IFR - Approaches 2

What does IAP stand for?

Instrument Approach Procedure

What is the ICAO definition of an Instrument Approach Procedure?

A series of predetermined maneuvers by reference to flight instruments providing obstacle protection from the initial approach fix or defined arrival route to a point where landing can be completed, or to a point where holding or enroute clearance criteria apply.

During an approach, how much does obstacle and terrain clearance reduce from departure phase?

From over 1000 feet down to as low as 200 feet.

In Canada, which document governs the development of instrument procedures?

TP 308, Criteria for the Development of Instrument Procedures.

What are the four basic segments of an instrument approach?

Initial, Intermediate, Final, Missed.

What are the three main types of Instrument Approach Procedures?

Precision Approach (PA), Non-Precision Approach (NPA), and Approach with Vertical Guidance (APV).

What defines a Precision Approach (PA)?

An approach with lateral and vertical guidance aligned with the runway centerline.

Which navigation systems are used for Precision Approaches?

ILS, MLS, and PAR.

What defines a Non-Precision Approach (NPA)?

An approach with only lateral (course) guidance and no vertical guidance.

Which navigation systems are used for Non-Precision Approaches?

LOC, VOR, NDB, RNAV (GNSS)

What defines an Approach with Vertical Guidance (APV)?

An approach providing lateral guidance equivalent to a localizer and vertical guidance.

Which navigation systems are used for APV approaches?

RNAV (GNSS)

What is the required obstacle clearance in the Initial Segment?

1000 feet.

What is the required obstacle clearance in the Intermediate Segment?

500 feet.

What is the required obstacle clearance in the Final Segment?

200+ feet (300+ for circling).

What is the obstacle clearance in the Missed Approach Segment?

Increases from final segment clearance back to 1000 feet.

What is the purpose of the Initial Approach Segment?

To transition from the enroute phase to the intermediate approach segment.

What marks entry into the Initial Approach Segment?

Crossing the Initial Approach Fix (IAF) or departing the enroute structure for approach.

What is the maximum angle between initial and intermediate segments when the initial segment is a course?

120 degrees.

If the turn required exceeds 90 degrees, what is charted?

A lead radial or bearing indicating 2 NM of lead.

What is the minimum arc radius for low altitude procedures?

7 NM.

How wide is the obstacle clearance area on the Initial Segment?

6 NM either side of the course/arc.

How much clearance is provided in the primary area of the Initial Segment?

1000 feet.

What is the descent gradient on the Initial Segment?

Optimum 250 feet per NM, maximum 500 feet per NM.

What extra clearance is provided for a procedure turn?

Extra clearance on the procedure turn side of the approach course.

What is a procedure turn used for?

To establish the aircraft on the intermediate segment when straight-in clearance is not possible.

How many basic variations of a procedure turn exist?

Five.

What must a pilot do before descending on a procedure turn?

Cross the fix and descend to the procedure turn altitude unless otherwise specified.

What does “No PT” mean on an approach plate?

No procedure turns are permitted; straight-in approach authorized.

What connects the initial and final approach segments?

The Intermediate Approach Segment.

When does the Intermediate Segment begin?

After completing a procedure turn or crossing the Intermediate Fix (IF).

What is the purpose of the Intermediate Segment?

To position the aircraft for final descent alignment.

What is the optimum descent gradient on the Intermediate Segment?

150 feet per NM.

What is the maximum descent gradient on the Intermediate Segment?

318 feet per NM (3 degrees).

What obstacle clearance is provided in the Intermediate Segment?

500 feet in the primary area.

What is the maximum alignment difference between intermediate and final segments?

30 degrees.

How long are intermediate segments typically for Non-Precision Approaches?

5 NM.

How long are intermediate segments typically for Precision Approaches?

2+ NM.

Where does the Final Approach Segment begin for NPAs?

At the Final Approach Fix (FAF) or Final Approach Course Fix (FACF).

Where does the Final Approach Segment begin for PAs?

At glideslope interception.

Where does the Final Approach Segment end for NPAs?

At the Missed Approach Point (MAP).

Where does the Final Approach Segment end for PAs?

At the Decision Height (DH).

What are stepdown fixes?

Points in a Non-Precision Approach where obstacle clearance changes after passage.

Where does the Missed Approach Segment begin in a PA or APV?

At the Decision Height (DH).

Where does the Missed Approach Segment begin in an NPA?

At the Missed Approach Point (MAP).

When must a missed approach be executed?

When required visual reference is not obtained at the DH or MAP.

If a landing is rejected below DH or MDA, what happens?

The aircraft may be below the obstacle clearance surface.

When can the pilot transition to visual flight?

Once the required visual reference is established at or after DH/MAP.

What options does a pilot have after obtaining visual reference at DH/MAP?

Transition to a straight-in landing or circle to land on another runway.

What must pilots continue doing after going visual?

Maintain instrument scan while integrating outside visual cues.

Why must instrument scanning continue after going visual?

To prevent reliance on misleading visual cues that could cause accidents.

What is the optimum reaction time available from 200 ft DH at 130 knots?

About 18 seconds, with 4 seconds used for orientation.

What are the three categories of instrument approach lighting hazards?

Obscured conditions, low visibility, and variable lighting.

How much obstacle clearance is provided in circling minima?

300 feet.

When can you descend below circling minimums?

When you have sufficient visual reference to make a normal descent and landing.

If you lose sight of the runway during circling, what must you do?

Initiate a missed approach using the published procedure for the approach flown.

What determines the size of the Visual Maneuvering Area?

Aircraft category based on IAS.

Within the Visual Maneuvering Area, how much obstacle clearance is provided?

300 feet.

What should be done when circling at night?

Use visual aids (PAPI/VASIS), plan carefully, monitor altitude and speed.

When must pilots report at uncontrolled aerodromes during approach?

5 minutes before EAT, at procedure turn fix, passing FAF, circling, final, and during missed approach.

At a controlled aerodrome, what must be included in the initial tower call?

The approach clearance (e.g., “Waterloo Tower, GOLP, Cleared ILS 26”).

How is the touchdown zone defined?

The first third of the runway or 3000 feet, whichever is less.

What governs whether approaches may be conducted or not?

Runway Visual Range (RVR).

What governs landings?

RVR.

What is the reference point for the 100-mile safe altitude on an approach plate?

The same point as the MSA 25 NM.

What is true about DME arcs?

They can be joined at any point along the depicted arc and provide 1000 ft of obstacle clearance.

What are the main categories of circling approaches based on?

Indicated Airspeed (IAS).

When is an approach designated as circling?

When the final approach track is misaligned by 30° or more from the runway centerline.

What is an NDB Approach?

A Non-Precision Approach where final track guidance is provided by a bearing to/from an NDB.

What identifies station passage on an NDB approach?

When the ADF bearing pointer stabilizes at the wingtip position (90°).

How accurate are NDB approaches compared to others?

Least accurate; usually have the highest minimums.

When may descent on final begin in an NDB approach?

When the aircraft is within 5° of the published track.

What are the two forms of NDB procedures?

Beacon on field and beacon off field.

What is an NDB approach?

A non-precision approach using a Non-Directional Beacon (NDB) for lateral guidance.

When is the final approach phase of an NDB approach considered critical?

When passing the beacon final (FAF).

During the outbound leg of an NDB approach, what should pilots do?

Make small heading corrections due to tracking difficulty.

What checklist should be completed before the final descent in an NDB approach?

The final approach checklist.

When is a missed approach mandatory in an NDB approach?

When the time to the MAP has elapsed without visual reference, a safe landing is not possible, ATC instructs a go-around, or track guidance is lost (NDB off air).

For an inbound NDB approach with the beacon on the field, what is true about the FAF?

There is no FAF; timing outbound is used to determine when to turn inbound.

Why is the outbound leg extended during an NDB on-field approach?

To ensure sufficient time to descend when inbound.

When should the final approach checklist be completed during an NDB on-field approach?

When completing the procedure turn.

What provides final approach track guidance in a VOR approach?

A radial to or from a VOR.

Are VOR approaches precision or non-precision?

Non-precision.

How do VOR minima compare to other non-precision approaches?

Lower than NDB but higher than LOC or RNAV.

What is the most common type of VOR approach?

VOR/DME.

What does the TO/FROM flag indicate in a VOR approach?

Whether the aircraft is flying to or from the VOR.

What defines the FAF and MAP in a VOR/DME approach?

The VOR itself and the DME distance.

How accurately must the aircraft track before descent on final?

Within ±5° (half-scale deflection).

What does an ILS consist of?

A localizer and glideslope aligned with the runway.

What guidance does the localizer provide?

Lateral guidance, about 2.5° either side of centerline.

What guidance does the glideslope provide?

Vertical guidance, approximately 0.7° either side of the glide path.

Is ILS a precision or non-precision approach?

Precision.

What are the three categories of ILS approaches?

CAT I, CAT II, CAT III.

What is the most common ILS category?

CAT I.

What equipment and training are required for CAT I?

No special aircraft or crew certification beyond standard ILS capability.

What determines the DH for CAT I ILS?

Barometric altimeter indications.

What are the basic minima for CAT I ILS?

200 ft above TDZE and ½ SM or RVR 2600.

What additional requirements apply to CAT II ILS?

Specific company, crew, aircraft, and airport authorization from Transport Canada.

What determines the DH for CAT II ILS?

Radio altimeter indications.

What are the basic minima for CAT II ILS?

100 ft above TDZE and RVR 1200.