# NTSB LAX99LA321: Cessna 172N, N738ZQ, Vacaville, CA, September 26, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 26, 1999, 12:00 local (19:00 UTC) - Place: Vacaville, CA - Coordinates: 38.35009, -121.930099 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.3501&lon=-121.9301&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report August 13, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 47522 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX99LA321 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/47522/pdf - Page: https://openairdocs.org/ntsb/LAX99LA321 ## Probable cause The pilot's inadequate compensation for the existing gusty crosswind condition and his subsequent failure to maintain directional control. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Dragged wing,rotor,pod,float or tail/skid, landing - flare/touchdown - weather condition - crosswind - weather condition - gusts - compensation for wind conditions - inadequate, pilot in command (cause) - directional control - not maintained, pilot in command (cause) ## Analysis The pilot overflew the airport to check the windsock and noted that the winds appeared to be coming straight down the runway. As he initiated the landing flare, he noted that the windsock indicated that the winds had shifted direction and were now about 90 degrees to his left. He attempted to go around, but the airplane turned left into the wind and began to stall. The airplane impacted the ground and bounced. While still in a stalled configuration, the airplane veered left off the runway. The pilot held the nose of the airplane down while accelerating in ground effect, then initiated a climb. He decided to return to his departure airport instead of attempting another landing. After landing at the departure airport, he noted damage to the wingtip, aileron, and secondary spar. He stated that he had not experienced any mechanical problems with the airplane prior to the accident. The recorded weather data from the airport weather observation facility reflected that the winds were from 350 degrees at 12 knots, gusting to 18 knots, at the time of the accident. The pilot had received a DUATS weather briefing the morning of the accident. ## Factual narrative On September 26, 1999, at 1200 hours Pacific daylight time, a Cessna 172N, N738ZQ, drug the left wing while landing at the Nut Tree Airport, Vacaville, California. The aircraft, owned and operated by the pilot, was substantially damaged. The private pilot and passenger were not injured. The personal cross-country flight was conducted under the provisions of 14 CFR Part 91 and originated from the Palo Alto, California, airport, about 1115, and was en route to Vacaville. Visual meteorological conditions prevailed and no flight plan was filed. The pilot reported that he encountered continuous light to moderate turbulence along his route of flight. When he neared the destination airport, he overflew the field to check the windsock. He stated that the winds appeared to be coming straight down runway 02. The pilot asked for a wind check over the common traffic advisory frequency and was told that the wind velocity was 10 to 15 knots. He stated that the final approach was very bumpy. As he initiated the landing flare, he noted that the windsock reflected that the winds had changed direction and were now about 90 degrees to his left. The pilot reported that as he applied full power to initiate a go-around the right wing rose up and the airplane turned left into the wind. The stall warning horn went off and the airplane began to settle. The pilot applied full aileron and right rudder while continuing the go-around procedure. He felt the aircraft hit the runway and bounce back up into the air. He stated that it felt as if the airplane had landed on the left gear only. He reported that the wings were level but the airplane had veered left of the centerline. He held the nose down and accelerated in ground effect. The pilot reported that once he attained a positive rate of climb and reached 500 feet agl, he looked at the left landing gear and noted that it appeared undamaged. He decided not to make a second attempt to land and instead began a return trip to Palo Alto. He reported that the arrival and landing at Palo Alto were uneventful. After shutdown, he placed chocks under the left tire and examined the propeller and right tire for damage, but found none. The pilot reported that subsequent examination of the airplane revealed left wingtip, aileron, and secondary spar damage. He further reported that he had not experienced any mechanical problems with the aircraft prior to the accident. The recorded weather data from the Vacaville airport weather observation facility reflected that the winds at 1153 were from 350 degrees at 12 knots, gusting to 18 knots. ## Aircraft - Registration: [N738ZQ](https://openairdocs.org/aircraft/N738ZQ), registered now, S/N 17270369, built 1978 (OpenAirDocs) - Reported make and model: Cessna 172N - Registry model: [Cessna 172N](https://openairdocs.org/model/cessna-172n) (registry code 2072434) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17270369 - Airframe hours: 5950 - Engines: Lycoming O-320-H2AD 160 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Alexander Rangel - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, September 26, 1999, 1 hours before - Departed: PAO, PALO ALTO, CA - Destination: VCB - Airport: VCB, Nut Tree Airport, runway 2, 3,800 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 37; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 311 total, 178 in this make and model, 223 as pilot in command, 32 in the last 90 days, 7 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 12 knots, gusting 18 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 93 °F, dew point 36 °F - Altimeter: 29.00 inHg - Observed at: VCB ## 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 19990926046779A](https://openairdocs.org/incident/19990926046779A), Sep 26, 1999: Cessna 172N, Vacaville, CA, No damage. (-23)On September 26, 1999, at 1200 hours PDT, a Cessna 172N, N738ZQ, lost control after encountering wind shear while landing at the Nut Tree Airport,… 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.