC) estimated time en route.

4. Assuming two-way communications failure, discuss the recommended procedure to follow concerning altitudes to be flown for the following trip:
The MEA between A and B is 5,000 feet; the MEA between B and C is 5,000 feet the MEA between C and D is 11,000 feet; and MEA between D and E is 7,000 feet. You have been cleared via A, B, C, D, to E. While flying between A and B, your assigned altitude was 6,000 feet and you were told to expect a clearance to 8,000 feet at B. Prior to receiving the higher altitude assignment, you experience two-way communication failure. (AIM 6-4-1)

The correct procedure would be as follows:
a. Maintain 6,000 feet to B, then climb to 8,000 feet (the altitude you were advised to expect).
b. Continue to maintain 8,000 feet, then climb to 11,000 feet at C, or prior to C if necessary to comply with an MCA at C.
c. Upon reaching D, you would descend to 8,000 feet (even though the MEA was 7,000 feet), as 8,000 feet was the highest of the altitude situations stated in the rule.

5. What procedures would you use if all communication and navigation equipment (complete electrical system failure)?

a. First, determine you have complete loss. Determine the cause (check circuit breakers, alternator, ammeter, etc.)
b. Review the preflight weather briefing for the nearest VFR; determine heading and altitude and proceed to VFR conditions, using VFR altitudes.
c. If VFR conditions are not within range of the aircraft, get off the airway and determine the heading to an unpopulated area relatively free of obstructions (terrain or man-made; i.e. rural areas, large lakes, ocean, etc.)
d. Establish a descent on a specific heading to VFR conditions; proceed VFR to the nearest airport.

6. What does Single-Pilot Resource Management refer to? (FAA-S-8081-4)

Single-Pilot Resource Management (SRM) refers to the effective use of all available resources; human resources, hardware, and information. Human resources include all decisions that are working with the pilot who are involved in decisions that are required to operate a flight safely. These groups include, but are not limited to; dispatches, weather briefers, maintenance personnel, and air traffic controllers. SRM is similar to Crew Resource Management (CRM) procedures.

E. Radio Orientation

1. What angular deviation from a VOR course is represented by half-scale deflection of the CDI? (FAA-H-8083-15)

Full Scale Deflection = 10°; therefore, half-scale-deflection = 5°

2. What is reverse sending? (FAA-H-8083-15)

Reverse sensing is when the VOR needle indicates the reverse of normal operation. This occurs when the aircraft is headed toward the station with a FROM indication or when the aircraft is headed away from the station with a TO indication. Also, unless the aircraft has reverse sensing capability and it is in use, when flying in bond on the back course or outbound on the front course of an ILS, reverse sensing will occur.

3. What is the procedure for determining an intercept angle when intercepting a VOR radial? (FAA-H-8083-15)

a. Turn to a heading to parallel the desired course, in the same direction as the course to be flown.
b. Determine the difference between the radial to be intercepted and the radial on which you are located.
c. Double the difference to determine the interception angle, which will not be less than 20° nor greater than 90°.
d. Rotate the OBS to the desired radial or inbound course.
e. Turn to the interception heading.
f. Hold this heading constant until the CDI centers, which indicates the aircraft is on course. (With practice in judging the varying rates of closure with the course centerline, you learn to lead the turn to prevent overshooting the course.)
g. Turn to the MH corresponding to the selected course, and follow tracking procedures inbound or outbound.
Note: Steps a. through c. may be omitted if you turn directly to intercept the course without initially to parallel the desired course.
4. What degree of accuracy can be expected in VOR navigation? (AIM 1-1-3)

VOR navigation is accurate to + / – 1°.

5. How do you find an ADF relative bearing? (FAA-H-8083-15)

A relative bearing is the angular relationship between the aircraft heading and the station, measured clockwise from the nose. The bearing is read directly on the ADF dial, measured clockwise from zero.

6. How do you find an ADF magnetic bearing? (FAA-H-8083-15)

A magnetic bearing is the direction of an imaginary line from the aircraft to the station or the station to the aircraft referenced to magnetic north. To determine, use this formula:
MH + RB = MB
(Magnetic heading + Relative bearing = Magnetic bearing)
If the sum is more than 360, subtract 360 to get the magnetic bearing to the station. The reciprocal of this number is the magnetic bearing from the station.

7. What is ADF homing? (FAA-H-8083-15)

ADF homing is flying the aircraft on any heading required to keep the ADF needle on zero until the station is reached.

8. What is ADF tracking? (FAA-H-8083-15)

ADF tracking is a procedure used to fly a straight geographic flight path inbound to or from an NDB. A heading is established that will maintain the desired track, compensating for wind drift.

9. You are tracking inbound to an NDB, your heading equals your course and the ADF needle is now pointing 10 degrees to the left. What procedure will you use for wind drift correction? (FAA-H-8083-15)

Turn 20° left. When the needle is deflected 20° (deflection = interception angle), track has been intercepted. The aircraft is on track as long as the RB remains the same number of degrees as the wind correction angle (WCA). Lead the interception to avoid overshooting the track. Turn 10°toward the inbound course. You are now inbound with a 10° left correction angle.

F. Unusual Flight Conditions

1. If a thunderstorm is inadvertently encountered, what flight instrument and what procedure should be used to maintain control of the aircraft? (AC 00-6A, Ch.11)

Attitude Indicator – establish power for the recommended maneuvering speed and attempt to maintain a constant attitude only. Do no attempt to maintain a constant altitude.

2. What are the conditions needed for major structural icing to form? (AC 00-6A, Ch.10)

Two conditions are necessary for structural icing in flight:
a. The aircraft must be flying through visible water such as rain or cloud droplets, and
b. Temperature at the point where the moisture strikes the aircraft must be 0°C or colder. Aerodynamics cooling can lower temperature of an airfoil to 0°C even though the ambient temperature is a few degrees warmer.

3. What action is recommended if you inadvertently encounter icing conditions? (FAA-H-8083-15)

a. Move to an altitude with significantly colder temperatures;
b. Move to an altitude with temperatures that are above freezing;
c. Fly to an area clear of visible moisture; or
d. Change heading and fly to an area of known non-icing conditions.

4. Which type of precipitation will produce the most hazardous icing conditions? (AC 00-6A, Ch.10)

Freezing rain produces the most hazardous icing conditions.

5. If icing is inadvertently encountered, how would your landing approach procedure be different? (AC 00-6A, Ch.10)

The following guidelines may be used when flying an airplane which has accumulated ice:
a. Maintain more power during the approach
b. Maintain a higher airspeed
c. Expect a higher stall speed
d. Expect a longer landing roll
e. A “no flaps” approach is recommended
f. Maintain a consistently higher altitude than normal
g. Avoid a missed approach (get it right the first time)

G. Radio Navigation

1. Within what frequency range do VORs operate? (AIM 1-1-3)

VORs operate within the 108.0 to 117.95 MHz VHF band.

2. What are the normal usable distances for the various classes of VOR stations? (AIM 1-1-8)

H-VORs and L-VORs have a normal usable distance of 40 nautical miles below 18,000 feet. T-VORs are short-range facilities which have a power output of approximately 50 watts and a usable distance of 25 nautical miles at 12,000 feet and below. T-VORs are used primarily for instrument approaches in terminal area, on or adjacent to airports.
Terminal = 1,000 to 12,000 AGL 25 NM
Low-altitude = 1,000 to 18,000 AGL 40 NM
High-altitude = 1,000 to 14,500 AGL 40 NM
High-altitude = 14,500 to 18,000 AGL 100NM
High-altitude = 18,000 to 45,000 AGL 130 NM
High-altitude = 45,000 to 60,000 AGL 100NM

3. What is the meaning of a single coded identification received only one every 30 seconds from a VORTAC station? (AIM 1-1-7 and 1-1-12)

The DME component is operative; the VOR component is inoperative. It is important to recognize which identifier is retained for the operative facility. A single coded identifier with a repeat interval every 30 seconds indicates DME is operative. If no identification is received, the facility has been taken off the air for tune-up or repair, even though intermittent or constant signals are received.

4. Will all VOR stations have capability for providing distance information to aircraft equipped with DME? (AIM 1-1-7)

No, aircraft receiving equipment ensures reception of azimuth and distance information from a common source only when designated as VOR / DME, VORTAC, ILS / DME, and LOC / DME stations.

5. For IFR operations off established airways, the “Route of Flight” portion of an IFR flight plan should list VOR navigation aids which are no further than what distance from each other? (AIM 5-1-8)

Below 18,000 feet MSL, use aids not more than 80 NM apart.
Between 14,500 feet MSL and 17,999 feet MSL in the conterminous U.S., H (high altitude service volume) facilities not more than 200 NM apart may be used.

6. Within what frequency range do NDBS normally operate? (AIM 1-1-2)

NDBs operate within the low-to-medium-frequency band – 190 to 535 kHz.

7. When a radio beacon is used in conjunction with an ILS marker beacon, what is it called? (AIM 1-1-2)

It is called a compass locator.

8. There are four types of NDB facilities in use. What are they and what are their effective ranges? (AIM 1-1-8)

HH facilities : 2,000 watts 75 NM
H facilities: 50 to 1,999 watts 50 NM
MH facilities: less than 50 watts 25 NM
ILS compass locator: less than 25 watts 15 NM

9. What limitations apply when using an NDB for navigation? (AIM 1-1-2)

Radio beacons are subject to disturbances that may result in erroneous bearing information. Disturbances result from factors such as lightning, precipitation static, etc. At night, radio beacons are vulnerable to interference from distant stations.

10. What operational procedure should be used when navigation or approaches are conducted using an NDB? (AIM 1-1-2)

Since ADF receivers do not incorporate signal flags to warn a pilot when erroneous bearing information is being displayed, the pilot should continuously monitor the NDBs coded identification.

11. What is an HIS? (FAA-H-8083-15)

The horizontal situation indicator is a combination of two instruments, a vertical heading indicator and a VOR / ILS indicator. The aircraft heading is displayed under the upper lubber line. A course indicating arrow shows the course selected (head) and the reciprocal (tail). The course deviation bat operates with a VOR / LOC navigation receiver to indicate left or right deviations for the course selected. The fixed aircraft symbol and course deviation bar display the aircraft relative to the selected course as though you were above the aircraft looking down. The triangular-shaped pointer is the TO-FROM indicator. The glide slope deviation pointer indicates the relation of the aircraft to the glide slope.

12. What is an RMI? (FAA-H-8083-15)

The radio magnetic indicator consists of a rotating compass card, a double-barred bearing indicator, and a single-barred bearing indicator. The compass card, actuated by the compass system, rotates as the aircraft turns. The bearing pointers display ADF or VOR magnetic bearings to the selected station. In most installations, the double-barred bearing indicator gives the magnetic bearing to the VOR or VORTAC and the single-barred indicator is an ADF needle which gives the magnetic bearing to the selected low-frequency facility.
The tail of the double-barred indicator tells you the radial you are on, and the tail of the single-barred indicator tells you your magnetic bearing from a low-frequency station.

13. What is DME? (AIM 1-1-7)

DME stands for Distance Measuring Equipment. Aircraft equipped with DME are provided with distance and ground speed information when receiving a VORTAC or TACAN facility. In the operation of DME, paired pulses at a specific spacing are sent out from the aircraft and are received at the ground station. The ground station then transmits paired pulses back to the aircraft at the same pulse spacing but on a different frequency. The time required for the round trip of this signal exchange is measured in the airborne unit and is translated into distance and ground speed. Reliable signals may be received at distances up to 199 NM at line-of-sight altitude. DME operates on frequencies in the UHF spectrum between 960 MHz to 1215 MHz. Distance information is slant-range distance, not horizontal.

14. When is DME equipment required? (14 CFR §91.205)

If VOR navigational equipment is required for flight at and above FL240, the aircraft must be equipped with approved distance measuring equipment. If the DME should fail at and above FL240, the pilot-in-command shall notify ATC immediately, and then may continue operations to the next airport of intended landing where repairs or equipment replacement can be done.

15. As a rule of thumb, to minimize DME slant range error, how far from the facility should you be to consider the reading accurate? (FAA-H-8083-15)

Slant range error will be at a minimum if the aircraft is one or more miles from the facility for each 1,000 feet of altitude above the facility.

16. What is RNAV? (P/CG)

Area Navigation (RNAV) provides enhanced navigational capability to the pilot. RNAV equipment can compute the airplane position, actual tract and ground speed and then provide meaningful information relative to a route of flight selected by the pilot. Typical equipment will provide the pilot with distance, time, bearing and cross track error relative to the selected “TO” or “active” waypoint and the selected route. Several distinctly different navigational systems with different navigational performance characteristics are capable of providing area navigational functions. Present day RNAV includes INS, LORAN, VOR / DME, and GPS systems.

17. What is LORAN? (P/CG)

LORAN is an abbreviation for Long Range Navigation. It is an electronic navigation system by which hyperbolic lines of position are determined by measuring the difference in the time of reception of synchronized pulse signals from two fixed transmitters. A LORAN receiver is basically an onboard computer capable of determining an aircraft’s position based on the measurement of time difference receipt of these different signals. LORAN receivers also have computer memory capable of storing information and useful programs such as airport locations, navigational aids, etc., and programs such as estimated time to station, ground speed, true air speed, bearing to nearest airport, etc.

18. Give a brief description of GPS. (AIM 1-1-19)

Global Positioning System (GPS) is a satellite-based radio navigation system that broadcasts a signal used by receivers to determine precise position anywhere in the world. The receiver tracks multiple satellites and determines a pseudo-range measurement that is then used to determine the user location.

19. What are the three functional elements of GPS? (FAA-H-8083-15)

a. The space element consists of 24 Navstar satellites (called a “constellation”). The satellites are in six orbital planes (with four in each plane) at about 11,000 miles above the earth. At least five satellites are in view at all times.
b. The control element consists of a network of ground-based GPS monitoring and control stations that ensure the accuracy of satellite positions and their clocks. In its present form, it has five monitoring stations, three ground antennas, and a master control station.
c. The user element consists of antennas and receiver-processors onboard the aircraft that provide positioning, velocity, and precise timing to the user.

20. Is an alternate means of navigation appropriate to the route of flight required if using GPS navigation equipment under IFR? (AIM 1-1-19)

Yes. Aircraft using GPS navigation equipment under IFR must be equipped with an approved and operational alternate means of navigation appropriate to the flight. Active monitoring of alternative navigation equipment is not required if the GPS receiver uses RAIM for integrity monitoring. Active monitoring of an alternate means of navigation is required when the RAIM capability of the GPS equipment is lost.
Note: Aircraft equipped with a WAAS receiver may use WAAS as a primary means of navigation. No additional equipment is required.

21. What is the purpose of “RAIM”? (AIM 1-1-19)

The GPS receiver verifies the integrity (usability) of the signals received from the GPS constellation through receiver autonomous integrity monitoring (RAIM) to determine if a satellite is providing corrupted information. At least one satellite, in addition to those required for navigation, must be in view for the receiver to perform the RAIM function; thus, RAIM needs a minimum of 5 satellites in view, or 4 satellites and a barometric altimeter (baro-aiding) to detect an integrity anomaly.

22. If RAIM capability is lost while conducting IFR en route or approach operations, can you continue flight using GPS information? (AIM 1-1-19)

No. Without RAIM capability, the GPS may no longer be providing the required accuracy. The pilot should select another type of navigation system until RAIM is restored.

23. Where can a pilot obtain RAIM availability information? (AIM 1-1-19)

Civilian pilots may obtain GPS RAIM availability information for non-precision approach procedures by specifically requesting GPS aeronautical information from an Automated Flight Service Station during preflight briefings. FAA briefers will provide RAIM information for a period of 1 hour before to 1 hour after the ETA, unless a specific time frame is requested by the pilot.

24. Can handheld GPS receivers and GPS systems certified for VFR operations be used for IFR operations? (AIM 1-1-19)

No, for the following reasons:
a. RAIM capability – VFR GPS receivers and all handheld units have no RAIM alerting capability. Loss of the required number of satellites in view, or the detection f a position error, cannot be displayed to the pilot by such receivers.
b. Database currency – In many receivers, an updatable database is used for navigation fixes, airports, and instrument procedures. These databases must be maintained to the current update for IFR operation, but no such requirement exists for VFR use.
c. Antenna location – In many VFR installations of GPS receivers, antenna location is more a matter of convenience than performance. In IFR installations, care is exercised to ensure that an adequate clear view is provided for the antenna to see satellites. If an alternate location is used, some portion of the aircraft may block the view of the antenna, causing a greater opportunity to lose navigation.
Note: VFR and handheld GPS systems are not authorized for IFR navigation, instrument approaches, or as a principal instrument flight reference. During IFR operations they may be considered only as an aid to situational awareness.

H. Airway Route System

1. What are the designated altitudes for the airways in the VOR and L / MF Airway System? (AIM 5-3-4)

The VOR and L / MF Airway System consists of airways designated from 1,200 feet above the surface (or in some instances higher) up to but not including 18,000 feet MSL. These airways are depicted on En route Low Altitude Charts.

2. What are the lateral limits of low altitude federal airways? (FAA-H-8083-15)

Each federal airways includes the airspace within parallel boundary lines 4 NM each side of the centerline.

3. How are federal airways depicted on En route Low Altitude Charts? (AIM 5-3-4)

Except in Alaska and coastal North Carolina, the VOR airways are predicated solely on VOR or VORTAC navigation aids; they are depicted in blue on aeronautical charts (black on En route Low Altitude Charts), and are identified by a “V” (Victor) followed by an airway number. A segment of an airway which is common to two or more routes carries the numbers of all the airways which coincide for that segment.

4. What is a “changeover point”? (AIM 5-3-6)

It is a point along the route or airway segment between two adjacent navigational facilities or way points where changeover in navigational guidance should occur.

5. What is a mileage breakdown point? (FAA-H-8083-15)

Occasionally an “x” will appear at a separated segment of an airway that is not an intersection. The “x” is a mileage breakdown or computer navigation fix and indicates a course change.

6. What is a “way point” (P/CG)

It is a predetermined geographical position used for route / instrument approach definition, progress reports, published VFR routes, visual reporting points or points for transitioning and / or circum navigating controlled and / or special use airspace. A waypoint is defined relative to a VORTAC station or in terms of latitude / longitude coordinates.

7. Are the courses depicted on an En route Low Altitude Chart magnetic or true courses? (FAA-H-8083-15)

They are magnetic courses.

8. Describe the climb procedure when approaching a fix beyond which a higher MEA exists. (14 CFR 91.177)

A pilot may begin a climb to the new MEA at the fix.

9. Describe the climb procedure when approaching a fix at which a MCA exists. (FAA-H-8083-15)

A pilot should initiate a climb so the MCA is reached by the time the intersection is crossed. An MCA will be charted when a higher MEA route segment is approached. The MCA is usually indicated when you are approaching steeply rising terrain, and obstacle clearance and / or signal reception is compromised.

10. VHF / UHF and LF / MF route data will be depicted in what specific colors on En route Low Altitude Charts? (En route Low Altitude Chart Legend)

VHF / UHF Black
LF / MF Brown

I. Airspace

1. What is Class A airspace? (AIM 3-2-2)

Generally, that airspace from 18,000 feet MSL up to and including FL600, including airspace overlying the waters within 12 nautical miles of the coast of the 48 contiguous states and Alaska; and designated international airspace beyond 12 nautical miles of the coast of the 48 contiguous states and Alaska within areas of domestic radio navigational signal or ATC radar coverage, and within which domestic procedures are applied.

2. What is Class B airspace? (AIM 3-2-3)

Generally, that airspace from the surface to 10,000 feet MSL surrounding the nation’s busiest airports in terms of IFR operations or passenger enplanements. The configuration of each Class B airspace area is individually tailored and consists of a surface area and two or more layers (some resemble upside down wedding cakes), and is designated to contain all published instrument procedures once an aircraft enters the airspace. An ATC clearance is required for all aircraft to operate in the area, and all aircraft cleared as such receive separation services within the airspace. The cloud clearance requirement for VFR operations is “clear of clouds”.

3. What is Class C airspace? (AIM 3-2-4)

Generally, that airspace from the surface to 4,000 feet above the airport elevation (charted in MSL) surrounding airports that have an operational control tower, are serviced by a radar approach control, and that have a certain number of IFR operations or passenger enplanements. Although the configuration of each Class C airspace area is individually tailored, the airspace usually consists of a 5NM radius core surface area that extends from the surface up to 4,000 feet above the airport elevation, and a 10 NM radius shelf area that extends from 1,200 feet to 4,000 feet above the airport elevation.

4. What is Class D airspace? (AIM 3-2-5)

Generally, that airspace from the surface to 2,500 feet above the airport elevation (charted in MSL) surrounding those airports that have an operational control tower. The configuration of each Class D airspace area is individually tailored and when instrument procedures are published, the airspace will normally be signed to contain those procedures.

5. When a control tower, located at an airport within Class D airspace, ceases operation for the day, what happens to the lower limit of the controlled airspace? (AIM 3-2-5)

During the hours the tower is not in operation, Class E surface area rules, or a combination of Class E rules down to 700 feet AGL and Class G rules to the surface, will become applicable. Check the A/FD for specifics.

6. What is Class E (controlled) airspace? (AIM 3-2-6)

Generally, if the airspace is not Class A, Class B, Class C, or Class D, and t is controlled airspace, it is Class E airspace. Class E airspace extends upward from either the surface or a designated altitude to the over lying controlled airspace. When designated as a surface area, the airspace will be configured to contain all instrument procedures. Also in this class are federal airways, airspace beginning at either 700 or 1,200 feet AGL used to transition to or from the terminal or en route environment, en route domestic, and offshore airspace areas designated below 18,000 feet MSL. Unless designated at a lower altitude, Class E airspace begins at 14,500 feet MSL over the United States, including that airspace overlying the waters within 12 nautical miles of the coast of the 48 contiguous states and Alaska, up to, but not including 18,000 feet MSL, and the airspace above FL600.

7. What is the floor of Class E airspace when designated in conjunction with an airport with an approved IAP? (14 CFR §71.71)

700 feet AGL.

8. What is the floor of Class E airspace when designated in conjunction with a federal airway? (14 CFR §71.71)

1,200 feet AGL.

9. Class E airspace within the contiguous United States extends upward from either 700 feet AGL or 1,200 feet AGL, up to but not including what altitude? (AIM 3-2-6)

Except for 18,000 feet MSL, Class E airspace has no defined vertical limit; rather, it extends upward from either the surface or a designated altitude to the overlying or adjacent controlled airspace. Unless designated at a lower altitude, Class E airspace begins at 14,500 feet MSL and extends up to, but not including 18,000 feet within 12 miles from the coast of the contiguous states.

10. What is Class G airspace? (AIM 3-3-1)

Class G airspace is that portion of the airspace that has not been designated as Class A, B, C, D, and E airspace.

11. What are the vertical limits of Class G airspace?

Class G airspace begins at the surface and continues up to but not including the overlying controlled airspace, or 14,500 MSL, or where Class E airspace begins, whichever occurs first.

J. Special Use Airspace

1. Define the following types of airspace. (AIM 3-4-1 through 3-4-7, and 3-5-7)

Prohibited Area – For security or other reasons, aircraft flight is prohibited.
Restricted Area – Contains unusual, often invisible hazards to aircraft, flights must have permission from the controlling agency, if VFR. IFR flights will be cleared through or vectored around it.
Military Operations Area – MOAs consist of airspace of defined vertical and lateral limits established for the purpose of separating certain military training activities from IFR traffic. Permission is not required for VFR flights, but extreme caution should be exercised. IFR flights will be cleared through or vectored around it.
Warning Area – Airspace of defined dimensions extending from 3 nautical miles outward from the coast of the U.S. containing activity that may be hazardous to non-participating aircraft. A warning area may be located over domestic or international waters or both. Permission is not required but a flight plan is advised.
Alert Area – Depicted on aeronautical charts to inform non-participating pilots of areas that may contain a high volume of pilot training or an unusual type of aerial activity. No permission is required, but VFR flights should exercise extreme caution. IFR flights will be cleared through or vectored around it.
Controlled Firing Areas – CFAs contain activities which, if not conducted in a controlled environment, could be hazardous to non-participating aircraft. These activities are suspended immediately when spotter aircraft, radar or ground look out positions, indicate an aircraft might be approaching the area. CFAs are not charted.
National Security Area – Airspace of defined vertical and lateral dimensions established at locations where there is a requirement for increased security and safety of ground facilities. Pilots are requested to voluntarily avoid flying through the depicted NSA. When it is necessary to provide a greater level of security and safety, flight in NSAs may be temporarily prohibited by regulation under the provisions of 14 CFR §99.7.
Temporary Flight Restrictions – TFRs are established to protect persons and property in the air or on the surface from an existing or imminent hazard associated with an incident on the surface when the presence of low flying aircraft would magnify, alter, spread, or compound that hazard. A NOTAM designated the area within which TFRs apply and specifying the hazard or condition requiring their imposition will be issued.

2. Where can information on special use airspace be found? (AIM 3-4-1)

The chart legend contains information on special use airspace such as times of use, altitudes, and the controlling agency.