In the context of aviation and aerospace, an "ADS-contract" refers to an "Authority to Deliver and/or Sell" contract. However, I couldn't find any information that links "ADS-contract" directly to a widely recognized term in the aviation and aerospace industry.

But, I found that in the context of the US Department of Defense (DoD), particularly in their procurement process, an "ADS" contract could potentially be referring to an "Authority to Deliver and/or Sell" contract.

Another possible expansion for "ADS" could be "Advance Design Series" or "Advanced Design Series" or something similar in some companies, but there isn't a direct, universally accepted definition for "ADS-contract."

However, it's also possible that "ADS" is an acronym for "Air Data System" or "Avionic Data System" or something similar in some companies.

If you're referring to a specific "ADS-contract" or have more context about this term, I'd be happy to help you understand it better.