# NTSB SEA96LA114: Cessna T188C, N4970J, Roundup, MT, June 7, 1996 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: June 7, 1996, 05:30 local (11:30 UTC) - Place: Roundup, MT - Coordinates: 46.439754, -108.509269 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.4398&lon=-108.5093&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report April 3, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 42385 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA96LA114 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42385/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=42385 - Page: https://openairdocs.org/ntsb/SEA96LA114 ## Probable cause failure of the pilot to maintain adequate airspeed, during a turn-around maneuver after a swath run, which resulted in an inadvertent stall. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, maneuvering - aerial application - low altitude flight/maneuver - initiated, pilot in command - airspeed - inadequate, pilot in command (cause) - stall - inadvertent, pilot in command (cause) - In flight collision with terrain/water, descent - uncontrolled ## Analysis The pilot stated that while maneuvering for an agricultural aerial application pass, his '...initiating...turn at a lower than normal [airspeed]...started a stall.' He stated that he hit the ground before he could recover due to the low altitude at which he had turned. The aircraft information manual stated that altitude loss during a stall recovery may be as much as 300 feet. ## Factual narrative On June 7, 1996, at approximately 0530 mountain daylight time, a Cessna T188C, N4970J, operated by Lemmon Flying Service of Roundup, Montana, collided with terrain approximately 20 miles northeast of Roundup during a 14 CFR 137 agricultural aerial application flight. The single-seat restricted-category agricultural airplane was destroyed and its commercial pilot suffered serious injuries. Visual meteorological conditions prevailed and no flight plan had been filed for the local flight out of Roundup. The pilot reported in a written statement to a FAA inspector: "Started with a missed G.P.S. approach and a turn out to the left to start a [different] approach. A drop in air [speed] in [first climbing] left turn and initiating second left turn at a lower than normal [airspeed] in [conjunction] with a [quartering] tail wind started a stall. I pushed it over to recover from stall and hit ground before I could pull up due to the low [altitude] at which I had turned." The T188C Information Manual lists power-off stall speeds for 4,400 pounds gross weight ranging from 67 MPH calibrated airspeed (at zero bank angle and 20 degrees flaps) to 100 MPH calibrated airspeed (at 60 degrees bank and flaps up), depending on bank angle and flap setting, and notes that altitude loss during stall recovery may be as much as 300 feet. The airplane's shoulder harness attach ring broke during the accident sequence. According to a copy of the aircraft logbooks furnished by the operator, a new seat belt and shoulder harness were installed on the aircraft in April 1993 at 1,224.4 hours airframe total time (AFTT). Other aircraft maintenance documented with this April 1993 logbook entry included: "Replaced fuselage with like serviceable item, replaced both wings with [serviceable] rebuilt wings, replaced right elevator and trim tab, both flaps, vertical fin and horizontal stabilizer with repaired serviceable parts...." The seat and seat belts were documented as being checked during the aircraft's last annual inspection, performed on April 5, 1996 at 1,226.7 hours AFTT. The operator reported an AFTT of 1,336 hours at the time of the accident. Photographs of the fractured part showed that the two fracture faces were on a 45 degree plane to the direction of load on the part. The fractures were through two legs of the triangle, along a line parallel to the third leg (which anchors the harness strap.) The attach ring bolts to the airframe at the apex of the triangle, opposite the third leg. A photograph of the manufacture tag sewn to the seat belt indicated that the belt assembly had a rated strength of 1,500 pounds and conformed to FAA Technical Standard Order (TSO) C22f. The tag indicated that the belt was manufactured by Aero Fabricators of Lyons, Wisconsin, on January 4, 1993. FAA Advisory Circular (AC) 20-36S indicates that Aero Fabricators holds a TSO-C22f authorization to manufacture safety belts. ## Aircraft - Registration: [N4970J](https://openairdocs.org/deregistered/N4970J-1999-07-12), registration cancelled 1999-07-12, S/N T18803792T (OpenAirDocs) - Reported make and model: Cessna T188C - Registry model: [Cessna T188C](https://openairdocs.org/model/cessna-t188c) (registry code 2073012) (OpenAirDocs) - Category: Airplane - Serial number: T18803792T - Airframe hours: 1336 - Engines: Continental TSIO-520-T 310 horsepower reciprocating - Damage: Destroyed - Flight: Aerial application, Part 137 - Registered owner: Darrell C. Lemmon - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, April 5, 1996, 110 hours before - Departed: RPX, MT - Flight plan: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 32; commercial; airplane ratings: single-engine land; medical: class 1, valid medical--no waivers/lim.; flight hours: 541 total, 78 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 190° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 61 °F, dew point 48 °F - Altimeter: 30.00 inHg - Observed at: BIL, 50 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 19960607013199A](https://openairdocs.org/incident/19960607013199A), Jun 7, 1996: Cessna T188C, Roundup, MT, Destroyed. Stalled during low level downwind procedure turn. No room to recover. Seat belt fractured at attach fitting. ## Other investigations on N4970J (1) 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. - [NTSB DEN88LA134](https://openairdocs.org/ntsb/DEN88LA134), Jun 22, 1988: Cessna T188C (N4970J), Big Timber, MT, substantial damage ## Docket (11 files) The files NTSB released with the investigation on January 23, 1997, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=42385. 751 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 253 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40423427&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Pilot Statement (item 2, .PDF, 49 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40423428&FileExtension=.PDF&FileName=Pilot%20Statement-Redacted.PDF - Diagram of Belt Assembly (item 3, .PDF, 71 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40060898&FileExtension=.PDF&FileName=Diagram%20of%20Belt%20Assembly-Master.PDF - Diagram of Shoulder Harness Attach Ring Damage (item 4, .PDF, 25 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40060899&FileExtension=.PDF&FileName=Diagram%20of%20Shoulder%20Harness%20Attach%20Ring%20Damage-Master.PDF - FAA AC 20-36S Excerpt (item 5, .PDF, 54 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40060900&FileExtension=.PDF&FileName=FAA%20AC%2020-36S%20Excerpt-Master.PDF - T188C Information Manual Excerpt (item 6, .PDF, 41 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40060901&FileExtension=.PDF&FileName=T188C%20Information%20Manual%20Excerpt-Master.PDF - Aircraft Logbook Excerpts (item 7, .PDF, 121 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40423429&FileExtension=.PDF&FileName=Aircraft%20Logbook%20Excerpts-Redacted.PDF - Photo 1. Arrow points to fractured shoulder harness attach ring. No Negative. (item 8, .PDF, 37 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40060903&FileExtension=.PDF&FileName=Photo%201.%20%20Arrow%20points%20to%20fractured%20shoulder%20harness%20attach%20ring.%20%20No%20Negative.-Master.PDF - Photo 2. Close-up of shoulder harness attach ring. Viewed from front. No Negative. (item 9, .PDF, 38 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40060904&FileExtension=.PDF&FileName=Photo%202.%20%20Close-up%20of%20shoulder%20harness%20attach%20ring.%20%20Viewed%20from%20front.%20%20No%20Negative.-Master.PDF - Photo 3. Shoulder harness attach ring. Viewed from above. No Negative. (item 10, .PDF, 26 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40060905&FileExtension=.PDF&FileName=Photo%203.%20%20Shoulder%20harness%20attach%20ring.%20%20Viewed%20from%20above.%20%20No%20Negative.-Master.PDF - Photo 4. Manufacture tag on seat belt. (item 11, .PDF, 36 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40060906&FileExtension=.PDF&FileName=Photo%204.%20%20Manufacture%20tag%20on%20seat%20belt.-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.