English: A representation of the aeroplane/airplane Julia set, one of the three quadratic polynomial having a periodic critical point of exact period 3.

This is a plot of 20 000 000 preimages of the point 1.91593702764165778419 by the mapping ${\displaystyle Q^{\circ 64}}$ where :

${\displaystyle Q_{c}(z)=z^{2}+c}$

${\displaystyle c=-{\frac {2.}{3.}}-1./3.*(\delta +1./\delta )}$

${\displaystyle \delta =-(1/2(1/4-3{\sqrt {69}}))^{1/3}}$.