Amateur-built RV-4 and Sukhoi SU-29 mid-air collision near Englewood, Colorado, May 11, 1996
On May 11, 1996 at about 5:34 pm local time, 2 aircraft, amateur-built RV-4 (N44AZ) and Sukhoi SU-29 (N55SU), were involved in a mid-air collision near Englewood, Colorado (Centennial airport). 1 person was killed; 1 other was unhurt. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
failure of the pilot of the RV-4, N44AZ, to comply with an ATC clearance by landing on the wrong runway, and the failure of the pilot of the SU-29, N55SU, to maintain an adequate visual lookout. Factors in the accident were: the failure of the air traffic controller to restate the landing runway to the pilot of the RV-4 during a critical period of flight, his failure to advise the pilot of the RV-4 that operations were being conducted on the adjacent runway, a high traffic workload which resulted from an airport open house, and a lack of coordination to accommodate the high traffic workload.
failure of the pilot of the RV-4, N44AZ, to comply with an ATC clearance by landing on the wrong runway, and the failure of the pilot of the SU-29, N55SU, to maintain an adequate visual lookout. Factors in the accident were: the failure of the air traffic controller to restate the landing runway to the pilot of the RV-4 during a critical period of flight, his failure to advise the pilot of the RV-4 that operations were being conducted on the adjacent runway, a high traffic workload which resulted from an airport open house, and a lack of coordination to accommodate the high traffic workload.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 11, 1996 · about 5:34 pm local time
- Place
- Englewood, Colorado · Centennial · map
- Type
- Accident · mid-air collision
- Injuries
- 1 person was killed; 1 other was unhurt.
- Weather
- visual conditions (good weather)
- Aircraft 1
- Amateur-built RV-4
- Registration
- N44AZ · registry record · serial 1
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
- Aircraft 2
- Sukhoi SU-29 · all SU-29s on the register
- Registration
- N55SU · no longer on the register · serial 73-05
- Damage
- Minor damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative for the amateur-built RV-4 final · quoted from the NTSB record
The pilot of the RV-4, N44AZ, had made initial contact with the control tower on the west arrival frequency, and was instructed to report entering a right downwind for runway 17R, which he acknowledged. At about the same time, the pilot of the Sukhoi SU-29, N55SU, made initial contact with the control tower on the east arrival frequency and was instructed to report on a left base for runway 17L. Both pilots were subsequently cleared to land on their respective runways. Instead of landing on his assigned runway 17R, the pilot of the RV-4 landed on 17L. The SU-29 then landed on top of the RV-4. The FAA's ATC handbook advises controllers to restate the landing runway whenever there is a possibilty of a conflict with another aircraft which is using or planning to use another runway. The threshold of runway 17R is 1,800 feet beyond the threshold of runway 17L. The airport was hosting an open house at the time, and airborne flights from a 'Parade of Flight' were in progress.
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 Sukhoi SU-29 final · quoted from the NTSB record
The pilot of the RV-4, N44AZ, had made initial contact with the control tower on the west arrival frequency, and was instructed to report entering a right downwind for runway 17R, which he acknowledged. At about the same time, the pilot of the Sukhoi SU-29, N55SU, made initial contact with the control tower on the east arrival frequency and was instructed to report on a left base for runway 17L. Both pilots were subsequently cleared to land on their respective runways. Instead of landing on his assigned runway 17R, the pilot of the RV-4 landed on 17L. The SU-29 then landed on top of the RV-4. The FAA's ATC handbook advises controllers to restate the landing runway whenever there is a possibilty of a conflict with another aircraft which is using or planning to use another runway. The threshold of runway 17R is 1,800 feet beyond the threshold of runway 17L. The airport was hosting an open house at the time, and airborne flights from a 'Parade of Flight' were in progress.
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 amateur-built RV-4 from the NTSB's investigation tables, in plain English
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 736 hours in all; 171 in this make and model; 663 as pilot in command
- Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
- Seat: frt
The aircraft
- Airframe total time: 223 hours
- Last inspection: annual inspection, April 29, 1996; 1 hours since
- Maximum gross weight: 1,500 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-320-E3D (piston); 0 hours total
The flight
- Departed from: 00V Peyton CO at 4:50 pm
- Destination: APA
- Flight plan: none
- Runway 17L, 10,001 ft by 100 ft
Weather at the time
- Light: daylight
- Wind: from 120° at 4 knots
- Visibility: 40 statute miles
- Sky: clear
- Temperature: 66°F (19°C), dew point 30°F (-1°C)
- Altimeter: 30.00 inHg
- Observation at 5:38 pm from APA
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
The factual record for the Sukhoi SU-29 from the NTSB's investigation tables, in plain English
Pilot
- Certificate: airline transport pilot, flight instructor, commercial pilot, flight engineer
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 21,000 hours in all; 35 in this make and model; 25 in the last 90 days; 8 in the last 30 days
- Medical certificate: Class 1 (valid medical--w/ waivers/lim.)
- Seat: rear
The aircraft
- Airframe total time: 123 hours
- Last inspection: 100-hour inspection, February 8, 1996; 29 hours since
- Maximum gross weight: 2,600 lb
- Seats: 2
- Landing gear: fixed
- Engine: Vendeneyev M-14P (piston); 0 hours total
The flight
- Departed from: FTG Watkins CO at 5:15 pm
- Destination: APA
- Flight plan: none
- Runway 17L, 10,001 ft by 100 ft
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 N44AZ the same tail number, which may have belonged to a different aircraft at the time
2016-03-10WPR16LA088 · accident near Prescott, AZ · substantial damage · no injuries
1991-07-04SEA91LA154 · accident near Yellowstonepark, WY · substantial damage · fatal
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.