B737-800 flight crew and flight attendant reported a 'dirty socks; musty' odor during takeoff. Fligh...

Attributes
ACN	1715441
Time
Date	202001
Local Time Of Day	0001-0600
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Takeoff
Flight Plan	IFR
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument
Experience	Flight Crew Total 19800
Person 2
Function	Pilot Flying First Officer
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor

Narrative:

During takeoff noticed [a] strong 'dirty sock' smell. Donned oxygen masks. Confirmed with flight attendants that smell was present throughout cabin. Advised ATC and returned to ZZZ. After blocking in; ZZZ maintenance told us; that they had done an engine wash the previous night. We were the first departure afterwards. Re-examine the engine wash procedure. This was my second odor and fumes event after an engine wash. Both ended in priority returns to the departure airport. The pack burn after an engine wash is apparently done at 70% power. Takeoff power is much higher!

Original NASA ASRS Text

Title: B737-800 flight crew and Flight Attendant reported a 'dirty socks; musty' odor during takeoff. Flight crew executed an uneventful return to departure airport.

Narrative: During takeoff noticed [a] strong 'dirty sock' smell. Donned oxygen masks. Confirmed with flight attendants that smell was present throughout cabin. Advised ATC and returned to ZZZ. After blocking in; ZZZ Maintenance told us; that they had done an engine wash the previous night. We were the first departure afterwards. Re-examine the engine wash procedure. This was my second odor and fumes event after an engine wash. Both ended in priority returns to the departure airport. The pack burn after an engine wash is apparently done at 70% power. Takeoff power is much higher!

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

B737-800 flight crew and flight attendant reported a 'dirty socks; musty' odor during takeoff. Flight crew executed an uneventful return to departure airport.