Narrative:

Our aircraft was dispatched with MEL xa-xx-X-X adp controller - auto function. The MEL operational procedures directed us to turn adp on - on ground prior to takeoff; and inflight prior to flap extension. On climb out; through about 10;000 feet we turned the adp off. Later in the climb; (around FL180); we received an EICAS msg C hydraulic system press. We ran the QRH procedure for this message; which directed us to turn the adp on; and note whether system press was restored or not. The msg remained; so the procedure then directed us to turn this pump off; along with the C1 and C2 electric pumps. This left us with the center hydraulic system inoperative; which would require an alternate flaps and gear extension at destination; and flaps 20 landing. We then contacted dispatch and [maintenance operations] to discuss our situation and options. The current weather and forecast at our destination was VFR. The extra time enroute would allow for a lower weight landing; using less runway. The runway at our destination was sufficient for our planned landing weight and configuration; so we elected to continue to our destination. Further along in the flight we noticed that the destination weather was reporting a 1;000 feet ceiling. Our dispatcher then issued an [amended release] listing the addition of an alternate with recomputed fuel burns and reserves. It later occurred to me that our dispatcher may not be aware that if we were to divert after an unsuccessful approach at destination; that we would have no way of raising our gear; therfore our fuel burn to our alternate would be higher. I then contacted dispatch and advised of this possibility; and was subsequently issued a second artr with a revised fuel burn to our alternate with the aircraft in a gear down configuration.

Google
 

Original NASA ASRS Text

Title: B767-300 flight crew reported the Dispatcher may have overlooked an important planning factor when they were dispatched with an MEL for C Hyd Sys inoperative.

Narrative: Our aircraft was dispatched with MEL XA-XX-X-X ADP Controller - Auto Function. The MEL operational procedures directed us to turn ADP ON - on ground prior to takeoff; and inflight prior to flap extension. On climb out; through about 10;000 feet we turned the ADP OFF. Later in the climb; (around FL180); we received an EICAS msg C HYD SYS PRESS. We ran the QRH procedure for this message; which directed us to turn the ADP ON; and note whether SYS PRESS was restored or not. The msg remained; so the procedure then directed us to turn this pump off; along with the C1 and C2 electric pumps. This left us with the Center Hydraulic system inoperative; which would require an alternate flaps and gear extension at destination; and flaps 20 landing. We then contacted dispatch and [Maintenance Operations] to discuss our situation and options. The current weather and forecast at our destination was VFR. The extra time enroute would allow for a lower weight landing; using less runway. The runway at our destination was sufficient for our planned landing weight and configuration; so we elected to continue to our destination. Further along in the flight we noticed that the destination weather was reporting a 1;000 feet ceiling. Our dispatcher then issued an [Amended Release] listing the addition of an alternate with recomputed fuel burns and reserves. It later occurred to me that our dispatcher may not be aware that if we were to divert after an unsuccessful approach at destination; that we would have no way of raising our gear; therfore our fuel burn to our alternate would be higher. I then contacted dispatch and advised of this possibility; and was subsequently issued a second ARTR with a revised fuel burn to our alternate with the aircraft in a Gear Down configuration.

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.