Stabilized Constant Descent Angle NPA’sStabilized Constant

Descent Angle NPA’s

OverviewOverview

• What is a Stabilized Constant Descent Angle (SCDA) Non- Precision Approach (NPA)?

• Why do we need it?• How do we fly it?• Considerations?

Legal-ApplicabilityLegal-Applicability

• CBAAC No. 0238 • applicable to operators under Subparts 703, 704

and 705 • Ops Spec 019, 303, or 503 • use the Minimum Descent Altitude (MDA) as a

Decision Altitude (Height) DA(H).

SCDA Training ProgramSCDA Training Program

• The operator should ensure that flight crews receive ground and simulator or flight training that addresses SCDA NPA procedure proficiency.

• The operator should have SOPs incorporating SCDA NPA procedures.

BackgroundBackground

• Precision Approach–An approach with both lateral and vertical

information used to guide the aircraft to a Decision Height

• Non Precision Approach–An approach with only lateral information

used to guide the aircraft to a minimum descent altitude

BackgroundBackground

• Stabilized approach–means a final approach flown to achieve a

constant rate of descent, at an approximate 3 degree descent flight path angle, with stable airspeed, power setting, and attitude, with the aircraft configured for landing.

What is a SDCA?What is a SDCA?

• means stabilized constant-descent-angle non-precision approach.

Traditional NPATraditional NPA

• Dive and Drive

The ApproachThe Approach

• Initial Approach– From the IAF to the IF (if defined)– Obstacle clearance 1,000 ft.

• Intermediate Approach– From the IF to the FAF – Obstacle clearance 500 ft.

• Final Approach– From the FAF to the MDA– Obstacle clearance 200 ft.

Traditional NPATraditional NPA

FAF

Final Approach Segment

3.3 nm

Constant Descent Final ApproachConstant Descent Final Approach

FAF

Final Approach Segment

3.3 nm

Advantages of the SDCAAdvantages of the SDCA

• Increased safety by employing the concepts of stabilized approach criteria and procedure standardization.

• Improved pilot situational awareness (SA) and reduced pilot workload.

• Improved fuel efficiency by minimizing the low-altitude level flight time.

Advantages of the SDCAAdvantages of the SDCA

• Reduced noise level by minimizing the level flight time at high thrust settings.

• Procedural similarities to precision approach operations.

• Reduced probability of infringement on required obstacle clearance during the final approach segment.

Statistics*Statistics*

*Flight Safety Foundation Approach and Landing Accident Reduction Task Force

Stabilized ApproachStabilized Approach• Aircraft on the correct flight path• Only minor changes required to maintain the

correct flight path• Airspeed between Vref and Vref +20 and

power properly set• Aircraft properly configured for landing• Sink rate no greater than 1,000 fpm• All briefings and checklists complete

SDCA CriteriaSDCA Criteria

• The approach is flown to straight-in minima.• The approach design should permit a final

approach segment descent angle of 2.9 to 3.5 degrees.

• The final approach course shall not be more than 15 degrees from runway centreline.

Approach ConsiderationsApproach Considerations

• Don’t forget temperature corrections • Take minimum altitudes at step-down fixes

into account when planning the final descent angle

Missed ApproachMissed Approach

• When flown correctly, the position where a missed approach is commenced following an SCDA NPA to MDA will occur before the published MAP.

• The missed approach climb will normally occur some distance before reaching the published MAP.

Missed ApproachMissed Approach

• Missed approach can begin before the MAP• Missed approach must begin at the MAP• For obstacle clearance, delay any turns

stated in the published missed approach procedure until the aircraft crosses the MAP

Missed ApproachMissed Approach

Missed ApproachMissed Approach

Missed ApproachMissed Approach

Missed ApproachMissed Approach

• Time required for a decision (reaction time);• Rate of descent at commencement of the

missed approach;• Pilot technique;• Aircraft performance; and• Baro altimeter lag.

CAP depictionCAP depiction

Questions???Questions???