Most modern fighters can attach drop tanks
Although they help increase the range of the aircraft, they also bring many limitations
So in the air battle, these fuel tanks will be thrown away for "lightweight"
Combat aircraft, especially fighters, often have very powerful engines and consume a lot of fuel, so their range is limited
If you want to increase their flight range, you must give them more fuel
So the external fuel tank was born to solve the problem
They help the fighter fly further in bomber escort or base transfer missions, allowing it to reach targets further away from the airfield
In some cases, they also give aircraft more fuel to refuel allied aircraft in the air
Because of such necessity, the auxiliary fuel tank appeared very early in the Spanish Civil War
became popular during World War II and is still fitted to most modern fighters today
Even all 5th generation stealth fighters such as the F-22 or Su-57 are equipped with it
regardless of this device causing the aircraft to lose its stealth ability
The extra fuel tanks increase air resistance, reducing the aircraft's speed
Their weight causes the aircraft to roll and rate of climb more slowly
They also increase the radar cross-section, making the aircraft more easily detected and locked from a distance
In addition, they also take up space on weapon hardpoints
In short, the extra fuel tank helps to increase the aircraft's range
but it reduces most of the flight characteristics, the ability to carry weapons and makes the aircraft easier to shoot down
So most of the extra fuel tanks on modern fighter jets are designed so that they can be removed when needed
When entering air combat or under attack, fighter jets will often remove the extra fuel tanks, regardless of whether there is fuel left in them or not
In this way, the aircraft can regain its most flexible state to engage with the enemy
maneuver to dodge missiles or accelerate to retreat
To reduce waste, the fuel in the auxiliary tanks will be used first and then the fuel inside the aircraft
An additional information, during the Vietnam War, American aircraft left the battlefield countless huge extra fuel tanks
So they become valuable materials for people to bring back to make pots and pans
Especially due to their elongated shape, optimized aerodynamics, these auxiliary fuel tanks are used as extremely good boats and canoes
They are both light, durable, and less resistant to water, and fuel efficient
If you come to Vietnam and see these boats, don't be surprised