|  Cessna 
                                    120/140
 by 
Budd Davisson, courtesy of 
www.airbum.com
 
                                    Stacking 
                                    Cessna's Littlest Against Other Classics 
                                    In 1946, when 
                                    factories were cranking-out little airplanes 
                                    like elves making cookies, Cessna didn't 
                                    want to be left behind. They had done their 
                                    own marketing studies and they too were 
                                    convinced a world awash in ex-military 
                                    pilots and GI's waving their GI bill checks 
                                    would want airplanes. Lots of airplanes. 
                                    They couldn't know how wrong they were. Cessna, however, didn't 
                                    have a design ready to go, where most other 
                                    manufactures had been cranking out two-place 
                                    training/recreational aircraft before the 
                                    war. Cessna had to start from scratch. 
                                    Although it isn't known how much, or if, 
                                    they studied the Luscombe, there are too 
                                    many configuration similarities to think 
                                    otherwise. It would have to be assumed, they 
                                    at least took note of that pre-war 
                                    airplane's size, construction and success 
                                    and took off from there. 120/140 Model 
                                    Differences.Let's start the conversation about 
                                    Cessna 120/140's off right by passing along 
                                    the phone and address of the Cessna 120/140 
                                    club. They are the people with all the 
                                    answers.
 Cessna 120/140 Club Dave Lowe-President
 Box 830082
 Richardson, TX 75083
 (502) 736-5392
 The littlest Cessnas are 
                                    not easy to tell apart and, for most of us, 
                                    it was a proud day when we finally 
                                    understood the subtle differences between 
                                    the three basic models of two-place classic 
                                    Cessnas, the 120, 140 and 140A. First of all, the 120 and 
                                    140 were initially produced concurrently. 
                                    It's unclear, however, whether the 120 was 
                                    to be an economy model of the 140 or the 140 
                                    was to be the luxury version of the 120. 
                                    However significant the marketing department 
                                    thought the differences to be in 1946, the 
                                    gap has narrowed to zero, since most 
                                    consider the airplanes to be nearly 
                                    interchangeable. The 140A, however, 
                                    signalled a relatively major design 
                                    improvement. 
                                     
                                    The 120 and 140All 
                                    Cessna 120s and 140s originally had fabric 
                                    wings, two steel struts and completely 
                                    aluminium structure. A few have had the 
                                    fabric replaced with metal in the half 
                                    century since their birth. In fact, a few of 
                                    the airplanes were even converted to 
                                    tricycle gear. Don't ask why, we don't 
                                    understand either. Both airplanes had the 85 
                                    hp Continental, although the 140 had an 
                                    electrical system as standard equipment. 
                                    These days it's seldom a 120 is seen without 
                                    an electrical system. However, it's a fact 
                                    that a straight, clean 120 sans electrical 
                                    will out fly the rest. In little airplanes, 
                                    weight is everything.
 The visual differences 
                                    between the two models include items which 
                                    only the 140 has: the rear quarter windows 
                                    and long, skinny flaps. We'll discuss the 
                                    flaps later, but they shouldn't be the 
                                    deciding factor between buying one model or 
                                    the other. Then, as if things aren't 
                                    confusing enough, a lot of 120s have 
                                    magically sprouted the quarter windows of 
                                    the 140. 140's received an 
                                    up-dated instrument panel in 1948 which 
                                    eliminated the "old-fashion" looking central 
                                    cluster of instruments. A new floating panel 
                                    spread the instruments across the cockpit. 
                                    Radios are usually mounted left of the 
                                    pilot's control yoke. Cessna 140AThe "A" model was introduced in 1949, 
                                    presumably in an attempt to jump-start 
                                    flagging sales. An estimated 525 were built, 
                                    including a small number of "Patroller" 
                                    versions with Plexiglas doors, 42 gallon 
                                    tanks (!) and a message tube though the 
                                    floor. The fuselage remained the same, but 
                                    the wings were completely redesigned for the 
                                    140A. The blunt, rounded planform 
                                    disappeared to be replaced by an even more 
                                    "modern" appearing semi-tapered shape. When 
                                    Fowler flaps were later added, these were 
                                    the wings which would be used on the 
                                    still-to-come 150s. The C-85 was replaced 
                                    with a C-90 in the 140A.
 140A wings are 
                                    stressed-skin aluminium, which eliminates 
                                    the need for the second strut. This is why 
                                    "A" models have a single, aluminum strut. 
                                    The ailerons run the entire length of the 
                                    tapered section and the tips are squared 
                                    off. The flaps were shortened, but are 
                                    several inches wider than straight 140 flaps 
                                    and seem to be a little more effective. "A" model landing gear 
                                    legs are swept forward to place the wheels 
                                    further ahead of the CG than on the earlier 
                                    airplanes. This was done to protect the 
                                    airplane from pilots transitioning out of 
                                    other two-place airplanes who had never 
                                    flown with toe-brakes. This is why it's 
                                    common to see 120/140's with steel 
                                    extensions bolted to the gear legs which 
                                    move the wheels ahead about four inches. 
                                    Many consider this to be overkill, as the 
                                    brakes have to be hit fairly hard to make 
                                    the tail come up. It's a training problem 
                                    more than a hardware design flaw. 
                                     
                                    
                                    Mechanical DescriptionIf you want to know how a 120/140 is 
                                    built, look at a C-150/152. Structurally, 
                                    with the exception of the welded steel 
                                    struts of the 120/140s, and the fabric 
                                    covered wings, they are almost identical.
 The spring steel landing 
                                    gear of the 120/140 was the first 
                                    large-scale application of Steve Wittman's 
                                    patent and it obviously worked. There have 
                                    been a few incidents of gears cracking 
                                    through the rivet holes (many are now 
                                    bolted) which hold the steel steps in 
                                    position but a simple Zyglo test will show 
                                    if there are problems there. Other than corrosion 
                                    problems typical of all old aluminium 
                                    airplanes (along the rear spars or anywhere 
                                    which can trap gravity-driven condensation), 
                                    the airplanes have been relatively free of 
                                    mechanical maladies. The most common 
                                    problems include cracked elevator hinges and 
                                    an occasional cracked rear fuselage 
                                    bulkhead. The brakes are one area 
                                    of concern. The originals were Goodyears 
                                    with floating disks held in alignment with 
                                    spring clips. They used small, round brake 
                                    pucks which have gotten terribly expensive 
                                    and many owners machine down automotive 
                                    pucks to fit (ssshhhh, the feds might hear). 
                                    A much bigger worry is the possibility of a 
                                    brake locking, if a retaining clip is lost 
                                    and the disk cocks over and gets jammed. 
                                    Converting to McCauley or Cleveland brakes 
                                    is the usual fix. Incidentally, because of 
                                    the outside storage and general age of the 
                                    airplanes, their wiring bundles are 
                                    sometimes frayed and brittle. Check all 
                                    wiring carefully. A note about the 
                                    airplane's mechanical character: This is an 
                                    airplane that responds beautifully to TLC 
                                    and elbow grease. Everything about it is 
                                    easy to take apart for cleaning and 
                                    painting. Flying CharacteristicsEach classic airplane has its own flying 
                                    personality and so does the 120-140. It's 
                                    important to remember it's a post war 
                                    design. Most of its contemporaries were 
                                    originally designed before the war to 
                                    perform on the A-50 or A-65 so they are 
                                    smaller and lighter. The C-120/140 is a 
                                    bigger airplane and is a little heavier 
                                    feeling and flying than something like a 
                                    Luscombe or a Taylorcraft. It doesn't feel 
                                    quite as much like a maple seed in the wind, 
                                    as do some of the others. Make no mistake, 
                                    however, it is still a very light airplane. 
                                    Depending on the model, they'll weigh-in 
                                    empty at 950-1000 pounds and gross at 1,425 
                                    pounds (525 pounds useful).
 
                                     The first thing you'll 
                                    notice on boarding a 120/140, is that 
                                    getting in isn't much of a hassle. Although 
                                    some purists de-cry the use of control 
                                    wheels rather than sticks, having the floor 
                                    free of obstacles does ease entry. Once in, the next thing 
                                    you notice is that seeing over the nose is 
                                    possible with only a slight stretch. With a 
                                    cushion behind them, the average-height 
                                    pilot can see the centreline without 
                                    stretching. The cockpit is slightly narrower 
                                    than the latest C-152, but about the same as 
                                    its contemporaries. This makes it fine for 
                                    the FAA-standard 170 pound pair but gets 
                                    crowded rapidly as crew dimensions increase.
 Unless converted to key start, the airplane 
                                    has a separate pull-to-start handle which, 
                                    to a pilot used to modern Spam cans, seems 
                                    unusual. Once the engine is running, the 
                                    straight exhausts are evident even at idle. 
                                    On takeoff they really bark. It's hard to 
                                    believe we all used to fly these without 
                                    headsets, as a matter of course. No wonder 
                                    we're all half-deaf.
 If the tailwheel is in 
                                    even remotely good shape, the airplane will 
                                    taxi nearly as effortlessly as a nosewheel 
                                    airplane, needing an occasional tap on the 
                                    brakes to make sharp corners. The excellent 
                                    visibility makes it that much easier. Take-off performance is 
                                    directly related to the amount of weight on 
                                    board. As with all lightly wing loaded, 
                                    low-powered airplanes, the two-place Cessnas 
                                    are different airplanes solo or dual. In no 
                                    case, however do they float off the ground 
                                    like a Cub or Luscombe. Actually, they 
                                    takeoff remarkably like a Cessna 152, 
                                    although without as much ground roll. When the tail is raised 
                                    during takeoff, the spring gear is 
                                    immediately noticeable because it doesn't 
                                    have the solid feel of a bungee gear and 
                                    "wallows" just a little. Here, it feels 
                                    almost exactly like a Citabria and for the 
                                    same reason. If the wind is on the nose, the 
                                    airplane will track almost perfectly 
                                    straight. It will, however, try to gently 
                                    turn into a crosswind. A little rudder 
                                    pressure takes care of that. If the crosswind is a 
                                    real howler, the pilot will have to work to 
                                    keep the wing down because the ailerons 
                                    don't get effective until there is a fair 
                                    amount of wind going across them. Somewhere 
                                    around 25-30 mph, they start coming alive. 
                                     
                                    The handbooks 
                                    say a Cessna 140 will climb at 700 fpm at 
                                    sea level and gross weight. There are 
                                    probably some that will do that, but most 
                                    are closer to 500-600 fpm in that situation. 
                                    As density altitude increases expect climb 
                                    to go down accordingly. Most pilots use fuel 
                                    load as the variable factor. With 22 gallons 
                                    usable and a fuel burn of only 5 gallons per 
                                    hour, leaving 60 pounds of fuel on the 
                                    ground, still gives a two-plus hour 
                                    endurance and affects climb performance 
                                    noticeably. Here again, overall performance 
                                    is in the ball park with the C-152. The climb and cruise 
                                    performance of 120/140's varies drastically. 
                                    The primary factors are propeller installed 
                                    and weight, with rigging coming close 
                                    behind. 100-115 mph is the normal range. 
                                    With a climb prop, which is good for at 
                                    least 100-150 fpm extra climb, expect to be 
                                    at the bottom of the speed range. The 
                                    cleaner airplanes with a cruise prop will 
                                    easily touch the top end, 115 mph. Weight 
                                    also changes cruise drastically. It's not 
                                    unusual for an airplane to give up 10 mph to 
                                    carry an extra person and full fuel. In cruise, the airplanes 
                                    are among the most comfortable and stable of 
                                    the breed. Visibility is excellent, 
                                    although, with your eyes just barely below 
                                    the wings, it's a good idea to raise the 
                                    inboard wing to clear before turning. Once 
                                    the airplane is "on the step" and trimmed, 
                                    it'll fly a straight line until running out 
                                    of fuel although it will ride the tiniest 
                                    thermals. Of the airplanes of its type, it 
                                    is one of the more stable cruisers, 
                                    primarily because it is heavier. It also has 
                                    some of the best over-the-nose visibility in 
                                    cruise. A headset, however, is mandatory for 
                                    comfort and hearing protection. When landing, thermals 
                                    aside, the airplane will hold approach speed 
                                    reasonably well if trimmed to it. If the 
                                    pilot tries to hold speed by hand, rather 
                                    than trimming, however, the airplane seems 
                                    to want to pick up speed. At 60-65 mph on 
                                    final the airplane gives the pilot all day 
                                    to set up the approach. Also, compared to 
                                    something like a Cub, it is a lousy slipping 
                                    machine. In fact, if you don't get the speed 
                                    down to around 65, a slip has almost no 
                                    effect. Most 140 pilots don't 
                                    bother with flaps on landing because they 
                                    have only a marginal effect. They do 
                                    increase drag slightly and kill just a 
                                    little float. 140A flaps seem more effective 
                                    and worth using. A three-point landing is 
                                    almost a non-event, as long as the airplane 
                                    touches down straight with no drift. Even if 
                                    put on crosswise, however, the airplane just 
                                    jumps and jiggles and has little tendency to 
                                    swerve quickly. This is one of the strong 
                                    points of the spring gear. It is very 
                                    forgiving of misalignment on touchdown. Even 
                                    if the airplane does decide to head for the 
                                    bushes, the rudder is quite effective and a 
                                    quick punch is generally all that's needed 
                                    to set it straight. It is only marginally 
                                    more demanding than a Cub and about the same 
                                    as a lightly loaded Citabria. Wheel landings take a 
                                    little getting used to because the airplane 
                                    seems so close to the ground. If the pilot 
                                    just tries his best to hold the airplane 
                                    barely off the ground, letting it find the 
                                    runway itself with no help from the pilot, 
                                    it will roll on smoothly. If the pilot tries 
                                    to "help" it find the ground with a gentle 
                                    push, a bounce is in the offing. Fighting 
                                    the urge to push is the most important 
                                    ingredient of a wheel landing with spring 
                                    gear. The Cessna 120/140 series 
                                    has always brought a premium price in the 
                                    two-place classic pack for a reason. The 
                                    airplane's near-modern utility combines with 
                                    a structure that can weather the elements in 
                                    outside storage better than most to make it 
                                    very attractive. This is an airplane with a 
                                    foot in both camps; classic and contemporary 
                                    and combines the best of both.  
 |