Approaches to a VOR or a LOC (Locator).
CANPA (Constant Angle Precision Approach)
An approach where the pilot receives only lateral information is called a "Non-precision approach"
This approach »is run as a« Constant Angle Precision Approach »
CANPA, to make it similar to running an ILS approach.
CANPA is flown as a DME approach or as a timed approach with a pre-determined angle
the constant angle of descent is published in an MDA "Minimum Descent Altitude".
If you contact the MDA (by entering it), a landing can be made; if you have no contact at the MDA
a lap around (frustrated) must be executed.
The VOR and LOC
A VOR approach is based on a VOR located somewhere near the runway. The path to the approach leg will not be the same as the ILS localizer to the same runway. Sometimes heading to the leg of
approach will differ quite a bit. In ENV in northern Norway it is 24º. This will result in the minimum height.
A LOC approach (to a localizer) is based on an ILS, but without a GP (Glide Path).
Both approaches are carried out in the same way.
VOR / DME approach to ESSA runway 01
ATC will normally give you vectors via radar to intercept a heading of 30º to the heading of the approach leg.
to the VOR. In the event that no radar is available, the approach will be a turn procedure or a DME Arc.
The heading to the approach leg is 003º, while the ILS locator is at 007º.
At the end of the IAL chart there is a vertical drawing of the approach.
2500ft to DME 8 (8 DME miles) 1510ft to DME 5 and a minimum of 590ft (feet).
On the left is a drawing of a table that gives advice on the different altitudes that will give a descent with a nose at 3.2º.
D5 is underlined and indicates a strict “HARD LEVEL” level. This is the lowest altitude at that point.
GS / KT is the GROUND SPEED in knots and the ROD is the corresponding Descent Range.
Automatic Pilot and Navigation Aids.
Initial approach
NAV 1 is set to the VOR frequency of ARL 116.00. The heading to the approach leg is 003º.
NAV 2 is also set at 116.00
The ADF is set to the frequency of the NDB OHT 370
the speed is 210kts and the altitude is 2500ft still above the radar vector with a heading of 340º.
The autopilot is set to the Locator's VOR and will capture it.
The A / T (Auto Throtle) is maintaining speed.
Time to slow down and prepare for the descent. It is important to slow down and have the landing configuration (A / C) before reaching 8 miles DME. This will greatly reduce the work and the estimated vertical speed will be more accurate.
Established and passing 6 miles DME.
The same settings for the Autopilot (A / P).
Some wind coming from the left.
The heading is 358º and the ground speed is 136kts.
The ADF needle begins to rotate forward to the left, you are approaching the outer OHT marker.
Watch out for the hard level at 5 miles DME.
Basic vertical speed is 800ft. The wind could change during the descent. In the event that you are lower than normal, reduce the vertical speed to 700ft and check your height at the next DME prompt. Of course another way to control if you are taking more height in the profile.
Reaching the MDA.
Everything under control?
Do you have the runway or approach lights in sight?
So - disengage the autopilot (A / P) and do the rest on your own. Self-landing is not possible in this kind of approach. The Auto Throtle (A / T) can of course be used all the way down.
You will have the track on your right, partly due to the approach leg course but also due to the skid. Its heading is 358º and the track is heading 007º.