B-29 Mechanic Pt 1

Discussion in 'Aviation' started by syscom3, Dec 30, 2010.

  1. syscom3

    syscom3 Pacific Historian

    Jun 4, 2005
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    I saw this in the B-29 forum.

    Credit is for john szalay <[email protected]>


    A lot of words have been written, and rightly so, about the men who flew
    the B-29's in World War II and in Korea. But outside of the standard
    cliche, "Ground crews worked through the night to get a maximum number
    of planes in the air", little mention has been made of the mechanics who
    kept the aircraft flying. The cuts, the burns, the gashes, the falls,
    the lousy weather, these did not make the job of aircraft mechanic one
    of the cushiest in the Air Force. Even now, fifty years later, I can
    count over forty scars on my hands and forearms.
    When you talk about working on airplanes, you have to start with the
    weather you were working in. We were lucky (?) being on Guam where we
    did not have to put up with frostbitten fingers. But Anderson AFB, at
    the northern end of the island, gets over 100 inches of rain a year
    (usually in twenty minute showers), the temperature seldom gets below
    80degrees, and the humidity is so high that you had to keep a 100 watt
    light bulb burning in your clothes locker to keep the fungi from eating
    your clothes. We worked in fatigue pants and tee shirts, the standard
    USAF-issue coveralls being just too hot to put up with. A few of the
    hardier souls with very high pain thresholds stripped down to PT shorts
    and GI shoes, but this was generally considered extreme. I tried it
    once and burned both legs and my ribs on sun-heated aluminum within an
    To all of us who worked on it, the Curtis-Wright R-3350 radial engine
    was an object of consuming hatred. Basically, it was two nine cylinder
    engines mounted on a double throw crankshaft. Voila! Instant eighteen
    cylinder engine. And a mechanic's nightmare. The aircraft itself was
    bad enough to maintain, but those engines! The two banks of cylinders
    created by the double mounting were so close together that the mounting
    bolt flanges on the cylinder bases had to have the edges planed down in
    order to fit next to each other on the engine housing. This engine had
    a reputation of being a voracious eater of valves and rings, as well as
    a prodigious swallower of oil, and cylinder changes were almost as
    common as engine changes. There is a Rule that allows only those
    cylinders on the bottom of the engine to fail. This is so that the oil
    can run out of the engine housing and drip ceaselessly into the
    mechanic's hair, ears, nose and down the back of his neck So. You have
    pulled the cylinder, gotten your oil bath for the day, and held the
    cylinder in place while your fumble-fingered partner got the mounting
    bolts started. You've run the bolts, all twenty-four of them, in tight
    and torqued them down to Tech Order requirements.
    Are we done yet? Hell, no! You still have to safety wire those twenty-
    four bolts. Picture the rough-cast, quarter inch thick aluminum
    cooling fins projecting from the bodies of each cylinder. Picture the
    cylinder mounting bolt heads three quarters of an inch away from each
    other and only an inch and a half away from the mounting bolts of the
    cylinders in the other bank.
    Picture the safety wire that had to be strung and pulled tight
    through each bolt head. Picture the bloody mess where your hands used
    to be after you finished safety-wiring twenty-four bolts and repeatedly
    dragging your knuckles across those cooling fins on each and every one
    of them.
    I have always maintained that I can look at a man's right wrist and
    tell you if he had been a B-29 mechanic. The secret mark of the
    fraternity is found there: a scar an inch or so long on the inside of
    the wrist directly below the thumb. A new mechanic collected his scar
    the first time he was assigned to drain the front oil sump. The front
    sump was located at the bottom rear of the nose section of the engine
    housing, a few inches lower than the lip of the ring cowl on the front
    of the engine. To supposedly make access easier, Boeing engineers, none
    of whom had obviously ever worked as mechanics, placed an eight inch
    square door in the upper surface of the air inlet. Theoretically,
    this allowed the mechanic to reach upward through the hole, put his _
    inch box end wrench on the sump plug, and by pulling forward, loosen the
    plug. Well, first of all, that plug NEVER just gradually loosened. It
    came loose with a snap, at the precise moment you were applying even
    more pressure to make it come loose at all. Secondly, Boeing did not
    believe in wasting production time or coddling mechanics by rounding
    edges on access doors and hatches. The edge of the hole you were
    putting your arm through was SHARP, very, very sharp. Plug snaps
    loose, arm jerks towards you, wrist hits edge of hole, and another
    cursing mechanic is seen carrying his bloody box end wrench in his
    equally bloody hand down to the welding shop, where he will have the
    wrench shaped so that he can get to the plug from above, through the
    ring cowl opening in front of the engine, where there are no sharp
    After you got the plug out, the sump drained, the magnet on the
    sump plug checked for metal chips (hoping you wouldn't find any and have
    an engine change on top of everything else), the plug back in, tightened
    and safety wired, your fun and games with engine oil were far from over.
    There was still the rear sump to be drained and checked. That was
    usually a real adventure.
    First you scrounged up a short work stand and placed it under the
    nacelle. Stepping up on the stand, the first step was to remove an
    access door approximately eighteen inches square. This allowed you to
    reach a similar door above it which formed part of the lower surface of
    the air intake. Removal of that door brought you to still another same-
    sized door on the upper surface of the air intake. Removal of that door
    finally got you into the bottom of the engine accessory compartment.
    CORRECTION: It allowed access to the accessory compartment. You got
    there by putting your right arm, clutching the inevitable _ inch box end
    wrench and a pair of dykes for cutting the plug safety wire, above your
    head and into the hole you had just opened. The workstand was climbed
    step by step until your hips were level with the bottom of the nacelle
    and you head and arm were in the accessory compartment. Putting the
    wrench down somewhere handy, the safety wire was removed and the dykes
    dropped in your breast pocket, it being the only one reachable. The
    wrench was retrieved and placed on the sump plug. One handed pressure
    was applied until the plug (eventually) loosened. It was then backed
    off until held in by only a couple of threads. The wrench was again
    stashed somewhere, and you yelled down to your buddy through the inch or
    so of space between your body and the edge of the hole to pass up the
    oil drain hose. He, of course, is not there, having been dragged off
    ten seconds earlier by the crew chief to empty ash trays, fluff the
    pilot's seat cushion, and to perform other similar critical maintenance
  2. syscom3

    syscom3 Pacific Historian

    Jun 4, 2005
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    So you climb down off the stand, carefully avoiding the sharp
    edges, put the drain line up in the hole and follow it with yourself.
    The drain line was a piece of two inch hose about eight feet long. The
    lower end was in a five gallon can and the upper end slipped over the
    outlet in the bottom of a rectangular metal box. The theory was that
    when you pulled the sump plug the oil drained into the metal box and ran
    down the hose into the waste bucket on the ground. That was the theory.
    In the real world, ruled by Murphy and his Law, no matter what the size
    and shape of the collector box, one of two things ALWAYS happened: the
    box overflowed or the line came off the outlet. Either way you got
    drenched from the middle of your chest to your toes with black, slimy,
    yucky engine oil. If you were very, very lucky, and the airplane had
    come back at midnight instead of half an hour ago, the oil had had a
    chance to cool. One usually was not lucky. It goes without saying
    that when hot oil is sloshed on you, you tend to jerk in a reflex
    action. Remember that little door by the front oil sump that you put
    your wrist through? Well, now you have your entire body through THREE
    doors. The swirling patterns to be seen in a mixture of black oil and
    fresh red blood are truly fascinating.
    Difficult as the job of safety wiring the cylinder mounting bolts
    was, it did not even come close to the sheer frustration and muscle
    cramps that were the lot of any mechanic who had to change a fuel
    injection pump. On later models of the R-3350 engine, the old
    carburetor system was replaced with direct fuel injection. The required
    gasoline was sprayed directly into each cylinder through a nozzle
    mounted above the rear spark plug. The flow of fuel to these nozzles
    came from two pumps, each about fifteen inches long and eight inches in
    diameter, mounted on opposite sides of the upper accessory section of
    the engine. The forward edge of the pump mounting flange was no more
    than three inches from the firewall separating the power section from
    the accessory section of the engine. When a pump was replaced it was
    not the bolts on the rearward half of the flange that were a problem.
    It was the bolts on the forward side that were bad news. Because of
    the spacing involved, to reach the forward-side bolts you had to reach
    around both sides of the pump, rather like putting your arms around a
    horizontal log. In order to do this, the mechanic had to lean in
    through the main access hatch on the side of the nacelle and feel for
    the holes on the forward side of the pump. With no more than three
    inches of total clearance back there, you were reduced to the use of
    fingertips just to start the threads on several of the bolts. Once
    the bolts were started by finger (and you were reasonably sure they
    weren't crossthreaded), it was juuuuust possible to get a socket with a
    universal joint drive on the bolt heads. Forget the torque wrench; no
    way. Unfortunately, there was barely enough room to move the ratchet
    one click. Turn one click, fingertip it back one click, forward one
    click, back one click ad nauseum. Finally, with cramps in every finger,
    the bolts were tightened down with what you hoped was sufficient torque
    to prevent any gasoline leakage.
    With the easy part of the job finished those rotten bolts that couldn't
    be seen and could barely be touched had to be safety wired. This was
    strictly a feel job, and the accepted practice on my crew was to cut off
    a piece of wire about three feet longer than you really needed. The
    wire had to be run through each bolt head from the upper left quadrant
    to the lower right quadrant to prevent the bolts from vibrating loose.
    The technique generally used was to feel for the appropriate wire hole
    with the tip of the wire. When you found it, you pushed a minimum of
    twelve inches of wire through the hole. This brought the end of the
    wire below the pump, where it could be grabbed with a pair of pliers and
    carefully drawn tight without kinking the wire. If it kinked, you
    ripped everything out and started over. All this was going on while the
    mechanic was bending sideways and the edge of the hatch was digging into
    his ribs. Just to add a little more joy to the mechanic's day, there
    was usually an Airplane Driver down on the ground yelling up something
    encouraging, like, "Sergeant! What the hell's the holdup? We would
    like to get off the ground sometime soon so that we can get back in time
    for Happy Hour at the Club tonight. Speed it up, will you?" Exactly
    what was needed for motivation. It usually motivated me into dropping a
    bolt and spending an additional twenty minutes trying to find it.
    My personal all-time favorite for raising the blood pressure was the
    reinstallation of the heat shield shrouding following a
    turbosupercharger change. Each nacelle on the B-29 held two
    turbosuperchargers, driven by engine exhaust gas diverted from the
    exhaust manifold, with a heat shield shrouding between the exhaust
    manifold and the engine accessory compartment. You had to pull the
    shrouding off when you changed a turbo, and reinstall it after the turbo
    was mounted and the holddown bolts safetied. There were several pieces
    of shrouding, and they fit together like a three dimensional jigsaw
    puzzle. In addition, they were usually badly distorted from the extreme
    temperatures that they were subjected to. Four pieces, the center, the
    upper center, upper forward and forward, had multiple planes, and all
    four overlapped forward and above the turbine bucket wheel. At the
    point of overlap, there was a bolt hole that ran through all four
    pieces. I defy anyone to get that hole lined up on the initial
    installation. The only way to handle it was to loosely install the
    shroud mounting bolts on all four pieces and then, starting with the
    bolts farthest away from the overlap, tighten here, loosen there, back
    and forth, back and forth, until eventually the holes in all four pieces
    lined up and you could run a bolt through them. Attacking the problem
    from the other direction, putting in the bolt and then trying to install
    the shroud mounting bolts never seemed to work, although I think every
    mechanic has wasted a half a day on it.
    We mechanics were really pressed to prove the adage that where
    there's a will there's a way during the first six months of the Korean
    War/Conflict/Police Action/Whatever. The 19th Bomb Group was stationed
    down at the other end of the field, and on the 27th of June, 1950, they
    moved out for Okinawa and four years of combat missions. The
    maintenance people of the 19th stripped the base shops of every engine
    and spare part they could put their sticky little fingers on. In fact,
    they snuck up into our area in the dead of night and stole all four
    engines off 44-86267, one of our shiny new airplanes. When the crew of
    267 got out to the flight line the morning of the 27th, the Bomb Group
    was gone, there was a jack under the tail and four gaping holes in the
    wings where the engines used to be. With the Bomb Group taking
    everything loose, and some things that weren't, the only parts we had
    available to us were those we had on hand in the Squadron Tech Supply
    hut. It wasn't much to keep eleven airplanes flying. Whenever we had
    to replace an engine, we had to send a wire to Japan, and then wait for
    them to pull an engine out of the pipeline and divert it to Guam. As
    for getting replacement parts, forget it. So, to paraphrase a current
    expression, we went into creative maintenance. One of our band of Rock
    Happy Fools spent all of his spare time boondocking (wandering through
    the jungle looking for Japanese souvenirs). Most of the time his
    finds were highly useful items such as 155mm cannon barrels without
    breech blocks, rusted out jeeps and weapons carriers, fifty-five gallon
    drums filled with unidentifiable liquids, and similar goodies. In our
    hour of travail he came through. In a small overgrown WW II dump
    between Anderson and Northwest Fields he came across a dozen large
    crates containing brand new R-3350 engines. They had been sitting there
    since 1945, but the cosmoline was still thick and, when we got the
    crates open, found that the desiccant bags were still active. We had
    our engine parts. A veritable plethora of magnetos, distributors, fuel
    and oil pumps, cylinders, injection valves, prop governors, all those
    good things. To keep the paper shufflers (and the Inspector General)
    off our necks, whenever we replaced a bad unit, say a magneto, with a
    dump part, we also swapped the manufacturer's data plates. This
    apparently kept the same model and serial number on the engine that the
    paperwork said was supposed to be there. If we hadn't covered our
    tracks on this, half the brass at FEAMA (Far East Air Material Area)
    would be swarming all over us, grounding everything in sight, while they
    tried to determine what to do about a problem that was not covered by
    The Book. It should be pointed out that the `dump parts' were used
    for interim replacement only; they were carefully checked for
    interchangeability and performance, and were immediately replaced when
    legitimate parts became available. Needless to say, we didn't tell
    the Operations people what we were doing, either. The flight crews were
    insecure enough without knowing that some very essential parts of their
    engines had come out of a dump.
  3. syscom3

    syscom3 Pacific Historian

    Jun 4, 2005
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    All I've talked about to this point is the problems B-29 mechanics
    had with the engines. Don't get the idea that the airframe maintenance
    was any easier; it wasn't. In fact, I am convinced that Boeing had a
    crew of people that went over all prototypes, saying things like, "This
    fitting is too easy to get at for maintenance, weld a panel in front of
    it." Have you ever changed a rudder in a fifteen to twenty mile an
    hour crosswind and have a hinge bolt hang up? Gotten drunk on, and
    suffered the world's worst hangover from, gas fumes flowing into your
    face while changing a center wing tank fuel booster pump? Had a main
    gear wheel dropped on your foot when pulling it for a brake change? Had
    to dump the relief can after a flight because the flight crew "forgot"?
    Spent two weeks scrubbing exhaust stains on the flaps and nacelles
    because the CO thought they looked "messy"? Tried to talk reason to a
    know-it-all Second Lieutenant, without getting court-martialled, who
    insisted that the clutch was slipping on a direct-drive electric flap
    motor? Passed out from the 120 degree heat in the tail section while
    installing the cables on a new elevator? Spent seven hours on a
    Saturday "looking busy" on the engines of an in-commission airplane
    because the CO thought a visiting VIP might want to inspect the flight
    line? And then have him drive past without stopping anywhere but the
    Officer's Club? Had a brand new junior assistant deputy OJT
    engineering officer order you to spend ten hours changing a cylinder
    because of low compression when experience told you it was probably only
    carbon on the valve seat that could be popped off in a few seconds by
    rapping the rocker arm with a mallet? Risked losing a hand every time
    you reached across the edge of the bomb bay doors to put a down lock on
    the door actuator? Got second degree burns from putting your hands on
    the aircraft skin in the middle of the day? Worked through the night to
    have the plane ready for an 0800 takeoff, only to be told at 0730 that
    the flight was cancelled? I don't regret my years as a B-29
    mechanic; in fact, I loved them. But it would have been so much nicer,
    if even just once, someone from the clean khakis crowd in Engineering,
    Operations and the CO's office had come out to oil and grease land and
    said, "Nice job, guys."

    Staff Member Moderator

    Apr 9, 2005
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    GREAT POST!!!!
  5. Aaron Brooks Wolters

    Aaron Brooks Wolters Well-Known Member

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