Beech J35 and Boeing CH-47D mid-air collision near Morgan Hill, California, February 11, 1998
On February 11, 1998 at about 11:25 pm local time, 2 aircraft, Beech J35 (N8343D) and Boeing CH-47D (ARNG), were involved in a mid-air collision near Morgan Hill, California. 1 person was killed; 4 others were unhurt. The weather was visual conditions (good weather).
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The NTSB's probable cause their words, unchanged
The pilot's failure to maintain visual separation from the flight of military helicopters approaching from his left. The pilot's failure to request VFR traffic advisories, to maintain an adequate visual lookout, an erratic transponder, and glare from the sun were factors.
The pilot-in-command's failure to maintain visual separation from N8343D approaching from his right. The controller's failure to provide a traffic advisory and the copilot's and flight engineer's inadequate visual lookout were factors.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 11, 1998 · about 11:25 pm local time
- Place
- Morgan Hill, California · map
- Type
- Accident · mid-air collision
- Injuries
- 1 person was killed; 4 others were unhurt.
- Weather
- visual conditions (good weather)
- Aircraft 1
- Beech J35 · all J35s on the register
- Registration
- N8343D · no longer on the register · serial D-5431
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
- Aircraft 2
- Boeing CH-47D · all CH-47Ds on the register
- Registration
- ARNG · no longer on the register · serial 91-0234
- Damage
- Substantial damage
- Flight
- Flight · military rules
The NTSB's narrative for the Beech J35 final · quoted from the NTSB record
A flight of two military helicopters was on a northerly heading while N8343D was on a converging northwesterly heading at the same altitude. There were no indications that the occupants of either aircraft saw each other prior to colliding in midair. The crew of the second helicopter saw the airplane approaching, but did not have time to radio a warning. After the collision, the airplane entered an uncontrolled descent. The helicopter pilot made a precautionary, run-on landing, and made an emergency shutdown. The 5 feet 2 inch airplane pilot used a pillow, placed on the seat bottom to increase his seated height. The seat did not have a vertical adjustment. The sun was in the southwest quadrant, with scattered clouds and 20 miles visibility. The top and bottom rotating beacons, as well as landing lights of both helicopters were illuminated. The helicopter pilot was flight following, but had not received any conflicting traffic advisories. The airplane pilot was not communicating with ATC. The transponder in the airplane was squawking 1200 but the altitude was reported as erratic and unreliable. The unreliable altitude returns from the airplane disabled the automatic intruder program. The controller did not see the airplane as a primary target because he was busy handling other traffic.
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 NTSB's narrative for the Boeing CH-47D final · quoted from the NTSB record
A flight of two military helicopters was on a northerly heading while N8343D was on a converging northwesterly heading at the same altitude. There were no indications that the occupants of either aircraft saw each other prior to colliding in midair. The crew of the second helicopter saw the airplane approaching, but did not have time to radio a warning. After the collision, the airplane entered an uncontrolled descent. The helicopter pilot made a precautionary, run-on landing, and made an emergency shutdown. The 5 feet 2 inch airplane pilot used a pillow, placed on the seat bottom to increase his seated height. The seat did not have a vertical adjustment. The sun was in the southwest quadrant, with scattered clouds and 20 miles visibility. The top and bottom rotating beacons, as well as landing lights of both helicopters were illuminated. The helicopter pilot was flight following, but had not received any conflicting traffic advisories. The airplane pilot was not communicating with ATC. The transponder in the airplane was squawking 1200 but the altitude was reported as erratic and unreliable. The unreliable altitude returns from the airplane disabled the automatic intruder program. The controller did not see the airplane as a primary target because he was busy handling other traffic.
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 for the Beech J35 from the NTSB's investigation tables, in plain English
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land
- Flight time: 6,058 hours in all; 5,648 as pilot in command
- Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 5,639 hours
- Last inspection: annual inspection, June 19, 1997; 63 hours since
- Maximum gross weight: 2,900 lb
- Seats: 4
- Landing gear: retractable
- Engine: Continental IO-470C (piston); 0 hours total
The flight
- Departed from: RHV San Jose CA at 11:10 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 290° at 8 knots
- Visibility: 20 statute miles
- Sky: scat at 3,000 ft
- Temperature: 63°F (17°C), dew point 43°F (6°C)
- Altimeter: 30.00 inHg
- Observation at 10:45 pm from RHV, 16 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
The factual record for the Boeing CH-47D from the NTSB's investigation tables, in plain English
Pilot
- Certificate: military
- Ratings: instrument: helicopter; rotorcraft: helicopter
- Flight time: 3,495 hours in all; 686 in this make and model; 39 in the last 90 days; 25 in the last 30 days
- Medical certificate: Unknown
- Seat: left
The aircraft
- Airframe total time: 4,404 hours
- Last inspection: approved inspection programme, February 6, 1998; 13 hours since
- Maximum gross weight: 50,000 lb
- Seats: 35
- Landing gear: fixed
- Engine: Lycoming T55-L-712 (turboshaft); 0 hours total
The flight
- Departed from: MRY Monterey CA at 11:05 pm
- Destination: SCK Stockton CA
- Flight plan: VFR
- Runway 0
- A second pilot was aboard
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 4 |
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The docket at the NTSB holds the report as a PDF and the investigation's photographs and documents. This site never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number LAX98FA086.