7 hours ago, Copper. said:

Since 747 normally lands with equal quantities in the respective mains, I'd like to correct my statement and say min fuel for hydraulic heat exchanger coverage is approx 10T.

That's about what I've surmised as well.  My planned minimum fuel remaining is 12T for simulation.

On 06/10/2017 at 0:17 AM, Beardyman said:

Then PMDG must be a bit more careful with data given in their manual, cause some people actually read those and take seriously :-)

 

Interesting fact about departure fuel ( 40T), from where it came Bertie ?

not Bertie but some operators have 25T. 

1 hour ago, phil747fan said:

Interesting fact about departure fuel ( 40T), from where it came Bertie ?

not Bertie but some operators have 25T. 

At least one airline I know of used 40T as a minimum despatch fuel figure when the 744 was first introduced, but this was subsequently reduced to 23T for a variety of reasons; not least being the rise in the price of oil and operational experience.  The take off on short flights is very interesting with the aircraft at very light weights, because the aircraft's performance (especially during the initial take-off and climb) will put any Ferrari's in the shade!  Extra care is also needed on wet or slippery runways, especially in a crosswind, because it is all too easy for the noswheel to lose grip on the runway if engine power is applied too quickly or if they spool up at slightly different rates.  With a fuel load of 23T it is not uncommon to see the main tank forward fuel pump low pressure lights illuminating during the climb if the body angle is allowed to exceed approx 15degs nose up.

As Dan has said, 12T (or 10T) is a reasonable landing fuel figure for simulator purposes, although the B744 Flight Manual Limitations section has no minimum fuel figure for hydraulic cooling purposes in the air.

Bertie    

One additional point which I should have mentioned.

My posts in this toipic are based on the B744 Pax aircraft fitted with Rolls Royce engines.  Different limitations will apply to other engine manufacturers and B744 variants.

Bertie

Bertie, my infos came from GE, PW and RR pax or Freighter versions ...

On 03/02/2017 at 5:45 PM, Meekg said:

With regards to normal fuel planning: legally you are required to land at destination with 30' of holding fuel at ISA conditions (commonly referred to as FINAL RESERVE) + ALTERNATE FUEL (required fuel for a missed approach at destination, diversion to alternate airport).

Some operators specify some conditions that allow pilots to use the ALTERNATE FUEL without actually diverting to the alternate if required.

These conditions may vary from certain weather and approach requirements to mere pilot judgement... it depends on the company.

I am not aware of any minimum fuel limitation for HYD cooling, but I'm not a 747 rated pilot.