Scud Running and RNAV Approaches: A Little Bit of Both

In most of the world, a shiny, new RNAV approach that lowers minimums by 500 feet is cause for celebration. Not so at Anaktuvuk Pass, Alaska. At least thats what one Alaskan pilot and IFR reader tells me. Our phone call puzzling out a potential solution revealed limitations of cockpit tech, the practicality of old-school scud running, and a potential remedy by blending the two.

jwanwest

Tuesday, April 12, 2016 at 12:00 AM ET

Verified

Key Takeaways:

The new RNAV (GPS)-A approach at Anaktuvuk Pass, Alaska, is largely unusable due to an excessively high Minimum Descent Altitude (MDA) of 4000 feet AGL.
The high MDA is primarily caused by terrain restrictions on the *missed approach* procedure, which demands wider tolerances and lower climb gradients.
Standard RNAV procedures cannot effectively resolve the issue for either runway, leading pilots to resort to informal "scud running" tactics.
A "charted visual segment" is proposed as a potential solution, allowing pilots to descend visually from the Missed Approach Point to the airport, blending instrument procedures with practical visual navigation and potentially lowering usable minimums.

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In most of the world, a shiny, new RNAV approach that lowers minimums by 500 feet is cause for celebration. Not so at Anaktuvuk Pass, Alaska. At least that’s what one Alaskan pilot and IFR reader tells me. Our phone call puzzling out a potential solution revealed limitations of cockpit tech, the practicality of old-school scud running, and a potential remedy by blending the two.

Anaktuvuk Pass airport is a gravel strip serving a village of about 300 people. The only way in is by snow machine or aircraft. There’s an NDB on the field that both served as the only approach navaid, and the terminus of airway A4—an NDB airway that stops at an NDB transmitting from almost 5000 feet below the peaks that surround the airport.