# NTSB LAX93LA342: Piper PA-24-250, N5523P, Hesperia, CA, September 4, 1993 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 4, 1993, 14:05 local (21:05 UTC) - Place: Hesperia, CA - Coordinates: 34.360912, -117.320007 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.3609&lon=-117.3200&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report September 26, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 28465 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX93LA342 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28465/pdf - Page: https://openairdocs.org/ntsb/LAX93LA342 ## Probable cause THE AIRCRAFT'S ENCOUNTER WITH A LOW LEVEL WINDSHEAR AND THE PILOT'S INADEQUATE COMPENSATION FOR THE EXISTING WIND CONDITIONS. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, approach - vfr pattern - final approach - object - fence - weather condition - windshear (cause) - compensation for wind conditions - inadequate, pilot in command (cause) - descent - not corrected, pilot in command ## Analysis THE AIRPORT IS LOCATED IN A BOWL SHAPED DEPRESSION AND IS SURROUNDED BY TREES ON ALL SIDES. THE PILOT SAID THAT HE WAS ON SHORT FINAL APPROACH WHEN THE AIRCRAFT ENCOUNTERED TURBULENCE AND A DOWNDRAFT. THE PILOT SAID THAT EVEN WITH THE APPLICATION OF FULL POWER HE WAS UNABLE TO ARREST THE DESCENT PRIOR TO THE LANDING GEAR COLLIDING WITH THE AIRPORT BOUNDARY FENCE. THE AIRCRAFT OWNER WAS ON BOARD AS A PASSENGER. THE OWNER AND THE SECOND PASSENGER STATED THAT ON FINAL APPROACH THE AIR WAS VERY TURBULENT, ESPECIALLY WHEN THE AIRCRAFT DESCENDED BELOW THE TOPS OF THE TREES WHICH SURROUND THE AIRPORT. THE AIRCRAFT OWNER STATED THAT HE THOUGHT THE AIRCRAFT ENCOUNTERED A LOW LEVEL WINDSHEAR CAUSED BY THE TREES. THE CLOSEST OFFICIAL WEATHER REPORTING STATION IS LOCATED 49 MILES NORTH WEST OF THE AIRPORT. AT THE TIME OF THE ACCIDENT, THE STATION WAS REPORTING WINDS FROM 240 DEGREES AT 18 KNOTS, WITH GUSTS TO 27 KNOTS. ## Factual narrative On September 4, 1993, at 1405 hours Pacific daylight time, a Piper PA-24-250, N5523P, collided with a boundary fence while landing at the Hesperia, California, airport. Visual meteorological conditions prevailed at the time and no flight plan was filed for the operation. The aircraft incurred substantial damage. The certificated private pilot and the two passengers were not injured. The flight originated at El Monte, California, on the day of the mishap, at 1330 hours as a personal cross country flight. The Hesperia airport is located in a bowl shaped depression and is surrounded by trees on all sides. In his statement, the pilot said that he was on short final approach when the aircraft encountered turbulence and a down draft. The pilot said that even with the application of full power, he was unable to arrest the descent prior to the landing gear colliding with the airport boundary fence. The aircraft owner was on board as a passenger. The owner and the second passenger stated that on final approach the air was very turbulent, especially when the aircraft descended below the tops of the trees which surround the airport. The aircraft owner stated that he thought the aircraft encountered a low level wind shear caused by the trees. The closest official weather reporting station is Edwards AFB, which is located 49 miles north west of the Hesperia airport. At the time of the accident, Edwards was reporting winds from 240 degrees at 18 knots, with gusts to 27 knots. ## Aircraft - Registration: [N5523P](https://openairdocs.org/aircraft/N5523P), registered now, S/N 24-586 (OpenAirDocs) - Reported make and model: PIPER PA-24-250 - Registry model: [Piper PA-24-250](https://openairdocs.org/model/piper-pa-24-250) (registry code 7102404) (OpenAirDocs) - Registry engine: [Lycoming 0-540 series](https://openairdocs.org/engine/lycoming-0-540-series) (registry code 41532, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 24-586 - Airframe hours: 4145 - Engines: LYCOMING O-540-A1D5 250 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Robert B. Hopkins - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 15, 1992, 21 hours before - Departed: EMT, EL MONTE, CA - Airport: L26, Hesperia, runway 21, 3,900 × 50 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 64; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 1,400 total, 105 in this make and model, 1,150 as pilot in command, 2 in the last 90 days, 1 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 240° at 18 knots, gusting 27 - Visibility: 45 statute miles - Lowest ceiling: none - Temperature: 95 °F, dew point 43 °F - Altimeter: 29.00 inHg ## 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 19930904033209A](https://openairdocs.org/incident/19930904033209A), Sep 4, 1993: Piper PA24250, Hesperia, CA, Substantial damage. Turbulence and downdraft on final. Struck airport boundry fence. 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.