October 2012
When I was living in Vero Beach in 1965, I got a summer job at the Piper plant. I was able to take lessons in a brand-new Cherokee 140 for just the price of gas and oil, and that year I soloed in the tough, forgiving 140.
What a great plane! Sometimes I think I could have flown it without any instruction at all—not because I’m an ace, but because the plane is just a good, solid, forgiving design. In fact, on my second hour of solo time—without any training for a flapped landing—I decided to pull the Johnson bar and deploy flaps on final, pulling in all 30 degrees of flaps just as I was entering ground effect.
The plane suddenly had a whole lot of lift and rose back up into the air so that I had to land again… and again. I sure showed everyone waiting to take off what real porpoising was all about! The touchdown was okay, and I learned my lesson about the importance of training.
Working at Piper I was so impressed by the construction of the Cherokee 140, that I own a 1965 Cherokee 140 today. It’s still the same strong forgiving design, except I added a few STCs to recover some lift from the Hershey bar wing and to make a few components easier to work on. Piper should be proud of having built this plane.
Tough, but not indestructible
It’s funny though, even a tough plane like the 140 comes with some easily breakable parts, and if a pilot wants to do things right, he or she will soon see how expensive the correct airplane parts can be—including the ones that the plane could (conceivably) fly just as well without.
You can’t blame Piper for these high-priced parts, though; they have a regulatory burden on them. In fact, I was always told that if you buy a plane, find out who the best mechanic around is for your type of aircraft, and pay him or her whatever they charge to work on it. Mechanics can also advise you (and keep you out of trouble) when you’re doing your own maintenance.
However, there is a temptation for some pilots to take shortcuts with the replacement, repair or maintenance of some of those things that are good to have, but aren’t directly involved with making the plane fly.
THE USUAL SUSPECTS>>>
CARB HEAT SHROUD
Probably the first part that a Cherokee driver would rather ignore but inevitably runs into is a cracked carb heat shroud. I have seen repairs to heat shrouds that will boggle the mind. The heat shroud is made of aluminum (much like a soda can) and attaches to the exhaust manifold with a couple steel brackets to capture heat which can be redirected through the carburetor should the airplane experience carburetor icing.
The plane might fly okay without it if carburetor ice was never a problem, which puts this item in the category of a costly breakable part that maybe a pilot could save money on if he or she didn’t buy a new one. Common fixes used to prevent spending a lot of money on a new shroud include riveting an aluminum patch to correct a crack or break; using aluminum patch weld from the auto parts store; or finding an artful welder to weld the cracks and breaks in the thin aluminum.
However, if you would like to purchase a new heat shroud with a proper part number it will probably cost in the neighborhood of $1,200.
Best Practice: Since this is a safety issue, purchase a rebuilt shroud at roughly half the price of a new one.
Whether you get a new or rebuilt shroud, it will look like a shiny, clean jewel when compared to the old broken and stained one that’s been on your airplane’s engine for some time. Best not take any chances with this if you live in an area with temperatures and humidity that may produce carb ice. If you get caught in a summer rainshower, your airplane could develop carburetor icing and may need carb heat.
PLASTIC AND FIBERGLASS
Another thing the Cherokee 140 driver sees and would rather ignore are the plastic and fiberglass parts. Most everyone is familiar with the wingtips and nosebowl which seem to get cracks in the gel coat, but it’s some of the smaller parts that will give you more of a headache.
Again, some of these parts are ones that the plane could (conceivably) fly just as well without. There are plastic covers underneath the plane that cover the wing spar bolts that seem to get cracked and brittle after going through a few annuals; the wheel fairings that really take a beating if you attend a lot of fly-ins and taxi on the grass a lot; and the miscellaneous fairings like the one that bridges the gap from the tail to the fuselage can get dinged as well. All are made of plastic that by now has become somewhat brittle and likely not able to take a whole lot more.
Now I’m not a chemist, but I get the definite impression that modern plastics are of a better material and much more flexible than they were 45 years ago. I suppose there is something to be said about plastic drying out over the years also, but lucky for Piper owners, plastic parts are readily available, alleviating the temptation to use duct tape on your airplane. Duct tape does not have a Piper part number!
Best Practice: Plastic parts can sometimes be repaired, but they are part of the airplane, and purchasing new, flexible plastic parts is recommended. It’s recommended not to make the plane fly better, but I think to prevent those red flags from popping up at a ramp check. It always seemed to me that an FAA inspector/examiner would make up their mind during the first 20 seconds of examining something, so even if you are getting great maintenance, cracked plastic and duct tape will advertise the opposite and the inspector may fail the aircraft’s ground check.
CABIN HEAT BOX
The cabin heat box is sometimes ignored until it’s very cold outside. The heat box is not used much in summer, so the constant heating and cooling of the vent door may cause you problems opening and closing it the next winter.
On early model Cherokees the heat box is at the bottom of the firewall, and has an open/close door operated by a cable from inside the cockpit. At least spraying a little lubricant on the open/close door doesn’t cost anything more than a low crawl under the airplane.
Best Practice:Lubricate the heat box in the fall and open and close it a few times—but do it before winter, as it’s no fun to lie on your back on the cold ground in winter. Wear safety glasses if you don’t want an eye full of lube. Remember, the heat box is where your heat comes from, so the open/close door needs to work.
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YOKE ISSUES
The yokes on my 1965 Cherokee 140 seem to be the original ones; they have closed loops and the yoke shaft is smaller in diameter than later models. The only problem I’ve had with them is dealing with the FAA’s ADs.
I hate to be facetious because I am very safety-minded. But because someone, somewhere had a plastic yoke break there is now AD 69-22-02 involving the removal of the faceplate every 100 hours to look for cracks. This is actually an easy AD to miss, but also an easy one to comply with.
Also because a few parts got drilled too close to the end of the yoke shaft, there is a one-time (and expensive) AD 2010-15-10 to disassemble the yoke shaft connector near the inside of the firewall and look at where the hole was drilled.
Both of these yoke ADs beg the question, “If it’s worked for years and years, is there not the presumption it might have been okay to begin with?”
Best Practice: Since these are safety issues—not to mention, directives—you must comply with the two ADs. It wouldn’t do for you to be doing a high performance landing on a windy day and lose control because the yoke came apart in your hands.
Get in compliance
No matter how tough your airplane is, it’s a fact of life that there will be cost associated with maintaining your Cherokee 140—or any Piper, for that matter. And sidestepping or ignoring seemingly less important items may come back to haunt you.
Instead, try to work with your A&P mechanic to find less expensive ways to handle issues and get your aircraft back in compliance. Don’t take shortcuts; after all, even tough aircraft need love from their owners.
Doug Allen has a commercial certificate and has logged 1,500 hours since first soloing in 1965. He likes rubbing it in that he’s paid for all of his hours, except while working summers at Piper Aircraft in Vero Beach, where he flew company planes for only gas and oil. Allen owns a 1965 Piper Cherokee 140, and in fact, may have worked on his own airplane as a teenager. The 140 has been perfect for commuting from Philly to Atlanta to Oshkosh. Allen is an avid flyer of EAA Young Eagles, and rarely misses a weekend breakfast run with his pilot association. Send questions or comments to editor@www.piperflyer.com.
