Jim Rosenow
Line Up and Wait
We owned N19795 (see cover ad) for several years. Didn't realize 'til after we sold it that it had been the original factory ad 'cover' plane. Still doing great when we passed her along.
Jim
For Sale: Aircraft 1973 Cessna 172M Good One!
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We owned N19795 (see cover ad) for several years. Didn't realize 'til after we sold it that it had been the original factory ad 'cover' plane. Still doing great when we passed her along.
Jim
Dan Thomas
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The M was the first model with the cuffed wing and the last with the bulletproof E2D engine. Last with the flap toggle. Second-to-last model with 40° flaps. Last model that could burn Mogas. It was a good airplane. Had three of them in the flight school.
Dan Thomas
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The R and S have integral tanks instead of the old separate fuel tanks. Integral tanks are just a sealed section of the wing between the spars, and the top and bottom have stiffeners inside to take the place of ribs in the tank area. Those stiffeners trap water, so five sump drains per tank are necessary. It takes at least ten seconds longer to sump both tanks. You only need a little squirt out of each one to see if there's water there. Don't need a whole jarful.
so...except for the flap toggle...perhaps the perfect 172 then!
RyanShort1
Final Approach
Personally, I prefer the K...
I like the M and N both... but I think the P model is my favorite.
Dan Thomas
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The toggle was simpler to maintain than the preselector. The toggle was an industrial DPDT center-off switch with spring return from the down position (and came with a special piece of paper that increased its value enormously). The preselect involved a lever, a cam, two microswitches, a spring, and a cable that ran up into the ceiling and connected to the flap carrythrough cable. A lot more stuff to maintain and replace and rig. Keeping it in rig was an ongoing hassle. The preselect stops were just notches in the aluminum instrument panel, and they wore off so that you had to pay attention that you didn't push the lever down too far if you didn't want full flaps all at once.
Deelee
Pattern Altitude
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Too funny this forum.
I am catching some flak on a different thread about wanting to buy a 172M as a first plane. It's the one I trained in and the one I know (and actually kinda love). Yeah, I haven't flown Arrows, Bonanzas or even 182s in my short hobby career (I have 100 hours almost.... ok 98). So maybe I don't know what I'm missing. And that these are overpriced compared to other higher performance aircraft.
The one I'm looking at is less that what this sold for, but more TT (like 9000). But still only like 900 on the engine. For about 20k less than this one sold for. They are asking $55k. Needs GPS, and maybe an autopilot but the engine, interior and paint are good. So maybe I'm not crazy. Seems like other folks like the ol' 172M as much as I do.
I am catching some flak on a different thread about wanting to buy a 172M as a first plane. It's the one I trained in and the one I know (and actually kinda love). Yeah, I haven't flown Arrows, Bonanzas or even 182s in my short hobby career (I have 100 hours almost.... ok 98). So maybe I don't know what I'm missing. And that these are overpriced compared to other higher performance aircraft.
The one I'm looking at is less that what this sold for, but more TT (like 9000). But still only like 900 on the engine. For about 20k less than this one sold for. They are asking $55k. Needs GPS, and maybe an autopilot but the engine, interior and paint are good. So maybe I'm not crazy. Seems like other folks like the ol' 172M as much as I do.
It's not a matter of not liking the 172. It's a great plane for what it's made for. But you can get a lot more airplane for the same amount of money with almost any other model. Just a fact.
Dan Thomas
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Keep in mind that the 172M is still an old airplane that can have many of the old-airplane problems other old airplanes have. Get a good prebuy on it. The weaknesses I encountered in maintaining the three we had:
The forward spar on the horizontal stab cracks outward from the center hole. It's caused by people pushing down on the stab to turn the airplane on the ground. They can also crush the nose ribs near that spot, too. I found one airplane that had its spar broken clear through, after I had ferried it. Could be a real killer.
The bottoms of the aft doorposts crack where they join the aft gear box, caused by taxiing over rough ground. Hard to see. Rear seat and doorpost covers have to come off and an inspection made from the aft side. No fun to fix, either. Cessna has a kit for it.
Some of the M's had a tendency to crack the forward doorposts at the lower hinge attachments. More repairs. It was, IIRC, due to a too-small bend radius there. It's serial-number specific, so find a mechanic with access to all the service bulletins for a prebuy. SBs are little warnings for buyers, too.
The bulkhead at the aft end of the main baggage compartment cracks near the bottom on both sides. Caused by the fuselage flexing due to yaw loads (rudder). The old airplanes without the back window were much better there. With the interior out and an assistant pushing sideways on the tail you can see that bulkhead flexing.
Tailstrikes can cause cracking of the rudder hinge brackets on the rudder itself. That big lead mass-balance weight at the top shoves the rudder down hard when the tail hits the pavement, and those brackets weren't intended to take such vertical loading. The aft bulkhead that carries the tail tiedown ring could crack, too.
Control cables wear and fray largely due to the wind moving the control surfaces even with the control lock installed. Above the headliner there are three small nylon pulleys that normally don't rotate because of the small arc of contact, so the cables skid over them and with some dirt on them they turn into little files that eat the cables. Can happen at the tops of the doorposts too where aileron and flap cables pass over the doorpost. On some airplanes there wasn't enough clearance allowed there, and adjusting the wing eccentrics to correct a wing-heavy condition can make the cable wear worse. The idler pulley on the forward aileron cable in the wing tends to seize and eat the cable. That happens to the trim cables too.
All the flight controls are often found way out of rig because some mechanics don't have the manuals or don't read them. They can make the airplane fly poorly.
The carb air box is a very expensive item that typically cracks up and the flapper valve bearings are needle bearings that ruin the shaft. McFarlane has better stuff for that. The front end has a plastic seal with rubber seal strips to stop ram air from entering the lower cowl around the intake and ruining the pressure differential necessary for good cooling. That plastic is ALWAYS busted up and it's stupidly expensive. Dynamic Propeller sells a PMA'd version made of fiberglass for way less.
The firewall cracks on both sides at the cowling shockmounts immediately below the step in the firewall, like right next to the oil cooler.
The left and right-side engine cooling baffles are two-piece affairs, with the front one lapping over the edge of the aft one. Well-intentioned mechanics see "smoking" there, caused by the aluminum sheets fretting, so they put a screw or rivet to stop the relative movement that the Cessna engineers wanted there. As the engine heats up the crankcase gets longer, further separating the front and rear cylinders to which those baffles are attached, and the screw or rivet causes a chunk of baffle to be torn out or the whole attachment to the cylinder is messed up. The better thing is to apply some PRC or silicone to one of the baffles at the overlap and let it set before reinstalling it so that the pieces aren't glued together. The PRC will stop the smoking. Or just live with it. It takes thousands of hours to eat through.
The top ends of the exhaust stacks crack near the flange where they bolt to the cylinder. That is one area I checked as soon as the cowling came off, as there was a good chance I'd find another crack and I'd have to order parts immediately. The carb heat box on the forward stack was another crack-prone item, and the screen in it would vibrate to pieces and guess where the pieces can go---into the intake. Check the left and right ends of the muffler for cracks where the stacks go into it. Acorn Welding and others have aftermarket mufflers. Welding up the cracks I would not recommend; the metal is work-hardened and thoroughly carbon-contaminated and the chromium in it forms chromium carbide on everything over time. I have seen the welds just develop new cracks right next to the weld bead. Money down the hole.
The control column tee rusts out at the lower end if water gets into the airplane and drips into the open top end of the tube. Leaky windshield on airplanes tied down outside, like. If that lower end fails you lose elevator control. Another SB, like so many of these things.
The seats and rails are a first-class wear item, and even though there's an AD on them I still found a lot of dangerous stuff. Locking pins that didn't engage far enough despite the signatures of previous mechanics certifying that everything was fine. Cracked rails. Seat back cams broken and seat back pivot hinge bolts missing their nuts and backing out. That's a lot more dangerous than it sounds. The infinitely-adjustable seats have the seat backs riding on clevis pins running against a steel cam and I used to find those worn more than halfway through, very near to breaking and letting the seat back flop right back, possibly during acceleration on takeoff. Good way to kill yourself: you'd reflexively pull yourself up using the hand on the control wheel. Use your imagination to see what happens next. The seat base on the adjustable seat has four legs made of thinwall aluminum tubing, and they crack at the tops of the machined slots where they fit over the lower base's bellcranks. Us heavy guys sliding in and out of the airplane force those things to flex sideways and they can't take it for 40 years.
There are more, but I retired a couple of years ago and not using this stuff every day tends to have it fade into the background.
If I was sent out to find a good used 172, it would be the M model I would prefer. There were an awful lot of them built and so there are plenty of aftermarket parts for them, and their faults were relatively few, though this post might make it seem otherwise. Don't be dismayed. Be realistic. The fleet is aging and many problems accumulate as annuals are sometimes too cheap and too casual so as to keep the customer coming back, or the customer keeps deferring stuff because he really can't afford the airplane. The buyer gets stuck with it if he's not careful.
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