# NTSB CHI01FA093: Cessna 172H, N733SS, Centralia, IL, February 21, 2001 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: February 21, 2001, 07:05 local (13:05 UTC) - Place: Centralia, IL - Coordinates: 38.520355, -89.120162 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.5204&lon=-89.1202&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 2 fatal - Status: Completed, report June 4, 2002 - Report: Approved by Office Director - Parties: Cessna, Lycoming, FAA - NTSB case key (mKey): 51810 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI01FA093 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/51810/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=51810 - Page: https://openairdocs.org/ntsb/CHI01FA093 ## Probable cause The student pilot allowed the airspeed to get too low and inadvertently stalled the airplane, and the CFI delayed in taking remedial action. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, approach - airspeed - low, dual student (cause) - stall - inadvertent, dual student (cause) - remedial action - delayed, pilot in command(cfi) (cause) - In flight collision with terrain/water, descent - uncontrolled ## Analysis The airplane was destroyed when it impacted terrain 1.2 miles from the airport on a magnetic bearing of 003 degrees from the approach end of runway 18. The CFI weighed approximately 149 pounds and the student pilot weighed approximately 310 pounds. A witness reported seeing the airplane traveling toward him from west to east. He reported hearing the airplane's engine initially, and that the engine was at a low power setting. He reported the airplane was low, about 500 feet, and the airspeed was slow. The airplane was in a steep angle of bank and in a turn to the right. He reported the airplane was in "...a kind of a climb in a bank." After 270 degrees of turn, the airplane flipped over on its back and became inverted. The nose of the airplane then went down. He reported the nose of the airplane started coming up and the airplane looked like it was going to recover when he lost sight of the airplane behind a tree line. He reported hearing the airplane's engine revving to full power before hearing it impact the terrain. An examination of the airplane's system revealed no anomalies. ## Factual narrative HISTORY OF FLIGHT On February 21, 2001, at 0705 central standard time, a Cessna 172H, N733SS, operated by AIRGO, Inc., was destroyed when it impacted terrain 1.2 miles from the Centralia Municipal Airport (ENL), Centralia, Illinois, on a magnetic bearing of 003 degrees from the airport. The Certificated Flight Instructor (CFI) and student pilot were fatally injured. The 14 CFR Part 91 flight departed from ENL approximately 0620 on a local instructional flight. No flight plan was filed. A witness reported seeing the airplane traveling toward him from west to east. The witness reported initially hearing the airplane's engine, and that the engine was at a low power setting. He reported the airplane was low, about 500 feet, and the airspeed was slow. He reported the airplane was in a steep angle of bank and in a turn to the right. He reported the airplane was in "…a kind of a climb in a bank." He reported that after 270 degrees of turn, the airplane flipped over on its back and became inverted. The nose of the airplane then went down. He reported the nose of the airplane started coming up and the airplane looked like it was going to recover when he lost sight of the airplane behind a tree line. He reported hearing the airplane's engine revving to full power. Then he heard the airplane impact the terrain approximately 1/4 mile away. PERSONNEL INFORMATION The 32 year old CFI was a commercial rated pilot with single and multi-engine airplane land and instrument pilot ratings. He held instructor ratings for single and multi-engine land airplanes and an airplane instrument instructor rating. He held a First Class Medical Certificate that was issued on July 1, 1999. The CFI was 5'7" tall and weighed approximately 149 pounds. He had a total of approximately 2,504 flight hours. He flew 112 hours in the last 90 days, which included 107 instructional flight hours. The CFI had received his CFI rating on March 22, 1999, and had been flying as an instructor pilot for the operator. He had successfully completed a FAA chief flight instructor check ride for FAR Part 141 operations on December 8, 2000. The CFI was designated as the Chief Flight Instructor for the operator's FAR Part 141 flight school. The CFI was a citizen of the United Kingdom. He did not have a visa waiver, a work permit card, or a "Green Card" issued by the United States Immigration and Naturalization Service (INS). The 55 year old student pilot held a Third Class Medical Certificate that was issued on July 29, 1999. He had approximately 98 total flight hours. He flew 17.9 hours, which included 2.5 solo flight hours, between January 21, 2001, and the day of the accident. Prior to January 21, 2001, the student pilot's last documented flight was on August 18, 2000. He had logged a total of 18.0 solo flight hours. The student pilot was 6'4" tall and weighed approximately 310 pounds. AIRCRAFT INFORMATION The airplane was a single engine Cessna 172H, serial number 17268518, manufactured in 1977. The airplane seated four and had a maximum gross weight of 2,300 pounds. The engine was a 160 horsepower Lycoming O-320-H2AD engine. The last 100 hour inspection was conducted on December 14, 2000, and the last annual inspection was conducted on April 3, 2000. The airplane had flown 61 hours since the last inspection and had a total airframe time of 8,563 hours. The engine had 4,181 hours since a major overhaul on June 10, 1991. At the time of the overhaul, the engine had a total time of 1,371.1 hours. The engine cylinder compression readings recorded on December 14, 2000, during the last 100 hour inspection, were 1) 74/80, 2) 78/80, 3) 75/80 and 4) 75/80. The operator had purchased the airplane on October 15, 1994. METEOROLOGICAL INFORMATION The 0655 observed weather at Mt. Vernon, Illinois, located 16 miles southeast of ENL, was: Winds 020 at 7 knots, 10 miles visibility, clear, temperature 27 degrees F, dew point 13 degrees F, altimeter 30.50. WRECKAGE AND IMPACT INFORMATION The wreckage site was located on the bank of Raccoon Lake, approximately 1.2 nautical miles from the threshold for Runway 18 at ENL and close to the runway centerline. The coordinates were 38 degrees 32.35 minutes N, and 089 degrees 04.42 minutes W. The wreckage path covered a distance of about 125 feet on a bearing of 130 degrees magnetic. The initial impact point was a tree root at the water's edge which had a piece of wing structure lodged in it. The main wreckage, located about 32 feet from the point of initial impact, came to rest against two hardwood trees about 10 feet above the lake's shoreline. The empenage remained attached to the fuselage and both were found in a 50 - 60 degrees nose down attitude with the longitudinal axis aligned to the northeast. The right side of the cabin impacted the trees at or just aft of the front seats. The right cabin door was found against the left side of the fuselage. Neither of the front seat lap belts were intact. The webbing of both lap belts was torn and shredded. Both shoulder harnesses were attached to the airframe, but only the right shoulder harness was attached to a lap belt. The instrument panel was separated from the fuselage and was not intact. The engine was partially separated from its engine mounts and was found under the left wing, inverted, and pointing in a northerly heading. The left wing remained attached to the fuselage and was located to the left of the fuselage. It exhibited aft compression of the leading edge and front spar along its span but remained intact. The wingtip had separated from the wing. Pieces of wing structure with electrical wiring in it were found crushed and embedded in a tree root at the initial point of impact. The right wing impacted the hardwood trees. The wing separated at Wing Station (WS) 100.5. The inboard section of wing that remained attached to the fuselage exhibited crushing and buckling of its leading edge and spar. The section of wing from WS 100.5 to WS 208.0 exhibited crushing and buckling. A three-foot section of the right wing spar web was located on the ground to the left side of the fuselage. All flight controls were found at the wreckage site. The flaps were retracted and the elevator trim was found 5 degrees up (nose down trim). Control cable continuity was established from the ailerons, elevator, and rudder to the respective cockpit controls. The aileron cables were found connected to the cockpit control yoke assembly. The aileron cables were found separated at approximately Fuselage Station (FS) 25 and the cables exhibited "broom straw" separations. The direct and crossover cables were connected at the left and right aileron bellcranks and exhibited continuity to FS 25 where the respective cables exhibited broom straw separations. The direct control cables had separated strands at the aileron direct cable pulleys in each wing. The National Transportation Safety Board (NTSB) retained the sections of cable with separated strands for further examination. The direct cable pulleys were found intact. There were no nicks, gouges, or scratches to the aluminum pulley bracket. Both pulleys rotated and they had no nicks, gouges, or scratches. Both pulleys had black grease residue on the side of the pulleys and in the pulley grooves. The cotter keys were intact. There were no signs of cable rub against any interior wing sections between the left and right wing aileron bellcranks and the wing roots. The engine examination revealed the crankshaft rotated and there was valve train continuity and rear accessory gear rotation. Thumb compression and suction were observed on all cylinders. The carburetor was broken at the mounting flange. The single shaft, dual magneto was found separated from the engine. The cap assembly, ignition wiring, and left side of the distributor assembly sustained damage. The drive ## Aircraft - Registration: [N733SS](https://openairdocs.org/deregistered/N733SS-2001-04-30), registration cancelled 2001-04-30, S/N 17268518 (OpenAirDocs) - Reported make and model: Cessna 172H - Registry model: [Cessna 172N](https://openairdocs.org/model/cessna-172n) (registry code 2072434) (OpenAirDocs) - Category: Airplane - Serial number: 17268518 - Airframe hours: 8563 - Engines: Lycoming O-320-H2AD 160 horsepower reciprocating - Damage: Destroyed - Flight: Instructional, Part 91 - Registered owner: AIRGO Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 14, 2000, 61 hours before - Departed: ENL, Centralia, IL - Airport: ENL, Centralia Municipal Airport, runway 18, 5,001 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 32; injuries: fatal; flight instructor, commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; last flight review August 13, 2000; seat: right; toxicology performed; flight hours: 2,504 total, 2,321 as pilot in command, 112 in the last 90 days, 20 in the last 30 days - Student pilot; age 55; injuries: fatal; student; medical: class 3, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 55 total ## Weather - Conditions: Visual (VMC), Day - Wind: 20° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 27 °F, dew point 12 °F - Altimeter: 30.50 inHg - Observed at: MVN, 16 nm away ## 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 20010221003509A](https://openairdocs.org/incident/20010221003509A), Feb 21, 2001: Cessna 172, Centralia, IL, No damage, 2 fatal. (-19) On February 21, 2001, at 0705 CST, a Cessna 172H, N733SS, operated by airgo, inc., was destroyed when it impacted terrain 1.2 miles from the Centralia… ## Docket (37 files) The files NTSB released with the investigation on May 14, 2002, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=51810. 13.9 MB in all. - Supplement A (item 1, .PDF, 235 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158138&FileExtension=.PDF&FileName=Supplement%20A-Master.PDF - Supplement B (item 2, .PDF, 328 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158154&FileExtension=.PDF&FileName=Supplement%20B-Master.PDF - Materials Laboratory Factual Report (item 3, .PDF, 48 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40356163&FileExtension=.PDF&FileName=Materials%20Laboratory%20Factual%20Report-Redacted.PDF - Record of Interview & Director of Maintenance Statement (item 4, .PDF, 92 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40356164&FileExtension=.PDF&FileName=Record%20of%20Interview%20%26%20Director%20of%20Maintenance%20Statement-Redacted.PDF - Mishap Site Information (item 5, .PDF, 65 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158161&FileExtension=.PDF&FileName=Mishap%20Site%20Information-Master.PDF - Airport Diagram & Approach Plate (item 6, .PDF, 100 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158163&FileExtension=.PDF&FileName=Airport%20Diagram%20%26%20Approach%20Plate-Master.PDF - NTSB Inspection of Aileron Cables & Pulleys (item 7, .PDF, 69 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158165&FileExtension=.PDF&FileName=NTSB%20Inspection%20of%20Aileron%20Cables%20%26%20Pulleys-Master.PDF - Excerpt From Cessna Service Manual (item 8, .PDF, 15 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158169&FileExtension=.PDF&FileName=Excerpt%20From%20Cessna%20Service%20Manual-Master.PDF - Lycoming Engine Report (item 9, .PDF, 291 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158172&FileExtension=.PDF&FileName=Lycoming%20Engine%20Report-Master.PDF - Pilot & Operator Information (item 10, .PDF, 388 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158173&FileExtension=.PDF&FileName=Pilot%20%26%20Operator%20Information-Master.PDF - CFI Pilot Logbook (item 11, .PDF, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158176&FileExtension=.PDF&FileName=CFI%20Pilot%20Logbook-Master.PDF - Excerpts From Maintenance Logbooks (item 12, .PDF, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158179&FileExtension=.PDF&FileName=Excerpts%20From%20Maintenance%20Logbooks-Master.PDF - Toxicological Report (item 13, .PDF, 191 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158180&FileExtension=.PDF&FileName=Toxicological%20Report-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 14, .PDF, 649 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158181&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Master.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 15, .PDF, 83 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158182&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Master.PDF - Photo 1. View of Wreckage Looking to the Southeast (item 16, .PDF, 470 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158187&FileExtension=.PDF&FileName=Photo%201.%20%20View%20of%20Wreckage%20Looking%20to%20the%20Southeast-Master.PDF - Photo 2. View of Wreckage Looking to the Northwest (item 17, .PDF, 444 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158188&FileExtension=.PDF&FileName=Photo%202.%20%20View%20of%20Wreckage%20Looking%20to%20the%20Northwest-Master.PDF - Photo 3. View of Left Wing (item 18, .PDF, 425 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158189&FileExtension=.PDF&FileName=Photo%203.%20%20View%20of%20Left%20Wing-Master.PDF - Photo 4. View of Right Wing Sections (item 19, .PDF, 405 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158190&FileExtension=.PDF&FileName=Photo%204.%20%20View%20of%20Right%20Wing%20Sections-Master.PDF - Photo 5. View of Empennage and Underside of Horizontal Stabilizer (item 20, .PDF, 398 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158191&FileExtension=.PDF&FileName=Photo%205.%20%20View%20of%20Empennage%20and%20Underside%20of%20Horizontal%20Stabilizer-Master.PDF - Photo 6. Engine and Propeller Under Left Wing (item 21, .PDF, 421 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158192&FileExtension=.PDF&FileName=Photo%206.%20%20Engine%20and%20Propeller%20Under%20Left%20Wing-Master.PDF - Photo 7. Empennage (item 22, .PDF, 343 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158193&FileExtension=.PDF&FileName=Photo%207.%20%20Empennage-Master.PDF - Photo 8. View of Cockpit (item 23, .PDF, 503 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158194&FileExtension=.PDF&FileName=Photo%208.%20%20View%20of%20Cockpit-Master.PDF - Photo 9. View of Engine and Cabin With Left Wing Removed From Wreckage (item 24, .PDF, 445 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158195&FileExtension=.PDF&FileName=Photo%209.%20%20View%20of%20Engine%20and%20Cabin%20With%20Left%20Wing%20Removed%20From%20Wreckage-Master.PDF - Photo 10. Left Aileron Cable at Roller (item 25, .PDF, 300 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158196&FileExtension=.PDF&FileName=Photo%2010.%20%20Left%20Aileron%20Cable%20at%20Roller-Master.PDF - Photo 11. Right Aileron Cable Segment and Roller on Top and Left Aileron Segment on Bottom (item 26, .PDF, 276 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158197&FileExtension=.PDF&FileName=Photo%2011.%20%20Right%20Aileron%20Cable%20Segment%20and%20Roller%20on%20Top%20and%20Left%20Aileron%20Segment%20on%20Bottom-Master.PDF - Photo 12. Propeller (item 27, .PDF, 306 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158198&FileExtension=.PDF&FileName=Photo%2012.%20%20Propeller-Master.PDF - Photo 13. View of Propeller Blade (item 28, .PDF, 281 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158199&FileExtension=.PDF&FileName=Photo%2013.%20%20View%20of%20Propeller%20Blade-Master.PDF - Photo 14. View of Second Propeller Blade (item 29, .PDF, 280 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158200&FileExtension=.PDF&FileName=Photo%2014.%20%20View%20of%20Second%20Propeller%20Blade-Master.PDF - Photo 15. View of Propeller Blade (item 30, .PDF, 17 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158201&FileExtension=.PDF&FileName=Photo%2015.%20%20View%20of%20Propeller%20Blade-Master.PDF - Photo 16. Right Aileron Cable Segment (item 31, .PDF, 21 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158202&FileExtension=.PDF&FileName=Photo%2016.%20%20Right%20Aileron%20Cable%20Segment-Master.PDF - Photo 17. Circumferential Rub Marks on Alternator Housing (item 32, .PDF, 372 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158203&FileExtension=.PDF&FileName=Photo%2017.%20%20Circumferential%20Rub%20Marks%20on%20Alternator%20Housing-Master.PDF - Photo 18. Wing Piece That Was Found Imbedded in Tree Root (item 33, .PDF, 406 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158205&FileExtension=.PDF&FileName=Photo%2018.%20%20Wing%20Piece%20That%20Was%20Found%20Imbedded%20in%20Tree%20Root-Master.PDF - Photo 19. View of Left Aileron Pulley (item 34, .PDF, 279 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158206&FileExtension=.PDF&FileName=Photo%2019.%20%20View%20of%20Left%20Aileron%20Pulley-Master.PDF - Photo 20. View of Left Aileron Pulley (item 35, .PDF, 253 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158207&FileExtension=.PDF&FileName=Photo%2020.%20%20View%20of%20Left%20Aileron%20Pulley-Master.PDF - Photo 21. View of Right Aileron Pulley (item 36, .PDF, 281 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158208&FileExtension=.PDF&FileName=Photo%2021.%20%20View%20of%20Right%20Aileron%20Pulley-Master.PDF - Photo 22. View of Right Aileron Pulley (item 37, .PDF, 289 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40158209&FileExtension=.PDF&FileName=Photo%2022.%20%20View%20of%20Right%20Aileron%20Pulley-Master.PDF 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.