Wing fails in flight

Aircraft: Piper Cherokee Six. Injuries: 5 Fatal. Location: Bryan, Texas. Aircraft damage: Substantial.

What reportedly happened: The instrument-rated private pilot and four passengers were flying on a cross-country flight in IFR conditions. The airplane was in cruise flight at an altitude of 8,000 feet MSL when it entered an area of heavy rain showers.

The pilot informed an air traffic controller that he was in “bad” weather and was going to try to get out of it. Following that transmission, radio and radar contact was lost.

A witness on the ground heard a sound resembling an explosion. She reported that at the time she heard the noise the rain was falling as a light drizzle. By the time she and her husband got outside to see what the explosion was, the rain started “pouring down.”

The airplane’s main wreckage about 450 feet southwest of their house. The main wreckage consisted of the airplane except for the left wing, vertical stabilizer, rudder, and the right wing tip fuel tank. Those components were located about 200 feet north-northeast of the main wreckage.

An examination of the left wing spar showed that the wing failed in positive overload. Flight control continuity was confirmed at the accident site.

The post-crash examination of the airplane’s engine and other systems did not reveal any pre-impact anomalies.

A weather study of conditions in the area at the time of the accident indicated the potential for heavy rain showers, thunderstorms, wind in excess of 45 knots, clear air turbulence, and low-level wind shear.

While the pilot’s toxicology testing results were positive for marijuana use, the levels were determined not to be impairing.

The airplane had a GPS unit with a current subscription for Next-Generation Radar (NEXRAD)onboard.

At the time of the accident the depiction in the cockpit would have reflected weather conditions that occurred a couple of minutes earlier. The GPS unit’s owner’s manual states that NEXRAD weather data should be used for “long-range planning purposes only,” and not to “penetrate hazardous weather,” as the “NEXRAD data is not real-time.” Investigators determined the total approximate time latency of the data was 8 minutes and 22 seconds. On the indicator in the airplane at 2144 CST, while the airplane was in a very strong rain shower, the 2145 CST XM data would have shown the line of rain showers one mile east of the airplane’s flight path.

Probable cause: The pilot’s inadvertent encounter with severe weather, which resulted in the airplane’s left wing failing in positive overload. Contributing to the accident was the pilot’s reliance on outdated weather information that he received on his in-cockpit Next-Generation Radar (NEXRAD).

NTSB Identification: CEN12FA108

This December 2011 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.

Comments

  1. BufordS says

    Personally I wouldn’t fly with anyone who has smoked Mary Jane any time. Anyone who’s that much of an idiot should not be flying planes in the first place; or driving a car for that matter.

  2. Douglas Manuel says

    Is there any information on advisories issued by ATC? I am wondering if it was a situation like Scott Crossfield faced (although there is debate about him having an active NEXRAD subscription) where ATC failed to issue advisories, per the 7110.65.

  3. John says

    Fwiw, the number of fatal accidents where MJ was detected in the blood, fat, or urine has a steadily upward trend in the past 10 years. CAMI has released a couple of reports on the last couple of decades that illustrated how the baseline has shifted for this drug.

    I wonder if the wing had any lift enhacing devices that would have altered the true Va? When the wing stalls at 3-5 kts slower it has to affedt Va in a linear or perhaps non-linear manner. Of course, the STC paperwork always has the caution that reminds it is up to the installer and operator (including the pilot) to determine how mods affect flight characteristics. Very ‘too bad’ that so many lives were lost in this accident.

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