NTSB Factual Report

HISTORY OF THE FLIGHT

On Wednesday, September 29, 1993, at 1630 eastern daylight time, N6489P, a Piper PA-24-250, owned by Aire Austin Inc. of Austin, Minnesota, and piloted by John Pluto of Austin, Minnesota, collided with terrain following an uncontrolled descent at Akron, Ohio. Visual meteorological conditions prevailed at Akron, and a flight plan was not filed. The certificated commercial pilot and his two passengers were fatally injured. The airplane was destroyed. The personal flight was conducted under 14 CFR 91, and had originated in Austin, Minnesota. The destination was Harrisburg, Pennsylvania.

The pilot and passengers were on a VFR (visual flight rules) flight to attend a car show in Hershey, Pennsylvania. He had obtained a weather briefing at Fostoria, Ohio, where he stopped to refuel. According to the briefer, he provided a briefing which indicated rain showers and marginal VFR weather on the pilot's route of flight. He stated that the pilot told him that the tops of the clouds on his flight from Minnesota were 13,000 feet. Radar data obtained from the Cleveland Air Route Traffic Control Center showed the airplane at 17,500 feet and making several turns. The pilot's last transmission to the air traffic controller at Cleveland Center was, "I am at 16,500 feet and in the soup."

Radar data recorded at the Federal Aviation Administration's Cleveland Air Route Traffic Control Center (ARTCC) were obtained for the accident aircraft. The radar data provide the latitude, longitude, and altitude of the airplane for approximately 13 minutes in an area west of the Akron Fulton International Airport. The radar data indicate the airplane's altitude varied from 17,500 feet MSL to 3,800 feet MSL and then began a descending right turn. The last recorded radar return shows the airplane descending through 3,800 feet MSL at a ground speed of over 150 knots. Details of the study are attached to this report.

According to Federal Aviation Regulation FAR 91.211, no person may operate a civil aircraft of U.S. registry at cabin pressure altitudes above 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen during the entire flight time at those altitudes.

A witness reported seeing the airplane "coming through the cloud layer...I heard a pop sound then I saw the plane spinning without one wing."

The accident occurred during the hours of daylight, at 41 degrees 3 minutes North and 81 degrees 30 minutes West.

PERSONNEL INFORMATION

The pilot held a commercial pilot certificate with single and multiengine land ratings. According to FAA records, the pilot's total flight time listed by him on his last FAA medical certificate was "over 1100 hours."

AIRCRAFT INFORMATION

The 1960 year model Piper PA-24-250 airplane, serial no. 24-1608 was equipped with a Lycoming O-540-A1B5 engine, serial no. L- 2744-40. According to the engine log book, the airplane had accumulated over 2816 hours of total flight time. This time was recorded on the last annual inspection that was completed on January 4, 1993. Examination of the airplane indicated that supplemental oxygen was not installed.

METEOROLOGICAL CONDITIONS

The 1950 hours surface weather observation for Akron Canton Regional Airport, about 8 miles south of the accident site was as follows:

"Sky condition, 2600 feet scattered; Ceiling, 3500 feet broken; visibility, 7 miles in light rain; temperature, 49 degrees (F); dew point, 42 degrees (F); wind condition, 220 degrees at 6 knots; and altimeter, 30.16 inches."

WRECKAGE AND IMPACT INFORMATION

The aircraft impacted the ground in a near-vertical attitude and much of the forward section of the aircraft had penetrated the ground. The vertical attitude was confirmed by forward-to-aft compression buckling of the left wing. Some soil had been displaced by the impact and a crater approximately 4 feet deep was created by the aircraft. The wreckage was oriented on a 270 degree magnetic bearing and most of the wreckage was in the crater.

Examination of the wreckage did not determine flight control continuity because of damage. The wreckage was scattered over about a 1.5 mile area. The right wing main spar was bent upward in positive overload approximately 9 feet inboard from the wing tip. Paint transfer from the separated wing onto the right side of the elevator indicated that the separated wing struck a 3 foot section of the right elevator separating it. Both separated wing and elevator sections were located about 1.5 miles from the main wreckage. Sections of the right wing panel, aileron and right flap were found along the wreckage path. Examination of the airframe did not reveal any pre-existing deficiencies.

Examination of the engine revealed that all the cylinders remained attached to the crankcase. The propeller separated and was located in the crater along with the engine. Due to the damage of the engine an examination was not done.

MEDICAL AND PATHOLOGICAL INFORMATION

A Medical Examination was done by Dr. William A Cox Medical Examiner for the State of Ohio, on September 30, 1993. According to the Medical Examiner's report, the pilot died as a result of the injuries received in the accident. Toxicological test results were negative for all screened drugs and volatiles.

ADDITIONAL INFORMATION

According to the FAA Flight Training Handbook, the characteristics of hypoxia are:

Hypoxia is a condition that results from having insufficient amount of oxygen in the body. There is a tendency to associate hypoxia only with flights at high altitude. Alcohol, many drugs used for medication, and heavy smoking can diminish the blood's ability to absorb oxygen or reduce the body's tolerance to hypoxia. In exposure to altitudes below 10,000 feet, the effects of hypoxia on the pilot are mild and considered acceptable. From 12,000 to 15,000 feet, though, impairment of judgment, memory alertness, and coordination are affected; and headache, drowsiness and either a sense of well-being or of irritability may occur. At cabin-pressure altitudes above 15,000 feet, peripheral vision deteriorates to a point where only central vision remains and cyanosis (blueness) of the finger nails and lips develops.

The wreckage was released to Harold Mesaris of Airco, the adjuster for the insurance carrier, on October 6, 1993.

NTSB Probable Cause

CONTINUED FLIGHT BY THE PILOT TO AN ALTITUDE THAT WAS NOT APPROPRIATE WITHOUT SUPPLEMENTAL OXYGEN, WHICH RESULTED IN A LOSS OF AIRCRAFT CONTROL DUE TO HYPOXIA AND SUBSEQUENTLY EXCEEDING THE DESIGN STRESS LIMITS OF THE AIRCRAFT. FACTORS RELATED TO THE ACCIDENT WERE: THE ADVERSE WEATHER CONDITIONS, AND CONTINUED FLIGHT BY THE PILOT INTO KNOWN ADVERSE WEATHER CONDITIONS.