The maximum allowable load $\mathrm{P}$ is determined such that neither ${\mathrm{F}}_1$ nor ${\mathrm{F}}_2$ exceeds their respective allowable forces.

To satisfy the allowable stress specified for member (1), $\mathrm{P}$ must produce no more than $554.4 \mathrm{kN}$ of axial force in member (1). Therefore, $\mathrm{P}$ must be limited to:

$$\begin{gathered} \mathrm{P}\le 1.06083 {\mathrm{F}}_1 \\ \le 1.06083(554.4 \mathrm{kN}) \\ \le 588.12 \mathrm{kN} \end{gathered}$$