Date: 201203
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class C ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Turbine Engine
Component problem: Malfunctioning; Design
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Human factors: Physiological - Other; Troubleshooting
Second reporter function: Flight Attendant (On Duty)
Anomaly: Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Attendant; Person Flight Crew
When detected: Taxi
Result: General Maintenance Action; General Physical Injury / Incapacitation
Contributing factors: Human Factors; Environment - Non Weather Related; Aircraft
Primary problem: Aircraft

Narrative: Shortly before push; the 'A' Flight Attendant called and said there was the smell of dirty socks in the forward cabin. The Captain went back to the cabin to investigate. When he returned; he said didn't smell anything and that he and the Flight Attendant agreed it was OK to go. On climb out below 10;000 FT; there was a faint musty odor which dissipated quickly as we climbed past 10;000 FT. The cruise portion of the flight was uneventful with no further complaints of the smell from the flight attendants. I used the lavatory several times during cruise and noticed no unusual smells at that time. On descent passing about 8;000 FT; we noticed the musty odor and it was stronger than we had on climb out. After landing the Captain entered the descent in the maintenance logbook. Two of the flight attendants later complained of dry throats in the van on the way to the hotel.


Second narrative: Upon initial push back from gate I immediately smelled a 'dirty sock' odor. I called the Captain and explained what I was smelling. He came out of the flight deck; walked to divider and back and said 'I don't smell a thing. What do you want to do?' I explained that I wanted him to be aware that I smelled something; that at that moment I wasn't feeling anything strange but I could definitely smell something that smelled like dirty sock smell. I could smell it until we reached higher altitude at which time it was intermittent during flight. At approximately 8;000 FT on descent the odor became very strong. Passengers were expressing concern. There was a Company Mechanic on board in First Class traveling with his wife. He said it smelled to him like burning oil. He also indicated that he had smelled it on taxi out from our departure airport. His wife was vomiting during flight; she indicated that she thought it was from her diabetes. We landed and the odor continued. As soon as we reached the gate and doors were disarmed I called the Captain to inform him.

Second callback: The Reporter stated that she also filed a report the day following this event on the same aircraft because of fumes and that aircraft was subsequently removed from service for an APU replacement.

Synopsis: A B737-800 Flight Attendant reported a dirty socks odor after engine start and the odor even stronger during descent for landing. The First Officer smelled it faintly during climb and stronger during descent. The APU was replaced.