Swearingen SW-4 and Airbus Industrie A-319 incident near Denver, Colorado, January 5, 2007
On January 5, 2007 at about 2:28 pm local time, 2 aircraft, Swearingen SW-4 (N425MA) and Airbus Industrie A-319 (N915FR), were involved in the same incident near Denver, Colorado (Denver International airport). No one was hurt; 51 people were on board or involved. The weather was instrument conditions (cloud, fog or low visibility).
The NTSB's probable cause their words, unchanged
The probable cause of the incident was the Key Lime Air flight 4216 pilot's inadvertant entry onto the active runway. A contributing factor to the incident was the failure of the Denver tower ground and local controllers to detect the aircraft on the airport movement area safety system (ASDE) display and issue a go-around instruction to the arrival flight crew.
The probable cause of the incident was the Key Lime Air flight 4216 pilot's inadvertant entry onto the active runway. A contributing factor to the incident was the failure of the Denver tower ground and local controllers to detect the aircraft on the airport movement area safety system (ASDE) display and issue a go-around instruction to the arrival flight crew.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- January 5, 2007 · about 2:28 pm local time
- Place
- Denver, Colorado · Denver International · map
- Type
- Incident
- Injuries
- No one was hurt; 51 people were on board or involved.
- Weather
- instrument conditions (cloud, fog or low visibility)
- Aircraft 1
- Swearingen SW-4
- Registration
- N425MA · registry record
- Damage
- Not recorded
- Flight
- Flight · rules the NTSB did not record
- Aircraft 2
- Airbus Industrie A-319 · all A-319s on the register
- Registration
- N915FR · no longer on the register · serial N915FR
- Damage
- Not recorded
- Flight
- Flight · scheduled airline rules (Part 121)
The NTSB's narrative for the Swearingen SW-4 final · quoted from the NTSB record
At 0728 MST (1428 UTC) a runway incursion occurred involving Key Lime Air (LYM) flight 4216, an SW4, and Frontier (FFT) flight 297, an A319, at Denver International Airport (DEN), Denver, Colorado. At 0725:00, the DEN ground controller instructed LYM4216 to taxi to runway 34 via taxiways M and AA. According the SW4 pilot, blowing snow reduced his visibility and taxiway SC was covered with snow that prevented him from seeing the centerline lighting. As he attempted to find the centerline lighting, he saw blue taxi lights, followed them and turned onto runway 35L. According to the recorded airport surface detection equipment (ASDE), LYM4216 entered runway 35L at taxiway M2 at 0727:06. At 0728:10, the ground controller asked the LYM4216 pilot his location. The pilot advised he was abeam Signature. Once the controller asked his location, the pilot stated that he noticed that he was on a runway. The First Officer of FFT297 reported, "the Captain and I were flying back to Denver from St. Louis. The weather had deteriorated in Denver so we prepared to fly a full instrument approach. We were cleared to land on runway 35L by tower. I believe we broke out of the clouds around 600 feet. The visibility conditions were ½ mile with blowing snow. We both looked down the runway and confirmed verbally to each other that the runway was clear. We didn't see the aircraft until we were about 100 to 50 feet or so above the deck. When it did come into sight, it was at least 2,000 feet down the runway. The winds combined with the prop wash from the aircraft along with blowing snow is what caused it to be obscured and out of sight. I immediately commenced a go around as soon as the aircraft was in sight. The tower was given warning from its collision avoidance system not more than a couple of seconds later." At 0728:17, AMASS provided an aural and visual alert for an occupied runway and 4 seconds later, the tower controller instructed FFT297 to "go around". The aircraft missed colliding by approximately 50 feet. Weather at the time of the incident was 600 overcast, 1100 broken, visibility 1/2 mile, light snow, mist, wind 030 at 12, runway visual range on runway 35L was 5,500 feet.
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 Airbus Industrie A-319 final · quoted from the NTSB record
At 0728 MST (1428 UTC) a runway incursion occurred involving Key Lime Air (LYM) flight 4216, an SW4, and Frontier (FFT) flight 297, an A319, at Denver International Airport (DEN), Denver, Colorado. At 0725:00, the DEN ground controller instructed LYM4216 to taxi to runway 34 via taxiways M and AA. According the SW4 pilot, blowing snow reduced his visibility and taxiway SC was covered with snow that prevented him from seeing the centerline lighting. As he attempted to find the centerline lighting, he saw blue taxi lights, followed them and turned onto runway 35L. According to the recorded airport surface detection equipment (ASDE), LYM4216 entered runway 35L at taxiway M2 at 0727:06. At 0728:10, the ground controller asked the LYM4216 pilot his location. The pilot advised he was abeam Signature. Once the controller asked his location, the pilot stated that he noticed that he was on a runway. The First Officer of FFT297 reported, "the Captain and I were flying back to Denver from St. Louis. The weather had deteriorated in Denver so we prepared to fly a full instrument approach. We were cleared to land on runway 35L by tower. I believe we broke out of the clouds around 600 feet. The visibility conditions were ½ mile with blowing snow. We both looked down the runway and confirmed verbally to each other that the runway was clear. We didn't see the aircraft until we were about 100 to 50 feet or so above the deck. When it did come into sight, it was at least 2,000 feet down the runway. The winds combined with the prop wash from the aircraft along with blowing snow is what caused it to be obscured and out of sight. I immediately commenced a go around as soon as the aircraft was in sight. The tower was given warning from its collision avoidance system not more than a couple of seconds later." At 0728:17, AMASS provided a aural and visual alert for an occupied runway and 4 seconds later, the tower controller instructed FFT297 to "go around". The aircraft missed colliding by approximately 50 feet. Weather at the time of the incident was 600 overcast, 1100 broken, visibility 1/2 mile, light snow, mist, wind 030 at 12, runway visual range on runway 35L was 5,500 feet.
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 Swearingen SW-4 from the NTSB's investigation tables, in plain English
Pilot
- Injury: no injuries
The aircraft
- Landing gear: fixed
- Operator: Key Lime Air
The flight
- Departed from: Denver CO
- Flight plan: IFR
Weather at the time
- Wind: from 030° at 12 knots
- Visibility: 0.5 statute miles
- Sky: broken clouds at 600 ft
- Temperature: 25°F (-4°C), dew point 23°F (-5°C)
- Altimeter: 29.81 inHg
- Observation at 7:30 am from DEN
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
The factual record for the Airbus Industrie A-319 from the NTSB's investigation tables, in plain English
The aircraft
- Landing gear: fixed
The flight
- Departed from: STL St. Louis MO
- Destination: DEN Denver CO
- Flight plan: IFR
- Runway 35L, 12,000 ft by 150 ft
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 5 | |||
| Passengers | 45 |
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 N425MA the same tail number, which may have belonged to a different aircraft at the time
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 documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text 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 OPS07IA001.