Excuse my ignorance but is B1 the first flight with B2, B3 ... subsequent flights to check the correction of any issues that arise on B1? If that is correct, is C1 the acceptance flight with C2, C3 ... subsequent flights if some issues arise on C1?

Also can someone let me know what the Load Date is? Is it the date that the aircraft is first placed and supported on its landing gear?

The Boeing spreadsheet that I use has the first flight of ZNK on 3 December and delivery on 16 December with C1 on 9 December.

B0 has been used for taxi runs
B1 is the first flight.
B+ are Boeing test flights to fix problems found on previous B flight(s).

One Boeing is happy it is handed over the Customer for testing.

C1 is the CUSTOMER acceptance testing.

Customer runs through a customer specific list of tests.

C+ are Customer test flight to check fixes from the previous C tests.

Delivery consists of signing document and transferring of funds.

I think (could be wrong) that the load date was when it was added to the spreadsheet.

Load date is the date when the first (central) body section is brought into the assembly building i.e. start date in Position 1.

Thanks very much guys for the explanation.

While the first leg was operated by ZNB, it turned around back to Melbourne as a positioning flight QF6157, before operating QF9. QF459 was cancelled.

Seems part of my Crystal Ball gazing was correct, ZND is currently en-route LAX-BNE operating QF56.
No explanation yet for the Melbourne 9 day maintenance lay over, nor the Los Angeles 5 day maintenance lay over.

VH-ZNJ is currently operating QF29 MEL-HKG which l predict will turnaround to operate QF128 back to SYD overnight. This will enable ZNJ to operate the first QANTAS B789 QF141/144/73/74 SYD-AKL-SYD-SFO-SYD services tomorrow 4/12/19.

Well, I was wrong with the swap over of 789s in HKG. ZNG is returning to SYD as QF128 and ZNJ is returning to MEL as QF30, which means that it looks as though ZNG will operate the inaugural QANTAS 789 flights to AKL and SFO from SYD tomorrow.

Possibly not, as VH-ZNC positioned Melbourne - Sydney this afternoon as QF6002, so either it or VH-ZNG will do the inaugural flights, and unless there is another swap, the other will do the day 2 flights - time will tell.

Well Peter, ZNC was a dark horse so to speak, relocating to SYD. ZNC is currently operating QF141 to AKL and will return as QF144 at 15:25. No movement of ZNG as yet, either as a domestic or positioning flight. You're right that a 789 needs to be in SYD for tomorrow's flights as there will not be any inbound aircraft from SFO to operate the flights to AKL and SFO.

Will see what happens during the day as to the aircraft that will be operating today's QF73 to SFO. B744 OEI is operating QF127 to HKG this morning so there hasn't been a change of aircraft there with a 789 substituted.