FLIGHT FINDINGSAVIATION OCCURRENCE MAP
Back to map

American Airlines Flight 1115

21 Nov 2004 · Denver, CO, United States

McDonnell Douglas DC-9-82 · Incident: in flight collision with object on approach

From Dallas Fort Worth International Airport (DFW) to Denver International Airport (DEN)

Report a problem

Event

NTSB case
DEN05IA027
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
Incident
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
Instrument Meteorological Cond

McDonnell Douglas DC-9-82

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
N234AA
Onboard fatalities
Unknown
Route
From Dallas Fort Worth International Airport (DFW), Fort Worth, TXTo Denver International Airport (DEN), Denver, CO
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
Approach
First occurrenceThe 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
In flight collision with object
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

  • Copilot/second pilot › Proper glidepath, not maintained
  • Pilot in command › Remedial action, inadequate

Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.

NTSB narrative

The first officer was hand-flying the airplane. During the descent for the approach, the crew received a special observation that the weather was ceilings 300 and 1,000 feet broken and 1/2 mile visibility and fog. The crew briefed the ILS approach for runway 35L. When approach control (TRACON) cleared the airplane for the ILS approach, the airplane was at 9,000 feet. The captain reported that as they continued, the glide slope indicator "came up and actually went below us," and that the airplane had not yet intercepted the localizer. The captain asked TRACON for a lower altitude. TRACON "apologized" and cleared the airplane to 7,000 feet, and then asked the crew if they would still be okay for the approach. The crew said they would be okay. The captain said the airplane was configured and was approaching the glide slope from above, as it was intercepting the localizer. He said the first officer was on the localizer and glide slope. At 100 feet, the captain called approach lights in sight, and the first officer acknowledged. When the captain called reaching the decision altitude, the first officer called landing. The captain said he started to see the threshold lights and then heard the "glide slope" GPWS (Ground Proximity Warning System) warning. The captain called "pull up" to the first officer. The captain said as they touched down he thought he could see some approach light bars below the nose, but did not feel or hear anything unusual. The landing roll out was normal. After parking, the crew discovered damage to the left main brake line and loss of hydraulic fluid from the right system. The airplane showed additional damage to the left main tires, bottom left aft portion of the fuselage, and to the left engine and left engine cowling. An examination of the runway showed one approach light, 19 feet from the beginning of the paved overrun, broken forward at its base. Approximately 49 feet from the start of the paved overrun surface, the beginning of two pairs of parallel-running tire marks were observed. The left pair of tire marks ran through three sets of center approach lights in the overrun, two runway threshold lights, a distance of 354 feet, and continued down runway 35L for approximately 700 feet. Light stanchions, broken lens pieces, and bulb debris was observed extending down the runway along the tire marks. An examination of the airplane's avionics equipment and the airport's ILS approach showed no anomalies. The flight data recorder (FDR) showed that the airplane captured the ILS glide slope 38 seconds prior to touchdown at a radio altitude of 734 feet. The FDR pitch, recorded 4 seconds later, indicated the airplane was tracking the glide slope and at a radio altitude of 617 feet. At 5 seconds prior to touchdown, the glide slope showed a 2 dots fly up deviation. The airplane was at a radio altitude of 114 feet. The glide slope warning was on. The glide slope continued to increase reaching 4.3 dots fly up at touchdown. The airplane's airspeed at touchdown was 133.5 knots. Vertical acceleration was 1.7 g's followed by 0.7 g's approximately 1/2 second later. Lateral acceleration was -0.15 g's. The right outboard spoiler began to deploy at touchdown plus 2.5 seconds. The hydraulic pressure low lights (left and right) remained in an "off" state throughout the incident sequence. Flight crews are administered a simulator check every 9 months, either by the company or the FAA. Crews do not fly practice approaches in the airplane. The first officer's last simulator checkride was 14 months prior to the incident. The first officer stated he could not recall when the last time was that he flew an instrument approach in the airplane in actual weather conditions.

Probable cause

the first officer's failure to maintain proper glide slope during the landing approach, and the captain's failure to adequately monitor the approach and landing, and his failure to challenge and/or intervene when the first officer continued to descend below the glide slope. Factors contributing to the incident were the first officer's lack of recent experience in flying a complete ILS approach in actual instrument conditions, the low ceilings and fog.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record DEN05IA027
Event ID
20041122X01849
Case number
DEN05IA027
Dataset
historical-pre2008
Source SHA-256
89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
  • 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: 17b2a5a49286be7cbaf6ffa355cd64b0b006e125b14ec6cac93f1cbbe053696b; retrieved 2026-09-18T15:11:52.469Z.