Issue link: https://iconnect007.uberflip.com/i/327747
52 The PCB Design Magazine • June 2014 Above all else, Tommy McGuire had three cardinal rules for P-38 pilots: 1. Never attempt combat at low altitude. 2. Never let your airspeed fall below 300 miles per hour. 3. Never keep your wing drop-tanks in a fight. The P-38 was a big, heavy airplane that per- formed poorly when going low and slow. There- fore, these three rules were designed to protect pilots from getting into a situation that would limit their productivity, or in a worst-case sce- nario, cost them their lives. So why would McGuire's story come to mind when I would consider skipping a DRC? McGuire's first rule of never attempting combat at low altitude could be translated as, "Are we positioned to be the most successful?" Are we being pushed by a schedule to finish a PCB design before it is really ready to finished? Are we allowing another agenda to force us into a bad decision regarding doing a final thorough check of our design? Obviously schedules are important, but there are usually more creative ways around a schedule problem than rushing a design to completion that is not ready. Have we become trapped? Do we need to reposition ourselves for success? McGuire's second rule was to ensure that his pilots kept their combat air speeds at a peak lev- el so that they would be prepared. How about PCB designers: Are we prepared? When we are tempted to skip that DRC, is it because we have become distracted from the job at hand? Do we want to just get through it so that we can move on to the next project or head home for the weekend? New projects and weekends are all fine. But is our attention where it really needs to be—on completely finishing the project in front of us? Are we prepared? The third rule was to always drop external fuel tanks during combat. Although they pro- vided extra fuel, those tanks hurt the plane's performance because they were an aerodynam- ic drag on the plane. How about PCB designers? Is there anything dragging us down and getting in the way of us performing at our best? Is it annoying to run those DRCs because we don't really understand the results? Are we tempted to avoid the DRC because the corrections they highlight will cause us to undo what took a lot of effort to do initially? Does it hurt our pride just a little to find out that we've made some er- rors along the way? My hand is up here. I know that I've run into all of these emotions. But it is important to put aside annoyance, frustrations, and pride in order to do what's best for the design. I've had to take the time to understand how to best work with DRCs and correctly interpret what the re- ports are telling me. Sometimes we just need to jettison those attitudes that drag us down so that we can be at our best. So I think that we could all agree that these are important rules. But are they really so seri- ous? To McGuire they were. Towards the end of the war, McGuire and three other pilots were on a mission deep into enemy territory when an enemy plane was sighted. The P-38s were configured for distance on this mission: low and slow and carrying drop tanks. This mission was important to McGuire; with a few more victories, he would become the leading American air ace of the war. He would return home a hero with the Medal of Honor hung around his neck. Maybe the pressure of success clouded his thinking. After all, here were four of the best pilots taking on a lone enemy plane. Perhaps he may have thought that with all of these fac- tors in his favor, the odds were with them and he could afford to bend his own rules this one time. So he gave the order to attack, at low alti- tude, at low speed, and with the drop tanks still attached. But the supposedly helpless enemy pilot was just as good as McGuire, if not better. With 80 eventual confirmed victories, Warrant Officer Akira Sugimoto was an instructor pilot with over 3,000 hours in his aircraft, and he was also the best of the best. And what had started out as an easy victory for McGuire's group now turned into a totally unexpected fight for survival. Before anyone could react, Sugimoto de- stroyed one P-38 and then flicked through a roll and was after a second one with guns hammer- ing. The big P-38s, low, heavy and flying slower than they should have been, were in perfect po- tim's takeaways DESIgN RULE CHECkS: FoR YoUR PRoTECTIoN continues