When maintenance determined the B767-300 flight was dispatched in a condition contrary to the deferr...

Narrative:

Upon landing following our first leg we observed an hpsov EICAS message. Maintenance was alerted and [they deferred the] right thrust reverser to allow continuation of flight. After departing; [trans-atlantic] enroute to our stateside destination (while approximately 450 NM west); we received an ACARS message from our dispatcher requesting we contact him immediately via satcom. Upon contacting flight control; we were directed to land immediately; due to a discrepancy with the deferral regarding the hpsov EICAS message. We were informed that due to the potential discrepancy; there was a risk that the thrust reverser could deploy in flight. The dispatcher suggested landing at ZZZZ; having done an analysis of the situation in advance of our contact. It was agreed that would be an acceptable airport; an emergency was declared with ATC; a turn made in the direction of the alternate; and center tank fuel was jettisoned. Crash fire rescue equipment was standing by; and an uneventful overweight landing (~342;000 pounds) was made approximately 40 minutes later.

Original NASA ASRS Text

Title: When Maintenance determined the B767-300 flight was dispatched in a condition contrary to the deferred item procedure for a HPSOV EICAS warning the flight reversed course over the Atlantic and made a timely; overweight landing at a convenient alternate.

Narrative: Upon landing following our first leg we observed an HPSOV EICAS message. Maintenance was alerted and [they deferred the] Right Thrust Reverser to allow continuation of flight. After departing; [trans-Atlantic] enroute to our stateside destination (while approximately 450 NM west); we received an ACARS message from our Dispatcher requesting we contact him immediately via SATCOM. Upon contacting Flight Control; we were directed to land immediately; due to a discrepancy with the deferral regarding the HPSOV EICAS message. We were informed that due to the potential discrepancy; there was a risk that the thrust reverser could deploy in flight. The Dispatcher suggested landing at ZZZZ; having done an analysis of the situation in advance of our contact. It was agreed that would be an acceptable airport; an emergency was declared with ATC; a turn made in the direction of the alternate; and center tank fuel was jettisoned. CFR was standing by; and an uneventful overweight landing (~342;000 pounds) was made approximately 40 minutes later.

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.

Attributes
ACN	1189494
Time
Date	201407
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZZ.ARTCC
State Reference	FO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B767-300 and 300 ER
Operating Under FAR Part	Part 121
Route In Use	Vectors
Flight Plan	IFR
Component
Aircraft Component	Pneumatic Valve/Bleed Valve
Person 1
Function	Pilot Not Flying
Experience	Flight Crew Last 90 Days 111 Flight Crew Total 11800 Flight Crew Type 1200
Person 2
Function	Other / Unknown
Events
Anomaly	Aircraft Equipment Problem Critical

When maintenance determined the B767-300 flight was dispatched in a condition contrary to the deferred item procedure for a hpsov EICAS warning the flight reversed course over the atlantic and made a timely; overweight landing at a convenient alternate.