A B777's FMC was slow uplinking during preflight and a requested update arrived after takeoff. The c...

Attributes
ACN	894264
Time
Date	201006
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZZ.Airport
State Reference	FO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B777-200
Operating Under FAR Part	Part 121
Flight Phase	Climb
Route In Use	Oceanic
Flight Plan	IFR
Component
Aircraft Component	FMS/FMC
Person 1
Function	Pilot Not Flying Captain
Experience	Flight Crew Last 90 Days 200 Flight Crew Total 17000 Flight Crew Type 2300
Person 2
Function	First Officer Pilot Not Flying
Experience	Flight Crew Last 90 Days 255 Flight Crew Total 9413 Flight Crew Type 2042
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types

Narrative:

I was the pilot not flying on a departure. I had requested a route uplink in the FMC while on the ground. It never arrived until after we were airborne. The first officer was flying the SID with LNAV engaged; when we received the route uplink. Immediately after executing the uplink; the FMC dropped out a portion of the SID navigation data. While I began to re-program; ATC said to fly a heading of 160 degrees. After another vector; I advised him that we had lost some navigation data. It was obvious after the event that my error was in activating any executable FMC data at a low altitude while flying a SID; although in no way did I anticipate that we would lose any FMC navigation ability. There was not any communication from departure control indicating that our track interfered with any other traffic. The flight continued normally to destination; and no problems suspected with the reliability of the aircraft navigation equipment.

Original NASA ASRS Text

Title: A B777's FMC was slow uplinking during preflight and a requested update arrived after takeoff. The Captain mistakenly activated the new routing which deleted the existing information leaving the aircraft in a non LNAV capable condition. ATC graciously provided vectors.

Narrative: I was the pilot not flying on a departure. I had requested a route uplink in the FMC while on the ground. It never arrived until after we were airborne. The First Officer was flying the SID with LNAV engaged; when we received the route uplink. Immediately after executing the uplink; the FMC dropped out a portion of the SID navigation data. While I began to re-program; ATC said to fly a heading of 160 degrees. After another vector; I advised him that we had lost some navigation data. It was obvious after the event that my error was in activating any executable FMC data at a low altitude while flying a SID; although in no way did I anticipate that we would lose any FMC navigation ability. There was not any communication from Departure Control indicating that our track interfered with any other traffic. The flight continued normally to destination; and no problems suspected with the reliability of the aircraft navigation equipment.

Data retrieved from NASA's ASRS site as of April 2012 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.

A B777's FMC was slow uplinking during preflight and a requested update arrived after takeoff. The captain mistakenly activated the new routing which deleted the existing information leaving the aircraft in a non LNAV capable condition. ATC graciously provided vectors.