Daher-Socata announced Tuesday that it will not build the moribund Grob SPn utility jet. Socata, which manufactures the TBM850 turboprop single, had been evaluating the all-composite SPn twinjet since late 2010 as a more economical alternative to a clean-sheet new aircraft program.

The SPn first flew in 2005, but the program stumbled after a prototype suffered structural failure and crashed in 2006. The continuing weight of the program forced Grob Aerospace, historically a glider and primary trainer manufacturer, into insolvency in 2008. The SPn was never certified and the assets of the program and the remaining prototypes were sold to Allied Aviation Technologies.

A Daher-Socata executive said the SPn program is not mature enough to provide substantial cost savings over a totally new design. Daher-Socata CEO Stephane Mayer said his company is continuing to seek development partners for its NTX twin-turboprop program, is entering into an agreement with an unidentified U.S. aircraft manufacturer to build composite parts, and was recently named a subcontractor on the Eurocopter X4 and Dassault Falcon SMS twinjet.

Mayer also announced that the company has received certification for the rapid-change interior of the new TBM850 Elite. The rear seats can be removed and middle-row seats rotated within 30 minutes to triple the airplane’s luggage volume capacity while doubling its maximum luggage weight capacity.