A Crew Chief Remembers To war with the Mustang By: by Merle Olmsted
Getting some work done at the maintenance hangar is P-51D Cooter—code G4-W, 44-14152. Its pilot was Hank Gruber, and its crew included M/Sgt. McGinnis (the tall man in the center by the drop tank) and S/Sgt. Robert Currie (left).
The relationship between a military aircraft mechanic (now called a "maintenance technician") and his airplane can be similar to that of a husband and wife. A mechanic sometimes finds his charge extremely frustrating, annoying and even downright nasty. Despite this, a great affection often develops for this cold piece of machinery—especially if it does well in its assigned mission and is treated right by its pilot or aircrew.
In September 2001, the 357th Fighter Group Association held its final reunion at Dayton, Ohio. As at previous gatherings, P-51 Mustangs with their familiar and much loved red-and- yellow noses were on hand for the festivities. The crowd of veteran pilots and ground crews surrounded the P-51s while having their pictures taken—a clear indication of their long-standing affection for the sleek, 60-year-old fighter. When the mighty Merlins were fired up, and Col. Bud Anderson and Brig. Gen. Chuck Yeager took off and flew several flypasts, there were doubtless many damp eyes watching. Nothing else sounds like the marvelous Merlin, and the veterans' affection for the P-51 is still strong after 56 years.
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Above left: one crewman of G4-P Rolla U-bar tinkers with an air compressor while the other services the oil tank. Right: S/Sgt. George Roepke refuels the left main tank on Satan, a P-51B—serial number 43-6987. Satan, under several different names, had a long life until it was destroyed in a fatal training accident in January 1945, with Lt. Richard Anderson.
Prelude
When I enlisted in the Air Corps/Army Air Forces in July 1942, my eyesight did not meet the standards for pilot or aircrew duties, so I was destined to become one of the many thousands of men who were needed to maintain and care for the scores of aircraft pouring out of U.S. factories.
After mechanics school, it was off to Hamilton Field, California, to join the newly formed 357th Fighter Group. This chance assignment had a major impact on the rest of my life, and I am forever grateful to the unknown person who typed my name on that roster.
The 357th received its aircraft (Bell P-39s) early in 1943, and pilots, ground crews and every other job specialist spent the next 10 months learning how to be a fighter group. Despite the loss of some 15 pilots during that period, the training was really quite effective, and when the group arrived in England late in 1942, it was about as ready for combat as it could have been.
From February 1944 through April 1945, the 357th Fighter Group compiled an outstanding record; only the 56th Fighter Group, which had been in combat much longer, had a slightly higher number of air victories. The group had 43 aces on its rosters, more than any other 8th Air Force group; 92 men died in the line of duty, and 57 became POWs.
Living with the Mustang
On arrival at our English base near the town of Leiston in East Anglia, we heard that our combat airplane was to be the P-51 Mustang. Other than a few pilots who had trained on Allison-powered P-51s, no one—neither pilot nor technician—had any experience with the type, and most had never seen one.
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The author (on wing) with his crew: armorer "Whitey" Viland (left), pilot Ed Hyman and S/Sgt. Ray Morrison. The plane's odd name is a combination girl's name and ranch brand, and the P-51—44-72489—survived the War and went to the Swiss Air Force, where it served for many years.
A few men were rushed off to RAF schools, but for the most part, the learning was done by doing—not the best way! The pilots checked themselves out, and the mechanics began to learn how to maintain this strange machine. A few of the early P-51s were handed down from the 354th Group or the RAF, but most were new P-5lBs and Cs, delivered from the huge depots in Northern England.
Of the three major U.S. fighters used in Europe, the P-51 was the easiest to maintain, the P-38 was very labor-intensive, and the P-47 was in between. Aircraft maintenance in the three squadrons was basically performed at two levels: by the hangar crews who did heavy maintenance and by the flightline crews, who were directly assigned to specific airplanes. There were also specialists such as those for propellers, sheet metal, instruments, etc., who worked out of their own sections. A further level of maintenance on the base was the 469th Service Squadron; they did the more complicated jobs.
As during training, I was assigned as a flightline mechanic and assistant crew chief with my partner from P-39 days, S/Sgt. Ray Morrison. The third man on the crew was the armorer, who cared for the four (later, six) M2 machine guns. The two mechanics for each aircraft shared the work equally, and the system worked very well.
The flightline mechanics' workday started when the Squadron CQ (charge of quarters) entered the Nissen hut, turned on the lights and jarred everyone awake by announcing the day's mission: "Briefing at 0700; max effort, max range." Usually, only the briefing time varied. The mechanics were now fully informed; they had no need to know targets, altitudes, weather, routes to targets, rendezvous times, etc.
The living areas were separated from the base proper by a mile or two; bicycles, jeeps, trucks and GI shoes provided transportation to the big, consolidated mess hall for breakfast and thence to each crews' individual hardstand—a concrete circle large enough to park one -51 (or sometimes two). Both crew members were usually on hand, but if one was off-duty or busy elsewhere, the other handled the preflight of the aircraft. We removed the canvas wing and cockpit covers and the pitot tube cover, and we pulled the propeller through a few turns, listening and feeling for anything unusual. Compared with more modern aircraft, the P-51 was remarkably unsophisticated. Nevertheless, the preflight inspection as directed in the manual was quite lengthy. Most of these were visual inspections, and many of them had been done the night before as part of the post-flight inspection. All fluid reservoirs were checked, including two separate coolant systems—one for the engine and one for the supercharger aftercooler—and the hydraulics, engine oil and fuel. We always inspected the underside of the aircraft for the coolant leaks that sometimes occurred after temperature changes. It was difficult to distinguish water from coolant just by looking at it, but one taste of the bitter liquid quickly resolved that question. Control surfaces, aileron, rudder and elevators were checked for free movement and to see whether all of their hinges were secure.
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Left: 363rd Squadron maintenance inspectors Ollerton and Kuykendall check and recheck a Merlin powerplant. Right: Lt. Tom McKinney (left) with his crew and the 364th Squadron dog. Round Trip Jr. was lost on July 30, 1944, with Lt. Daniel Finley who became a POW but died in prison camp. McKinney survived his combat tour and scored 3.5 victories.
When we were satisfied with all visual and service checks, the engine run was next. We used the battery cart to start it, thus saving the internal battery. Because the seat was sufficiently deep to accommodate the pilot's dinghy pack, an extra cushion in the seat helped us reach the brakes and provided a better view. With wheel chocks in place, we set the brakes and fastened the seatbelt around the control stick to provide up-elevator during the power check. With the fuel selector set to either main tank, we "cracked" open the throttle and set the mixture control to idle cutoff. We left the flaps down until engine start.
After visually checking the area around the prop and yelling "Clear," we engaged the direct-drive starter along with the engine primer. As soon as the engine cylinders began to fire, we moved the mixture control to "run." The propeller was already at full flat pitch, and the throttle was set at 1,300rpm for warmup. Since this article isn't a P-51 manual, I will only mention a few of the various checks. After engine coolant and engine temperatures were "in the green," we ran the engine to 2,300rpm and checked the magnetos. With either left or right mag off, the maximum allowable rpm drop was 100. The propeller governor was also checked and the prop "exercised" by running it through to high pitch and back to low; 3,000rpm was maximum for the Merlin, but this was for takeoff and wasn't used on ground run.
The Merlin's ignition systems were sometimes troublesome. The magnetos or wiring were occasionally the culprits, but usually, it was just the spark plugs. Rough engines were common during preflight and flight. At least one source of the problem was the highly leaded fuel that was used, especially late in the War when 150-grade fuel was tried for a while. Sometimes, the fouling could be burned off the plugs by going to higher power settings; this would cause the engine to smooth out. If this didn't work, however, a plug change was called for. British spark plugs gave the best service, but even they seldom held up for more than 15 or 20 hours. The exhaust plugs were no problem to change, as they were on the outside of the cylinder banks, but the intake plugs were difficult to get to—especially on a hot engine. Burned fingers and hands dropped many a plug between the intake manifolds, where they were very difficult—sometimes impossible—to retrieve.
An unfortunate aspect of the "rough engine" syndrome was that a very few pilots who didn't want to fly the mission used it as an excuse to abort and return to base. In these cases, when the crew chief couldn't find any defect, the pilot's flight leader would run (or fly) the airplane and take appropriate action if he couldn't find a defect.
After we shut down the engine and if everything had checked out OK, it was mostly a matter of waiting. Fuel and oil trucks usually cruised the taxiway, and all tanks were topped off after the engine run. Windshield, canopy and rearview mirror were polished for the 10th time or so; the armament man had long since arrived to do his checks and charge the guns, so all aircraft on the field had "hot" guns long before takeoff time. Sometimes, if the gun switch had been left on, an accidental touch of the trigger on the control stick could cause everyone in the area to look for a ditch. As far as is known, none of these incidents resulted in injury, but the sound could cause considerable panic!
