# NTSB CHI94LA275: Thunder and Colt 120A, N416TC, Bloomington, IL, August 16, 1994 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: August 15, 1994, 20:00 local (Aug 16, 1994, 01:00 UTC) - Place: Bloomington, IL - Coordinates: 40.469352, -88.970001 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.4694&lon=-88.9700&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 2 serious, 1 minor, 3 uninjured - Status: Completed, report April 5, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 9634 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI94LA275 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9634/pdf - Page: https://openairdocs.org/ntsb/CHI94LA275 ## Probable cause the unforcast, unanticipated adverse wind conditions and thermal activity. A factor was the powerlines. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Altitude deviation,uncontrolled, approach - weather condition - unfavorable wind (cause) - In flight collision with object, descent - uncontrolled - object - wire,static (contributing factor) ## Analysis IN HIS WRITTEN STATEMENT, THE PILOT REPORTED HE RECEIVED THOROUGH WEATHER INFORMATION AND THE FIRST 20 MINUTES OF THE FLIGHT WERE UNREMARKABLE. WINDS WERE ABOUT THREE KNOTS. THE BALLOON WAS UNEXPECTEDLY ENTRAINED IN A 'LARGE THERMAL' AND CIRCLING WINDS. THE PILOT MADE THREE APPROACH ATTEMPTS, AND ABORTED EACH. ON THE FOURTH ATTEMPT, HE MADE AN APPROACH TO A PARKING LOT THEN ATTEMPTED TO LAND ON THE ROOF OF A BUILDING. THE BASKET SLID OVER THE BUILDING AND THE ENVELOPE CONTINUED INTO POWERLINES ON THE LEEWARD SIDE. HE SAID THERE WAS A 'LOUD POP AND A BRIGHT FLASH' AND THE BASKET SETTLED GENTLY TO THE GROUND. ## Factual narrative On August 15, 1994, at 2000 central daylight time, a Thunder & Colt 120A free balloon, N416TC, owned and operated by Walter R. Rudy of Bloomington, Illinois, sustained substantial damage when it contacted powerlines while landing in Bloomington, Illinois. The commercial pilot and two passengers reported no injuries. Two passengers sustained serious injuries and one passenger sustained minor injuries. The sight-seeing revenue flight originated near Bloomington, Illinois, about 1930 and was conducted under 14 CFR Part 91 in visual meteorological conditions. In his written statement, the pilot reported he received weather information from Direct User Access Terminal Service (DUATS), from commercial television, and from the Bloomington Tower. Also, a helium pilot observation balloon (PIBAL) was launched. He said the first 20 minutes of the flight were unremarkable and winds were about three knots. He said that while descending through 1,600 feet mean sea level (MSL) the balloon began to circle with the wind and was "pulled" toward downtown Bloomington. The pilot reported the balloon was entrained in a "large thermal." He made three approach attempts, and aborted each because of the "circling wind." He said the balloon was moving "precariously close" to a tower and the downtown area. He made an approach to a parking lot then attempted to land on the roof of a building. The basket slid over the building and the envelope continued into powerlines on the leeward side. He said there was a "loud pop and a bright flash" and the basket settled gently to the ground. Ten flying wires on the balloon were melted. The nomex skirt was torn and several panels were scorched and abraded. ## Aircraft - Registration: [N416TC](https://openairdocs.org/aircraft/N416TC), registered now, S/N 2187USA, built 1992 (OpenAirDocs) - Reported make and model: Thunder and Colt 120A - Registry model: [Thunder & Colt Airborne Amer COLT 120A](https://openairdocs.org/model/thunder-colt-airborne-amer-colt-120a) (registry code 2301201) (OpenAirDocs) - Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs) - Category: Balloon - Serial number: 2187USA - Airframe hours: 181 - Engines: unknown - Damage: Substantial damage - Flight: Part 91 - Registered owner: Walter R. Rudy - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 6, 1994, 73 hours before ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 34; commercial; airplane ratings: single-engine land; flight hours: 464 total, 105 in this make and model, 411 as pilot in command, 68 in the last 90 days, 26 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 5 knots - Visibility: 20 statute miles - Lowest ceiling: 4,000 ft broken - Temperature: 73 °F, dew point 54 °F - Altimeter: 30.00 inHg - Observed at: BMI, 3 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 19940815022379A](https://openairdocs.org/incident/19940815022379A), Aug 15, 1994: Colt COLT120A, Bloomington, IL, Substantial damage. Encountered large thermal. Tried three landing attempts. Tried land on building roof. Slid off into powerline. 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.