When Embraer spinoff Eve on Dec. 21 confirmed plans to combine with Zanite Acquisition Corp., it became the sixth company in the urban air mobility space to link up with a special purpose acquisition company (SPAC). Rather than speak to the continued strength of SPACs, however, the deal illustrates the funding vehicle’s decline as an ample source of outside capital — even as it cements Embraer’s strategy of using partnerships to expand into new markets.