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We had just finished one of many instructive films which we are subjected to regularly, and the boys were discussing correct procedure to be followed should the electrical system go "out" on the 38. We encounter this situation so seldom that there was a variety of suggestions as to what to do first. The discussion was short-lived however, because one of the fellows had just completed a series of tests on the electrical system and proceeded to give us the "word." We thought you might be interested because should your left engine be shot away in combat, your generator will go with it, and then, my lads, your electrical system will be entirely dependent on your battery which at best will be able to "put out" for no longer than an hour. (Remember... your one and only generator on the 38 is on the left engine.) |
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Because it takes a lot of juice to turn the engines over, we always use a battery cart. Once in a while we do set down at a field where a battery cart is unavailable and then we have to use the plane's battery. We have found that the following procedure will start the engines with a minimum drain on the battery... (This should be done only in emergencies since it is an excessive drag on the generator.) Start the left engine first, and after turning on the generaror switch, rev her up till the ammeter shows a good charge, indicating the generator is working. Then start the right engine. The added boost from the generator will offset to a large extent the heavy drag needed to turn the engine over, thus saving the battery. |
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We respect that old axiom about the ounce of prevention with regard to electrical failure, and make it a point to check both the generator and battery before takoff. After checking the generator switch "on" at the head of the runway, we run up the left engine to 35 inches. The amperage will at first read high but after about 30 seconds will fall off and stabilize. If it stabilizes above 70 amps it indicates that the battery is low and the generator is really having to work. Because there might not be enough juice in the battery to govern the props on takeoff, we recommend returning to the flight line and having the battery checked. Never start on a long mission with a low battery --- there is too great a chance of overworking your generator and developing electrical failure. Should the generator go bad in flight the first indication will be zero readings on both the ammeter and voltmeter, and the prop governors will start acting up. They will become sluggish and fail to hold proper RPM indicating that the battery is low and the generator is doing little good. We immediately shut off all electrical switches and put our prop selectors in a fixed pitch. The RPM at which we set our props is dependent on our mission. If we are on a long range hop the props should be set in a fixep pitch at the RPM we had pre-determined in our flight plan. Assuming this to be a low RPM-1600 to 1800, an efficient cruise setting -- we must remember we are not going to have any extra power to go around the field again should we overshoot our landing. |
| Ernie Claypool* says: "BOOST PUMPS ARE A HEAVY DRAG ON YOUR BATTERY AND SHOULD BE SHUT OFF IMMEDIATELY WHEN YOU DISCOVER YOUR BATTERY IS DOWN." |
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* Lockheed Production Test Pilot Commercial Pilot Forestry Patrol and Charter Pilot CPT Pilot Barnstormer |
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On the other hand if we are making a local flight and have plenty of fuel when trouble is encountered, we recommend a fixed pitch which will give us a power setting of 25 inches with 2500 RPM and 150 MPH at 5000 feet. This insures plenty of power to go around again should we need it. With the props in Fixed Pitch, turn off all electrical switches including your generator and boost pumps which are a heavy drag on the battery. In fact, with the generator "out" at 20,000 feet and above, your boost pumps will drain your battery enough in just a few minutes to stop your engines. |
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Therefore the instant we discover we have "lost" our generator, we head down to an altitude where the engines will operate with the boost pumps off. This altitude will vary with planes. We have run tests by throttling back and cutting the boost pump switches at each one thousand foot level until we reached an altitude where the fuel pressure alone was sufficient to keep the engines running. Twenty thousand feet was about as high as we could operate with booster pumps off. On some P-38s, the radio must be switched off separately because it is wired in behind the battery switch, and will drag your battery down in no time if left on. If you must use the radio, use it only momentarily --- use your transmitter only in an emergency. A battery will build itself up sometimes just by standing idle. Give it a chance. Use your electrical instruments only as long as necessary and then switch them off. On long range hops, you should check your remote compass every 15 minutes for resetting the gyro. |
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Intelligent conservation of electrical power may be the difference between returning to your base and having to set down behind enemy lines. If your generator is "out" or your battery "down" we recommend the following: 1. Put props in fixed pitch. |
TEAMWORK In April 1943 a squadron of P-38s was on its way out'to a German target. Lt. William L Bolton, an Element Leader in one of the Flights, developed electrical trouble and was forced to turn around and head for his home base. Lt. Edwin H. Schneider, Bolton's Wingman, remained with his disabled leader. On their way home over enemy territory over North Africa they were attacked by seven German fighters; four Messerschmitt 109s and three Focke Wulf 190s. During the dogfight that ensued Bolton got on the tail of and destroyed one of the Messerschmitts. At the same time a Focke Wulf pulled in behind and below Bolton's plane. Schneider had the remaining five fighters on his tail. However, seeing his leader in distress Schneider - with complete disregard to his own personal safety - went after and destroyed the plane on Bolton's tail. After a running dogfight Bolton and Schneider succeeded in evading the other five Germans and returned safely to their home base. Lt. Edwin H. Schneider received the Distinguised Flying
Cross for this action |
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