NTSB Incident Report on the Piper PA-28-236 at Alton, NH (IAD97FA043)

NTSB Identification: IAD97FA043

Accident occurred JAN-17-97 at ALTON, NH
Aircraft: Piper PA-28-236, registration: N8263Y
Injuries: 2 Fatal.

HISTORY OF FLIGHT

On January 17, 1997, at 1335 eastern standard time, a Piper PA-28-236, N8263Y, wasdestroyed when it collided with trees near Alton, New Hampshire. The pilot and onepassenger were fatally injured. Visual meteorological conditions prevailed and a flightplan was not filed. The personal flight was conducted under 14 CFR Part 91. The flightoriginated from Farmingdale (FRG), New York, at approximately 1115. The intendeddestination was Saranac Lake, New York.

According to Air Traffic Control (ATC) records, at 1117, the pilot radioed New YorkATC, and advised the controller that he was 4 1/2 miles north of FRG at 3,000 feet, andrequested flight following. The flight then proceeded uneventful for the next 25 minutes.

At 1139, the controller radioed the pilot and instructed him to contact the Boston AirRoute Traffic Control Center (ARTCC), but there was no response. At 1141, the pilot ratedpassenger (PRP) transmitted that they were in trouble, and that the pilot was notresponding. She told the controller that she was the co-pilot, and only had pilotexperience in a Cessna 172.

At 1142, the controller advised the PRP that they were basically the same aircraft, andthat they just land a little differently. He instructed her to do a shallow left turnsouthbound, and he would keep her VFR to help talk her down to an airport. He also advisedher to descend if she could, and to stay clear of the clouds.

At 1143, the PRP advised the controller that she could see the ground while making theturn, and that the pilot was throwing up. The controller informed the PRP that she wasover the Danbury Airport, Danbury, Connecticut. During the next 16 minutes, the controllerand the pilot of another airplane (POAA) provided directions and instructions to the PRP.

At 1156, the PRP radioed that she was getting tired, and she was nauseated. At 1158,the POAA asked the PRP to lower the nose of the airplane and to start descending, and thePRP responded that she was trying to "activate" the pilot. At 1200, she repeatedshe was very tired. The POAA told the PRP where the control wheel was, and that she shouldtrim the airplane. At 1204, the controller advised the POAA that the airplane had turnednorthbound, and that it was slowly climbing. The controller told the POAA that the PRP wasresponding with idents.

At 1207, the controller advised the POAA that the airplane was at 8,200 feet, and thatthere were no further idents from the PRP. At 1209, the controller advised the POAA thatthe airplane was holding it's heading and altitude of 8,800 feet. At 1210, the controllerradioed the PRP and told her to open a vent on the airplane and get some fresh air asthere might be carbon monoxide in the cockpit.

At 1212, the controller radioed the PRP and told her to lower the nose because theairplane was probably trimmed to climb. The transmission was not acknowledged. At 1217,the controller radioed the PRP, and told her that maybe the autopilot was on, and that wasprobably why it was difficult to descend. Shortly thereafter, the controller advised thePOAA that the PRP's airplane was descending rapidly.

At 1221, the controller advised the POAA that the airplane was at 7,800 feet, and thatthe bases of the clouds were around 5,000 feet. The POAA advised the controller that hewas at 5,000 feet, and that it was VFR. The controller that had coordinated the twoairplanes, contacted Bradley Approach Control, and coordinated the handover of the twoairplanes to their airspace. The airplanes were then handed off to the Boston ARTCC at1249.

At 1313, the POAA reported that he had the airplane in sight. At 1318, the POAAreported that he saw smoke coming out of the engine, and at 1320, the POAA reported thatnobody was sitting up, and it appeared the entire cabin was full of smoke and that theengine was smoking.

At 1324, the POAA reported that the airplane was descending rapidly. At 1326, the POAAreported that the PRP had crashed into trees.

The airplane impacted trees in a heavily wooded area during the hours of daylight about43 degrees 32 minutes North latitude, and 71 degrees, 12 minutes West longitude.

PILOT INFORMATION

The pilot held a Private Pilot Certificate with ratings for airplane single engineland, and instrument airplane. The pilot had recorded a total flight experience ofapproximately 352 hours, upon the completion of his instrument flight test on January 13,1991. From January 13, 1991, until the last log book entry dated January 4, 1996, thepilot only logged events such as adverse weather, actual instrument time, and the tachtime at each refueling. On his application for a third class medical that was issued onAugust 1, 1995, he reported over 700 hours of total flight experience.

The pilot rated passenger held a private pilot certificate with a single engine landrating. According to her application for a third class medical certificate dated December28, 1993, she reported 165 hours of total flight experience.

METEOROLOGICAL CONDITIONS

At 1251, Concord Municipal Airport, Concord, New Hampshire, located about 26 milessouth of the accident site, reported the following observation:

Sky condition, ceiling 7000 broken; visibility, 10 miles; temperature, 9 degreesFahrenheit (F); dew point, -14 degrees F; winds from 290 at 14 knots with wind gusts up to33 knots; and altimeter, 29.74 inches Hg.

WRECKAGE AND IMPACT INFORMATION

The airplane wreckage was examined at the accident site on January 18 and 19, 1997.Examination of the accident site revealed impact scars at the tops of trees. The airplanewreckage was distributed over an area approximately 150 feet long by 25 feet wide,oriented on a magnetic heading of 060 degrees. All major components of the airplane wereaccounted for at the scene.

The main wreckage, which consisted of the empennage, top of the fuselage and remainderof the right wing were found about 130 feet beyond the initial impact point (IIP). Theengine was separated from the fuselage and located about 150 feet beyond the IIP.

The lower forward section of the fuselage was destroyed. The cockpit section along withthe right front seat, cabin door, and a section of the right side fuselage skin werelocated adjacent to the main wreckage against a tree. This area contained the rear freshair vents, which were in the closed position. The front fresh air vents were separated,and found near the main wreckage. One vent was closed while the other vent was partiallyopened.

The overhead vent knob and the overhead vent were in the open position. The panelmounted fan switch was in the high position. The heater control box remained attached tothe fuselage and was in the open position. The two forward floor heat vents were also inthe open position.

The stabilizers and rudder remained attached to the main wreckage. The verticalstabilizer was crushed aft at the top. The rudder was crushed down and aft from the top tothe top hinge. The rudder was compressed below the hinge from the leading edge to thetrailing edge. The left side and right side horizontal stabilizer were damaged and werenot functional. The elevator trim measured 3 threads. According to the Piperrepresentative, this corresponded to 1.8 degrees tab up.

The propeller hub and propeller separated from the engine. One blade was bent aft whilethe other blade was straight. The blades displayed some chordwise scratches and gouges atthe tips.

The engine was removed from the wooded area and examined in a hangar at the LakesRegion Airport, Wolfeboro, New Hampshire, on January 19, 1997, under the supervision ofthe National Transportation Safety Board (NTSB).

When the muffler shroud was removed, it revealed a large hole in the muffler that, wasshared by the #5 and #6 cylinder exhaust stacks. The hole was near the left end (#6side),and measured approximately 4.5 inches long and 1 inch wide. The muffler was removed andsent to the NTSB laboratory for further examination.

TESTS AND RESEARCH

The muffler was examined at the NTSB laboratory. According to the Metallurgists factualreport, the inlet end of the muffler case on the left side was crushed and contained alarge crack that extended approximately two thirds of the muffler circumference. Mostportions of the crack were darkly-discolored, as if they had been exposed to exhaust gasesfor a period of time. Other areas were shiny, as if they were recently created. The leftinlet port of the muffler contained a welded in repair patch; however, the examinationrevealed that the crack was not associated with the repair welds.

In the area located about 5 inches from the inlet end of the muffler, a piece of themuffler case had separated creating an irregular hole. The fracture faces surrounding thehole had brittle appearance, and were covered with a layer of dark deposits. A section wascut from the muffler for Xray energy dispersive spectroscopy (EDS) and metallographicexamination.

The EDS analysis of the fracture surface showed the presence of large quantities oflead and bromine, elements associated with the combustion of aviation fuel. The EDSanalysis of the cut surface generated a spectrum typical of a stainless steel, withchromium and nickel as the primary alloying elements.

Metallographic examination revealed heavy pitting corrosion and high temperatureoxidation on the interior surface of the muffler case.

MEDICAL AND PATHOLOGICAL INFORMATION

Autopsies and toxicological testing of the pilot and passenger were conducted by Dr.James A. Kaplan, Acting Chief Medical Examiner of the State of New Hampshire, on January18, 1997.

The toxicological testing report from the FAA Toxicology Accident Research Laboratory,Oklahoma City, Oklahoma, showed the pilot's lung fluid had a Carboxyhemoglobin (CarbonMonoxide) saturation of 43%, while the passenger's blood had 69%.

ADDITIONAL DATA/INFORMTION

According to the Piper Maintenance Manual, it states in part:

"The entire exhaust system, including heat exchange shroud, muffler, mufflerbaffles, stacks, and all exhaust connections must be rigidly inspected at each annual or100 hour inspection. The possibility of exhaust system failure increases with use. Thesystem must also be checked carefully before winter operation when the cabin heater willbe in use. Remove or loosen all exhaust shields, carburetor, and cabin heat muffs,shrouds, heat blankets, etc., as required to permit inspection of the system. Clean andinspect all external surfaces for dents, cracks, and missing parts.

Pay particular attention to welds, clamps, supports, and support attachment lugs, slipjoints, stack flanges, and gaskets. Inspect internal baffle or diffusers. Any cracks,warpage, or severe oxidation are cause for replacement.

If any component is inaccessible for a visual inspection, conduct one of the following:

1. Conduct a submerged pressure check of muffler and exhaust stack at 2 psi airpressure. 2. Conduct a ground test using a carbon monoxide indicator. Head airplane intothe wind. Warm engine on the ground. Advance throttle to full static RPM with cabin heatvalves open, and take readings of heated airstream inside cabin at each outlet (includingrear seat heat outlet, if installed) Appropriate sampling procedures applicable to theparticular indicator must be followed. If carbon monoxide concentration exceeds 0.005percent or if a dangerous reading is obtained on an indicator not calibrated inpercentages, the muffler must be replaced."

According to the airplane's engine log book, the last annual inspection was completedon January 17, 1996, by Shakalis Aviation Services Inc., and the airplane had accumulatedover 88 hours since the inspection. The inspection included replacing the #1 cylinderexhaust gasket. The pilot had contacted the above maintenance facility, and scheduled anannual inspection for January 27, 1997. There was no entry in the airplane or engine logsthat the muffler had been checked or replaced.

According to the Army Aeromedical Training Handbook for Flight Personnel, it states inpart:

"...The effects of carbon monoxide (CO) are subtle and deadly. CO is perhaps themost common gaseous poison in the aviation environment...It is a colorless, odorless gasslightly lighter than air...A relatively low concentration of CO in the air can, in time,produce high blood concentrations of CO. If an individual inhales a 0.5 percentconcentration of CO for 30 minutes while at rest, a 45 percent concentration of CO willresult. This is enough to produce total collapse... ."

The aircraft wreckage was released on January 23, 1997, to Allen A. Ryan, arepresentative of the owner's insurance company.