In principle, this mechanic is already in the game and it used to be functional. When an airbase gets strat bombed, there is a probability (BASE_STRATEGIC_BOMBING_HIT_PLANE_CHANCE) of wings without active missions getting damaged, 50% . The damage scale (how many planes are lost per damaged HP on the airbase) was nerfed however in patch 1.4:
Despite what the changelog says, the scale (BASE_STRATEGIC_BOMBING_HIT_PLANE_DAMAGE_FACTOR) was changed from 50 to 0.2, so reduced to 1/250th. When an airbase now loses X HP from strat bombing,
there is a 50% probability for each grounded wing to lose round(X * 0.2 / 100) planes. As a building can never lose more than 100 HP at once (and even that takes fantastical amounts of bombers), the number of destroyed planes is always rounded down to zero. With the old value, a plane was destroyed for every 2 HP damaged.