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      pilot report the Piper Cub 
                                    
                                    
                                    
                                    Setting the Baseline...the Piper Cub  
                                    
                                    by 
Budd Davisson
                                    
                                    
                                     
                                    
                                    
                                    This sentence begins a whole new series for 
                                    Sport Aviation and the Experimental Aircraft 
                                    Association. You might call it Comparing the 
                                    Classics. Or Classics Explained. Actually, 
                                    you can call it anything you want. We call 
                                    it an educational reference for those 
                                    thinking about diving into the wide variety 
                                    of post-war classics. Since over 35,000 
                                    airplanes were produced in 1946 alone, we 
                                    certainly have plenty to chose from. 
                                    Not so many years ago, 
                                    evaluating post war classics would have been 
                                    unnecessary since every pilot had flown most 
                                    of them. That's no longer the case. Nearly 
                                    half of the pilots flying today learned in 
                                    the last 15-20 years. How many do you 
                                    suppose learned in a Cub? Or had a Cessna 
                                    120 available to rent for $8.50 an hour? 
                                    Another sobering fact: 
                                    Just short of half of the EAA members now 
                                    active joined since 1985. Nearly 70% joined 
                                    since 1980. To them the classics fall right 
                                    in with antique airplanes are just as 
                                    foreign. 
                                    The goal of this series, 
                                    which will eventually touch on each and 
                                    every airplane of the period, is to explain 
                                    those airplanes in commonsense terms. We 
                                    aren't going to get into "stick force per 
                                    "G"" or "spiral divergence" or any of the 
                                    other 3-D tech-talk we've come to associate 
                                    with well-done pilot evaluations. We want 
                                    people to understand how these airplanes 
                                    compare to airplanes they either have 
                                    already flown, or which are readily 
                                    available for comparison. 
                                    
                                       
                                    Citabria and C-152 are 
                                    the Datum Points 
                                    Since so many classic aircraft have the 
                                    little wheel at the back, we selected the 
                                    Citabria as the base-line airplane for those 
                                    handling and performance factors having to 
                                    do with ground handling. The Citabria is the 
                                    only tailwheel airplane which is readily 
                                    available at flight schools and even it is 
                                    sometimes hard to find. 
                                    We selected the Cessna 
                                    152 as the datum for all other comparisons, 
                                    once off the ground, unless otherwise noted. 
                                    The comparisons will be in the vein of 
                                    "...during roll-out the airplane tends to 
                                    wander a little more than a Citabria..." or 
                                    "...the ailerons are a fair amount heavier 
                                    than a C-152, but the airplane responds to 
                                    aileron input much more quickly..." 
                                    We'll put these 
                                    comparisons into a chart which rates a 
                                    number of performance and handling factors 
                                    against the datum aircraft. They will 
                                    represent zero and the evaluation aircraft 
                                    will be rated plus (better, easier or 
                                    quicker) or negative (worse, slower or 
                                    harder) on a scale of 1 to 5, plus and 
                                    negative. 
                                    The J-3 Cub 
                                    To kick this thing off we thought we'd 
                                    evaluate what used to be the airplane to 
                                    which all others were compared, the J-3 Cub. 
                                    There are bound to be a 
                                    lot of folks out there who are saying, 
                                    "What? Another Piper Cub pirep? That's so 
                                    basic it's like explaining dirt. Everyone 
                                    has flown a Cub!" 
                                    Only a few years ago 
                                    would have been a valid statement but go 
                                    back and look at the earlier statistics. 
                                    Between the total take-over of the tricycle 
                                    gear trainer and the exploding prices of 
                                    Cubs, with very few exceptions, if you want 
                                    to fly a Cub, these days, you have to buy 
                                    one. They have become so popular because of 
                                    three basic facts: They are very nostalgic, 
                                    they are lots of fun, they are cute as a 
                                    bug. 
                                    Mechanical Description 
                                    We're going to ignore the history of the 
                                    airplane, since everyone knows it and get 
                                    right down to the nuts and bolts. 
                                    The fuselage of the Cub 
                                    is welded steel tubing with the landing gear 
                                    being a welded "V" with external bungee 
                                    springing. The wings are attached right in 
                                    the middle of the cabin where the fuselage 
                                    truss comes together in an inverted "V". 
                                    This means the entire top of the cabin and 
                                    the windshield framing is made of 
                                    light-gage, bent steel "U" channels which 
                                    are often bent and filled with extra screw 
                                    holes. 
                                    
                                      
                                    As with all aircraft of 
                                    its type, the fuselage is prone to longeron 
                                    rust at the tail post from water running to 
                                    the low point. Remember, these airplanes 
                                    weren't always hangar queens, so most have 
                                    had, or need, repairs in that area. 
                                    Another area of corrosion 
                                    concern is the struts. The original struts 
                                    were unsealed and could rust internally at 
                                    the bottom end where moisture collects. That 
                                    problem, combined with the integrity of the 
                                    strut forks themselves, is why there's an 
                                    inspection AD on them. That's also why so 
                                    many people simply buy new, sealed struts 
                                    from Univair and be done with it. 
                                    The wings used what was 
                                    to become the standard Piper rib 
                                    construction in that they never went to 
                                    stamp metal ribs as did Taylorcraft or 
                                    Luscombe. Piper ribs are fragile trusses of 
                                    "T" sections formed by folding extremely 
                                    thin aluminium into the required "T" cross 
                                    section. They are strong, but there are a 
                                    lot of pieces involved and, once broken, 
                                    require patience to patch in a clean manner. 
                                    Wing spars come in two 
                                    varieties, wood and extruded aluminium. Wood 
                                    spars are seen in every variation from a 
                                    single plank, to laminated, to laminated 
                                    with the individual laminates made up of 
                                    different length pieces scarfed together. 
                                    Properly varnished and cared for, all 
                                    variations are fine, but need inspection 
                                    before buying. Beware grey, flaking varnish 
                                    or dark wood. This is an indication moisture 
                                    may have found its way in. 
                                    
                                      
                                    The post-war aluminium 
                                    spars are modified "H" sections and need 
                                    only be inspected for corrosion on the top 
                                    side of the lower caps which can trap 
                                    moisture. Also inspect for extraneous screw 
                                    holes. 
                                    The original leading 
                                    edges were .016, soft aluminium and won't 
                                    take much abuse before assuming the visual 
                                    character of a ploughed field. When 
                                    restoring them, most opt for slightly 
                                    heavier, harder material which makes a 
                                    tremendous difference. 
                                    Tires and brakes are both 
                                    strong and weak points for the Cub. The 
                                    original expander-tube brakes use an 
                                    inflatable doughnut to force a multitude of 
                                    small blocks against the drums. As brakes 
                                    go, they stink. That's also their strongest 
                                    point because the airplane needs almost no 
                                    brake for normal operations and the original 
                                    brakes can't overpower it. The brakes 
                                    biggest problem is that they are very 
                                    expensive to rebuild. The tubes and blocks 
                                    have sky rocketed. So have the original 8.00 
                                    x 4, smooth tires. This is one reason so 
                                    many have gone to Cleveland wheels and 
                                    brakes and 6:00 x 6 tires. That amount of 
                                    brake, however, is far more than the 
                                    airplane actually needs. With expander tube 
                                    brakes it's hard to brake it hard enough to 
                                    pick up the tail. With Clevelands it will go 
                                    over on it's back in a heart beat. 
                                    The usual engine is the 
                                    Continental A-65, which is probably the most 
                                    important thing to happen to light aviation. 
                                    This engine made little airplanes practical. 
                                    If even remotely maintained it will start 
                                    and run beautifully. Magneto coils are just 
                                    about the only reason the engines won't 
                                    start easily. TBO is a little vague, assumed 
                                    at about 1,200-1,400 hours, but think how 
                                    long it takes to put 1,000 hours on an 
                                    airplane like a Cub. 
                                    The engines are still 
                                    relatively inexpensive to overhaul mainly 
                                    because we haven't yet reached the bottom of 
                                    the barrel which was originally filled to 
                                    overflowing by the military. The bottom of 
                                    the barrel, however, is beginning to peek 
                                    through. 
                                    The most common 
                                    conversion to the airplanes is the simple 
                                    replacement of the A-65 by a C-85. The 
                                    additional horsepower makes the airplane 
                                    into an entirely different animal. It still 
                                    has its basic pasture goodness but with very 
                                    spirited performance. Unfortunately, the 
                                    85's and C-90s are getting increasingly 
                                    harder to overhaul. In fact, there is an STC 
                                    to put the more common 0-200 crank into the 
                                    C-90 case. 
                                    
                                      
                                    From a performance point 
                                    of view, a metal propeller is preferably 
                                    because it lets the engine reach peak RPM, 
                                    but the wooden prop is much prettier. 
                                    Neither is cheap. 
                                    Flight 
                                    Characteristics.  
                                    To fly the airplane, you have to get in 
                                    it, which in a Cub, isn't as easy as it 
                                    sounds. You have to master the entry-dance. 
                                    Right foot in the step, lean forward over 
                                    the front seat, left foot past the stick, 
                                    bring right foot in, lower yourself 
                                    backwards. There that wasn't so hard, was 
                                    it? The canvas sling back seat is much more 
                                    comfortable than the front seat. 
                                    Over-average height folks will be folded 
                                    like a pocket knife in the front seat. 
                                    If it's your first time 
                                    in a Cub, you'll think you're sitting at an 
                                    impossibly steep tail down angle. And you 
                                    are. Few Classics have such a tail down 
                                    stance, but the feeling of blindness is 
                                    largely one of perception. Because the 
                                    airplane is so narrow, only a small wedge is 
                                    taken out of the visual field. 
                                    Unfortunately, it's directly in front of 
                                    you. 
                                    Contact! Brakes! Mags 
                                    hot!. A good engine will catch on the first 
                                    blade. If it's your first flight, close the 
                                    door, as it causes some perceptual 
                                    difficulties because, with it open, you can 
                                    see so much better out of the right than the 
                                    left. 
                                    
                                    
                                      
                                    
                                    
                                    The first thing you'll notice in manoeuvring 
                                    on the ramp is how hard the stupid heel 
                                    brakes are to get at because they're 
                                    snuggled under the seat. That's good. That 
                                    way you won't be tempted to use them on 
                                    landing where they aren't needed. 
                                    "S" turns are absolutely 
                                    necessary to see ahead, but they also give 
                                    you rudder practice. For some reason, maybe 
                                    it's the light tail, the Cub is quicker to 
                                    respond to the rudder than most light 
                                    taildraggers, including the Citabria. It's 
                                    only a minor difference but noticeable. On 
                                    takeoff and landing it makes it a little 
                                    easier than some to over-control. 
                                    By all means, do a full 
                                    360° turn to clear the pattern before 
                                    taxiing onto the runway. The pilot sits so 
                                    far back in the airplane vision is sharply 
                                    limited by the narrow tunnel of the fuselage 
                                    and the wings and a full turn is mandatory. 
                                    Lined up, suck the stick 
                                    back and move the throttle smoothly forward. 
                                    The noise turns into kind of a rattling roar 
                                    and the airplane will begin accelerating at 
                                    about the same rate as a heavily loaded 
                                    Cessna 152. As soon as the power is full on, 
                                    ease the stick smoothly forward and bring 
                                    the tail up. If you're of average height you 
                                    won't quite be able to see over the nose but 
                                    the visibility improves drastically anyway. 
                                    There is so much airplane between you and 
                                    the outside world, there is no doubt when 
                                    the nose tries to move. 
                                    The rudder becomes 
                                    effective as soon as the power is on and 
                                    you'll notice the tail moves each time your 
                                    foot does. The airplane is very stable 
                                    directionally. In fact, if there is no 
                                    crosswind, the tail won't move sideways on 
                                    its own. If it is, stop moving your feet for 
                                    a second to see if it isn't you causing the 
                                    movement. 
                                    Even on a calm day, the 
                                    Cub will fly off the ground long before you 
                                    can get in serious trouble. If there is just 
                                    a few knots of wind on the nose, it'll leave 
                                    the ground almost as soon as the tail is up. 
                                    Solo it leaps off. Dual it takes much 
                                    longer. The airplane really reacts to extra 
                                    weight. 
                                    
                                    
                                    A Cub 
                                    telegraphs everything it does, especially 
                                    when it is getting too slow to climb. Play 
                                    with the speed a few knots at a time, while 
                                    climbing, and you'll find a point where you 
                                    can actually feel the drag building, control 
                                    effectiveness falling off and the climb 
                                    slowing as the nose is brought up. Every Cub 
                                    likes a slightly different climb speed, 
                                    usually because the airspeeds are so far 
                                    off, so just feel it out. 
                                    
                                    With one on 
                                    board, a 65 hp Cub in 75 degree air may give 
                                    as much as 400-500 fpm. 85 hp adds at least 
                                    another 200 rpm and a C-90 makes you feel 
                                    like you have a fly-weight tiger by the 
                                    tail. The increased power is also very 
                                    noticeable on takeoff acceleration. 
                                    As you level off and the 
                                    speed rockets ahead (read that with a lot of 
                                    sarcasm), be suspicious of any speed above 
                                    80 mph indicated. 75 mph is a pretty 
                                    standard Cub cross-country speed. 
                                    The controls in a Cub set 
                                    the standard for most of the long-wing 
                                    Pipers to follow. There's a fair amount of 
                                    system friction because everything is cable 
                                    and pulley operated. These days the friction 
                                    is almost always aggravated by at least one 
                                    pulley that isn't turning. The friction 
                                    helps build the perception that the aileron 
                                    forces are heavy, but they really aren't. 
                                    The airplane responds very much in 
                                    proportion to the amount of stick put into 
                                    it and will actually roll into a bank much 
                                    faster than people expect, if they put their 
                                    shoulder into it. The pressures are much 
                                    lighter and the response higher than a 
                                    Citabria, for instance. Compared to a C-152, 
                                    they are about even, although it's hard to 
                                    compare pressures between a stick and a 
                                    yoke. 
                                    Elevator pressures and 
                                    rates are matched to the ailerons and you 
                                    won't even notice the rudder because it 
                                    mixes in so naturally. And you will need 
                                    rudder. The airplane has noticeably adverse 
                                    yaw and the pilot who doesn't coordinate 
                                    will polish the bottom of his jeans smooth. 
                                    That's one of the things that makes it such 
                                    a great trainer 
                                    Stalls in a Cub can be 
                                    what you make them. Normally, they are soft 
                                    and floppy with very little edge to them. 
                                    Feeling goes out of the controls in such a 
                                    noticeable fashion, as the stall approaches, 
                                    your hand will tell you something is 
                                    happening, if nothing else does. If you have 
                                    the door open, the bottom half will begin to 
                                    float up as the stall is approached. If you 
                                    crowd the stick back hard or persist in an 
                                    exaggerated nose-high attitude, it will 
                                    pay-off, drop the nose and make you light in 
                                    the seat. 
                                    Coming in to land, power 
                                    back opposite the end of the runway, you 
                                    risk a stretched muscle as you lean forward 
                                    trying to get the carburettor heat on the 
                                    right side wall by your foot. Crank, crank 
                                    the elevator trim and the airplane will hold 
                                    an approach speed of 60 mph by itself. It 
                                    can fly the approach much slower, but 
                                    there's no reason to. 
                                    The Cub is dirtier than 
                                    most of its contemporaries so its glide 
                                    slope is a little steeper. It comes down 
                                    even faster than a Citabria or 152, but at 
                                    such a slow speed, the pattern is still not 
                                    super-tight or rushed. Also, there is no 
                                    such thing as "too high" in a Cub, as it is 
                                    one of the best slipping airplanes ever 
                                    invented. 
                                    A secret for getting 
                                    consistent, good landings: Break the glide 
                                    just a little higher than you think you need 
                                    to. If you fly it into ground effect 
                                    expecting to burn off speed and three-point 
                                    it, you'll almost certainly touch the mains 
                                    before getting the tail down. For some 
                                    reason, Cubs appear to have less ground 
                                    effect than many airplanes. 
                                    The nice thing about a 
                                    Cub landing is that it happens at a 
                                    near-walk. Actual touch down is around 35 
                                    mph, so even if your technique is sloppy, 
                                    everything is happening so slowly you have 
                                    all day to set it straight. If you don't 
                                    have much tailwheel time, try not to think 
                                    about it. Get the airplane on more or less 
                                    straight and it will roll more or less 
                                    straight. Start fighting the rudders simply 
                                    because it's a taildragger and you think you 
                                    should be doing something, and it will do a 
                                    slow motion dance. Best advice in landing a 
                                    Cub is to make sure it is straight and not 
                                    drifting and leave it alone after touch 
                                    down. There's a reason for the saying 
                                    "...lands easy as a Cub..." 
                                    
                                    
                                      
                                    
                                    A word about 
                                    crosswinds and gusts: The airplane is really 
                                    lightly wing loaded and rides thermals and 
                                    gusts like a cork. It will, however, handle 
                                    much more crosswind than most think it will, 
                                    providing the pilot has a firm hand and a 
                                    good head. It can, however be overwhelmed. 
                                    Winds which are an annoyance in a 152 are a 
                                    challenge in a Cub. In a pinch, diagonal the 
                                    runway, or turn into the wind at the end of 
                                    roll-out. Then you have to worry about 
                                    taxiing. It's entirely possible to land in a 
                                    wind which is too high to taxi in. In that 
                                    case, keep the nose into the wind and wait 
                                    for help to walk you in. More than one pilot 
                                    has had to coast past the hangars at fifty 
                                    feet with the door open and the throttle 
                                    back while yelling for help before landing. 
                                    One common J-3 variation 
                                    seen, by the way, is the Reed Clipped Wing 
                                    conversion which removes 40 1/2" from each 
                                    wing root. To many, this makes a good 
                                    airplane even better. Besides making it 
                                    capable of loop, roll, spin, type of 
                                    aerobatics, with 85 hp, it will cruise at 
                                    nearly 90 mph and its entire handling 
                                    package tightens up, becoming quicker and 
                                    more crisp. It will also handle much more 
                                    wind with the short wings. 
                                    Market forces almost 
                                    always place a price premium on products 
                                    which have proven themselves both in 
                                    aesthetics and use. No where is this more 
                                    obvious than in the J-3 Cub, as it is easily 
                                    the most expensive airplane in its category. 
                                    This is a distinction many believe to be 
                                    well deserved. 
                                    
                                    
                                     
                                    
      
        
                                                
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