# NTSB ATL99LA076: Schempp-Hirth MINI-NIMBUS, N100GG, Groveland, FL, April 28, 1999 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: April 28, 1999, 14:00 local (18:00 UTC) - Place: Groveland, FL - Coordinates: 28.5599, -81.849441 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=28.5599&lon=-81.8494&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report June 22, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 46201 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL99LA076 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46201/pdf - Page: https://openairdocs.org/ntsb/ATL99LA076 ## Probable cause The pilot's inability to locate a thermal and the in-flight encounter with a down draft. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, approach - weather condition - downdraft (cause) - weather condition - thermal lift - compensation for wind conditions - not possible, pilot in command - Forced landing, approach - On ground/water collision with object, emergency landing - object - fence (contributing factor) ## Analysis After the tow release at 1600 feet, the pilot began to search for thermal pockets. Failing to find a thermal, the pilot elected to return to the airport. The pilot stated that he encountered downdrafts which increased his rate of descent to approximately 1000 feet per minute. Realizing that there was not sufficient altitude to return to the airport safely, the pilot elected to make an emergency landing in a nearby field. The glider subsequently collided with a barbed wire fence during the emergency landing, causing substantial damage. The glider sustained damage to both wings and a broken canopy. No mechanical problems with the glider were reported by the pilot. ## Factual narrative On April 28, 1999, at 1357 eastern daylight time, a Shempf-Hirth Mini-Nimbus Glider, N100GG, collided with a fence one-quarter mile north of the Seminole Lake Glider Port, in Clermont, Florida. The glider was operated by the pilot under the provisions of Title 14 CFR Part 91, and visual flight rules. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed for the local flight. The commercial pilot received minor injuries and the glider sustained substantial damage. The flight originated in Clermont, Florida, at an unspecified time. According to the pilot, the glider was released from the tow plane at an altitude of 1600 feet. After release from the tow plane, the pilot began to search for thermal pockets. Failing to find a thermal, the pilot elected to return to the to the airport. The pilot stated that he encountered downdrafts which increased his rate of descent to approximately 1000 feet per minute. Realizing that there was not sufficient altitude to return to the airport safely, the pilot elected to make an emergency landing in a nearby field. The glider subsequently collided with a barbed wire fence during the emergency landing, substantially damaging the glider. The glider sustained damage to both wings and a broken canopy. No mechanical problems with the glider were reported by the pilot. ## Aircraft - Registration: N100GG (not matched to a registry record) - Reported make and model: Schempp-Hirth MINI-NIMBUS (MINI-NIMBU) - Category: Glider - Serial number: 84 - Engines: unknown - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Seminole Flying & Soaring Inc - Airworthiness certificate: Special, Experimental (Special) - Departed: 6FL0, SEMINOLE LAKE, FL - Airport: 6FL0, Seminole Lake Glider Port, runway 36, 3,000 × 200 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 59; private; airplane ratings: multi-engine land, single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: center; flight hours: 2,400 total, 2 in this make and model, 5 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 16 knots - Visibility: 8 statute miles - Lowest ceiling: 5,500 ft broken - Temperature: 81 °F, dew point 64 °F - Altimeter: 29.00 inHg - Observed at: MCO, 30 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 19990428019779A](https://openairdocs.org/incident/19990428019779A), Apr 28, 1999: Sphrth NIMBUSMINIC, Groveland, FL, Substantial damage. On April 28, 1999, at 1357 eastern daylight time, a mini-nimbus "c" glider, N100GG, collided with a fence one-quarter mile north of the seminole lake glider… 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.