20150518013589I

Incident · Minor damage

FAA incident report · Boeing 737-990ER · Seatac, WA · May 18, 2015

Date
May 18, 2015 · 00:07 local
Place
Seatac, WA
Airport
Seattle-Tacoma International
Phase of flight
Landing: Touchdown
Operating rules
Air carrier (Part 121)
Operator
ASAA
Damage
Minor damage
Aircraft
N462AS
Reported as
Boeing 737-990ER
Reported engine
CFM International CFM56-7B27E
People aboard
178
Fatal injuries
0
Other injuries
0
Pilot’s certificate
Airline transport
Pilot’s flight hours
9,941 total7,363 in this make and model241 in the last 90 days

From the FAA’s Accident/Incident Data System (AIDS), through its Aviation Safety Information Portal, as reported. The NTSB investigates accidents separately, and its record of an accident is the fuller one. The aircraft is matched to the registry by N-number and event date, checked against the reported make and model; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

What happened

The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.

Upon touchdown on runway 34R in ksea, both left main landing gear tires failed. After stopping the aircraft on the runway, the flight crew requested emergency equipment. There was no fire and there were no injuries. No evacuation was initiated.

The left main landing gear wheel assembly was inspected by the manufacturer, Honeywell. This inspection revealed evidence of heat damage, including rotors which were welded to stators. It appears that the position 1 wheel did not rotate upon touchdown, likely due the welding that occurred sometime prior to touchdown. The number 2 position tire deflated sometime prior to touchdown and was shredded after touchdown. Notwithstanding the damage created by excessive heat and damage from the landing rollout, the left main gear assembly appeared to have no abnormalities.

Following replacement of the left main wheel assembly, the airline conducted functional tests on the aircraft?s braking system, included high-speed taxi tests. No additional anomalies were discovered and the aircraft was returned to service.

The aircraft departed runway 7R in klas at 0511Z. Wind direction and speed at the time of departure was not available. Klas METAR at 0456Z, 15 minutes prior to departure indicated winds from 180 at 13 knots and a temperature of 23. This wind direction and speed would have subjected the aircraft to a 12 knot crosswind and a 5 knot tailwind at departure.

The FAA interviewed the flight crew. The first officer (pilot flying) and the captain (pilot monitoring) each provided written statements. Neither pilot?s statement provided additional insight on what may have caused excessive heat to the left main wheel assembly. Each pilot reported normal operation of all systems during the flight prior to touchdown.

As the FAA filed it

UPON TOUCHDOWN ON RUNWAY 34R IN KSEA, BOTH LEFT MAIN LANDING GEAR TIRES FAILED. AFTER STOPPING THE AIRCRAFT ON THE RUNWAY, THE FLIGHT CREW REQUESTED EMERGENCY EQUIPMENT. THERE WAS NO FIRE AND THERE WERE NO INJURIES. NO EVACUATION WAS INITIATED.

THE LEFT MAIN LANDING GEAR WHEEL ASSEMBLY WAS INSPECTED BY THE MANUFACTURER, HONEYWELL. THIS INSPECTION REVEALED EVIDENCE OF HEAT DAMAGE, INCLUDING ROTORS WHICH WERE WELDED TO STATORS. IT APPEARS THAT THE POSITION 1 WHEEL DID NOT ROTATE UPON TOUCHDOWN, LIKELY DUE THE WELDING THAT OCCURRED SOMETIME PRIOR TO TOUCHDOWN. THE NUMBER 2 POSITION TIRE DEFLATED SOMETIME PRIOR TO TOUCHDOWN AND WAS SHREDDED AFTER TOUCHDOWN. NOTWITHSTANDING THE DAMAGE CREATED BY EXCESSIVE HEAT AND DAMAGE FROM THE LANDING ROLLOUT, THE LEFT MAIN GEAR ASSEMBLY APPEARED TO HAVE NO ABNORMALITIES.

FOLLOWING REPLACEMENT OF THE LEFT MAIN WHEEL ASSEMBLY, THE AIRLINE CONDUCTED FUNCTIONAL TESTS ON THE AIRCRAFT?S BRAKING SYSTEM, INCLUDED HIGH-SPEED TAXI TESTS. NO ADDITIONAL ANOMALIES WERE DISCOVERED AND THE AIRCRAFT WAS RETURNED TO SERVICE.

THE AIRCRAFT DEPARTED RUNWAY 7R IN KLAS AT 0511Z. WIND DIRECTION AND SPEED AT THE TIME OF DEPARTURE WAS NOT AVAILABLE. KLAS METAR AT 0456Z, 15 MINUTES PRIOR TO DEPARTURE INDICATED WINDS FROM 180 AT 13 KNOTS AND A TEMPERATURE OF 23. THIS WIND DIRECTION AND SPEED WOULD HAVE SUBJECTED THE AIRCRAFT TO A 12 KNOT CROSSWIND AND A 5 KNOT TAILWIND AT DEPARTURE.

THE FAA INTERVIEWED THE FLIGHT CREW. THE FIRST OFFICER (PILOT FLYING) AND THE CAPTAIN (PILOT MONITORING) EACH PROVIDED WRITTEN STATEMENTS. NEITHER PILOT?S STATEMENT PROVIDED ADDITIONAL INSIGHT ON WHAT MAY HAVE CAUSED EXCESSIVE HEAT TO THE LEFT MAIN WHEEL ASSEMBLY. EACH PILOT REPORTED NORMAL OPERATION OF ALL SYSTEMS DURING THE FLIGHT PRIOR TO TOUCHDOWN.