The plane's mass is 1111.76 kg. This is calculated using the formula of finding centripetal force; F = mv?/r, where F is the centripetal force, m the mass, v the velocity and r the radius. Find v? = 56.6*56.6 = 3203.56. Then, 3203.56 ? 188.5 = 16.995 = 17 rounded off. Therefore, 17m = 1.89 x 10^4. Divide both sides by 17to get a mass of 1111.76 kg.