$10\mathrm{.}5$ In $1985,$ Japan Airlines $($JAL$)$ bought $$3$ billion of foreign exchange contracts at $Y\frac{180}{\text{\$}}1$ over $11$ years to hedge its purchases of U$.$S$.$ aircraft. By $1994,$ with the yen at about Y$100/$$$1,$ JAL had incurred over $$1$ billion in cumulative foreign exchange losses on that deal.

$($a$)$ What was the likely economic rationale behind JAL's hedges?