# NTSB LAX97LA058: Cessna T210N, N4788C, Scottsdale, AZ, November 30, 1996 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: November 30, 1996, 09:34 local (16:34 UTC) - Place: Scottsdale, AZ - Coordinates: 33.60947, -111.890625 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.6095&lon=-111.8906&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 5 serious - Status: Completed, report September 30, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 29695 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX97LA058 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/29695/pdf - Page: https://openairdocs.org/ntsb/LAX97LA058 ## Probable cause detonation/pre-ignition for unknown reason(s), which resulted in failure of the number two piston, loss of engine power, and a subsequent forced landing on rough/uneven desert terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, climb - engine assembly,piston - overtemperature (cause) - misc,engine pre-ignition and/or detonation (cause) - engine assembly,piston - failure (cause) - Forced landing, emergency descent/landing - In flight collision with terrain/water, emergency landing - terrain condition - rough/uneven (contributing factor) ## Analysis While the airplane was climbing after departure, the engine lost power, then the pilot made a forced landing, and the airplane was damaged. Postaccident examination of the engine revealed that the piston in the #2 cylinder had failed. The #2 piston crown was severely eroded over 80 percent of the piston circumference. Erosion, scoring, and metal transfer was evident on the piston skirts. Before removal of the #2 cylinder, heat discoloration was noted on the cylinder base. A report from the engine manufacturer stated that the failure was due to detonation/preignition. The entire fuel system, both magnetos, and the turbo controller were functionally tested at the respective manufacturer's facilities. All of the components met the FAA approved test data. ## Factual narrative On November 30, 1996, at 0934 hours mountain standard time, a Cessna T210N, N4788C, was substantially damaged during a forced landing following a loss of power upon departure from Scottsdale, Arizona. The pilot and four passengers received serious injuries. Visual meteorological conditions prevailed for the personal cross-country flight and an IFR flight plan was filed. The flight was en route to San Diego, California. Postaccident examination of the engine revealed that the number 2 piston exhibited detonation/preignition damage with upper ring land failure and heavy piston scoring, erosion, and metal transfer to the piston skirt. A burn hole was observed through a piston ring groove into the interior of the piston. The top rings were fragmented. The lower ring was intact, but seized in its groove. The top edge of the piston crown was melted and eroded away over 80 percent of the piston circumference. The piston was shipped to the engine manufacturer for examination and analysis under the supervision of the FAA MIDO inspector. According to the report, the failure was caused by detonation/preignition due to undetermined causes. The report also listed some possible causes of this type of event. Both of the engine driven magnetos were shipped to the manufacturer's facility at Atlanta, Georgia. Functional testing and teardown examination was conducted under the supervision of the FAA MIDO inspector. According to the report, all installed parts were appropriate part numbers and in proper condition and adjustment. The magnetos were functional tested to the FAA approved TCM data. Both magnetos meet the test specifications of the data. The turbo controller was hand carried by a Safety Board investigator to the Allied Signal turbo division at Torrance, California, for functional testing. According to the test results the controller met the manufacturer's FAA approved test data. The engine fuel system was removed and shipped to the manufacturer, Continental Motors. The examination and functional testing was supervised by the FAA MIDO inspector. Some of the "O" ring seals had dried out from storage without fuel. The examination revealed that they exhibited the ability to flow fuel and appeared to be capable of functioning properly on the engine's fuel system. The items that were functional tested met the manufacturers specifications. According to a dictionary of aeronautical terms, detonation (a reciprocating engine condition) is an uncontrolled explosion inside the cylinder of a reciprocating engine. Detonation occurs when the pressure and temperature inside the cylinder become higher than the critical pressure and temperature of the fuel. The pressure rise inside the cylinder caused by the fast moving flame front can heat and compress the unburned fuel-air mixture enough for it to explode, or release it's energy almost instantaneously. Detonation releases the energy faster than the engine can accept it, and the engine is likely to be damaged. Preignition (reciprocating engine malfunction) is ignition of the fuel-air mixture inside the cylinder of an engine before the normal spark occurs. Preignition can be caused by an incandescent piece of carbon or by any other sharp edge or point inside the cylinder that gets red-hot. ## Aircraft - Registration: [N4788C](https://openairdocs.org/deregistered/N4788C-1998-06-12), registration cancelled 1998-06-12, S/N 21063625 (OpenAirDocs) - Reported make and model: Cessna T210N - Registry model: [Cessna T210N](https://openairdocs.org/model/cessna-t210n) (registry code 2073456) (OpenAirDocs) - Category: Airplane - Serial number: 21063625 - Airframe hours: 5374 - Engines: Continental TSIO-520-R 310 horsepower reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Operator: Scottsdale Flyers LLC - Registered owner: Leonard Zaagman - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 18, 1995, 95 hours before - Departed: SDL, AZ - Destination: MYF, SAN DIEGO, CA - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 52; airline transport; airplane ratings: single-engine sea, multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: right; flight hours: 12,000 total, 35 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 170° at 4 knots - Visibility: 60 statute miles - Lowest ceiling: none - Altimeter: 30.00 inHg - Observed at: SDL ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19961130036909A](https://openairdocs.org/incident/19961130036909A), Nov 30, 1996: Cessna T210N, Scottsdale, AZ, Substantial damage. Lost power on climbout. Damaged landing. NR2 cyl detonation damage. Cause of pre ignition unknown. Carbon possible. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.