Other companies soon followed suit. Losses from any other perils not specified were not covered. Today there are only about 12. Production of new aircraft, especially lower priced single-engine models, has dropped dramatically over the past 10 years. Today we have fewer aviation insurance underwriters chasing fewer new accounts.
Companies have to be innovative to attract business on the classes of business they want to write.
Such coverages are not available for all types of risks. Only a few are provided for commercial risks. May be a contract pilot. Most were originally provided in an endorsement to the policy when the company felt the risk worthy or wanted the business badly enough. The specific wordings for each may vary among companies and some are broader than others.