Piper PA-46-500TP N477MD

Summary

On 28 June 2007 at about 13:15 local time, a Piper PA-46-500TP registered N477MD, operated by David L. McCormick, was involved in an accident near Wellsville, Missouri, United States. 3 people were on board and 3 died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

28 June 2007 at 13:15

Classification

Accident

Location

Wellsville, Missouri, United States

Coordinates

39.1236, -91.5783

Aircraft

Piper PA-46-500TP

Registration

N477MD

Category

Airplane

Engines

1

Operator

David L. McCormick

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

St Louis → Buffalo

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

CHI07FA183

3 people died.

The pilot's failure to activate the pitot heat as per the checklist, resulting in erroneous airspeed information due to pitot tube icing, and his subsequent failure to maintain aircraft control. Contributing to the accident was the pilot's continued flight in an area of known adverse weather.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot, before departure, obtained a weather briefing that indicated there were thunderstorms and areas of heavy precipitation along the route of flight. The pilot told the briefer that the airplane was equipped with onboard radar for weather avoidance. After takeoff, the pilot received two adverse weather advisories from the departure air traffic controller. The pilot acknowledged, requested and was cleared for course deviations to avoid the weather. The pilot was subsequently told to contact an en route traffic control center. The pilot did not request an update on, nor was he advised of, any additional adverse weather after switching over. Avionics data recovered from the wreckage showed the airplane encountered decreasing outside air temperatures (OAT) during the en route climb to a cruise altitude. The OAT decreased below freezing as the airplane climbed through 15,900 feet mean sea level. The primary flight display's (PFD) airspeed data decreased from about 140 knots indicated airspeed (KIAS) to 0 KIAS. During the loss of airspeed, the airplane's recorded climb rate decreased and the airplane entered a left turn. At this point, the en route controller asked the pilot if he had been given a clearance to deviate around weather. The pilot responded, "mike delta we've got problems uh... ." There were no additional communications received from the pilot and radar contact with the airplane was lost shortly thereafter. The recovered PFD data indicated that the airplane exceeded its maximum structural operating speed during a rapid descent. In the descent, the airplane reached a ground speed of 250 knots and vertical loads reaching 5g. The recovered data and witness marks from the right wing indicated the airplane sustained an in-flight breakup after exceeding the airplane's maximum load factor limit. A review of the available weather data indicated that there was an area of extreme precipitation associated with thunderstorms east of the accident site and that the airplane was likely in instrument meteorological conditions at the time of the upset. An on-scene investigation did not reveal any pre-impact anomalies with the airplane and its related systems. Analysis of the recovered PFD and Multi-Function Display (MFD) data indicated that the pilot did not utilize the available pitot tube heat that would have afforded ice protection. Recovered PFD/MFD data, along with a weather analysis, indicated that the airplane was operating in an environment conducive for pitot tube icing. Additionally, recovered data showed airspeeds were recorded during the rapid descent at altitudes lower than the observed freezing level. The before takeoff checklist indicated, "Pitot Heat ... ON."

Quoted verbatim from the NTSB record.