# NTSB LAX95LA160: Cessna 170A, N1276D, Woodland, CA, April 11, 1995 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 11, 1995, 11:30 local (18:30 UTC) - Place: Woodland, CA - Coordinates: 38.710052, -121.85083 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.7101&lon=-121.8508&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report August 23, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 29073 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX95LA160 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/29073/pdf - Page: https://openairdocs.org/ntsb/LAX95LA160 ## Probable cause the pilot's improper recovery from a bounced landing. The mechanic's inadequate annual inspection by failing to determine the worn condition of the crosswind landing gear detent stop groove and snubber pin and the soft terrain were factors in this accident. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - on ground/water, landing - roll - landing gear,gear locking mechanism - worn (contributing factor) - maintenance,annual inspection - inadequate, other maintenance personnel (contributing factor) - recovery from bounced landing - improper, pilot in command (cause) - On ground/water encounter with terrain/water, landing - roll - terrain condition - soft (contributing factor) ## Analysis THE PILOT WAS COMPLETING A VFR PERSONAL FLIGHT IN A CONVENTIONAL GEAR AIRPLANE. ON LANDING, THE AIRPLANE BOUNCED AND CONTINUED TO PORPOISE, GROUND LOOPED, AND EXITED THE RIGHT SIDE OF THE RUNWAY. THE PILOT TOLD A GROUND WITNESS THAT SHE MESSED UP THE LANDING. THE PILOT REPORTED IN THE ACCIDENT REPORT THAT THE RIGHT LANDING GEAR WHEEL 'LOCKED UP.' EXAMINATION OF THE BRAKES, TIRES, AND FLIGHT CONTROL SYSTEMS REVEALED THAT THEY WERE IN GOOD CONDITION. HOWEVER,THE AIRPLANE CROSSWIND LANDING GEAR DETENT STOP AND SNUBBER PIN WERE WORN. THIS CONDITION ALLOWED THE LEFT WHEEL TO UNLOCK PREMATURELY AND WITHOUT WARNING. ## Factual narrative On April 11, 1995, at 1130 hours Pacific daylight time, a Cessna 170A, N1276D, ground looped while landing on runway 36 at Watts-Woodland Airport, Woodland, California. The pilot was completing a visual flight rules personal flight. The airplane, registered to and operated by Grass Valley Aviation, Inc., Grass Valley, California, sustained substantial damage. Neither the certificated private pilot nor the two passengers were injured. Visual meteorological conditions prevailed. The flight originated at Nevada County Airpark, Grass Valley, California, at 1030 hours. National Transportation Safety Board investigators conducted a telephone interview with the pilot on April 13, 1995. The pilot said that the approach was normal. On touchdown, the airplane bounced. The pilot arrested the bounce, but the airplane began to drift to the left. She said that she applied right rudder to arrest the drift. However, the right wheel locked and the airplane ground looped and exited the runway. When the airplane exited the runway, the tailwheel stuck in the soft terrain causing the AFT fuselage section to fold. The pilot repeated her telephone statement in the National Transportation Safety Board Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1/2; however, the pilot did not show in the accident report that the airplane experienced any preimpact mechanical malfunctions or failures. A Federal Aviation Administration (FAA) airworthiness inspector from the Sacramento (California) Flight Standards District Office conducted the on-scene investigation. The inspector reported that the pilot told him the " . . . right brake locked up causing the aircraft to ground loop . . . ." The inspector said that his examination of the airplane brake system revealed that the brakes and tires were in good condition; the tires did not display any abnormal scuff or wear marks. He also said that the flight controls operated normally. The inspector did not examine the airplane crosswind landing gear system. A line worker for a fixed-base operator at the airport told the inspector that the airplane made a normal approach to the runway. When the airplane tail touched the ground, the airplane began a porpoise and then ground looped. The line worker said that the pilot told him " . . . she had messed up the landing . . . ." The Safety Board retained a mechanic from Sierra Mountain Aviation, Grass Valley Airport, to inspect the airplane crosswind landing gear system. The mechanic reported that he found that the landing gears detent stop groove and snubber pin were worn. He said that the findings resulted in the "brake-out" force of the left gear to be half of the force required for the right landing gear. The left main gear was able to unlock (kick-in) prematurely and without warning. This condition allowed the airplane to rotate to the right. ## Aircraft - Registration: [N1276D](https://openairdocs.org/aircraft/N1276D), registered now, S/N 20124, built 1951 (OpenAirDocs) - Reported make and model: CESSNA 170A - Registry model: [Cessna 170A](https://openairdocs.org/model/cessna-170a) (registry code 2072304) (OpenAirDocs) - Registry engine: [Continental C145 series](https://openairdocs.org/engine/continental-c145-series) (registry code 17012, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 20124 - Engines: CONTINENTAL O-300-A 145 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Grass Valley Aviation, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 26, 1994, 57 hours before - Departed: 017, GRASS VALLEY, CA - Destination: O41 - Airport: O41, Watts-Woodland, runway 36, 3,770 × 60 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 156 total, 59 in this make and model, 113 as pilot in command, 6 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Visibility: 25 statute miles - Lowest ceiling: none - Temperature: 64 °F ## 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 19950411048299A](https://openairdocs.org/incident/19950411048299A), Apr 11, 1995: Cessna 170A, Woodland, CA, Substantial damage. Pilot lost control of the aircraft on land. Aircraft porpoised, ground looped off the runway and caught a main wheel in mud. Pilot admitted "messing up the… 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.