EMBRAER EMB-145AMERICAN EAGLE AIRLINES INC
Chicago, IL, USA · 2011-06-03·N607AE
What happened
NTSB summary, verbatimThe pilots reported that they felt one brake pedal fully release and then reapply during the landing roll. Air traffic control tower personnel saw a puff of smoke and asked the flight crew if a tire had blown on landing. The pilots taxied the airplane to a hold pad for further examination; however, the emergency brake would not hold the airplane stationary. The pilots also received caution messages for the brakes, and hydraulic fluid was observed on the tires and ground. An examination revealed the brake pressure plate and rotor failed. Separated brake parts were also found on the landing runway. Further examination of the incident brake and four other brakes revealed that they all contained varying levels of oxidation development. The brake manufacturer had previously provided the operator with a maintenance procedure which involved using a fingernail or a specified plastic tool to check brakes for oxidation. The operator developed and provided related training to its maintenance personnel based on the manufacturer's procedures. However, interviews with airline and contract maintenance personnel revealed that they were not familiar with the inspection and were not issued the plastic tool. Subsequently, the brake manufacturer and operator provided additional related training to the operator's maintenance personnel, and the operator stocked their maintenance system with the specified tool.
Photographs
2the aircraft, and what the investigators foundPhotographs are NTSB docket attachments — works of the US government, in the public domain. Captions are the Board’s own.
Probable cause
the Board's determinationThe overheat and failure the brake during landing due to oxidation of the brake rotors, which went undetected by maintenance personnel. Contributing to the accident was maintenance personnel’s lack of familiarity with detailed brake oxidation inspection procedures.
Occurrence sequence
3 stepsNTSB coding · CICTT taxonomy- 1 · Prior to flightAircraft maintenance event
- 2 · Landing-landing rollSys/Comp malf/fail (non-power)defining event
- 3 · Landing-landing rollPart(s) separation from AC
Findings
5 causal · 1 contributing- CAUSEAircraft › Aircraft systems › Landing gear system › Brake — Damaged/degraded
- CAUSEAircraft › Aircraft systems › Landing gear system › Brake — Failure
- CAUSEAircraft › Aircraft systems › Landing gear system › Brake — Inadequate inspection
- CAUSEPersonnel issues › Experience/knowledge › Knowledge › Knowledge of procedures — Maintenance personnel
- CAUSEPersonnel issues › Experience/knowledge › Training › Training with equipment — Maintenance personnel
- FACTOROrganizational issues › Support/oversight/monitoring › Oversight › Parts/tools tracking — Operator
Sequence of events
3 timed eventsfrom the FDR factual report · claude-fable-5-1 (in-session)- 06:03:58 CDTtouchdownp.2Air/ground switch first recorded ground at 132 kts indicated airspeed, then air for 2 s before ground again (bounce/skip)
- 06:04:00-06:04:10 CDTlanding rollp.2Brake pressures #1 and #3 increased, peaking at 1,426 and 1,534 psi within 10 s; maximum longitudinal deceleration -0.39 g at 06:04:10
- after 06:04:10 CDTlanding rollp.2#3 brake pressure decreased to a nominal value and stayed there for the rest of the recording (brake failure/separation)
NTSB analysis
from the final reportThe pilots reported that they felt one brake pedal fully release and then reapply during the landing roll. Air traffic control tower personnel saw a puff of smoke and asked the flight crew if a tire had blown on landing. The pilots taxied the airplane to a hold pad for further examination; however, the emergency brake would not hold the airplane stationary. The pilots also received caution messages for the brakes, and hydraulic fluid was observed on the tires and ground. An examination revealed the brake pressure plate and rotor failed. Separated brake parts were also found on the landing runway. Further examination of the incident brake and four other brakes revealed that they all contained varying levels of oxidation development. The brake manufacturer had previously provided the operator with a maintenance procedure which involved using a fingernail or a specified plastic tool to check brakes for oxidation. The operator developed and provided related training to its maintenance personnel based on the manufacturer's procedures. However, interviews with airline and contract maintenance personnel revealed that they were not familiar with the inspection and were not issued the plastic tool. Subsequently, the brake manufacturer and operator provided additional related training to the operator's maintenance personnel, and the operator stocked their maintenance system with the specified tool.