Air carrier flight crew reported encountering multiple bird strikes shortly after takeoff from sfo r...

Narrative:

After takeoff at about 800 ft and before raising flaps; we struck a flock of approximately 20 birds. We probably hit about 6 of them. Both windscreens were partially obscured and the 'windshear' alert sounded. The birds were spotted just before impact so it was obvious that we hadn't encountered windshear. After the encounter; the captain's airspeed was showing approximately 80 knots when the standby and first officer's airspeed read approximately 190 kts. Control of the aircraft was transferred to the first officer who continued the climb and retracted flaps on schedule. ATC was notified of the bird strike and location. We requested an initial climb to 10;000 ft and advised them there were some systems affected by the bird strike and that we would be working the problem. The flight directors were not working; and LNAV and VNAV seemed unreliable. The first officer hand flew the airplane. The autopilot was later engaged as we determined that it worked in 'right.' the first officer flew the airplane and handled most of the radio work with the second observer backing him up. The captain and first observer accomplished the 'IAS disagree or airspeed unreliable' checklist. This brought back the captain's airspeed indicators to normal. An analysis of the aircraft's condition and equipment status was done. The flight directors had biased from view; LNAV was inoperative; the airplane seemed to turn slower than normal; and we did not know what other damage had been done. We request ATC to provide vectors for us to prepare for dumping and used satcom for conference call with dispatch and maintenance. We did not feel it was safe or wise to continue to destination so began preparation to return to sfo. The aircraft weight was approximately 830;000 lbs so we dumped approximately 200;000 lbs of fuel to bring weight down to 630;000 lbsin preparation for landing back in sfo. Logbook entries; approach preparation; briefings; and checklists were accomplished during dumping which took approximately 45 mins. The bdega 2 arrival and ILS runway 28R were flown by the captain using the autopilot in heading sel and flch; then GS and localizer to approximately 1200 ft; then hand flown for landing with flaps 30.

Original NASA ASRS Text

Title: Air carrier flight crew reported encountering multiple bird strikes shortly after takeoff from SFO resulting in spurious flight instrument indications. After dumping fuel; a return to the departure airport was safely accomplished.

Narrative: After takeoff at about 800 ft and before raising flaps; we struck a flock of approximately 20 birds. We probably hit about 6 of them. Both windscreens were partially obscured and the 'Windshear' alert sounded. The birds were spotted just before impact so it was obvious that we hadn't encountered windshear. After the encounter; the captain's airspeed was showing approximately 80 knots when the standby and First Officer's airspeed read approximately 190 kts. Control of the aircraft was transferred to the First Officer who continued the climb and retracted flaps on schedule. ATC was notified of the bird strike and location. We requested an initial climb to 10;000 ft and advised them there were some systems affected by the bird strike and that we would be working the problem. The flight directors were not working; and LNAV and VNAV seemed unreliable. The First Officer hand flew the airplane. The autopilot was later engaged as we determined that it worked in 'R.' The First Officer flew the airplane and handled most of the radio work with the second observer backing him up. The Captain and First Observer accomplished the 'IAS Disagree or Airspeed Unreliable' checklist. This brought back the Captain's airspeed indicators to normal. An analysis of the aircraft's condition and equipment status was done. The flight directors had biased from view; LNAV was inoperative; the airplane seemed to turn slower than normal; and we did not know what other damage had been done. We request ATC to provide vectors for us to prepare for dumping and used Satcom for conference call with dispatch and maintenance. We did not feel it was safe or wise to continue to destination so began preparation to return to SFO. The aircraft weight was approximately 830;000 lbs so we dumped approximately 200;000 lbs of fuel to bring weight down to 630;000 lbsin preparation for landing back in SFO. Logbook entries; approach preparation; briefings; and checklists were accomplished during dumping which took approximately 45 mins. The BDEGA 2 arrival and ILS Runway 28R were flown by the captain using the autopilot in HDG SEL and FLCH; then GS and LOC to approximately 1200 ft; then hand flown for landing with Flaps 30.

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	1490078
Time
Date	201710
Local Time Of Day	0601-1200
Place
Locale Reference	SFO.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Widebody Transport
Operating Under FAR Part	Part 121
Flight Phase	Initial Climb
Flight Plan	IFR
Component
Aircraft Component	Air Data Computer
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 200 Flight Crew Total 21000 Flight Crew Type 13000
Person 2
Function	Relief Pilot
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 90 Flight Crew Total 11800 Flight Crew Type 8000
Events
Anomaly	Aircraft Equipment Problem Less Severe Inflight Event / Encounter Bird / Animal

Air carrier flight crew reported encountering multiple bird strikes shortly after takeoff from sfo resulting in spurious flight instrument indications. After dumping fuel; a return to the departure airport was safely accomplished.