Another cpl performance issue
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Another cpl performance issue
If a echo aircraft is ZFW loaded with it's cgravity loaded aft, what is the minimum
ballast fuel required in the main tanks for the aircraft to remain in balance in all stages of flight, 5kg sand bags also available for ballast
Would this mean the first thing to do would be to load front locker with 55kg of sand ballast to bring c gravity forward then work out how much ballast fuel is then required
ballast fuel required in the main tanks for the aircraft to remain in balance in all stages of flight, 5kg sand bags also available for ballast
Would this mean the first thing to do would be to load front locker with 55kg of sand ballast to bring c gravity forward then work out how much ballast fuel is then required
performance question
The most common trick to this one is to load up the front baggage locker as stated. Two considerations however. Firstly the max is 55kg but be aware that you may be given ballast in 6 kg bags or something similar. Therefore get as many whole bags in as possible.
The second limitation to consider is that once those bags are in you have not exceeded your ZFW limitation of 2630 kg.
Once that is sorted then in to your formula to see how many kg of fuel needs to be added. Check your answers carefully as you may do the calculation and come up with 23kg for example.
a) 23 USG
b) 9 USG
Obviously a couple of other options. A is not the answers as the units are not correct. Good luck. Cheers. Glen.
The second limitation to consider is that once those bags are in you have not exceeded your ZFW limitation of 2630 kg.
Once that is sorted then in to your formula to see how many kg of fuel needs to be added. Check your answers carefully as you may do the calculation and come up with 23kg for example.
a) 23 USG
b) 9 USG
Obviously a couple of other options. A is not the answers as the units are not correct. Good luck. Cheers. Glen.
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I think where I went wrong is the question stated what is the minimum fuel required in the main tanks for ballast to enable the flight to remain in balance at all stages, the load is to remain unchanged
Yet it then states 5kg sand bag ballasts also available
I think the trick question is if you add sand ballast to the forward compartment you would then be changing the load which is not permitted
Yet it then states 5kg sand bag ballasts also available
I think the trick question is if you add sand ballast to the forward compartment you would then be changing the load which is not permitted
performance
I think you will find they are specifying no change (shift) can be made to the existing load.
When you are asked to use min. fuel as ballast you must use hard ballast first, then use fuel as ballast.
Easiest way is to write the complete question on here and ill run through it with you. Cheers.
When you are asked to use min. fuel as ballast you must use hard ballast first, then use fuel as ballast.
Easiest way is to write the complete question on here and ill run through it with you. Cheers.
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An echo aircraft has a basic empty weight and moment of 1962kg and 474.8 index units respectively. It is loaded as follows
row 1 165kg
row 2 170kg
row 3 160kg
rear compartment 140kg
hard ballast is available in the form of 5kg sand bags.
The minimum amount of ballast fuel that must be carried in the tanks to keep the aircraft in balance through the flight, if no chande is made in the existing load, is closest to-
55 US gal
20 US gal
nil
33 US gal
My first step was to add 55kg of sand bag ballast to the forward compartment, this resulted in a loaded weight of 2652kg and centre of gravity 2678mm , this would indicate no ballast required in main tanks.
yet when i selected nil i was incorrect.
This was a Bob tait practice exam so I am not sure what the correct answer is.
row 1 165kg
row 2 170kg
row 3 160kg
rear compartment 140kg
hard ballast is available in the form of 5kg sand bags.
The minimum amount of ballast fuel that must be carried in the tanks to keep the aircraft in balance through the flight, if no chande is made in the existing load, is closest to-
55 US gal
20 US gal
nil
33 US gal
My first step was to add 55kg of sand bag ballast to the forward compartment, this resulted in a loaded weight of 2652kg and centre of gravity 2678mm , this would indicate no ballast required in main tanks.
yet when i selected nil i was incorrect.
This was a Bob tait practice exam so I am not sure what the correct answer is.
performance
BEW 1962 KG 474.8 IU
R1 165 KG 37.8 IU
R2 170 KG 56.1 IU
R3 160 KG 68.8 IU
FWD
WING
REAR 140 KG 70.0 IU
___________________________
ZFW 2597 KG 707.5 IU
The next step is MZFW of 2630-your ZFW of 2597 means only 33kg of hard ballast can be added. Due to 5kg units only 30 kg can be added. Load this into the forward baggage and your new ZFW is 2627 kg and new moment is 709 IU. Therefore the new c.g is 2699 mm (19mm outside aft limit)
Weight to add formula with ballast fuel in main tank.
2627 X 19 / 2680-1780 = 55kg (20 USG)
Your problem is that you exceeded the ZFW of 2630 kg.
If i havent made this clear send me a PM. i will give you my mobile number and you can give us a call. Cheers.
R1 165 KG 37.8 IU
R2 170 KG 56.1 IU
R3 160 KG 68.8 IU
FWD
WING
REAR 140 KG 70.0 IU
___________________________
ZFW 2597 KG 707.5 IU
The next step is MZFW of 2630-your ZFW of 2597 means only 33kg of hard ballast can be added. Due to 5kg units only 30 kg can be added. Load this into the forward baggage and your new ZFW is 2627 kg and new moment is 709 IU. Therefore the new c.g is 2699 mm (19mm outside aft limit)
Weight to add formula with ballast fuel in main tank.
2627 X 19 / 2680-1780 = 55kg (20 USG)
Your problem is that you exceeded the ZFW of 2630 kg.
If i havent made this clear send me a PM. i will give you my mobile number and you can give us a call. Cheers.
thank you, it is very clear now I forgot to consider MZFW,
