# NTSB DFW07FA004: Aero Commander 690A, N55JS, Antlers, OK, October 15, 2006 - Type: NTSB accident investigation - Classification: Accident · Fatal · Field investigation · Final report - Date: October 15, 2006, 13:03 local (18:03 UTC) - Place: Antlers, OK - Coordinates: 34.180831, -95.707221 - Nearby events: https://openairdocs.org/map.md?lat=34.1808&lon=-95.7072&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 4 fatal - Status: Completed, report December 20, 2007 - Report: Approved by Office Director - Parties: Twin Commander Aircraft, Federal Aviation Administration, Honeywell Aerospace - NTSB case key (mKey): 64696 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DFW07FA004 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/64696/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=64696 - Page: https://openairdocs.org/ntsb/DFW07FA004 ## Probable cause The pilot's failure to reduce airspeed while operating in an area of moderate turbulence, resulting in an in-flight break up. Contributing factors were the pilot's decision to exceed the maximum takeoff weight, and the prevailing turbulence. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, cruise - weather condition - turbulence (contributing factor) - airframe - overload - design stress limits of aircraft - exceeded, pilot in command (cause) - aircraft weight and balance - exceeded, pilot in command (contributing factor) - In flight collision with terrain/water, descent - uncontrolled - terrain condition - ground ## Analysis Approximately 37 minutes after departing on a 928-nautical mile cross-country flight under instrument flight rules, the twin-engine turboprop airplane experienced an in-flight break-up after encountering moderate turbulence while in cruise flight at the assigned altitude of FL230. In the moments preceding the break-up, the airplane had been flying approximately 15 to 20 knots above the placarded maximum airspeed for operations in moderate turbulence. The airplane was found to be approximately 1,038 pounds over the maximum takeoff weight listed in the airplane's type certificate data sheet (TCDS). The last radar returns indicated that the airplane performed a 180-degree left turn while descending at a rate of approximately 13,500 feet per minute. There were no reported eyewitnesses to the accident. The wreckage was located the next day in densely wooded terrain. The wreckage was scattered over an area approximately three miles long by one mile wide. An examination of the airframe revealed that the airplane's design limits had been exceeded, and that the examined fractures were due to overload failure. ## Factual narrative HISTORY OF FLIGHT On October 15, 2006, approximately 1303 central daylight time, an experimental Aero Commander 690A twin-engine turboprop airplane, N55JS, was destroyed following an in-flight breakup while in cruise flight near Antlers, Oklahoma. The airline transport rated pilot, airline transport rated co-pilot, and both passengers sustained fatal injuries. The airplane was registered to and operated by the pilot. Instrument meteorological conditions prevailed and an instrument flight rules flight plan was filed for the 14 Code of Federal Regulations Part 91 personal flight. The 928-nautical mile cross-country flight departed the Wiley Post Airport (PWA), near Oklahoma City, Oklahoma, approximately 1225, and was en route to the Executive Airport (ORL), near Orlando, Florida. The reported purpose of the flight was for the occupants to attend the National Business Aviation Association's annual convention. According to line crew personnel, on the morning of the accident they had been instructed to pull the airplane from its hangar and to service the main fuel tanks for an approximate 1000 departure. About 0800, one of the line crew proceeded to the airplane's hangar intending to pull the airplane outside for fueling. When he arrived at the hangar he found 4 or 5 employees, installing the airplane's interior, servicing the landing gear struts with nitrogen, and completing "other miscellaneous orders." He was informed that the airplane was not yet ready to be fueled. Around 0900 the airplane was brought out to the flight line. About this time the line crew was instructed, by one of the ServiCenter managers, that in addition to servicing the airplane's main fuel tanks, the "slipper" fuel tanks should also be completely filled with fuel. The line crew proceeded by servicing the airplane as requested with 489 gallons of Jet A fuel. The line crew reported that both pilots arrived around 1000. One pilot performed a preflight inspection of the airplane while the other called flight service for a weather briefing. According to the McAlester Flight Service Station, the pilot contacted them by telephone at 1050 and received a full weather briefing. Following the briefing the pilot filed an IFR flight plan from PWA to ORL. The cruise altitude requested for the flight was 27,000 feet MSL. The pilot stated the flight would take three hours and thirty minutes and there would be four persons on board. The pilots received their IFR clearance at 1215 and were cleared for takeoff at 1225. Approximately 37 minutes after departure, radar information revealed N55JS was flying on a southeasterly heading at a cruise altitude of 23,100 feet mean sea level (MSL). At 1302, radar control tracking indicated the airplane performed a left 180-degree turn while descending at a rate of approximately 13,500 feet per minute. The last radar contact was at 1303 while at 15,100 feet MSL. The airplane was located the next morning by local law enforcement personnel, scattered across a densely wooded area. There were no reported witnesses to the accident. PERSONNEL INFORMATION There were two airline transport pilots (ATP) onboard the airplane at the time of the accident. According to line personnel, the pilots were occupying the front two seats during departure. The pilot seated in the front left seat had called flight service for the weather briefing and had filed the fight plan. The flight plan listed the individual seated in the right seat as the pilot-in-command for the flight. A review of information on file with the FAA Airman's Certification Division, Oklahoma City, Oklahoma, revealed the right seat pilot held an airline transport pilot certificate for airplane multi-engine land. The pilot also held a commercial certificate with ratings for airplane single-engine land, and instrument airplane. In addition, the pilot held a flight instructor certificate for airplane single-engine land, multi-engine land, and instrument airplane. The pilot held a second-class medical certificate issued on July 27, 2006, with no restrictions. The pilot's personal flight records were not located during the course of the investigation; however, on August 6, 2006, the pilot reported having logged 6,450 hours total time of which 150 were in the same make and model of airplane, with 80 hours in the previous 90 days. A review of information on file with the FAA Airman's Certification Division, revealed the left seat pilot held an airline transport pilot certificate with ratings for airplane multiengine land. The pilot also held a commercial certificate with ratings for glider, airplane single engine land, and instrument airplane. The pilot held a third-class medical certificate issued on October 13, 2005, with restrictions. The pilot's personal flight records were not located during the course of the investigation; however, on August 6, 2006, the pilot had reported having logged 6,500 hours total time of which 2,000 were in the same make and model of airplane, with 50 hours in the previous 90 days. AIRCRAFT INFORMATION The 1974-model experimental Aero Commander 690A, serial number 11195, was a high wing, semi-monocoque airplane, with a retractable landing gear, and was configured for eight occupants. The airplane was powered by two Honeywell Aerospace TPE331-10T-515K turboprop engines which were driving five bladed composite MT-Propellers. According to the airframe logbook, the airplane's most recent 150 hour periodic inspection was completed on December 16, 2005, at an airframe total time of 7,923 hours. Investigators were not able to locate the airplane's Hobbs meter during the course of the investigation and were unable to determine the airplane's total time at the time of the accident; however, the airframe logbook listed the total time as 7,943.7 hours on October 6, 2006. The engine maintenance records revealed that the left and right engines had been last inspected in accordance with a Periodic 150 hour inspection on October 16, 2005. At the time of inspection the left engine had accumulated approximately 4,491.1 hours, and the right engine 4,904.1, since overhaul. At last inspection each engine had accumulated 35 hours since the last hot section inspection. A review of the airframe maintenance records revealed that "slipper type" external fuel tanks were installed on October 6, 2006, in accordance with a supplemental type certificate (STC). These external tanks consist of two externally mounted fuel tanks attached to the airplane's wing just outboard of both engine nacelles. Each of the two "slipper" tanks can hold 50 gallons of fuel for a combined total of 100 gallons. With both tanks full the added weight of fuel to the airplane would be 670 lbs. The airplane was awarded an experimental certificate on October 11, 2006, for the purpose of "Market Survey." This was due to the installation of two, five bladed composite propellers that did not meet the airplane's original type design. No pre impact anomalies were noted with either propeller during the investigation. Along with the experimental certificate, 26 limitations were placed on the airplane by the Federal Aviation Administration (FAA). Limitation number 11 stated, "No person may be carried in this aircraft during flight unless that person is essential to the purpose of flight." Investigators performed weight and balance calculations using fueling records and the airplane's weight and balance statement dated the day of the accident, October 15, 2006. The calculations were performed using the FAA's standard weight of 170 pounds for each of the four occupants, 200 pounds estimated weight for luggage and loose equipment, and an estimated fuel burn off of 50 pounds consumed before takeoff. According to the airplane's Type Certificate Data Sheet (TCDS), the airplane's maximum takeoff weight was 10,250 pounds. The total takeoff weight of the acc ## Aircraft - Registration: [N55JS](https://openairdocs.org/deregistered/N55JS-2009-11-05), registration cancelled 2009-11-05, S/N 11195, built 1974 (OpenAirDocs) - Reported make and model: Aero Commander 690A - Registry model: [Aero Commander 690A](https://openairdocs.org/model/aero-commander-690a) (registry code 0141722) (OpenAirDocs) - Registry engine: [Garrett TPE331-10T](https://openairdocs.org/engine/garrett-tpe331-10t) (registry code 29065, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 11195 - Airframe hours: 7943 - Engines: Honeywell Aerospace TPE33110T515K 776 horsepower turbo prop - Damage: Destroyed - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, December 1, 2005 - Departed: PWA, OKLAHOMA CITY, OK - Destination: ORL, ORLANDO, FL - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; injuries: fatal; flight instructor, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; seat: right; toxicology performed; flight hours: 6,450 total, 150 in this make and model - Co-pilot; age 71; injuries: fatal; airline transport, commercial; airplane ratings: multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 3, with waivers/limitations; seat: left; toxicology performed; flight hours: 6,500 total ## Weather - Conditions: Instrument (IMC), Day - Wind: 80° at 3 knots - Visibility: 1.75 statute miles - Lowest ceiling: 2,200 ft overcast - Temperature: 57 °F, dew point 57 °F - Altimeter: 29.84 inHg - Observed at: AQR, 28 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 20061015021169A](https://openairdocs.org/incident/20061015021169A), Oct 15, 2006: Gulstm 690A, Antlers, OK, Destroyed, 4 fatal. (-23) On October 15, 1006 at 1303 CDT, a twin commander 690A, N55JS impacted terrain after departing controlled flight three miles west of Antlers, OK. Review… ## Docket (20 files) The files NTSB released with the investigation on November 15, 2007, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=64696. 10.6 MB in all. - Meteorology 5 - Factual Report of Group Chairman (item 1, .PDF, 965 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40269955&FileExtension=.PDF&FileName=Meteorology%205%20-%20Factual%20Report%20of%20Group%20Chairman-Master.PDF - Line Crew Statement 1 (item 2, .PDF, 153 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285029&FileExtension=.PDF&FileName=Line%20Crew%20Statement%201-Redacted.PDF - Line Crew Statement 2 (item 3, .PDF, 88 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285031&FileExtension=.PDF&FileName=Line%20Crew%20Statement%202-Redacted.PDF - Map of wreckage (item 4, .PDF, 74 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285032&FileExtension=.PDF&FileName=Map%20of%20wreckage-Master.PDF - Fuel receipt (item 5, .PDF, 43 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285033&FileExtension=.PDF&FileName=Fuel%20receipt-Master.PDF - Airspeed Calculations (item 6, .PDF, 15 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285035&FileExtension=.PDF&FileName=Airspeed%20Calculations-Master.PDF - Weight and Balance Info (item 7, .PDF, 125 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285038&FileExtension=.PDF&FileName=Weight%20and%20Balance%20Info-Redacted.PDF - Radar Map (item 8, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285039&FileExtension=.PDF&FileName=Radar%20Map-Master.PDF - Radar Data (item 9, .PDF, 39 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285040&FileExtension=.PDF&FileName=Radar%20Data-Master.PDF - ATC Transcript (item 10, .PDF, 117 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285041&FileExtension=.PDF&FileName=ATC%20Transcript-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 11, .PDF, 72 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285042&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 12, .PDF, 37 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40411503&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Redacted.PDF - Pilot 1 Tox (item 13, .PDF, 58 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285044&FileExtension=.PDF&FileName=Pilot%201%20Tox-Master.PDF - Pilot 2 Tox (item 14, .PDF, 58 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285045&FileExtension=.PDF&FileName=Pilot%202%20Tox-Master.PDF - Digital Photo 1, Front View (item 15, .PDF, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285046&FileExtension=.PDF&FileName=Digital%20Photo%201,%20Front%20View-Master.PDF - Digital Photo 2, Top View (item 16, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285047&FileExtension=.PDF&FileName=Digital%20Photo%202,%20Top%20View-Master.PDF - Digital Photo 3, Aft View (item 17, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285048&FileExtension=.PDF&FileName=Digital%20Photo%203,%20Aft%20View-Master.PDF - Digital Photo 4, Aft Section View (item 18, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285049&FileExtension=.PDF&FileName=Digital%20Photo%204,%20Aft%20Section%20View-Master.PDF - Digital Photo 5, Crew Luggage (item 19, .PDF, 969 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285050&FileExtension=.PDF&FileName=Digital%20Photo%205,%20Crew%20Luggage-Master.PDF - Digital Photo 6, Layout View.JPG (item 20, .PDF, 983 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40285051&FileExtension=.PDF&FileName=Digital%20Photo%206,%20Layout%20View.JPG-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.