CAD helps turn old Mooneys into new

At Mod Works (Punta Gorda, FL) a team of about 20 engineers are turning old Mooney airplanes into new ones. The company is retrofitting existing aircraft with Smart Panel, an integration of cockpit displays and instruments developed as part of NASA's AGATE program. The original Mooney panel was split into two sections, one tilting slightly away from the pilot and the other--containing the radio stack, engine instruments, and circuit breakers--mounted vertically. As new systems were added to the cockpit the panel head became cluttered and harder to expand, especially given the recent AGATE advancements. After manually modifying a Vision Microsystems-equipped Glasair III panel to fit an old Mooney F-model, the engineering crew decided there had to be an easier way. One of the biggest problems, says panel designer Eric Wilson, was that "you are unable to move the Mooney's fuselage tubes and flight controls, so everything must be made to fit in the space available." The solution: solid-model the interior using Parametric Technology's Pro/ENGINEER. Engineers began by gutting the interior of a M20F. Initial CAD inputs obtained from measurements of the airplane and its instruments were used to create a 3D computer model. They then created a database of all the instruments and avionics on the market today. "By placing the desired equipment in the 3D space of the interior model we were able to optimize location, viewing angle, hand access, and visibility," says Tim Coons, company president and owner. The engineering team was also able to check clearances to the airframe and airplane controls and check drafts to make sure the panel was manufacturable. "The software helped us meet FAA requirements by producing drawings of the models," says Sonja Englert, panel designer. And, after climbing the learning curve on the first aircraft, they were able to cut the time spent on future jobs by about 50%. To create molds for the instrument panel, they transferred 3D data to Mississippi State University, where it went to a computerized milling machine. "Many of the panel improvements were made possible through advanced technology," says Coons. "We have the advantage of starting with a clean sheet of paper to design the platform to meet current avionics requirements, and at the same time reducing the amount of boxes necessary to fly safely.