Beech D-45 and Beech T-34 mid-air collision near Oswego, Illinois, October 1, 1999
On October 1, 1999 at about 9:00 pm local time, 2 aircraft, Beech D-45 (N300SH) and Beech T-34 (N5367G), were involved in a mid-air collision near Oswego, Illinois. 1 person was killed; 1 other was unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
the visual lookout not obtained by the pilot of the Beech T-34 and the inadequate procedure by the Lima Lima Flying Squadron. The delayed entry into the maneuver by the pilot of the Beech D-45 was a contributing factor.
the visual lookout not obtained by the pilot of the Beech T-34 and the inadequate procedure by the Lima Lima Flying Squadron. The delayed entry into the maneuver by the pilot of the Beech D-45 was a contributing factor.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 1, 1999 · about 9:00 pm local time
- Place
- Oswego, Illinois · map
- Type
- Accident · mid-air collision
- Injuries
- 1 person was killed; 1 other was unhurt.
- Weather
- visual conditions (good weather)
- Aircraft 1
- Beech D-45 · all D-45s on the register
- Registration
- N300SH · no longer on the register · serial CN2
- Damage
- Destroyed
- Flight
- Flight of an unrecorded kind · general aviation rules (Part 91)
- Aircraft 2
- Beech T-34 · all T-34s on the register
- Registration
- N5367G · no longer on the register · serial BG243140909
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · general aviation rules (Part 91)
The NTSB's narrative for the Beech D-45 final · quoted from the NTSB record
N300SH, a Beech D-45, was destroyed on impact with terrain following a midair collision with N5367G, a Beech T-34, during a practice maneuver by the Lima Lima Flying Squadron. Both aircraft departed in sequence from 6-ship delta formation to perform a maneuver called a pop top break. The pop top break involved each aircraft to depart from the formation in sequence by entering a climbing 180-degree turn to follow the lead aircraft in trail. The narrow area of the human eye's visual field is approximately 10-15 degrees. A video tape of the accident flight shows a delayed entry into the turn by the D-45 relative to the T-34's entry into the maneuver. The pilot of the T-34 stated that he did not see the D-45 prior to the midair collision. The Lima Lima Flying Squadron did not have procedures in place to recover or adjust for maneuvers that were not successful.
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 Beech T-34 final · quoted from the NTSB record
N300SH, a Beech D-45, was destroyed on impact with terrain following a midair collision with N5367G, a Beech T-34, during a practice maneuver by the Lima Lima Flying Squadron. Both aircraft departed in sequence from 6-ship delta formation to perform a maneuver called a pop top break. The pop top break involved each aircraft to depart from the formation in sequence by entering a climbing 180-degree turn to follow the lead aircraft in trail. The narrow area of the human eye's visual field is approximately 10-15 degrees. A video tape of the accident flight shows a delayed entry into the turn by the D-45 relative to the T-34's entry into the maneuver. The pilot of the T-34 stated that he did not see the D-45 prior to the midair collision. The Lima Lima Flying Squadron did not have procedures in place to recover or adjust for maneuvers that were not successful.
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 D-45 from the NTSB's investigation tables, in plain English
Pilot
- Certificate: airline transport pilot, commercial pilot
- Ratings: multi-engine land; single-engine land
- Flight time: 16,066 hours in all; 85 in this make and model
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: frt
The aircraft
- Last inspection: inspection type not recorded
- Maximum gross weight: 2,950 lb
- Seats: 2
- Landing gear: retractable
- Engine: Continental IO-520-BB (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: LL10 Naperville IL at 8:35 pm
- Destination: CGX Chicago IL
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 010° at 3 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 61°F (16°C), dew point 0°F (-18°C)
- Altimeter: 30.00 inHg
- Observation at 8:53 pm from ARR, 5 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
The factual record for the Beech T-34 from the NTSB's investigation tables, in plain English
Pilot
- Certificate: airline transport pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 20,000 hours in all; 600 in this make and model; 57 in the last 90 days; 25 in the last 30 days; 15 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: frt
The aircraft
- Last inspection: annual inspection, September 9, 2000
- Maximum gross weight: 3,050 lb
- Seats: 2
- Landing gear: retractable
- Engine: Continental IO-520-BA (piston); 0 hours total
The flight
- Departed from: LL10 Naperville IL at 8:35 pm
- Destination: CGX Chicago IL
- Flight plan: none
- Runway 0
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
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.
Other NTSB records under N300SH the same tail number, which may have belonged to a different aircraft at the time
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.