Orlando, FL, USA
N9336H
Cessna 172M
The airplane experienced a total loss of engine power and collided with wires and a power line pole while descending for a forced landing. The pilot-rated student reported that while returning to the departure airport (KORL), he noted a smell of something burning which triggered him to look at the engine gauges; he noted "...that we had no oil pressure." No oil was noted by the student on the windscreen or on the sides of the airplane. The flight continued towards KORL, and 5 minutes 3 seconds after an occupant first advised the controller of having no oil pressure, an occupant advised the controller that the engine quit. The CFI took the controls and maneuvered the airplane towards a nearby golf course for a forced landing. He made several s-turns to lose altitude with full flaps extended, but while maneuvering to possibly land on a nearby road, the airplane collided with power lines, then a power pole. Postaccident, an oil film was noted on the exterior surface of the fuselage bottom skin, and in the engine compartment area on the aft side of the baffling. During postaccident testing, a leak was noted from a flexible hose near the oil cooler end; the cure date of the hose was the 3rd quarter 1981. Ten ounces of oil were drained from the engine, which exhibited internal evidence of oil exhaustion with resulting failure of the No. 2 cylinder connecting rod cap and bolt. The engine was overhauled last in 2001. The engine manufacturer recommends replacement of oil hoses at normal engine overhaul. A note in the airplane maintenance manual indicates that rubber engine compartment hoses are to be replaced every 5 years or at engine overhaul, whichever occurs first. Examination of the hose by the NTSB Materials Laboratory revealed a .7 inch long crack located approximately 4.25 inches from the oil cooler adapter end. The crack was oriented "slightly away from the longitudinal axis." Bench binocular microscope (BBM) examination of the hose revealed the woven fiber strands were missing in the cracked area. Scanning electron microscope (SEM) and BBM examination of the face of the crack revealed the thickness of the outer layer of rubber was reduced, and a portion of the reduced outer layer of rubber that was located midspan of the crack was missing. Additionally, the fiber strands that were located between the inner and outer rubber layers were fractured. The inner layer of rubber was found to contain fracture lines that emanated from the outer surface layer in an area that contained an impression of fiber strands from the fibers between the 2 rubber layers. The lines on the surface crack indicated that cracking of the inner layer propagated towards the inner diameter of the hose; cracking on a flat plane was noted to within .01 inch of the inside surface of the hose. Examination of other areas of the inside surface of the hose revealed extensive longitudinal cracks. Additionally, the exterior surface of the contained abrasion damage in three areas other than the cracked area of the hose; the abrasion damage did not extend through the outer layer of rubber.
HISTORY OF FLIGHT On January 11, 2005, about 1647 eastern standard time, a Cessna 172M, N9336H, registered to Grady and Francis, Inc., operated by CAP Flying, Inc., experienced a total loss of engine power and collided with wires and a power line pole while descending for a forced landing near Orlando, Florida. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 CFR Part 91 instructional, local flight, from the Orlando Executive Airport, Orlando, Florida. The airplane was substantially damaged and the certified flight instructor (CFI) was fatally injured, while the pilot-rated student (student) sustained serious injuries. The flight originated about 1526, from the Orlando Executive Airport. According to a transcription of communications with Orlando Executive Airport (KORL) Air Traffic Control Tower (ATCT), the CFI contacted the facility at 1639:36, and advised the controller, "yeah we are about 8 miles northwest of you ah we are showing no oil pressure we are coming in we would like to ah do a straight in on one three." The controller cleared the flight for a straight in landing on runway 13, which was acknowledged. The flight continued and at 1641:48, the controller stated, "cessna three six hotel I just want ah to verify you are ah having you are getting no oil pressure indication or low oil." The CFI responded, "ah looks like zero oil indication", which the controller acknowledged. At 1642:01, the controller advised the flight crew that the equipment was responding and, "you will see them standing by"; the CFI acknowledged that transmission. At 1644:39, or 5 minutes 3 seconds after the CFI first advised the controller of having no oil pressure, the CFI stated, "executive tower niner three three six hotel just had an engine failure ahm looks like we are coming in on runway one three." The controller advised the flight crew that they were number one cleared to land on runway 13, and provided wind information. At 1645:01, the CFI stated, "doesn't look like we're going to make the runway so we are going to turn around for the golf course." The controller acknowledged that transmission, and established contact with a news helicopter that was airborne in the area at 1645:34. The controller requested that the flight crew of the helicopter maintain visual contact with the aircraft and track the flight for him. At 1647:03, a flight crew member of the news helicopter advised the controller, "... he just crossed Edgewater high real bad." The student seated in the left seat stated in writing that they had been practicing commercial maneuvers, and after completion, decided to return to the airport for some 180-degree power off approaches. On the flight back to the airport he smelled something burning, which "... triggered me to look at my gauges and notice that we had no oil pressure." The CFI contacted the KORL ATCT, and advised the controller of the situation. Both he and the CFI continued to look for a place to land if required, and the flight climbed a little bit to have more altitude to allow for a longer "glide time." He reported that a few minutes passed, and they started a slow descent for the airport. When leaving approximately 2,000 feet, the engine quit. The CFI took the controls of the aircraft, and advised the controller of the engine failure and his intention to land on a golf course. He (student) turned off the fuel, mixture, magnetos, and the alternator, but left the battery on for communications. When the flight was close to the ground "...we realized that we were going to have to make a steep approach. Dan put in all the flaps and did his best to fly down the fairway, keeping clear of all people and obstacles. Dan made a last minute decision to go to the left to possibly fly and land on the road, when we collided with the power lines, then the power pole which is where we came to rest. I remember very little after that." The student verbally advised the Federal Aviation Administration (FAA) inspector-in-charge (IIC) that no oil was noted on the windscreen or on the sides of the airplane after noting there was no oil pressure. He also reported beginning to descend when the flight was approximately 4 miles northwest of KORL, and while flying at an altitude of approximately 1,500 feet, the engine began to vibrate then failed. The CFI took the controls and maneuvered the airplane towards the Dubsdread Golf Course which was to the left of their position at the time of the engine failure. The CFI made several s-turns to lose altitude, an approached the golf course fairways from an easterly to westerly direction. It appeared that the aircraft was going to overfly the point of intended landing, but the CFI did not slip the aircraft to lose altitude. The flight crossed trees at the easterly end of the golf course fairways, and was too high. The CFI maneuvered the aircraft in an attempt to find a suitable location to land, and the left-wing collided with wires causing the airplane to rotate approximately 90 degrees to the right. He did not see the wires prior to the collision, and does not remember the collision with the power pole. PERSONNEL INFORMATION The left seat occupant is the holder of a commercial pilot certificate with airplane multiengine land, and instrument airplane ratings. He also holds a single-engine land rating at the private level. He was issued a first-class medical certificate on May 27, 2003, with no limitations. He listed on the NTSB "Pilot/Operator Aircraft Accident Report" that he had a total flight time of 654 hours, of which 175 were in the accident make and model airplane. The right seat occupant was the holder of a commercial pilot certificate with airplane single-engine land, airplane multiengine land, and instrument airplane ratings. He was also the holder of a flight instructor certificate with airplane single-engine, and instrument airplane ratings. He was issued a first-class medical certificate on September 2, 2004, with a restriction "must wear corrective lenses." He listed a total time of 1,620 hours on the last medical certificate application. AIRCRAFT INFORMATION The airplane was manufactured by Cessna Aircraft Company in 1975, as a 172M, and designated serial number 17266094. It was certificated in the normal and utility categories, and was equipped with a 150 horsepower Lycoming O-320-E2D engine, and a McCauley 1C160/DTM7553 fixed pitch propeller. The airplane and engine were last inspected on November 4, 2004, when they received a 100-hour inspection. At the time the accident, the airplane had accumulated approximately 91 hours since the last inspection, and 6, 620 total flight hours. METEOROLOGICAL INFORMATION A METAR weather observation taken at the Orlando Executive Airport, Orlando, Florida, at 1653, or approximately 6 minutes after the accident, indicates the wind was from 190 degrees at 3 knots, the visibility was 10 statute miles, scattered clouds existed at 6,000 feet, the temperature and dewpoint were 26 and 15 degrees Celsius, respectively, and altimeter setting was 30.18 inHg. COMMUNICATIONS There were no reported communication difficulties. WRECKAGE AND IMPACT INFORMATION Examination of the accident site and wreckage by an FAA Aviation Safety Inspector revealed the airplane came to rest at the base of a concrete power pole located at 28 degrees 34.94 minutes North latitude and 081 degrees 22.96 minutes West longitude. The airplane was recovered for further examination. Examination of the airplane and engine following recovery was performed by representatives of the airframe and engine manufacturer with NTSB and FAA oversight. The examination of the airplane revealed no evidence of flight control preimpact failure or malfunction; the flaps were fully extended. The right side of the cabin, and the airplane forward of the instrument panel was crushed. Both front seats remained attached to the seat rails but were impact damaged. The right seat was noted to be positioned aft of the left front seat. The exterior surface of the fuselage bottom skin was noted to have a thin film of oil, and the engine cowling was noted to have a fresh oil stain in the vicinity of the oil dipstick opening. The upper portion of the oil dipstick tube remained secured to the engine by safety wire; the threads of the tube that screw in the lower tube were damaged. A crack was noted in the threaded area of the lower tube. The engine oil dipstick was bent approximately 90 degrees. Oil was also noted on the right rear interior surfaces of the engine cowling, on the back of the engine, and on the firewall; however, very little oil was noted on the engine forward of the pressure of baffling. The oil cooler, both flexible hoses connected to it, and the flexible oil pressure hose were removed and checked for leaks using compressed air. The oil pressure indicator hose, oil cooler, and the "Hose Assy Cooler To Engine" did not leak when checked using compressed air; the flexible oil pressure hose was noted to have a data tag indicating "3Q79." The flexible hose "Hose Assy Engine To Cooler", Cessna P/N S1167-6-0260, was noted to have a leak near the oil cooler end when tested for leaks using compressed air; the hose was retained for further examination. The engine was removed from the airplane for further examination. Examination of the engine revealed 10 ounces of oil were drained from the oil sump; ferrous material was noted in the bottom of the sump. The engine could only be rotated through approximately 25 degrees before resistance was encountered; continuity to the accessory case was noted during the partial rotation of the engine. The oil suction screen was noted to have contamination that was consistent with silicon rubber. Ferrous material was noted in the oil filter canister. Disassembly of the engine revealed no damage to the camshaft, lifters, pushrods, valve rockers, valve springs, valves, or oil pump. The No. 2 cylinder connecting rod was separated from the crankpin; the crankpin and connecting rod exhibited evidence of high heat. The connecting rod cap was fragmented and one of the connecting rod bolts was bent and fractured. The remains of a separated connecting rod bolt and bearing shell material were found in the crankcase. Examination of the remaining connecting rod bearings revealed the surface conditions were, "...best described as 'wiped'." No damage was noted to the main or camshaft bearings. No obstructions were noted in the crankcase oil galleys, camshaft bearing oil passages, or the passages to the hydraulic tappet bodies. MEDICAL AND PATHOLOGICAL INFORMATION A postmortem examination of the CFI was performed by the District Nine Medical Examiner's Office, Orlando, Florida. The cause of death was listed as blunt trauma to head and torso. Toxicological analysis of specimens of the CFI was performed by the Wuesthoff Reference Laboratory (Wuesthoff), Melbourne, Florida, and the FAA Toxicology And Accident Research Laboratory (CAMI), Oklahoma City, Oklahoma. The result of analysis by Wuesthoff was negative for the immunoassay screen, and volatiles; caffeine was detected. The result of analysis by CAMI was negative for carbon monoxide, cyanide, volatiles, and tested drugs. TESTS AND RESEARCH Following manufacture of the engine, it was shipped to Cessna Aircraft Company on May 17, 1974, where it was installed in another airplane (N1641V). The engine remained installed in that airplane until removed for overhaul on an unspecified date after June 25, 1982. The engine was overhauled on August 18, 1982, and installed in the accident airplane on August 27, 1982. The entry in the engine logbook for that date indicates "replaced all flammable fluid carrying hoses...." The engine remained installed in the accident airplane until it was removed for overhaul again on an unspecified date after February 1, 2001. The engine was signed off as being overhauled on March 9, 2001, and installed in the accident airplane the following day. The engine remained installed in the airplane from March 10, 2001, until postaccident removal. There was no entry in the airframe or engine logbooks indicating the oil cooler hoses had been replaced since 1982; the airplane had accumulated approximately 4,652 hours since the "flammable fluid carrying hoses" were changed. According to the mechanic who had maintained the airplane since January 2000, and installed the engine following overhaul in 2001, he reportedly manufactured and installed replacement oil cooler hoses when the overhauled engine was installed. He also reported it was common practice for him to replace all engine compartment rubber hoses when an engine is installed following overhaul. He obtained the hose material from 11-foot sections of hose he obtained from "API" or "Air Parts of Miami." The Lycoming Engine Overhaul Manual, Section 3, "General Overhaul Procedures", indicates all engine hoses are to be replaced at normal overhaul regardless of their apparent condition, and references Service Bulletin No. 240 for further information. A note in the airplane maintenance manual indicates that rubber engine compartment hoses are to be replaced every 5 years or at engine overhaul, whichever occurs first. A marking on the failed "Hose Assy Engine to Cooler", Cessna P/N S1167-6-0260, indicates "3Q81", or 3rd Quarter 1981. Review of the engineering drawing for the hose revealed a requirement that hoses have the "Cure Date of Hose Used In Hose Assembly" legibly marked. Examination of the "Hose Assy Engine To Cooler", Cessna P/N S1167-6-0260, which was noted to have a leak, was performed by the NTSB Materials Laboratory, located in Washington, D.C. A crack approximately .7 inch in length was located approximately 4.25 inches from the oil cooler adapter end. The crack was oriented "slightly away from the longitudinal axis." Bench binocular microscope (BBM) examination of the hose revealed the woven fiber strands were missing in the cracked area. Scanning electron microscope (SEM) and BBM examination of the face of the crack revealed the thickness of the outer layer of rubber was reduced, and a portion of the reduced outer layer of rubber that was located midspan of the crack was missing. Additionally, the fiber strands that were located between the inner and outer rubber layers were fractured. The inner layer of rubber was found to contain fracture lines that emanated from the outer surface layer in an area that contained an impression of fiber strands from the fibers between the 2 rubber layers. The lines on the surface crack indicated that cracking of the inner layer propagated towards the inner diameter of the hose; cracking on a flat plane was noted to within .01 inch of the inside surface of the hose. Examination of other areas of the inside surface of the hose revealed extensive longitudinal cracks. Additionally, the exterior surface contained abrasion damage in three areas other than the cracked area of the hose; the abrasion damage did not extend through the outer layer of rubber. A review of the "Pilot's Operating Handbook" revealed an emergency procedure dealing with "Low Oil Pressure." The amplied procedure indicates, "If a total loss of oil pressure is accompanied by a rise in oil temperature, there is good reason to suspect an engine failure is imminent. Reduce engine power immediately and select a suitable forced landing field. Use only the minimum power required to reach the desired touchdown spot." ADDITIONAL INFORMATION The wreckage minus the retained flexible hoses to and from the oil cooler was released to Buck Williams of Sample International, Inc., on January 13, 2005. The retained hoses were also released to Buck Williams on October 4, 2005.
The failure of the CFI to initiate a precautionary landing after noticing zero oil pressure with corresponding oil temperature increase, resulting in total loss of engine power due to oil exhaustion. A contributing factor in the accident was the failure of company maintenance personnel to replace the flexible oil cooler hoses during engine installation following overhaul, as recommended by the engine manufacturer.
Source: NTSB Aviation Accident Database
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