Plane & Pilot
Tuesday, March 9, 2010

Safety’s Ideal World

Unfortunately, we don’t always learn from example

STAY AHEAD OF TROUBLE. Looking at multiple NTSB investigations into pilot failure to activate pitot heat, a pattern emerges: Carelessness often leads to disaster.
In an ideal world, once the probable cause of an accident is identified, there never will be an accident like it again. The NTSB would figure out everything leading to the accident, and armed with that knowledge, aviators would have an easy time preventing the same thing from happening again. Unfortunately, it’s not that simple in the real world, where we often see repeats of the same probable causes.

No one has devised a foolproof way to prevent pilots from failing to maintain airspeed, continuing VFR into instrument conditions, or neglecting checklist items. For example, the NTSB spotlighted neglecting to turn on pitot heat 35 years ago, and then again 18 years ago: In a July 1992 special investigation on PA46 accidents, the NTSB examined PA46 pilots’ failure to use pitot heat while operating in freezing instrument meteorological conditions. Several months ago, the Safety Board again focused on failure to turn on pitot heat as a safety concern.

In November 2009, the NTSB determined that an accident involving a turboprop Piper PA46-500TP Malibu Meridian, in which all three occupants were killed, was caused by the pilot’s failure to activate the pitot heat as called for on the checklist. This resulted in erroneous airspeed information due to pitot tube icing. At 8:15 a.m. on June 28, 2007, the PA46 suffered an in-flight breakup and crash near Wellsville, Mo. The IFR flight had originated from Spirit of St. Louis Airport, near Chesterfield, Mo., at about 7:50, and was destined for Buffalo Municipal Airport, near Buffalo, Minn.

At 7:11, the pilot contacted flight service to file an IFR flight plan and get an abbreviated weather update. The briefer told the pilot that there was heavy rain and thunderstorm activity in Missouri along the planned route of flight. The pilot said that he had onboard radar for weather avoidance.

At 7:50, the pilot contacted St. Louis Departure Control, and two minutes later, was cleared to climb to 4,000 feet. The controller advised of light to moderate precipitation three miles ahead of the aircraft. The pilot was approved for a northerly course deviation for weather avoidance. At 7:53, the pilot was cleared to climb to 10,000 feet. The controller then advised of additional areas of moderate and heavy precipitation, gave the pilot information on the location and extent of the weather areas, and suggested a track to avoid them. The pilot responded that he saw the same areas on his onboard radar. Radar data showed that the airplane flew northwest, then turned toward the west. Subsequently, the flight was handed off to Kansas City Center.


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