Friday 15 March 2013

The Cessna 140


CESSNA 140


CESSNA 140
Role:Light utility aircraft
Manufacturer:Cessna Aircraft Company
Introduction:1946
Produced :1946-1950
Number built:7,664
Unit cost :US$3495 (Cessna 140 in 1946)
The Cessna 120 and the Cessna 140 are single engine, two-seat, conventional landing gear, light general aviation aircraft that were first produced in 1946, immediately following the end of World War II. Production ended in 1950, and was succeeded by the Cessna 150, a similar two-seat trainer which introduced tricycle gear. Combined production of both aircraft was 7,664 units in five year

CESSNA 140 ON TAKEOFF:
The Cessna 140 was originally equipped with an Continental C-85-12 or C-85-12F horizontally-opposed, aircooled, four-cylinder piston engine of 85 hp (63 kW). The Continental C-90-12F or C-90-14F of 90 hp (67 kW) was optional, as was the 108 hp (81 kW) Lycoming O-235-C1 engine, an after-market installation authorized in the type certificate. This model has a metal fuselage and fabric wings with metal control surfaces. The larger Cessna 170 was a four seat 140 with a more powerful engine.

CESSNA 120:
Cessna 120, built 1947
The Cessna 120 was an economy version of the 140 produced at the same time. It had the same engine as the 140 but lacked wing flaps. The rear-cabin "D" side windows and electrical system (radios, lights, battery and starter) were optional.A 120 outfitted with every factory option would be nearly equivalent to a 140, but the International Cessna 120/140 Association believes that no 120s were originally built this way. Despite this, many decades' worth of owner-added options have rendered many 120s almost indistinguishable from a 140 aside from the absence of wing flaps. The 120 was dropped from production upon introduction of the 140A in 1949.

CESSNA 140A;
Cessna 140A with the single wing strut
In 1949, Cessna introduced the 140A, a new variant with aluminum-covered wings and single wing struts instead of the fabric wing covering, dual "V" struts, and jury struts fitted on earlier models. Standard engines were the Continental C-90-12F or C-90-14F of 90 hp (67 kW), with the 85 hp (63 kW) Continental C-85-12, C-18-12F, or C-18-14F engines optional. The spring steel gear was moved 4 in (10 cm) forward, so wheel extenders were no longer necessary to counter nose over tendencies during heavy application of brakes.[1][2][5][6] Despite these improvements, sales of the 140 lineup faltered, and the 140A comprised only 7 percent of overall 120/140 production.

MODIFICATIONS:
Common modifications to the Cessna 120 and 140 include:
"Metalized" wings, where the fabric is replaced with sheet aluminum, eliminating the need to periodically replace the wing fabric.[1][4]
The installation of landing gear extenders to reduce the tendency of the aircraft to nose-over on application of heavy braking. These were factory-optional equipment.
Installation of rear-cabin "D" side windows on 120s that were not originally so equipped.
Installation of electrical systems on 120s that were not originally so equipped, allowing owners to install an electric starter, more sophisticated avionics and/or lights for night flying.
Installation of a more powerful engine. A popular conversion is to replace the original C-85 or C-90 with a 100 hp (75 kW) Continental O-200. A kit is available to install a Lycoming O-320 but this conversion is less prevalent due to a roughly 100 lb (45 kg) weight penalty and a sharp increase in fuel consumption.

SPECIFICATIONS (Cessna 140):
A typical Cessna 140 cockpit.
1946 Cessna 140 Interior
Data from The Complete Guide to the Single-Engine Cessnas[1] and AOPA Pilot
General characteristics
Crew: one
Capacity: one passenger
Length: 21 ft 6 in (6.55 m)
Wingspan: 33 ft 4 in (10.16 m)
Height: 6 ft 3 in (1.91 m)
Wing area: 159.3 sq ft (14.80 m2)
Empty weight: 890 lb (404 kg)
Gross weight: 1,450 lb (658 kg)
Fuel capacity: 25 US gallons (95 litres)
Powerplant: 1 × Continental C-85 four cylinder, four stroke, horizontally opposed aircraft engine, 85 hp (63 kW)
Propellers: 2-bladed Sensenich

PERFORMANCE:
Maximum speed: 125 mph (201 km/h; 109 kn)
Cruise speed: 105 mph (91 kn; 169 km/h)
Stall speed: 45 mph (39 kn; 72 km/h) flaps down
Never exceed speed: 161 mph (140 kn; 259 km/h)
Range: 450 mi (391 nmi; 724 km)
Service ceiling: 15,500 ft (4,724 m)
Rate of climb: 680 ft/min (3.5 m/s)
Wing loading: 9.1 lb/sq ft (44 kg/m²)

ABOUT CESSNA 140
The goal of the Cessna 140 project is to bring together a community of aviation enthusiasts to locate and photograph as many of these beautiful aircraft as possible.

Production of the Cessna 140 (and Cessna 120) commenced in 1946 and ended in 1950, with 7,664 aircraft being built.

Over the past 60+ years these aircraft have become scattered around the globe.

If you own a 140, or know where one is located, please try and submit a photo or video using the link below.

*Disclaimer: Unless stated otherwise I do not own many of the photos posted here and all credit goes to there original creators. If you find a photo of yours on here that you would like removed, please contact me and I will do so as quickly as possible.

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.

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, signaled a relatively major design improvement.


The 120 and 140
All Cessna 120s and 140s originally had fabric wings, two steel struts and completely aluminum 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.


MECHANICAL DESCRIPTION:
If 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 aluminum 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 CHARACTERISTICS:
Each 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 centerline 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.


Regards,

Jagriti Shrivastava [B.Tech ] 
Web Developer / Blog Master 

On Line Assistence :

4 comments:

  1. great work jagriti ... keep it up ..

    ReplyDelete
  2. Have gone through the blog. Packed with information, it stands out for clarity of content. All the best!!

    ReplyDelete
  3. good work. keep it up.......

    ReplyDelete