Training and Safety
IFR Fix: The 'other' published departure
It’s foggy this morning in the Berkshires. Temperature and dew point both stand at 18 degrees Celsius. The wooded ridges of the western Massachusetts hill country, charming to viewers on a clear day, barely show through the mist.
The arrival into Great Barrington’s Walter J. Koladza Airport several days ago concluded under bright skies, saving a ground trek from Barnes Municipal in distant Westfield. That tower-controlled airport northwest of Bradley International was the alternate in case weather was too much for Great Barrington’s nonprecision RNAV (GPS) and NDB approaches.
You’d love to keep the vacation going, but the world is calling. The passengers decide to slip away for one more canoe outing on Long Pond. They frown when you decline in favor of flight planning—and then off they go.
Great Barrington airport strikes a visitor as one of those wonderful general aviation havens where it must be common for out-of-state autos to nose up to the fence and a vacationer with a pilot certificate to dismount and survey the scene “for next time.” The nontowered airport (elevation 739 feet msl) with its 2,579-foot Runway 11/29, doubtless makes it onto many lists for fall-foliage flights, surrounded as it is by all that country elegance.
From the IFR pilot’s perspective, that short runway, hills, and instrument conditions for departure mean skipping the canoe trip and focusing on departure planning.
No standard instrument departure (SID) exists for Great Barrington, but there is an example of that other kind of published departure: an obstacle departure procedure (ODP) to assure safe egress above the hills. According to the Instrument Flying Handbook, both SIDs and ODPs “provide obstacle clearance provided the aircraft crosses the end of the runway at least 35 feet AGL; climbs to 400 feet above airport elevation before turning; and climbs at least 200 feet per nautical mile, unless a higher climb gradient is specified to the assigned altitude.”
Know that ODP, and know how to calculate your aircraft’s climb per nautical mile from tables or a flight computer.
Fortunately, you are scrupulous about checking notices to airmen—and you discover that one is currently WIE for Great Barrington, increasing the departure procedure’s altitude before turning from 2,200 feet msl to 2,400 feet.
The canoers have returned, and inquire, “Are we ready to go?”
September 10, 2012