Mastering NDB Approaches with OBS on Garmin G1000 at EGTC

Executing the NDB Approach with OBS at Cranfield (EGTC)

The execution phase requires methodical progression through each segment of the approach. The OBS function transforms your GPS into a VOR-like navigation aid, providing precise course guidance even when the approach isn't in your database.

Step-by-Step Procedure

Phase 1: Initial Approach

Waypoint Activation: Once the NDB frequency is active, navigate directly to the EGTC waypoint using the G1000's direct-to function. This establishes your initial reference point for the approach.

Outbound Course Establishment: Upon reaching the NDB, maintain your initial approach altitude (typically 2500 feet) and activate the OBS function. Rotate the course selector to establish the outbound course (219 degrees from EGTC). This configuration allows you to treat the GPS fix like a VOR radial, providing familiar navigation cues.

Phase 2: Outbound Segment

Tracking Outbound: Monitor both your bearing pointer (ADF needle) and the GPS distance readout. Fly outbound on the selected course until reaching the designated distance—typically 9 nautical miles DME from EGTC for the Cranfield approach.

Phase 3: Inbound Segment

Inbound Turn and Course Set: At the outbound limit, execute a left turn to intercept the inbound course (032 degrees for Runway 03 at Cranfield). Adjust the OBS course selector to this inbound heading. The CDI will now provide lateral guidance for the final approach segment.

Descent and Configuration: Identify the Final Approach Fix (FAF) at 6.6 nautical miles DME from EGTC. Begin your descent from the initial approach altitude (2500 feet) to the Minimum Descent Altitude (730 feet for this approach). Configure the aircraft with appropriate flaps and manage your target airspeed between 95-100 knots. Set the MDA in your altimeter pre-select for enhanced situational awareness.

Phase 4: Final Approach

Final Approach Segment: Continuously monitor the NDB bearing pointer and your GPS for lateral guidance. Make heading adjustments as needed to maintain the inbound course. Cross-reference your progress with the current NDB approach chart, ensuring compliance with all published restrictions.

Missed Approach Procedure: If visual references are not established at the MDA, initiate the published missed approach procedure. This typically involves climbing to a safe altitude and executing a specific turn or hold, often returning to the NDB to enter a holding pattern. Use heading mode initially, then transition to OBS mode to manage the holding entry efficiently.

Essential Tips for OBS and NDB Approaches

Technical Specifications and Performance

Conclusion

Mastering the NDB approach at Cranfield Airport (EGTC) using the OBS function on your Garmin G1000 significantly enhances your manual navigation skills and builds critical instrument flying proficiency. This approach represents a valuable skill set that extends beyond just NDB navigation—it develops your ability to fly approaches that may not be in your avionics database and strengthens your fundamental instrument flying capabilities.

By diligently following the procedures outlined in this guide and incorporating the practical tips provided, you can execute complex approaches safely and precisely. The combination of traditional NDB navigation with modern G1000 technology creates a powerful tool for instrument pilots seeking to expand their operational capabilities.

Regular practice of these techniques, particularly in simulator environments, will build the muscle memory and decision-making skills necessary for real-world application. Remember that proficiency in manual navigation techniques like the OBS approach serves as both a backup to automation and a foundation for advanced instrument flying skills.