Md-11 captain reported strong oily fumes during descent.

Attributes
ACN	1669655
Time
Date	201907
Local Time Of Day	0001-0600
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	MD-11
Operating Under FAR Part	Part 121
Flight Phase	Cruise Descent
Flight Plan	IFR
Component
Aircraft Component	Air Conditioning and Pressurization Pack
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument
Events
Anomaly	Aircraft Equipment Problem Less Severe Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor

Narrative:

There was a faint smell of oily fumes during departure and cruise which seemed normal since the aircraft had just come out of maintenance. Upon initial descent into ZZZ; the fumes became much more prevalent. We donned our oxygen masks [advised] with ATC. We described our emergency and asked to continue expeditiously to land at ZZZ. We had no other indications other than the strong smell of fumes. We continued without further incident and landed safely at ZZZ. Fire and rescue did a visual inspection of the aircraft as we cleared the runway and permitted taxi to and shutdown at the gate. The mechanics have been working on the aircraft today. They cleaned air conditioning ducts and appear to have found the problem within systems on engine number 1.

Original NASA ASRS Text

Title: MD-11 Captain reported strong oily fumes during descent.

Narrative: There was a faint smell of oily fumes during departure and cruise which seemed normal since the aircraft had just come out of maintenance. Upon initial descent into ZZZ; the fumes became much more prevalent. We donned our oxygen masks [advised] with ATC. We described our emergency and asked to continue expeditiously to land at ZZZ. We had no other indications other than the strong smell of fumes. We continued without further incident and landed safely at ZZZ. Fire and rescue did a visual inspection of the aircraft as we cleared the runway and permitted taxi to and shutdown at the gate. The mechanics have been working on the aircraft today. They cleaned air conditioning ducts and appear to have found the problem within systems on engine number 1.

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.