# NTSB DEN99LA169: Schweizer G-164A, N8731H, Animas, NM, September 23, 1999 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: September 23, 1999, 13:35 local (19:35 UTC) - Place: Animas, NM - Coordinates: 31.939407, -108.830482 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=31.9394&lon=-108.8305&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report June 23, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 47428 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN99LA169 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/47428/pdf - Page: https://openairdocs.org/ntsb/DEN99LA169 ## Probable cause A inadvertent stall during initial climb following takeoff. Factor were: high gross weight, high density altitude, inadequate preflight planning and preparation, and soft terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, takeoff - initial climb - weather condition - high density altitude (contributing factor) - stall/mush - inadvertent, pilot in command (cause) - aircraft weight and balance - excessive, pilot in command (contributing factor) - preflight planning/preparation - inadequate, pilot in command (contributing factor) - Forced landing, takeoff - initial climb - Nose over, landing - roll - terrain condition - soft (contributing factor) ## Analysis On an aerial application flight, during initial climb following takeoff at maximum gross weight and a density altitude of 7,400 feet, the aircraft entered a stall/mush condition. The pilot attempted a forced landing in a field, which was soft, and the aircraft nosed over during landing roll. ## Factual narrative On September 23, 1999, at 1335 mountain daylight time, a Schweizer G-164A, N8731H, impacted terrain following takeoff from Cotton City Airport, a private facility, near Animas, New Mexico. The aircraft sustained substantial damage and the commercial pilot received minor injuries. The flight was an aerial application flight operating under Title 14 CFR Part 137. Visual meteorological conditions prevailed and no flight plan was filed. According to information supplied by witnesses and the pilot, both of whom provided verbal statements to the New Mexico State Police, the aircraft appeared to stall/mush during initial climb following takeoff from the 2640-foot dirt airstrip. In his written statement, the pilot provided information that the aircraft did not have a mechanical failure or malfunction but began to "shudder and settle" immediately following lift off and he attempted to conduct a forced landing to a field. During landing roll, the aircraft nosed over in soft terrain. Based on a reported full fuel load and full chemical load, the computed aircraft weight at the time of the accident was 4,500 pounds, which is the maximum certificated gross weight. No performance data was available. Weather conditions at the time of the accident were visual conditions with variable wind at 6 knots and a computed density altitude of 7,400 feet above mean sea level (msl). ## Aircraft - Registration: [N8731H](https://openairdocs.org/deregistered/N8731H-2013-12-11), registration cancelled 2013-12-11, S/N 1506, built 1975 (OpenAirDocs) - Reported make and model: Schweizer G-164A - Registry model: [Grumman Acft ENG Cor-Schweizer G-164A](https://openairdocs.org/model/grumman-acft-eng-cor-schweizer-g-164a) (registry code 3952801) (OpenAirDocs) - Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 1506 - Airframe hours: 8985 - Engines: P&W R-1340-AN-1 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Farm & Ranch Aviation Company - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Continuous airworthiness, March 9, 1999, 80 hours before - Destination: DMN, DEMING, NM - Airport: NONE, Cotton City, runway 8, 2,640 × 75 ft, dirt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 66; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 18,328 total, 4,000 in this make and model, 17,978 as pilot in command, 220 in the last 90 days, 60 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 0° at 6 knots - Visibility: 40 statute miles - Lowest ceiling: none - Temperature: 90 °F, dew point 52 °F - Altimeter: 30.00 inHg - Observed at: DMN, 55 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 19990923037139A](https://openairdocs.org/incident/19990923037139A), Sep 23, 1999: Scwzer G164A, Animas, NM, Substantial damage. (-23) On 09/23/99 at 1330 MDT, N8731H, a Grumman ag cat model 164A, impacted the ground following take-off from a crop duster strip located in Cotton City, NM,… 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.