# NTSB LAX90LA277: Thunder and Colt AX9-140 SLI, N9112R, Napa, CA, August 7, 1990

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: August 7, 1990, 07:45 local (14:45 UTC)
- Place: Napa, CA
- Coordinates: 38.550693, -122.150695 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.5507&lon=-122.1507&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 5 minor, 1 uninjured
- Status: Completed, report November 9, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 26884
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX90LA277
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26884/pdf
- Page: https://openairdocs.org/ntsb/LAX90LA277

## Probable cause

FLIGHT'S ENCOUNTER WITH A PROBABLE MICROBURST WEATHER PHENOMENA WITH DOWN DRAFTS AND WINDS BEYOND THE PERFORMANCE CAPABILITY OF THE BALLOON.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- In flight encounter with weather, cruise
  - weather condition - microburst/dry (cause)
- In flight collision with terrain/water, descent - uncontrolled
  - aircraft performance,climb capability - exceeded (cause)
  - terrain condition - high obstruction(s) (contributing factor)

## Analysis

SEVENTEEN BALLOONS LAUNCHED FROM VARIOUS LOCATIONS AROUND THE NAPA VALLEY FOR LOCAL SIGHTSEEING FLIGHTS. STATEMENTS FROM PILOTS, PASSENGERS AND GROUND WITNESSES SAID THAT WHILE THE BALLOONS WERE IN NORMAL DRIFTING FLIGHT A MICROBURST LIKE CONDITION SUDDENLY OCCURRED WHICH AFFECTED ALL OF THE BALLOONS. THE WEATHER PHENOMENA ENCOUNTERED INCLUDED STRONG GUSTING SURFACE AND ALOFT WINDS IN ADDITION TO SEVERE DOWN DRAFTS. THE BALLOONS WERE RAPIDLY FORCED TOWARD THE GROUND AS THEIR GROUND SPEED INCREASED RADICALLY. THE PILOTS OF SEVERAL BALLOONS REPORTED THAT THE SHAPES OF THEIR BALLOON ENVELOPES WERE SEVERELY DISTORTED BY THE SUDDEN MOVEMENT OF THE AIRMASS. EIGHT OF THE 17 BALLOONS ATTEMPTED FORCED LANDINGS. FOUR OF THE BALLOONS SUCCESSFULLY LANDED. THE OTHER FOUR BALLOONS COLLIDED WITH OBSTRUCTIONS AND THE GROUND DURING THE ATTEMPTED LANDINGS. AT THE TIME OF THE INCIDENT, A LARGE THUNDERSTORM WAS REPORTED 30 MILES TO THE NORTH.

## Aircraft

- Registration: [N9112R](https://openairdocs.org/deregistered/N9112R-2013-06-07), registration cancelled 2013-06-07, S/N 996, built 1987 (OpenAirDocs)
- Reported make and model: Thunder and Colt AX9-140 SLI (AX9-140 SL)
- Registry model: [Thunder Balloons AX9-140 SII](https://openairdocs.org/model/thunder-balloons-ax9-140-sii) (registry code 8970116) (OpenAirDocs)
- Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs)
- Category: Balloon
- Serial number: 996
- Engines: unknown
- Damage: Substantial damage
- Flight: Part 91
- Registered owner: Balloon Aviation Of Napa Valle
- Departed: NONE
- Destination: NONE

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 42; commercial; flight hours: 4,030 total, 60 in this make and model, 4,000 as pilot in command, 63 in the last 90 days, 23 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 20 knots, gusting 30
- Visibility: 30 statute miles
- Lowest ceiling: 30,000 ft overcast
- Temperature: 70 °F, dew point 57 °F
- Altimeter: 29.00 inHg
- Observed at: APC

## 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 19900807031119A](https://openairdocs.org/incident/19900807031119A), Aug 7, 1990: Thundr AX9140S2, Napa, CA, Substantial damage. Severe wind gust and down draft forced balloon down to hard landing. Wad 30 miles from forecast thunderstorm.

## Other investigations on N9112R (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 LAX90LA206](https://openairdocs.org/ntsb/LAX90LA206), May 2, 1990: Thunder and Colt AX9-140 (N9112R), Napa, CA, no damage. Probable cause: THE PILOT'S IMPROPER FLARE TECHNIQUE WHICH RESULTED IN A HARD LANDING. A FACTOR IN THE ACCIDENT WAS THE SUDDEN APPEARANCE OF A HIGH WIND CONDITION.

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.

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