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Care and Feeding of B-29's and the R-3350 Engine

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Rambertsan
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2006/07/25 00:45:13 (permalink)
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Care and Feeding of B-29's and the R-3350 Engine

HOW TO START THE  R-3350-57
FUEL-INJECTED ENGINE
.
 
            The ranks of people who have flown with or maintained the B-29 and the R-3350 engine are shrinking by the day as these people age.  I feel that it behooves those still around to get our experiences with the planes and engines on paper and available on sites such as this forum
            To that end, I intend to periodically post pieces such as this dealing with the day-to-day care and feeding on the B-29 and that cantankerous R-3350 engine for the benefit of younger members. I think in the next one I might fully explain just what a ‘Magic Wand’ was and how it was used
 
 
            In the post-war years Tech Order 02-1-28 spelled out a standardized starting procedure for aircraft engines, with variations only as authorized by the aircraft handbook and engine involved.  The steps of the starting procedure, as modified for the B-29 and the R-3350 engine were:
 
1.  Check that Master Ignition Switch and individual engine switches are in “OFF” position.
2.  Putt-putt (auxiliary power unit in rear un-pressurized compartment) is started and on-line, producing electrical power
3.  Propeller should be pulled through by hand a minimum of six blades or, from about 1953, by intermittently engaging the starter ( T.O. 02A-1-8).  If a hydraulic lock is found, caused by accumulation of oil in lower cylinders, remove the  spark plugs from the lower cylinders and pull the crankshaft through several rotations until the oil lock is cleared.
4.  Safety first.  Brakes on and locked, wheel chocks in place..
5.  Before starting engine, check propeller control to make sure it is set to full low-pitch (high rpm) setting.  Propeller control should remain in low-pitch setting for all normal ground engine operation.
6.  Check Turbo Boost Selector dial on Pilot’s aisle stand.  Dial should be set at “0”, turning off the turbosupechargers during all normal ground engine operation. .
7.  Check flap position.  For safety purposes flaps should be in the “UP” position during engine operation.  Prop blast on start with the flaps down on a B-29 could cause the plane to jump the wheel chocks
8. Set fuel valves in tank-to-engine position.
9. Set throttles in the 1000 to 1200 position.  Use lettering on throttle quadrant as reference point.
10. Set mixture control in IDLE CUT-OFF position.  
11.  Turn Master Ignition Switch “ON”.  Leave individual engine switches in “OFF” position.
12.  Energize the starter by holding energizing switch ( labeled “START” on B-29 Engineer’s panel) in “ON” position for approximately 15 seconds or until voltmeter returns to maximum reading.
13.  When starter has wound up to full rpm, push Engage switch (labeled “MESH” on B-29 Engineer’s panel). 
13, a.  No priming is necessary on a fuel injected engine, but the mixture control must be moved from IDLE CUT-OFF to AUTO-RICH  as soon as the propeller makes one revolution.
13 .b.  When the prop has made at least one complete revolution, turn the engine ignition switch to the “BOTH” position.
14.  Warm engine.  Run at smoothest setting between 1200 and 1600 rpm.  Monitor engine instruments during this time to assure that cylinder head temperatures do not climb above the green arc on the instrument.   If oil pressure is not up to normal (green arc on instrument) within one minute of starting, shut down engine by moving mixture control to IDLE CUT-OFF.
 
At this point the engine is fully operational and ready for taxiing, or engine performance checks such as mag(neto), full power and injection pumps synchronization tests
 
15.  Engine Shutdown.  Run engine at 1000 to 1200 rpm long enough to bring down cylinder head temps.  After CHT has stabilized, move mixture control to IDLE CUT-OFF.  When propeller has stopped turning, move engine ignition switch  from “BOTH to “OFF”  Do not turn off the Master Ignition Switch until all four engines have stopped turning.
 
A few observations for the novice.
1.  The R-3350, during ignition, throws out enough blue-gray smoke to make you think you are in a really heavy San Francisco fog.  Don’t panic, especially if you are a fire guard, it’s normal.
2.  When running checks at a specific rpm, e.g., a magneto check at 2200 rpm, always tap the tachometer a few times to make sure the needle is not sticking and giving an erroneous rpm reading.
3.  Always have someone in the aircraft commanders seat during run-up in case the plane jumps the chocks and starts moving. 
 
Sources: 
AF Manual 52-9, Department of the Air Force, Engine Conditioning for Reciprocating Engines
Tech Order 02-1-28, Title unknown
T SGT William “Willie” Watts, Crew Chief of WB29 44-62094, and my boss and teacher for 18 months.
 

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    Rambertsan
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    RE: Care and Feeding of B-29's and the R-3350 Engine 2006/07/26 07:58:40 (permalink)
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       Came across the photo below in my files and decided there is a story associated with it that, unlike the "Magic Wand", will never be found in history books and articles.
       One of the B-29 mechanic's routine chores on a post-flight inspection was the draining of the front and rear oil sumps and therein lies the  tale.
        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 a square door in the upper surface of the air inlet (see photo).  Theoretically, this allowed the mechanic to reach upward through the hole, put his 3/4 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 edges. And so another Special Tool is born.
        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 3/4 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 work stand 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 tasks.
         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

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    Rambertsan
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    RE: Care and Feeding of B-29's and the R-3350 Engine 2006/07/28 23:05:10 (permalink)
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    Thanks for the kind words.  I really feel  that these details of the plane, the engine and the mechanics who maintained them are disappearing fast and have to be preserved.
    I hope to get to a description of the Magic Wand and it's use later tonight.  Wherever possible in these writeups I try to give the standard/official procedure as well as how the guys on the line sometimes modified those procedures.
     
    Bob Mann
     
    jpeters140
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    RE: Care and Feeding of B-29's and the R-3350 Engine 2006/07/28 23:13:31 (permalink)
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    Bob...I have a Magic Wand...it looks as if it has never been used. I picked it up years ago for avout  $20-30.00.
     
    Jim :-)

    James S. Peters Sr. T/Sgt B-17 Flt Engr, 27 missions 99 BG, 348BS, 5th Wing, 15th AAF Tortorella, (Foggia#2), Italy My Tour was from 12/03/44-06/19/45 M/Sgt USAF (Retired)
    Ken a B24 Fan
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    RE: Care and Feeding of B-29's and the R-3350 Engine 2006/07/28 23:23:20 (permalink)
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    Bob, As always you accounts make facinating reading.

    Always a treat.

    Ken


    Ken Alexander
    Proud son of 1st Lt. Clair B. Alexander Jr.
    Pilot, B-24s: 10/12/1944 - 04/24/1945
    15th AF, 49th Wing, 461st BG, 764th BS
    Torretta Airfield, Cerignola, Italy
    Rambertsan
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    RE: Care and Feeding of B-29's and the R-3350 Engine The Magic Wand 2006/07/29 01:45:26 (permalink)
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    The Magic Wand
     
    aka Cold Cylinder Check
     
                The flight crew had finished the engine run-ups,  but instead of taxiing out,  the engines were pulled back to idle and the Aircraft Commander dropped out of the nose wheel hatch and headed in your direction.  He’s about to tell you there was a 100 rpm drop on #3 engine when both the right and left mags were checked and how fast could we fix it so they could get off the ground?
                Answer?  We’ll be on it as soon as the engineer shuts down the engines.  The crew chief turns to his troops and says “Mag drop on #3.  It’s agic Wand time.  Hop to it.”  By the time the AC got back in the plane and told the FE to first run  #3 on the right mag and when the cylinder head temperature  maximizes, to shut the engines down, the ground crew  had moved a maintenance stand in front of the engine waiting for the prop to stop turning.  As soon as it did, the stand was pushed in close to the front of the engine and two mechanics swarmed up to do another Magic Wand performance.
                Let’s set the stage.  Each of the eighteen cylinders of the R-3350 engine has two spark plugs, front and back.  There are two magnetos for each engine.  The front plugs are fired by the right magneto and the rear plugs by the left.  A mag drop ( loss of rpm when switching the magneto switch from “Both” to either “Right” or “Left”) indicates that all is not well in the firing process for that bank of spark plugs.  But which of the eighteen cylinders has the problem?
                Enter the Magic Wand.  Most of the one’s I’ve seen were simply a temperature probe mounted on a three foot piece of tubing, with wires running through the tube and connecting to a temperature gauge.  It’s purpose was to measure the relative temperatures of each cylinder when the engine had been running on one mag.  
                As quickly as possible the two mechs mounted the stand and the Wand man grounded the probe to the engine or prop, and then touched to probe to either a solid boss on the combustion chamber part of number one cylinder or in the spark plug recess..  Whichever, use the same place in all eighteen cylinders.  Moving as quickly as possible he touched the probe to all cylinders, calling out the temperature registered on the gauge.  This was recorded by the other mechanic. 
                After getting temperatures for all the cylinders, numbers 1 and 2, as well as any low-reading cylinders were checked again to determine the amount of cooling that  had occurred during the measuring process.
                Then the stand was pulled back from the engine, which was re-started and run on the other magneto to maximize cylinder temperatures.  The engine was then shut down, the stand moved in and the measuring process repeated.  A typical set of temperature readings might look like this:
     
                            Cylinder #                      Right mag                  Left mag
                            1                                  180                               170
                            2                                  170                               175
                            3                                  170                               170
                            4                                  145                               150
                            5                                  150                               155
                            6                                  100                               150
                            7                                  155                               160
                            8                                  70                                 155
                            9                                  160                               145
                            10                                 150                               65
                            11                                 150                               145
                            12                                 145                               150
                            13                                 150                               145
                            14                                 145                               145
                            15                                 60                                 50
                            16                                 145                               140
                            17                                 140                               135
                            18                                 115                               140
     
                So what does this tell us?  On the right mag the front plugs on #’s 8 & 15 are dead and those in #’s 6 & 18 are firing intermittently.  In the rear bank, number’s 10 and 15 are dead with the rest looking good.  The Solution?  With the flight crew breathing over our shoulders – figuratively, because they were NOT invited up on the maintenance stand – was to just change the six dead and darn-near-dead plugs as fast as possible and get the plane on its way..
                The rear plug on the #10 cylinder was the one that would cause a small slow-down.  To get to it, you had to drop what was called The Tub.  It was a part of the air scoop that ran directly under the engine and made it impossible to get to the lower cylinders without removing it.  Pulling it was a two man job and the men who did that just went ahead, changed #10 and re-installed The Tub.
                The cause of the intermittent firing on six and eighteen would be the basis of some concern.  There are a number of causative factors: faulty spark plugs, defective ignition leads, faulty fuel injection nozzles, defective injection pump check valves and incorrect valve clearances.  These areas would all be looked at when the plane returned as part of the continuing preventative maintenance all good crews practiced.
     
                I can’t end this without a short story of an impatient Aircraft Commander  and a spark plug that was being difficult.  We were scheduled as the mission ship for the day’s Vulture George weather track and, during pre-flight run-up a 100 plus rpm mag drop was noted on one of the engines.  It was decided that all 36 plugs would be changed and the entire crew pitched in to get it done.  I was doing the upper rear plugs on one side of the engine and T/SGT Watts, the crew chief, the other.  Willie had no qualms about getting his hands dirty.  I finished up and Willie was on #18.  The rear plug on that cylinder sat on a thermocouple, rather than a washer, which transmitted the cylinder head temp to the engineer’s panel,. Care had to be taken to make sure the thermocouple lead did not touch the cylinder itself, which would give erroneous temperature readings.  Just as Willie asked me to use a screwdriver to keep the lead  off  the cylinder wall while he tightened the plug, there was a shout from the Aircraft Commander.  “How much longer are you going to take, Sargeant?  We would like to get off the ground before our sandwiches go stale.” 
                Willie quietly asked me to slip him a hammer.  Then he called down, “Almost there, Captain.  This last plug doesn’t want to go in.”  Just as he said that he whacked the induction manifold three good ones which resulted in three very loud noises.
                Then he called out, “I think we got it started that time Captain, it’ll just be a minute.”  It took the Captain five to ten seconds to realize he was being told to go away – we don’t tell you how to drive, you don’t tell us how to fix.
     
    Bob Mann        
               
    Rambertsan
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    RE: Care and Feeding of B-29's and the R-3350 Engine The Magic Wand 2006/07/31 00:26:23 (permalink)
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                 Looking over my last post (pertaining to the Magic Wand), I have a feeling a discussion of the relationship between the ground crews and the flight crews might be beneficial.  I want to emphasize that I am talking about the 514th/54th Weather Recon Sq  1949 - 1951, and, if time and space permits, the 55th WRS at McClellan AFB 1951 – 1952.  These are the only two squadrons I can speak about.
                The 514th/54th, during my time, never had a flight crew assigned to a specific aircraft.  I have seen squadron documents from the 1947 – 48 time period that assigned planes to flights and (flight) crews to planes.  But in the two years from my arrival in the Fall of ’49, no way.  Maybe the planes could  have been assigned to flights as a paper exercise, but if they were, no one ever told the mechs out on the line, and, frankly, they wouldn’t have cared if someone did.
                As to the notion that flight crews were assigned a specific plane, forget it.  It was very uncommon to have a crew fly the same plane twice in succession, the luck of the draw more than anything else.  The 514th/54th operated with an average strength of eleven planes, half of which were out of commission at any given time for parts, maintenance problems or inspections.  Another plane, for not-quite-ever-resolved structural problems was not released for recon flights and was used for transition and proficiency flying within sight of Guam.  The remaining planes were committed to one weather track every day, another every other day and unforeseeable typhoon recon Specials from both Guam and TDY at other bases.  So operational scheduling that married a crew to ‘their’ plane was virtually impossible.
                And the final proof of no crew assignment to a given plane was impossible to miss.  If flight crew X was assigned to my plane, how come in two years, I never saw any of them, not once, out at the hardstand cleaning the plane, pumping gas or pulling props?  We did occasionally see a radio operator or weather technician at the plane, but they were functioning as repair specialists, not crewmen.
                OK, that takes care of that.  Let’s move on to the plane.  It belonged not to the Air Force, not to the Air Weather Service, not to the squadron, not to a flight crew – it belonged to the Crew Chief and his band of merry men.  It was OURS  by right of possession.  We were the guys who spent ten, twelve, sometimes twenty-four hours, getting that beast ready to go again, collecting gashes, burns, cuts and bruises on a daily basis while doing it.  So when a mag drop shows up on the pre-flight that required changing all thirty-six spark plugs on the offending engine, can you blame us for being a little antagonistic when some driver, who only comes out  to the flight line to fly, starts yelling at us because we obviously are not working at what he considers the proper speed?
                Not to say we stood there and glared and glowered at them like they had come to foreclose on Granny’s farm.  Some of the crews  we got along with fine, having them come out to the hardstand to fly the plane was met with friendliness and respect on both sides.    But others – you could hear the low moan from our bunch when the crew truck showed up and we saw who was getting off.  These were the guys who hardly ever cleaned up their garbage in the crew compartments, who seemed to somewhat frequently ‘forget’ to empty the relief tube can up front, who wrote up all kinds of nit-picking ‘problems’ on the Form 1 – ‘problems’ that generally could not be duplicated, or even identified, on the ground.   This latter, incidentally, sometimes made the Form !  hilarious.  The Air Force classic in this respect was the response to a write-up that “Number 4 engine missing’.  The Crew Chief’s clearing notation?  “Number 4 engine found in nacelle on right wing.”
                I think I’ll hold off on a discussion of the maintenance setup in the 55th.  That was a different situation that requires some explanation.
     
    Bob Mann
    Ken a B24 Fan
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    RE: Care and Feeding of B-29's and the R-3350 Engine The Magic Wand 2006/07/31 11:14:01 (permalink)
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    Bob,

    Were you assigned one aircraft as "yours?"

    In my father's group, the original planes were named by the original flight crews. The replacement aircraft did not have air crews assigned to one plane, so the ground crews named many of them. Did you have the honor of naming a B-29?

    Ken

    Ken Alexander
    Proud son of 1st Lt. Clair B. Alexander Jr.
    Pilot, B-24s: 10/12/1944 - 04/24/1945
    15th AF, 49th Wing, 461st BG, 764th BS
    Torretta Airfield, Cerignola, Italy
    Rambertsan
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    RE: Care and Feeding of B-29's and the R-3350 Engine 2006/07/31 15:55:36 (permalink)
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    Ken -
       During my time with the 514th/54th  we did not name planes.  There were two with names; 45-21838, the Typhoon Goon, was named in '47 or '48 by the original squadron personnel,  and 45-21824, The Thing, had the name on it when we got it from the Depot in 1950.  They started naming planes after I left in late '51.  The one's I know of were Snoopy Droopy, The Black Sheep, Dyin' Duck and Typhoon Goon II.  Goon II was lost in a typhoon 10/26/52.
       All the planes had a dedicated ground crew of its own.  Ours was 44-62094.  She flew, but occasionally got cantankerous.  We had the normal complement; four engine mechanics, a airplane general mechanic, a crew electrician  plus crew chief and his assistant.  Specialists, i.e., props, instruments, sheet metal, hydraulics, were squadron-available on a on-call basis.
       Good place to get into the (ground crew) situation in the 55th.  Sometime around the end of '51 - beginning of '52.  someone had a brain(?)storm  and Engineering was re-organized into four super crews - their terminalogy -  each consisting twelve engine mechanics and 3 apg mechanics plus a crew chief, who were available to help the dedicated crew chiefs and their assistants of three planes.  I don't know what this was supposed to prove.  When only one plane required maintenance we were falling all over each other.  When all three needed help it was no different then the full crew organization.
       I said to hell with it and went to see M/SGT "Big Al" Deemie, the Line Chief, about working somewhere else.  Big Al put me on the nose dock swing shift where nobody bothered us after 1800.  The price was being one of the two alert crewmen who were on call for bad weather during the night.  We had to check every plane for locked control surfaces, locked brakes, chocks, closed windows, etc.  But the benefit was we were excused from squadron duty details during normal duty hours.  
       The big negative of the 'super crew' system was that the mechanics had no rapport with, or pride in, 'their' plane(s).  They just jumped from plane to plane, never getting to 'know' the engines they were working on as they would have on a dedicated crew.  Most of the veteran mech's just lost interest and went thriough the motions, waiting for discharge.  Shame, because some of those people I know had planned on making the AF a career.
     
    Bob Mann
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