Piper PA-42 N332SM

Summary

On 9 July 2012 at about 01:14 local time, a Piper PA-42 registered N332SM, operated by Clear Blue Sky Aviation LLC, was involved in an accident near Charleston, West Virginia, United States. 3 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

9 July 2012 at 01:14

Classification

Accident

Location

Charleston, West Virginia, United States

Coordinates

37.7856, -81.1211

Aircraft

Piper PA-42

Registration

N332SM

Category

Airplane

Year built

1981

Engines

2

Operator

Clear Blue Sky Aviation LLC

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Charleston → Macon

Aircraft damage

Substantial

Weather

IMC

Light

Night

NTSB number

ERA12LA435

Nobody was injured.

The airplane’s encounter with a gravity-wave duct atmospheric phenomenon.

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

Read the full NTSB narrative

The pilot reported that, before takeoff, he obtained a weather briefing that depicted an area of convective activity moving east of the departure airport. The airplane was equipped with an onboard satellite weather receiver, and, once airborne, the pilot contacted air traffic control and requested a deviation due to weather. The air traffic controller issued a deviation left of the planned course, and the pilot deviated accordingly. Shortly after reaching a cruise altitude of 23,000 feet mean sea level (msl) while in instrument meteorological conditions, the pilot saw a lightning flash, and the airplane subsequently entered a rapid ascent. Shortly after, he disconnected the autopilot and neutralized the flight controls, the stall warning sounded, and the pilot felt a "falling and twisting sensation." At this point, he suspected that the airplane was in a steep spiraling descent or spin; however, he could not confirm the airplane's attitude because the gyroscopic instruments had tumbled. Shortly after, the airplane exited the clouds, the pilot saw ground lighting, and he then initiated a recovery to a level flight attitude at an altitude of about 8,300 feet msl. After regaining control of the airplane, the pilot returned to the departure airport and subsequently landed without incident. The left and right elevators sustained substantial damage during the rapid descent. A significant meteorological information advisory and a severe thunderstorm watch were valid for the accident area at the time of the accident and warned of the potential for severe thunderstorms, hail, extreme turbulence, and wind gusts. The preflight weather briefing obtained by the pilot included this information. Postaccident review of upper air soundings and weather radar images indicated that the airplane passed through an area with gravity waves that likely caused extreme updrafts and/or downdrafts, windshear, and turbulence. Although current weather forecasting technology is able to predict environments conducive to the generation of gravity waves and gravity-wave ducts, the technology lacks the ability to predict if, where, and at what intensity these phenomena may form. Therefore, neither the pilot's preflight weather briefing nor his onboard weather satellite receiver would have detected the gravity-wave conditions along the airplane's flight route.

Quoted verbatim from the NTSB record.