B757 flight crew reported diverting to an alternate airport after loss of cabin pressure.

Attributes
ACN	1620398
Time
Date	201902
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Pressurization Control System
Person 1
Function	Pilot Not Flying Captain
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 152.7 Flight Crew Total 13072.00 Flight Crew Type 7036.80
Person 2
Function	First Officer Pilot Flying
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 43.02
Events
Anomaly	Aircraft Equipment Problem Less Severe

Narrative:

At FL390 [we] had a right engine bleed trip. Followed QRH and elected to descend; cabin began climbing and we had a subsequent auto pressurization controller failure. Followed QRH; but could not control cabin pressure. Got further descent from ATC. When we determined we were still unable to control the cabin pressure rising I donned the mask and followed QRH procedures. Made uneventful landing in [an alternate airport]. No passenger masks were deployed.

Original NASA ASRS Text

Title: B757 flight crew reported diverting to an alternate airport after loss of cabin pressure.

Narrative: At FL390 [we] had a right engine bleed trip. Followed QRH and elected to descend; cabin began climbing and we had a subsequent auto pressurization controller failure. Followed QRH; but could not control cabin pressure. Got further descent from ATC. When we determined we were still unable to control the cabin pressure rising I donned the mask and followed QRH procedures. Made uneventful landing in [an alternate airport]. No passenger masks were deployed.

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.