IFR Fix: The 200-knot gust

November 30, 2012

The weather is benign at the summit of New Hampshire’s Mount Washington on a late fall morning. Temperature of minus 2 Fahrenheit, wind 34 knots from the northwest, giving a bracing wind chill of minus 31.7 degrees. That’s still an improvement over yesterday, when squalls from an early Arctic blast dumped nine inches of new snow on the peak and arranged it into four-foot-high drifts.

Mount Washington, in New Hampshire’s White Mountains, is something of a weather shrine. At 6,288 feet above sea level, the summit is at the highest elevation in the northeast. A renowned observatory there supplies a steady stream of snowy statistics that help residents of the lower levels feel less assaulted by the region’s winter weather.

The second-highest surface gust humanity has ever observed, 231 mph, happened here, in 1934. Although dwarfed by western peaks—indeed, below many western states’ airport field elevations—Mount Washington can be, as the observatory states, “the home of the world’s worst weather.”

Keep that in mind when ATC clears you for the approach to Mount Washington Regional Airport in nearby Whitefield, where even a clear-day’s arrival from downwind of the mountain can take you through zero visibility in blowing snow, and amusement-park-grade turbulence.

For non-RNAV aircraft, an unusual LOC/NDB procedure is the way down to the airport’s lone 4,002-foot runway, via a transition from one of several VORs located up to 47 nautical miles away.

There’s not an instrument pilot on the planet who won’t constantly be wondering where the mountain is during an approach to the airport (elevation 1,072 feet msl) in instrument conditions.

In case of emergency, it’s worth knowing that the approach architecture includes a minimum safe altitude of 7,500 feet msl for the areas near the highest peaks, and two other MSA sectors of 5,000 feet and 6,100 feet. Magnetic bearings to the MAHN NDB define the sector boundaries.

Check airport weather on the automated surface observing system (ASOS) frequency. Meteorologically majestic Mount Washington also reports weather (identifier: KMWN)—useful for comparison.

On the morning after the squalls, the airport reported clear skies, calm winds, and visibility of 10 miles.

This was the mountain’s METAR: 1455Z 33034KT 120SM FEW/// FEW140 SCT160 BKN180 M19/M34 RMK TPS LWR FEW030 NNNN.

That could mean bumps during the letdown, but with 120 miles’ visibility, you’ll have the airport in sight.

Dan Namowitz

Dan Namowitz | Aviation Writer

Dan Namowitz is an aviation writer and flight instructor. He has been a pilot since 1985 and an instructor since 1990.