An instrument approach operation describes the operation of an aircraft with reference to navigation guidance information. The operation must be in accordance with an authorised instrument approach procedure (IAP).
To conduct a flight under the Instrument Flight Rules (IFR), you must:
- either be receiving flight training with an authorised flight instructor
- or hold an instrument rating
- or hold a Multi-crew pilot licence (Aeroplane) or an Air transport pilot licence (Aeroplane) with a valid instrument proficiency check.
2D IAP and 3D IAP endorsements
To conduct an IAP, you must have either an IAP 2D or 3D instrument endorsement.
We specify that 2D IAP and 3D IAP endorsement provide some flexibility for a person seeking an instrument rating. This is due to limited access to some IAP, or pilots not needing to conduct 3D instrument approach operations (for example, only operating in remote parts of Australia.)
2D IAP
A 2D IAP endorsement authorizes you to conduct a 2D instrument approach operation. In 2D operations, you:
- use instrument displays that provide lateral (directional) navigation information to navigate in accordance with the IAP
- manage the vertical path of the aircraft without reference to any vertical path guidance information to comply with any descent limitations of the procedure
- must not descend below the minimum descent altitude/height (MDA/H) unless there is visual reference that you can maintain.
A flight test for an instrument rating must include the issue of at least a 2D IAP endorsement.
3D IAP
A 3D IAP endorsement authorises you to conduct a 3D instrument approach operation. In 3D operations, you:
- use instrument displays that provide both lateral and vertical navigation guidance information to navigate in accordance with the IAP
- must not descend below the MDA/H or any intermediate limiting step if the IAP does not include a decision altitude/height (DA/H), or when the vertical guidance is not valid and is advisory only
- must initiate a missed approach at the decision altitude/height (DA/H) if the required visual reference is not established.
Some aircraft navigation systems provide vertical navigation (VNAV) guidance information, even when a procedure is for lateral navigation guidance only. This guidance is advisory only and may not ensure protection from all obstacles. In those cases, you must comply with descent limitations for 2D instrument approach operations.
When conducting an instrument approach operation using advisory VNAV guidance to manage the vertical path of the aircraft, it is an 3D instrument approach operation, even thought descent below the MDA/H is not permitted. This is due to the use of the VNAV guidance cue to manage the aircraft rate of descent, rather than using cognitive skills. Consequently, you cannot use such an approach to satisfy the recent experience requirement for 2D instrument approach operations.
Lateral navigation guidance
Aircraft navigation systems display lateral navigation guidance information as either lateral deviation from a desired track. This is also referred to as a course deviation indicator or an angular deviation from a specified point, described as azimuth guidance.
Azimuth guidance operations
Azimuth guidance operations are where the instrument uses a needle pointer to show relative bearings to or from a station or waypoint.
The Automatic Direction Finder (ADF) displays a bearing to or from a station in the form of azimuth guidance.
Course deviation indictor operations
Course deviation indicator operations are where the instrument shows the lateral displacement of the aircraft from a selected track.
On the display, you may see the deviation from the track as angular displacement or as horizontal distance. The scale of the deviations may vary dependent on the navigation system used to generate the guidance information.
Instrument approach procedures (IAP)
We base an IAP on criteria that enables a descent below the minimum safe altitude (MSA) which positions the aircraft to safely approach and land.
The IAP relies on ground or satellite navigation infrastructure. Aircraft navigation systems use these to generate navigation guidance information. Some systems give lateral (directional) guidance while others can provide both lateral and vertical navigation guidance information.
Recent experience requirements for approaches
We use recent experience requirements to maintain a pilots knowledge and skills when conducting instrument approach operations.
When conducting an approach to satisfy a recent experience, pilots should recognise the purpose of the approach is to maintain their competency to conduct such operations.
Simulating IMC, when safe to do so, will enhance the purpose of the approach. Conducting the approach provides some effective practice. Each approach type has recent experience requirements that you must complete in an aircraft or flight simulation training device.
Approach type | Recent pilot experience needed |
---|---|
General | Must have carried out at least 3 instrument approach operations in the last 90 days. |
Aircraft category | Must have carried out at least one instrument approach operation in an aircraft of the same category (for example, aeroplane or helicopter) in the last 90 days. |
2D approach | Must have carried out at least one 2D instrument approach operation in the last 90 days. |
3D approach | Must have carried out at least one 3D instrument approach operation in the last 90 days. |
Azimuth guidance | Must have carried out at least one 2D instrument approach operation using azimuth guidance in the last 90 days. |
Course deviation indicator | Must have carried out at least one instrument approach operation using a course deviation indicator in the last 90 days. |
Instrument approach procedures
There are different kinds of instrument approach procedures. The Part 61 Manual of Standards specifies the following kinds of IAP’s that demonstrate competency for the 2D IAP and 3D IAP endorsements.
Procedures applicable to the 2D IAP endorsement, also referred to as non-precision approach procedures, are:
- NDB
- VOR and LOC (if you have shown competency conducting VOR approaches, we consider you skilled enough to conduct LOC approaches)
- DGA (DME/GNSS arrival)
- RNAV GNSS LNAV (RNP LNAV) or RNAV GNSS LP (RNP-LP) which utilises a space based augmentation system (SBAS) not currently available within Australia.
Procedures that may show competency for the 3D IAP endorsement, referred to as a precision approach are ILS, GLS, MLS.
Due to variations in aircraft navigations system capabilities RNP LNAV/VNAV, approach procedures are not currently permitted to demonstrate competency for the issue of a 3D IAP endorsement.
You must ensure the aircraft is appropriately equipped and authorised to conduct the approach in accordance with the kind of IAP.
RNAV GNSS LP and LPV minima are not currently available for IAP’s published for locations within in Australia.
Approach limits
Circling-approach limits
Pilots must meet one of the circling approach requirements to conduct a circling approach. You need to show competency conducting circling approaches. You can show this through:
- the flight test for the instrument rating
- your most recent instrument proficiency check.
Instrument approach procedure limits
There are limits on using particular kinds of IAPs. Pilots may only use an IAP if they have:
- completed training, and
- previously demonstrated competency in conducting an approach using the same kind of procedure to a flight examiner.
For example, you might hold a 2D IAP endorsement and have only shown competency conducting an approach in accordance with a VOR IAP.
You need to complete training and demonstrate competency conducting an instrument approach operation in accordance with an NDB IAP prior to using that kind of procedure.
Regulations on instrument approach operations
The rules for instrument ratings are in these sections of Part 61 of CASR Flight crew licensing:
- 61.105 and 61.110 - Definitions of instrument flight and instrument ground time
- 61.860 Limitations on exercise of privileges of instrument ratings - general
- 61.865 Limitations on exercise of privileges of instrument ratings - endorsements
- 61.870 Limitations on exercise of privileges of instrument ratings - recent experience: general
- 61.875 Limitations on exercise of privileges of instrument ratings - recent experience: single pilot
- 61.900 Limitations on exercise of privileges of instrument endorsements.