Flight Training - March 2012 - 32

For a VFR pilot, this is more than just a serious predicament, it’s downright dangerous. At the very least, a letdown through clouds may be required—with success hanging on the bare-boned prospects of the pilot being able to fly, with minimal experience, headings and altitudes by reference to instruments until breaking out into clear air and finding a runway somewhere. “The most common type of weather accident, and one of the most consistently fatal, continues to be the attempt to fly by visual references in instrument meteorological conditions, often called VFR into IMC,” said the AOPA Air Safety Institute’s 2010 Joseph T. Nall Report of accident trends and factors for 2009. There were 14 VFR-into-IMC accidents in 2009, the report said; 12 of them were fatal.

with attitude-control instruments can fly an ASR approach. “The only airborne radio equipment required for radar approaches is a functioning radio transmitter and receiver,” explains the discussion of radar approaches in Section 5-4-11 of the Aeronautical Information Manual. “The radar controller vectors the aircraft to align it with the runway centerline. The controller continues the vectors to keep the aircraft on course until the pilot can complete the approach and landing by visual reference to the surface.” The procedure “may be given to any aircraft upon request and may be offered to pilots of aircraft in distress or to expedite traffic.” In the case of a VFR pilot requiring a descent through clouds, expect your flight to be handled as an emergency if

(MDA) is 400 feet mean sea level, or 358 feet above ground level. For Runway 4R, the MDA is 480 feet. In both instances minimum visibility is one mile. As you fly an ASR approach, the radar controller provides headings to align the aircraft with the extended centerline of the landing runway, as well as altitudes for descent—especially the minimum altitude from which the pilot must be able to complete a landing visually, or miss the approach. “In addition, the pilot will be advised of the location of the Missed Approach Point (MAP) prescribed for the procedure and the aircraft’s position each mile on final from the runway, airport, or heliport or MAP, as appropriate,” says the AIM. If requested by the pilot, the controller will recommend altitudes each mile.

AS YOU FLY AN ASR APPROACH, THE RADAR CONTROLLER PROVIDES HEADINGS TO ALIGN THE AIRCRAFT WITH THE EXTENDED CENTERLINE OF THE LANDING RUNWAY.
RADAR CAPABILITIES. If your route of flight has brought you close to Lafayette (Louisiana) Regional Airport or certain other airports with similar radar capabilities, a procedure known as an airport surveillance radar (ASR) approach can be used to get you safely down when an easier escape is not possible. At locations where either ASR or precision approach radar (PAR) approaches are available, radar can be used for IFR approaches or to help rescue a VFR pilot who needs assistance getting back on the ground. The catch? There are relatively few ASR/PAR-capable facilities out there, so using radar for instrument approaches is the exception rather than the rule. Airport listings in the Airport/Facilities Directory indicate any radar approach availability, and the hours when the service may be provided. And in a time of urgency, ATC likely can point the way to the nearest radar approach when asked. The good news for a VFR pilot in distress is that even a basic training aircraft
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you haven’t already declared one. If you have any doubts that this is an emergency situation, remember that noninstrument-rated pilots can quickly become disoriented when visual references are lost—and a student pilot is not allowed to fly without visual reference to the surface. Although equipment requirements are minimal, flying an ASR will remain a serious challenge to a noninstrument-rated pilot. Heading changes must be made by instrument references alone, using gentle standard-rate turns (3 degrees per second) to keep bank angles shallow. That prevents an aircraft’s overbanking tendency from taking hold, and also helps you avoid spatial disorientation. Descents must be made at a safe but affirmative rate. As with any instrument approach, you may emerge into clear air only a few hundred feet above the ground—when you must decelerate and configure your aircraft for landing in much less time than your VFR traffic pattern practice has provided. On an ASR approach to Runway 29 at Lafayette, the minimum descent altitude

MOST ASR AND PAR approaches are available from military facilities, such as Pease International Tradeport (PSM)—a former Air Force base—in Portsmouth, New Hampshire, shown here.

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Flight Training - March 2012

Table of Contents for the Digital Edition of Flight Training - March 2012