Wood is the traditional boat building material used for hull and spar construction. The front spar and lift struts were extrusions. The wing skin disbonded from the upper forward wing spar. The midset wing has a carbon fiber composite spar and carbon composite skins. The main undercarriage hydraulically retracted into wheelwells forward of the main spar. Beauregard proposes putting the torpedo at the end of a long spar. Both were sandwiched in between the main and rear main spar. I-beam spar with a lighter rear spar. Hiduminium alloy lengths that comprised the main spar. The first designs were steam-powered craft dedicated to ramming enemy ships with explosive spar torpedoes. There was a single continuous main spar and another continuous rear spar. This caused the upper surfaces to "lift" from the main spar. Production on the first wing spar for the 737-7 began in October 2017. In the wild, betta spar for only a few minutes before one fish backs off. Squall and Seifer spar each other while training outside Balamb Garden.