Atlantic Southeast Airlines Flight 4904
Bombardier CL600 2D24 900 and Delta Air Lines Boeing 767 332 · Accident: ground collision while standing
Event
- NTSB case
- DCA11CA084
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Airline
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Aircraft 1 · Bombardier CL600 2D24 900
- Aircraft type
- Bombardier CL600
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N132EV
- Operator
- Atlantic Southeast Airlines
- Onboard fatalities
- Unknown
- Route
- From Boston Logan International Airport (BOS), Boston, MATo Raleigh-Durham International Airport (RDU), Raleigh-Durham, NC
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 121: Air Carrier
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Standing
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Ground collision
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Aircraft 2 · Boeing 767 332
- Aircraft type
- Boeing 767
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N185DN
- Operator
- Delta Air Lines
- Onboard fatalities
- Unknown
- Route
- From Boston Logan International Airport (BOS), Boston, MATo not recorded
- Aircraft age
- About 16 years (built 1995)
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 121: Air Carrier
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Taxi · to runway
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Ground collision
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Minor
Cause areas
- Personnel issues › Action/decision
- Personnel issues › Psychological
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
On July 14, 2011, about 1933 eastern daylight time, Delta Air Lines flight 266, a Boeing 767-300ER, N185DN, was taxiing for departure when its left winglet struck the horizontal stabilizer of Atlantic Southeast Airlines flight 4904, a Bombardier CL-600-2D24 (CRJ900), N132EV, which was on taxiway M holding for departure on runway 09 at Boston Logan International Airport (BOS), Boston, Massachusetts. The CRJ900 sustained substantial damage and the 767 sustained minor damage. There were no injuries to any of the passengers and crew aboard either airplane.
Flight 4904, the CRJ900, was stopped behind two other airplanes on the south side of taxiway M awaiting takeoff clearance for runway 9. Flight 266, the B767, was taxiing for departure on runway 4R and was instructed by the ground controller to hold short of runway 4L on taxiway B. After holding short of runway 4L for a few minutes, the ground controller instructed them to "taxi to runway 4R, good rate around the corner." The captain recalled the ground controller had said the landing traffic was four miles out on final approach. The flight crew stated that they looked for the landing traffic and saw a "heavy" airplane approaching the airport with its landing gear extended were not sure if the landing traffic was going to runway 4L, runway 4R or runway 9. The captain indicated he expedited the taxi to cross the runway 4L approach path and estimated a taxi speed of more than 20 knots when they crossed the 4L approach path.
After the B767 crossed the runway 4L approach path, ATC said "nice job, monitor tower on 132.22, should get you right outta here at this next arrival." The B767 first officer (FO) stated he then was changing to the tower frequency when he looked up and saw that they were closing the distance to the CRJ900 faster than he had expected and said "watch this guy". The captain stated that after turning on to taxiway B, he noticed the CRJ900 that was stopped on taxiway M and thought that it looked clear of taxiway B. The captain stated that it looked like they would be clear of the CRJ900 but the distance was going to be close so he steered the B767 slightly to the right (about three feet) of the taxiway centerline and applied light braking when the collision occurred. According to the accident captain and a Delta check airman, the B767 wingtips are not visible from the cockpit unless the windows are opened. The CRJ900 sustained substantial damage to the horizontal tail and vertical tail and fluid was lost in all three hydraulic systems.
Probable cause
the B767 flight crew's failure to maintain a safe clearance with the CRJ900 that was stopped on a taxiway.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DCA11CA084
- Event ID
- 20110715X40120
- Case number
- DCA11CA084
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (5)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: d5f61a7ba097447198d712aeb3dbcee49de1c72166dc55d4fc822e6e5d976bd5; retrieved 2026-09-13T18:19:50.919Z.
- Corrected after a review of the NTSB narrative, which states these values explicitly: destination. Destination label misspells Raleigh (RDU).