Fuel concerns

Hi IFC I thought I’d post a topic about a current concern of mine at the moment. I’m flying from Frankfurt, Germany to Rio Dejanerió, Brazil in a Lufthansa Boeing 747-800. Before takeoff I put 16 hours and 45 minutes of fuel for a 12 hour and 20 minute flight just to be safe, as I have had problems with fuel consumption using this aircraft in the past. As you can see under the ETE to Dest it says 11:10 FUEL. I know there has been problems with this aircraft regarding fuel, am I likely to make it to my destination in time? The number for FUEL under ETE is frequently changing (going up and down). Should I be worried, or am I likely to make it to my destination in time with enough fuel?

Hi there!
Currently you are probably too heavy which causes the engines to use extra thrust:
More weight = More thrust
Less weight = Less thrust
This problem should go away as you get lighter and closer to your destination.
Also, do not forget to step climb when you are heavy;
Higher alt = Less air
Less Air = More thrust

1 Like

Thanks so much for letting me know. If that is the case then hopefully I can make it to Rio with enough fuel of course. 🤞🤞

Or fuel dump as you can’t step climb anymore

Don’t worry you will :)
Good news - there are some strong tailwinds over the Atlantic :)

2 Likes

Thanks so much this is so helpful. :)
What app do you use to monitor the winds by the way? I need it!!!

I don’t believe that is nessecary at the moment.

It’s called Windy.com
But be careful, there is one called Windy which is the wrong one and one called Windy.com which is the right one! The app is also called Windy.com

1 Like

Thank you once again I will be using that from now on

1 Like

Hey there! A great suggestion, is to slowly adjust the trim between 50-70%. It will make a large difference.

Your 'fuel remaining ’ might say anywhere up to 3-4 hours less than the destination once at cruise, but you should be fine

1 Like

Yes definitely do that! It helps to save fuel :)

1 Like

I did this route in a 747-400 this morning. All went fine with 70% trim, I usually keep at 60%.

1 Like

Hi! Thanks for replying, I don’t necessarily use trim that often as I feel that it hasn’t really affected my aircraft when landing or on take off and I don’t fully understand the concept of it. I do know that is that it helps with back pressure on an aircraft but haven’t regularly used it incase I’m doing something wrong. Can I use trim throughout the entire flight? If it’s going to help with fuel consumption I’ll definitely implement it in this flight.

1 Like

yes you can use trim the entire time!

1 Like

So 60% to 70% (slowly increasing) should do the job?

1 Like

yes, I flew from ELLX-SCEL in a 748 last night and the trim helped a lot

1 Like

Basically trim helps with lifting/pushing down the nose. Positive trim will help you lift the nose, as an example in real life you wouldn’t have to pull back the yoke as much. Negative will do the opposite.

Trim is used in T/O and Landing. Personally I use 15% on T/O and 25% on Landing. However, this is not a rule or anything, you can adjust on how you feel.

Trim is not used IRL during cruise I believe, however because of the 747s bad physics in IF, it does help conserve fuel, a lot.

2 Likes

The Boeing 747 has horribly inaccurate physics (weight to lift and lift to drag ratios) which makes it use much more power and burn much more fuel to maintain speed than how the plane works

I use 10 degrees flaps because it decreases angle of attack and drag therefore reducing required power to maintain speed, try that out. I know it’s not realistic but then again the physics of the plane are even more unrealistic

1 Like

That makes sense, so when would I use negative trim?

To be honest I do not use negative trim, and I am not sure why and when it is used in real life either.

1 Like