Aviation Accident Summaries

Aviation Accident Summary MIA95FA042

PLANT CITY, FL, USA

Aircraft #1

N33456

PIPER PA-32-260

Analysis

The pilot informed ATC that he had a loose engine cowling, and that he would be proceeding direct to the destination airport. The airplane was observed on radar diverting to an alternate airport. Another pilot saw the airplane on final approach with something streaming from the airplane. The airplane was observed to terminate the approach to the south, as if the pilot was making a simulated forced landing. Another witness observed the airplane descending until it collided with trees and terrain. Examination of the wreckage, revealed the engine cowling latch penetrated the oil cooler, resulting in total exhaustion of engine oil, engine failure, and forced landing.

Factual Information

HISTORY OF FLIGHT On December 28, 1994, about 1637 eastern standard time, a Piper PA-32-260, N33456, registered to C 2 Air Inc., operating as a 14 CFR Part 91 personal flight, reported a loose engine cowling to Tampa Approach Control, and crashed about 1 1/2 miles west of Plant City Airport, Plant City, Florida, while attempting a forced landing. The airplane was destroyed. Visual meteorological conditions prevailed and no flight plan was filed. The private pilot sustained serious injuries. The flight originated from Tampa, Florida, about 7 minutes before the accident. Transcripts of recorded communication between Tampa Approach Control and N33456 revealed that the pilot contacted Tampa Approach Control at 2130:27 (1630:27 EST), stating he was off Vandenberg Airport, requesting an ILS approach at Lakeland, Florida, with a full stop. N33456 was assigned transponder code 0105. At 2131:47 (1631:47 EST), the pilot reported a loose engine cowling, and informed Tampa Approach Control to forget the ILS, that he would proceed direct to Lakeland. Tampa Approach informed the pilot that Plant City was off his left front if he needed to land right now. The pilot stated at 2132:06 (1632:06 EST), " Ah I think it's going to hold until I get there." Tampa Approach informed the pilot at 2132:08 (1632:08 EST), that radar service was terminated and instructed the pilot to change to Lakeland Tower, which was acknowledged by the pilot. The airplane was observed on radar turning towards Plant City. Tampa Approach informed Lakeland Tower at 2133:44 (1633:44 EST), that it appeared the airplane was going to land at Plant City Airport. The pilot of N33456 did not contact Lakeland Tower. At 2136:05 (1636:05 EST), the pilot of N33456 called Tampa Approach and stated, "Tampa Approach this is cherokee three three four five six declaring an ema (cut off)." The pilot was informed that his position was 2 1/2 miles south of the Plant City Airport, and asked if he could turn northbound. The pilot did not acknowledge the radio call. The airplane was last observed on radar 1 1/2 miles south of the airport. A witness who was in the traffic pattern for landing at Plant City, Florida, observed N33456 descending on final to runway 9, and saw something streaming from the airplane. The airplane turned southbound, and the witness thought the pilot was performing a practice forced landing. Another witness located 1 mile south-southwest of the Plant City Airport observed the airplane on what appeared to be on a left crosswind departure from the Plant City Airport. Another witness observed the airplane descending over a house on Juanita Drive, Plant City, Florida, towards a tree line. The witness stated the engine was not running. The airplane disappeared from view and was heard to collide with trees and terrain. PERSONNEL INFORMATION The pilot, Carlos A. Hernandez, stated in an interview with the NTSB and the FAA on January 13, 1995, that he has no memory of the accident flight. Additional information pertaining to the pilot is contained in NTSB Form 6120.1/2 and NTSB Form 6120.4. AIRCRAFT INFORMATION Examination of the airplane and review of the airframe logbook revealed the emergency locator transmitter (ELT) was not installed. The engine oil was last recorded as changed on December 26, 1994. Additional aircraft information is contained in NTSB Form 6120.1/2 and NTSB Form 6120.4. METEOROLOGICAL INFORMATION Visual meteorological conditions prevailed at the time of the accident. For additional weather information see NTSB Form 6120.4. WRECKAGE AND IMPACT INFORMATION The wreckage of N33456 was located behind a house located at 3106 Juanita Drive, Plant City, Florida. Examination of the crash site revealed the airplane collided with trees about 20 feet above the base of the trees on a heading of about 070 degrees separating the right wing at the wing root and 97 inches outboard of the wing root. The airplane rolled right, and the left wing collided with a tree separating the wing at the wing root. The left and right auxiliary tip tanks separated and were ruptured. The left and right fuel tanks were ruptured. The airplane collided with the ground and came to rest on a heading of 080 degrees. The left side forward and rear engine cowling fasteners were fastened. The right side forward and rear engine cowling fasteners were not fastened, and the cam lock fasteners were missing. The lip of the right hand rear latch is painted with light blue paint. Oil was present on the right rear cowling latch, inside and outside of the engine cowling, fragments of the windshield, cabin roof, extending rearward to the tail section and stabilator. No oil was present on the bottom side of the fuselage. The oil cooler was covered with oil and was punctured. Light blue paint was present at the puncture hole. Torsional twisting and "s" bending, and chordwise scarring was present on both propeller blades. Examination of the airframe, and flight controls revealed no evidence to indicate a precrash failure or malfunction. All components necessary for flight were present at the crash site. Continuity of the flight control system was confirmed for pitch, roll, and yaw. Examination of the engine revealed the No. 6 cylinder piston was wedged in the cylinder with the main beam of the connecting rod and piston intact. One connecting rod bearing arm was broken off and the other arm was heavily deformed. Severe evidence of overheating was present on the bearing end of the connecting rod, on separated pieces of the rod arm, rod bolt, and bearing inserts. The oil cooler, upper cowling assembly with cowling latch, No. 6 cylinder, connecting rod, connecting rod bolt, and pieces of bearing inserts, was forwarded to the NTSB laboratory for further analysis. MEDICAL AND PATHOLOGICAL INFORMATION The pilot, Carlos A. Hernandez, was transported to the Tampa General Hospital, Tampa, Florida, with serious injuries. Toxicology studies of specimens from the pilot were requested but were not performed. TEST AND RESEARCH Examination of the oil cooler, upper cowling assembly with cowling latch, No. 6 cylinder, connecting rod, connecting rod bolt, and pieces of bearing inserts was performed by the NTSB Materials Laboratory. The oil cooler has an approximate 2-inch long through-the-wall penetration between two adjacent corrugations on the top surface of the oil cooler. The cooling fins contained evidence of crush damage down and inward. The bent edges of the oil cooler wall on both sides of the opening contained distinct rub marks and specks of blue color paint was on the surface of the fin. The fracture faces on the opening had features typical of overstress separations with no evidence of progressive or preexisting cracking. Examination of the cowling latch assembly revealed the latch plate that attaches to the upper cowling was torn off from the surface of the cowling. The latch was deformed out of shape and contained two areas of sharp bends. The cowling and the latch were painted with light blue and white color stripes. The skirt of the No. 6 cylinder was broken off. The fracture face contained features typical of an overstress separation. The connecting rod was slightly deformed and twisted in the I-beam section. One of the connecting rod bearing arms was broken off, and the other arm was heavily deformed. The fracture in the broken arm revealed features typical of gross overstress. The bearing end of the connecting rod, separated pieces of the rod arm, rod bolt, and bearing inserts contained evidence of severe overheating. The connecting rod contained numerous impact marks in the bearing arm, and similar marks were observed on the wall of the No. 6 cylinder. (For additional information see, NTSB Metallurgist's Factual Report No. 95-81). ADDITIONAL INFORMATION Mr. Nick Koran, a co-owner of N33456, stated the pilot of N33456 changed the oil on the airplane on December 26, 1994. The airplane was not flown again until the day of the accident. The wreckage was released to Deputy Sheriff Jeffrey S. Quandahl, Hillsborough County Sheriffs Office, on December 29, 1994. The engine was released to Mr. Fred E. Ware, Florida Aero Services, on December 30, 1994. The aircraft logbooks were released to Mr. Carlos A. Hernandez, on January 6, 1995. The engine oil cooler, cowling latch assembly, No. 6 cylinder with a connecting rod, separated pieces of the connecting rod, connecting rod bolt, and bearing inserts were released to N. Hernandez, on April 24, 1995.

Probable Cause and Findings

The opening of the engine cowling latch in cruise flight for undetermined reasons. This resulted in the puncture of the engine oil cooler, total exhaustion of the engine oil, failure of the No. 6 connecting rod, rod bolts, forced landing while on final approach, and subsequent in-flight collision with non suitable terrain.

 

Source: NTSB Aviation Accident Database

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