# NTSB SEA98LA132: Grumman American AA-5B, N28299, Chico Hot Sprgs, MT, July 12, 1998 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: July 12, 1998, 11:30 local (17:30 UTC) - Place: Chico Hot Sprgs, MT - Coordinates: 45.310844, -110.760925 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.3108&lon=-110.7609&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor, 3 uninjured - Status: Completed, report January 11, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 43221 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA98LA132 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/43221/pdf - Page: https://openairdocs.org/ntsb/SEA98LA132 ## Probable cause The pilot-in-command's selection of the wrong runway for takeoff. Factors contributing to the accident were high density altitude, rising terrain and a fence post. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, takeoff - initial climb - weather condition - high density altitude (contributing factor) - terrain condition - rising (contributing factor) - object - fence post (contributing factor) - wrong runway - selected, pilot in command (cause) ## Analysis The pilot-in-command was briefed by the hotel operations manager that takeoffs to the south were 'not normally allowed,' but the pilot elected to depart to the south due to wind conditions. The manager then insured that the roadway serving as runway 14/32 was properly blocked off and manned. During the left turning crosswind climbout, the aircraft's left wing struck a fence. The aircraft then impacted terrain and came to rest. Terrain to the south and east was upsloping and higher than the takeoff runway elevation. The high elevation of the airstrip (5,280 feet) coupled with the warm ambient air temperature, created a high (7,784 foot) density altitude condition. ## Factual narrative On July 12, 1998, approximately 1130 mountain daylight time, a Grumman-American AA-5B, N28299, registered to Catherine Haas, and being operated/flown by a private pilot, was substantially damaged when the aircraft collided with terrain following an impact with a fence post shortly after takeoff at Chico Hot Springs, Montana. The pilot and two passengers sustained no injuries while the remaining passenger sustained minor injuries. Visual meteorological conditions prevailed and no flight plan had been filed. The flight, which was personal, was to have been operated under 14CFR91, and was destined for Gallatin Field, Bozeman, Montana, located approximately 35 nautical miles northwest. The pilot reported that with an air temperature of 75 to 80 degrees Fahrenheit and a wind of 15 to 20 knots down the runway these conditions "favored a takeoff to the south." After back-taxiing to the departure end of the runway, a paved highway (refer to DIAGRAM I and ATTACHMENT I), he completed a run-up, adjusted the mixture and began his takeoff to the south. The pilot reported that he lifted off at 70 knots indicated airspeed and then executed a climbing left crosswind turn during which he "felt some light turbulence and the indicated airspeed dropped about 20 knots." The stall warning horn activated and the pilot "lower(ed) the nose a little and reduce(d) the turn rate to follow descending terrain. However, the stall horn continued to sound intermittently and the airspeed did not come up." The aircraft's left wing outboard leading edge (refer to photograph 1) then impacted a fence post. The aircraft then impacted terrain and slid to a stop (refer to photograph 2). The hotel operations manager, who was responsible for insuring the roadway serving as runway 14/32 was properly blocked off and manned prior to aircraft use, provided a statement regarding his involvement in the pre-departure events of the accident. He reported speaking with the pilot "about taking off into the wind rather than with the wind." The pilot stated "that he wanted to taxi to the north end of the runway and then take-off towards Chico." The manager explained that "this was not normally allowed" but he would allow it if that was what the pilot wished. The manager also informed the pilot about "the tricky cross winds coming across the runway, and the obvious mountain at the end of the runway" (refer to ATTACHMENT S-I). The takeoff on the road provides approximately 4,400 feet of straight, paved surface available and, when executed to the south provides an uphill gradient towards rapidly upsloping terrain (refer to DIAGRAM I). Additionally, the Montana Airport Directory (1994) provides a graphic overview of the airstrip including a length of 6,000 feet, a width of 35 feet, and remarks "Land to South. Takeoff to North." (Refer to ATTACHMENT I). Meteorological conditions reported for Livingston, Montana, 23 nautical miles north, at 1154 MDT were as follows: Surface temperature: 81 deg F. Wind Direction: 210 deg mag. Wind Speed: 21 knots Wind gusts: 28 knots Altimeter: 30.05 inches mercury Livingston elevation: 4,656 feet above sea level The calculated density altitude at Livingston under these conditions was 7,014 feet. The estimated density altitude at the accident site (5,280 feet above sea level), based upon the same temperature and altimeter setting at Livingston, was 7,784 feet. ## Aircraft - Registration: [N28299](https://openairdocs.org/deregistered/N28299-2001-04-02), registration cancelled 2001-04-02, S/N AA5B0537 (OpenAirDocs) - Reported make and model: Grumman American AA-5B - Registry model: [Grumman American Avn. AA-5B](https://openairdocs.org/model/grumman-american-avn-aa-5b) (registry code 3960105) (OpenAirDocs) - Category: Airplane - Serial number: AA5B0537 - Airframe hours: 3020 - Engines: Lycoming O-360-A4K 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Hall, Robert, C. - Registered owner: Haas, Catherine, S. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 20, 1998, 60 hours before - Destination: BZN, BOZEMAN, MT - Airport: Chico Hot Springs, runway 14, 6,000 × 35 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 46; private; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 319 total, 126 in this make and model, 257 as pilot in command, 32 in the last 90 days, 16 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 21 knots, gusting 28 - Visibility: 30 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 43 °F - Altimeter: 30.00 inHg - Observed at: LVM, 23 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 19980712016429A](https://openairdocs.org/incident/19980712016429A), Jul 12, 1998: Amrgen AA5B, Chico Hot Spgs, MT, Substantial damage. Took off on county road toward higher terrain. Collided with terrain. Density altitude 7500FT. Possible over gross. (.4)the pilot-in-command was briefed by the… ## Other investigations on N28299 (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 LAX97LA236](https://openairdocs.org/ntsb/LAX97LA236), Jul 9, 1997: Grumman American AA-5B (N28299), Susanville, CA, substantial damage. Probable cause: the pilot's inadvertent encounter with unfavorable weather conditions during the landing, and his failure to maintain runway alignment. The sudden onset of crosswind gusts beyond the capability of… 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.