Project: Lifting the Helicarrier (The Avengers)

No matter your opinion on Marvel’s Cinematic Universe, one thing cannot be denied – The long-running film series never fails to deliver spectacle. One of the more memorable spectacles of the 2012 team-up movie, The Avengers, comes in the form of SHIELD’s massive flying aircraft carrier, referred to simply as the Helicarrier. The vehicle initially floats in the water, appearing to be little more than an ordinary carrier, but it then lifts off from the ocean using a quartet of massive propellers. Though the visual impact of such a machine is certainly quite impressive, the question remains as to whether the four large propellers could actually generate enough force to lift the Helicarrier out of the water and into the sky. In order to answer this question, we must assess the physics behind the scene. The propeller physics used will be based on NASA’s plane propeller physics, but on a much larger scale. On the simplest level, the requirements for the Helicarrier to be scientifically feasible are that the propellers generate enough lift force to exceed the force of gravity bearing down on the incredibly heavy vehicle. The propellers seem to be large enough in size, but they must also spin fast enough to generate the necessary lift force without exceeding the speed of sound in air. Assuming that the propellers were designed to operate at velocities below the speed of sound, as the majority are, moving at supersonic speeds would actually damage them. As such, the speeds of the propellers will likely reach close to the speed of sound, but they cannot break it and remain physically viable.

In order for the ship to rise, the ship’s lift force must exceed its force of gravity.

FL > FG

The formula we will be using is NASA’s propeller thrust formula, slightly adjusted to conform to the downward-facing propellers on the Helicarrier.

FT = 0.5pAVe^2

In which

FT = Thrust force of propellers

p = Density of air

A = Area of propeller

Ve = Exit velocity of air.

We already know that FL = 4 FT, and that FT > FG/4.

To determine the force of gravity pushing the helicarrier down, we must multiply the vehicle’s considerable mass by 9.8 m/s^2. I used the mass (90,718,474kg) of a Nimitz-class aircraft carrier. Each propeller unit looks to be about a fourth of the ship’s main body in size, so the mass is effectively doubled. This leaves us with a mass of 181,436,948kg. After multiplying, we get 1,778,082,090 kg/m/s^2, or Newtons. We can also ascertain the area of each propeller, which lands at around 5,436.714583m^2.

In order to keep things simple, the density of and speed of sound in air we will be using is that of dry air at sea level, with a temperature of 0 degrees Celcius.

So far, we know that:

FG = 1,778,082,090 kgm/s^2

p = 1.2922 kg/m^3

A = 5,436.714583m^2

Speed of sound in air = 331.30 m/s

Ve < 331.30 m/s

Once these variables are inserted, the formula appears as

FT = 3,512.6612920763 kg/m x Ve^2.

Which, since FL = 4 FT, then becomes

FL = 4(3,512.5512920763 kg/m x Ve^2)

FL = 14,050.6451683052 kg/m x 4Ve^2. 

In order to establish the Ve^2, we will assume it is close to the speed of sound without breaking it, so that the Helicarrier has a higher chance of being lifted, and in accordance with the massive size of its propellers. 

Ve = 330 m/s

FL = 14,050.6451683052 kg/m x 4(330m/s)^2

FL = 14,050.6451683052 kg/m x 435,600 m/s

Therefore, the 

FL = 6,120,461,035.313745 kgm/s^2

The lift force indeed exceeds the force of gravity:

FG = 1,778,082,090 kgm/s^2

vs

FL = 6,120,461,035.313745 kgm/s^2

Therefore, the Helicarrier, despite its apparent outlandishness, could potentially actually lift itself out of the water without breaking the speed of sound. The issues of powering such a machine and keeping it in the sky are much harder questions in the event of producing a real-life Helicarrier, but we can leave that up to the Avengers to figure out.