Understanding GPS Substitution in VOR Approaches
⚠️ Critical Requirement
A VOR receiver is still required for VOR approaches, and an ADF for NDB approaches; GPS does not replace this essential onboard equipment.
Why Conventional VOR Approaches Still Matter
In an era dominated by GPS approaches, you might wonder about the relevance of VOR. The truth is, conventional VOR approaches can offer lower minimums at specific airports.
| Approach Type | Runway | Minimum Altitude | Visibility | Advantage |
|---|---|---|---|---|
| VOR 26 | 26 | 760 feet | 1 mile | Lower minimums |
| GPS 26 | 26 | 800+ feet | 1+ miles | More common |
These lower minimums can be a decisive factor in challenging weather conditions, making mastery of VOR approaches an invaluable asset.
Step-by-Step: Configuring Your G1000 for VOR 24 at KPOU
Let's walk through setting up your G1000 for the VOR 24 approach at Poughkeepsie (KPOU), ensuring your HSI and RMI provide accurate guidance.
1. Access Bearing Options
On your Primary Flight Display (PFD), push the PFD softkey to access additional display options.
2. Configure Bearing One
Locate the Bearing One option. A single click will align it with NAV1, which should be tuned to the Kingston VOR – your primary navigation aid for this approach.
💡 Pro Tip
You'll see a small blue needle head pointing directly under the magenta GPS CDI needle. This indicates that both systems agree on your inbound course.
3. Verify Alignment
Observe your HSI. You should be tracking the 218° course inbound to the VOR, as specified on the approach plate. The RMI needle is your critical verification tool, ensuring you are following the correct radial or course.
4. Divergence Protocol
Should your VOR and GPS needles begin to diverge, prioritize the VOR needle as your primary guidance. In such cases, a missed approach is often the safest course of action to re-evaluate and correct your navigation.
Real-World Application: When to Configure Your HSI
While simulators allow for on-the-fly adjustments, in actual flight, you should configure your HSI and RMI during a low-workload phase of flight. The ideal time is typically during cruise, well before you initiate the approach, to avoid adding to your cockpit workload during critical phases.
✅ Best Practice
Configure your navigation displays during cruise flight, at least 15 minutes before beginning your approach descent. This reduces cockpit workload during critical phases of flight.
The Unsung Hero: Importance of the RMI Needle
The RMI needle is often overlooked, yet it's crucial for verifying your adherence to the VOR course. By allowing the flight director and autopilot to follow GPS guidance while simultaneously monitoring the RMI needle, you achieve a harmonious and accurate approach.
Ready to Master VOR Approaches?
Enhance your instrument flying skills with personalized guidance from our certified flight instructors.
Book Your One-on-One Instruction Today!