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Accidents · NTSB WPR10LA284 · Final report

Piper PA-46-310P accident near Ontario, California, June 10, 2010

On June 10, 2010 at about 11:27 pm local time, a Piper PA-46-310P, registered N121HJ, was substantially damaged in an accident during enroute (climb to cruise) near Ontario, California (Ontario International Airport). It was an instructional flight under general aviation rules (Part 91). 1 person was seriously injured and 1 person had minor injuries. The weather was visual conditions (good weather).

The NTSB's probable cause their words, unchanged

A loss of engine power due to the in-flight separation of the 1-3-5 cylinder induction tube elbow, which was caused by the improper installation of the induction tube elbow by maintenance personnel.

Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.

What the record shows

Date
June 10, 2010 · about 11:27 pm local time
Place
Ontario, California · Ontario International Airport · map
Type
Accident
Injuries
1 person was seriously injured and 1 person had minor injuries.
Weather
visual conditions (good weather)
Aircraft
Piper PA-46-310P · all PA-46-310Ps on the register
Registration
N121HJ · registry record · serial 468508105
Damage
Substantial damage
Flight
Instructional flight · general aviation rules (Part 91)

The NTSB's narrative final · quoted from the NTSB record

The pilot was conducting a cross-country flight with a certified flight instructor (CFI). During the climb-to-cruise phase of the flight, as the airplane was ascending through 16,000 feet mean sea level (msl), the pilot noticed a reduction in manifold pressure. He advanced the throttle and observed an increase of one or two inches of manifold pressure. Shortly thereafter, the pilot heard a loud bang originate from the engine followed by an immediate loss of engine power. The pilot and CFI attempted to troubleshoot the engine anomalies and noted that it seemed to respond with the low boost "on", however it began to run rough whenever the throttle was advanced more than half way. They diverted to a nearby airport and conducted an emergency descent. As the airplane approached the airport, the pilot descended through an overcast cloud layer and attempted to enter the airport traffic pattern. While on final approach to the airport, the pilot thought the airplane was high and extended the landing gear and applied flaps. Shortly thereafter, the airspeed and altitude decreased drastically and the pilot realized he was too low. The pilot applied throttle and noticed no change in engine performance. The airplane subsequently struck a fence and landed hard in an open field just short of the airport, which resulted in structural damage to the fuselage and wings. A postaccident examination of the engine revealed that the induction elbow for cylinders 1-3-5 (right side) was displaced from the throttle and metering assembly where the elbow couples with the throttle and metering assembly by an induction hose and clamp. The clamp was secure to the induction hose, however, the portion of the clamp that should have been installed beyond the retention bead on the throttle and control assembly was observed on the inboard side of the bead on the induction elbow. Review of the aircraft maintenance logbooks revealed that cylinders 4 and 5 were recently replaced prior to the accident flight due to low compression. The replacement of these cylinders required removal of the induction system to allow for cylinder removal and installation. In addition, a manufacturer service bulletin stated that during the reinstallation of the induction system, one must slide the induction hose and clamp(s) onto one of the tubes to be joined and that the connection joint and both tube beads are to be positioned in the center of the induction hose. The clamps should be installed in a position centered between the tubing bead and end of the induction hose.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.

The factual record from the NTSB's investigation tables, in plain English

What happened, in order

  1. Aircraft maintenance event during prior to flight
  2. Loss of engine power (total) during enroute (climb to cruise) defining event
  3. Off-field or emergency landing during landing (flare/touchdown)
  4. Collision with terrain or object (not controlled flight into terrain) during landing (flare/touchdown)

The NTSB's findings

  • cause Aircraft › Aircraft power plant › Power plant › Air intake › Failure
  • cause Aircraft › Aircraft power plant › Power plant › Air intake › Incorrect service/maintenance
  • cause Personnel issues › Task performance › Maintenance › Installation › Maintenance personnel

Pilot

  • Certificate: private
  • Ratings: multi-engine land; single-engine land; instrument: airplane
  • Flight time: 850 hours in all; 1 in this make and model; 2 in the last 30 days
  • Last flight review: April 20, 2010
  • Medical certificate: Class 2 (without waivers/limitations)
  • Seat: left
  • Injury: minor injuries

Flight instructor

  • Certificate: flight instructor, commercial pilot
  • Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: instrument airplane; instrument: airplane
  • Flight time: 5,735 hours in all; 192 in this make and model; 24 in the last 90 days; 17 in the last 30 days; 5,685 as pilot in command; 4,517 on instruments
  • Last flight review: February 8, 2010
  • Medical certificate: Class 2 (with waivers/limitations)
  • Seat: rgt
  • Injury: serious injuries

The aircraft

  • Airframe total time: 4,803 hours
  • Last inspection: annual inspection, September 23, 2009
  • Maximum gross weight: 4,100 lb
  • Seats: 6
  • Landing gear: fixed
  • Engine: Cont Motor IO-550 SERIES (piston); 0 hours total

The flight

  • Departed from: SMO Santa Monica CA at 10:50 pm
  • Destination: HII Lake Havasu AZ
  • Flight plan: none
  • A second pilot was aboard

Weather at the time

  • Light: daylight
  • Wind: from 260° at 8 knots, gusting 16
  • Visibility: 10 statute miles
  • Sky: broken clouds at 3,700 ft
  • Temperature: 72°F (22°C), dew point 55°F (13°C)
  • Altimeter: 29.85 inHg
  • Observation at 11:51 pm from ONT, 1 miles away

Injuries

FatalSeriousMinorNone
Flight crew11

Documents from the investigation the NTSB's docket: the evidence folder behind the report

The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.

Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.