# NTSB LAX94LA021: Beech 76, N5148M, Scottsdale, AZ, October 22, 1993 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 21, 1993, 18:40 local (Oct 22, 1993, 01:40 UTC) - Place: Scottsdale, AZ - Coordinates: 33.389545, -111.710914 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.3895&lon=-111.7109&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report August 1, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 28575 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX94LA021 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28575/pdf - Page: https://openairdocs.org/ntsb/LAX94LA021 ## Probable cause the flight instructor's failure to adequately supervise the flight, follow proper procedures/directives regarding leaning and clearing the idling engine, and his delay in applying power to the idling engine. The fouled spark plugs were a factor in this accident. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - nonmechanical, go-around (vfr) - 1 engine - ignition system,spark plug - fouled (contributing factor) - supervision - inadequate, pilot in command(cfi) (cause) - procedures/directives - not followed, pilot in command(cfi) (cause) - remedial action - delayed, pilot in command(cfi) (cause) - Forced landing, descent - emergency - On ground/water encounter with terrain/water, landing - flare/touchdown - gear retraction - intentional, pilot in command(cfi) ## Analysis THE CFI RETARTED THE THROTTLE ON THE LEFT ENGINE TO A ZERO THRUST SETTING. THE DUAL STUDENT CONTACTED THE AIRPORT AND WAS CLEARED FOR A STRAIGHT-IN APPROACH. DURING THE APPROACH, THE CFI FAILED TO INSTRUCT THE STUDENT TO MOMENTARILY CLEAR THE LEFT ENGINE. DURING THE ENSUING GO-AROUND, THE DUAL STUDENT APPLIED FULL POWER ON THE RIGHT ENGINE, BUT THE AIRPLANE WOULD NOT CLIMB. THE CFI DELAYED INSTRUCTING THE STUDENT TO APPLY FULL POWER ON THE LEFT ENGINE. WHEN HE DID INSTRUCT THE STUDENT TO APPLY FULL POWER ON THE LEFT ENGINE, THE ENGINE DID NOT RESPOND AND THE AIRPLANE WAS UNABLE TO MAINTAIN SUFFICIENT ALTITUDE. THE CFI ELECTED TO LAND THE AIRPLANE IN AN OPEN FIELD. THE OPERATOR REPORTED BOTH ENGINES OPERATED NORMALLY DURING THE EXAMINATION AND THE LEFT ENGINE SPARK PLUGS CONTAINED HIGH CARBON AND SOOT DEPOSITS. ## Factual narrative On October 21, 1993, at 1840 hours mountain standard time, a Beech BE-76, N5148M, collided with terrain while attempting to go-around at Scottsdale Airport (SDL), Scottsdale, Arizona. The pilot was conducting a local visual flight rules instructional flight. The airplane, operated by Aero/Mech Inc., Scottsdale, sustained substantial damage. Neither the certificated commercial pilot/flight instructor (CFI), the certificated commercial pilot/dual student, nor the nonrevenue passenger was injured. Visual meteorological conditions prevailed. The flight originated at Scottsdale Airport at 1710 hours. The CFI reported that the dual student was practicing a simulated single-engine landing with the left engine throttle retarded to a zero thrust setting. When the flight was on final approach at 300 feet above ground, the local controller instructed the flight to go-around. The dual student applied full power on the operating engine and began a singe-engine go-around. The operating engine did not produce sufficient power and the dual student then applied full power on the idling engine. The engine did not respond to the power application. When the CFI realized that the airplane was unable to maintain sufficient altitude to return to the airport, he elected to land, gear-up, in an open field. The CFI also said that during the initial descent the student did not "clear the engine", nor did he instruct him to do so. Mr. Michael Brown, Aviation Safety Inspector, Federal Aviation Administration (FAA), Scottsdale Flight Standards District Office, told Safety Board investigators that he spoke with the operator's maintenance manager. The manager told him that both engines operated normally when tested after the accident. He said that the left engine spark plugs contained extensive carbon and soot deposits. These signatures are indicative that the engine was idling for a prolonged period at a rich mixture setting. ## Aircraft - Registration: [N5148M](https://openairdocs.org/deregistered/N5148M-2003-01-30), registration cancelled 2003-01-30, S/N ME-43, built 1978 (OpenAirDocs) - Reported make and model: BEECH 76 - Registry model: [Beech 76](https://openairdocs.org/model/beech-76) (registry code 1153005) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: ME-43 - Airframe hours: 6491 - Engines: LYCOMING O-360-A1G6D 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Aero/Mech Inc. - Registered owner: Belgian Aviation School, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, October 8, 1993, 33 hours before - Airport: SDL, Scottsdale Municipal, runway 3, 8,251 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 35; commercial, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: right; flight hours: 1,880 total, 129 in this make and model, 1,668 as pilot in command, 73 in the last 90 days, 47 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 70° at 5 knots - Visibility: 40 statute miles - Lowest ceiling: 25,000 ft broken - Temperature: 79 °F, dew point 36 °F - Altimeter: 30.00 inHg - Observed at: SDL, 1 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 19931021040389A](https://openairdocs.org/incident/19931021040389A), Oct 21, 1993: Beech 76, Scottsdale, AZ, Substantial damage. Advised by tower go around during practice single engine. Operating engine not cleared. Over boosted idled engine. 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.