Have you done anything to ensure the top flange of the tank opening is flat? If there is a bend or warp, then it may prevent a clean seal of the gasket. I would be making it up to suggest a way to check; I think like a dentist, a piece of carbon paper in a block of wood slightly tapped on the open tank. Check for an ink deposit all around.
Now I admit this is a guess and I am not saying you should deposit quantities of carbon flakes in your tank. But there has to be something. Maybe a crayon on the tank flange and then paper and wood to transfer an imprint on the paper? Anyway, that is just a suggestion, YMMV and always be careful you do not accidentally contaminate fuel.
I am not sure what answer serves you best, and what I will offer will be disappointing. The FAA says that you can interpolate the performance charts, but should not extrapolate. In simpler english, you can determine a value between two known points on a chart (interpolate), but you should not try to determine a value outside the known points (extrapolate).
Consider most any of the curves we encounter, for example consider the stall speed compared to bank angle, that graph goes exponential. But any extrapolation would become a straight line extension which would be "below" the actual. That means you would think you are further from stall speed than you actually are.
Someone might have insight that can help you, I really sympathize that this can mean there are either days you do not fly or you assume a lot of risk and become a test pilot.
Actually, like I said, my A&P installed the connection to the battery with the in-line fuse. The cigarette lighter would not work because it is dead when the master is off. So the batter connection is direct to the regulator. The bottom picture shows the inside the cabin connection. I changed plugs to use those orange ones as I was able to make them more sturdy (filled with epoxy and a better grip). I left the default plug for the battery line to the regulator; I did not like two identical plugs for different purposes. I disconnect the charger when I fly. Since it is not connected, as you said, no approval needed.
It works great and in my cigarette lighter is one of those voltage display USB adapters so I can monitor that line voltage.
All done, it works great and the cord gets in the way of the headphone jack, to help make sure I remember to disconnect! (and yes, it is also in my checklist)
Parts from harborfreight.com, THUNDERBOLT SOLAR
1.5 Watt Solar Battery Charger
Put this compact solar battery charger on your car's dashboard for a steady trickle charge
Voltage Regulator $19.99
100 Watt Solar Charge Regulator
Prevent battery overcharge and discharge
I spoke to a concorde battery representative and he agreed that these 2 parts would provide a controlled trickle which would not hurt the battery. (note, YMMV)
I have had this installed for years and my battery is always strong (except when it was about 7 years old). I began using this when the battery was brand new!
I understand this is not a TSO'd addition. I asked for help from an A&P who wired the regulator direct to the battery with an inline fuse.
I did not use the cigarette lighter because it is not powered all the time.
I think this is the original B-Box in my 172M (Juliet) and I have a concorde battery. It works well. I am in a tiedown so I put a solar charger with voltage regulator on it. Keeps the battery conditioned and topped off.
The concern about the seat rail is that the hole into which the pin drops starts to wear and get wider and sloped edges. My mechanic showed me the AD and his device for measuring the wear on that hole. There are more details, but the AD did have some objective specification on what would be considered "bad". On my 1975 M model, the rails had been replaced once already, but were very worn. I was already doing some interior work and decided to replace the rails too (owner assisted). I bought rails AND the drilling guides. I was also lucky that the rails were now installed with nuts and bolts. My lessons learned:
1- get a set of new screws, do not reuse. It just can make things easier and remove any doubt or worry about old/worn screws.
2- Use the drill guides very carefully (clamp very securely to the old rails, drill through old screw holes and the guide, then clamp securely to the new rails, and drill a small hole first, then enlarge to correct size.),
3- Keep track of which rail is front or to where, they are not all alike,
4- be SUPER careful to clamp the guides to the same location on the rails (like end to end),
5- do not let the guide moving while drilling.
6- measure twice, cut/drill once.
7- put tape over one side of the wrench and use grease to secure a nut because you might find you can barely reach in to hold the nut.
Assume you will, at some point, cut you hand, the metal edges of the access holes are not perfect. and work slowly and carefully, it took me, with occasional mechanics help, about 5-6 hours to remove, drill and install. Every step was more effort than I thought.
I am glad that I will probably never have to do this again in my plane!
First, I own an M model so cannot give P specific advice. But have recently purchased another airplane let me offer some advise. It is a hot sellers market and there are many scams out there. I had one plane almost purchased until I discovered the low time engine was from a junker! Big red flags I learned were:
1- Lots of other interested people, so if you want it you have 1-2 weeks to do you diligence and buy, or lose the opportunity. Do not let the rush cause you to cut corners.
2- Lots of shops on the field with the aircraft, you may use one of them to inspect. Do not let any shop which has touched the airplane do the inspection, they are biased. Also avoid shops on the planes home field as the seller may be able to call in some debts.
3- Do not use an annual as a pre-buy. Annual checks many things for legal flight, only what is required. Other problems may exist. For example, the annual does not guarantee the radios work. Usually a pre-buy includes what an annual would cover so, for a price, the pre-buy inspection can become an annual if you make the buy. That also means that you pay for the pre-buy and the owner does NOT get a free annual.
4- If the paint is really new, it probably covers something very old. Be suspicious and look to see if the fresh paint is quality or just trying to make the plane look pretty.
Of course, if you know the plane intimately then these cautions could be relaxed. But do your diligence. The pre-buy helps you know what you are getting. My pre-buy missed that the single radio was 50Khz increments so frequencies like 133.075 or 133.025 were impossible, I could only get ###.#0 or ###.#5, so I needed a new radio immediately.
I would suggest a review of the Savvy material describing why an annual is not a pre-buy. Certainly it could be, but having seen the Savvy pre-buy list and process for a cherokee I just purchased I would say they covered stuff not necessary in an annual.
So the annual may cover 75% (my guess) of what the Savvy experts ask the mechanic to look for. When we were happy, and continuing we did have the mechanic sigh off for an annual. But I would not want to pay for an annual to then walk away from a plane that is not meeting my need/expectation.
Also, an annual is typically a all-for-one event. The Savvy pre-buy checked major things first for AD or other airworthiness issues. This is broken out as a separate fee because if the owner and seller cannot come to an agreement the process is over. No full annual price is paid. If there is agreement, then the mechanic continues with part 2 and delivers a robust report of everything found. This is not to whittle price as much as make the buyer aware. Another thing is that many components in an annual are "good or not" but being wear items an annual is all about passing (think Cessna seat rails); a good pre-buy starts to report how good. Tires worn but pass, no problem, but 5 more landings might make the fail, an annual is NOT OBLIGATED to tell you any of that and might not want to be bothered.
At this point, if the buyer leaves the deal, the owner has not benefited from an annual paid for him. If the deal continues the buy has a much deeper picture of what is being purchased.
I have owned my cessna for 8 years, assisted in all my annuals, learned a heck of a lot from both ownership and the asking a lot of questions. I have learned so much, but not being an A&P and knowing there are scammers out there right now (because it is a sellers market) I would not trust myself and was willing to pay for Savvy help.
There can be other companies, but I found Savvy and they have assisted for other things, so I trust them. And reading the published materials from Mike Busch adds to their credit. Scammers are smarter than me, so I got help.
Good luck if you go it alone. It your decision is based on costs, I suggest you rethink owning your own plane. It will cost more than you think.
They do a log review, but as a free service they do not always review logs from day 1. I think they kept us at about 5 years worth and we had to get the pictures sorted and organized for them. It is a free service so expect to have to do some work.
Yes I read the hand written log entries too. I was looking to account for all hours on the engine and determine if it was overhauled or replaced. The best way to understand what you might get in the engine is to review it from its start.
I learned a lot about buying a plane after my first. And yes, I said that right, it was not until after the purchase the I really learned a lot about buying a plane. AOPA was a big help. They have a service that got me all the records and such. I also had a lawyer who answered questions. I did not know how much I did not know, but I was very lucky. This time I applied all I know and ended up walking away from 6 airplanes all of which looked good at first.
Get copies of the logs and organize them into engine, aircraft and prop. If you are lucky there is some form of avionics log too. Once in these category type create a picture of each log entry. Name the picture "YYYYMMDD type". Now you can read the logs in time sequence and it becomes a story.
Also ask if there is an oil analysis performed on each or frequent oil changes. Those results tell a great story too. Good luck.
Split the actions of locating the plane, pre-buy inspection and purchase.
Once you locate put down a deposit and have a written agreement for refund until conclusion of pre-buy with all airworthiness issues and ADs resolved. Do not let an annual replace the pre-buy inspection. use www.savvyaviation.com/savvyprebuy/ for the pre-buy inspection process. They are a great help and super smart. They have custom lists of things to look and look out for. They have a clearly defined process and I suggest you read about it before you start your purchase. They prevented me from buying 3 different airplanes that all looked good at first glance.
There are scammers out there, I found one guy who was selling a good plane and engine until I discovered deep in the logs some discrepancy. With Savvy assistance we discovered it was not a valid log entry for the engine replacement. Turned out the owner had swapped the burned out engine with one (claimed to be low time) from a junker.
Personally, if trying to build time, I think a partnership is the most cost effective, but if you can afford your own plane, I hope you find a gem and love it a long and happy time!
in March 2019 I replaced the vertical tail beacon on my 1975 172M with a Whelan LED Beacon part # 7105500. It required the removal of the beacon resistor (my A&P did it). But I love how bright it is AND the very low current draw. Aircraft Spruce PN: 11-04541. Good luck. The PN for my A/C is C17325-Dome Flashing Beacon, C17330 gasket, C17326-clamp assembly, C17331-6 plate mounting, C17313 socket assembly, OR-95-1.5 beacon resistor, C594502-0102 flasher assembly beacon light.
My 1975 172M had about the same hours when I bought her in 2013. She has lots more now and the airframe is doing great. She had been corrosion protected at one time, but there are no signs. My experience is not to worry if everything else pans out. One other comment. I had a mechanic (who was working on my autopilot) tell me (about 3 years ago) my plane was on last legs and that they "wear out". I asked why and he showed me 2 rivets that were just beginning to fret (show wear). I nodded thoughtfully, flew home. I spoke to my mechanic who laughed. He asked me to look at planes on the field. He points to 40 and 50 year old cessnas and many others with similar or more hours. Then he said that was a scare tactic because if correct, those planes would be rust buckets.
One more thought. My engine was an upgrade performed at Air Plains. They have been very helpful to me in the past and they sell a number of parts. Try them. Also maybe one of those other engine upgrade places? They may have primer lines off a removed engine.
I have used Huber for my hose needs, and they are super helpful. I know the primer lines you ask about, I recently had to remove and clean all 3 of mine! While Huber may not have copper lines, they may be able to point you at a source. www.herberaircraft.com/markets_aviation.php#
I realized I had misunderstood what I heard. I do not think this question any longer holds value and would cancel if I knew how.
I think she has participated in overhauls. She is very familiar with auto engines. I just think this time she overstated or over thought what could happen without really thinking the practical side of a few extra seconds and how lean cruise would probably burn stuff off it any was to actually appear. I do not want to question her skill and integrity; I believe she is a great instructor. I just think this one time there is more (or I misunderstood her) and am wondering if there is any hitory of this as a problem.
Recent discussion with my instructor resulted in something I do not understand. I get what she meant, but in my over-analyzing the topic...
During mag check, I switch to right to observe the drop and then check oil temp and pressure, and then check EGT/CHT (I have monitors on each cylinder). Then I return to both and let the engine settle (5 seconds or so) and then switch left to repeat the process.
The comment was made after I hesitated for both left and right in order to check ammeter and vacuum. There is no need to check ammeter and vaccum since they are not affected by mags. I agree.
But also stated that the extra few seconds is possibly detrimental to the engine because the unburned fuel could cause carbon build-up.
My observation: if unburned fuel could cause carbon during mag check, would it have noticeable impact when I switch to the other side. I feel that a few seconds makes no noticeable difference and the next runup would pass/fail mag check and I would burn off the excess carbon. It feels chicken and egg.
Given your earlier comment, we know your oil cooler is mounted on the firewall? And there is a scat tube (probably 3 inch) which connects from the baffle to the oil cooler. Where do you have the opening in the baffle which you closed. Mine is in the upper corner behind the #3 cylinder, is that where yours is too?
I am amazed that by covering the oil cooler air intake you actually saw cooler temps. Was that due to the cooler daytime temp or the better airflow over the 1 and 2 cylinders.
If you are in an experimenting state of mind, I was thinking about a small curved baffle mounted on the upper cowling which diverts some air flow down between the cylinders. I just have a few problems trying this: 1) I am NOT an A&P and unable to craft such an appliance, and 2) I am not an A&P and regardless of what i learn I am not sure I could do anything since the plane is certified.
But you bring an interesting question, would #1 and 3 be cooler with better air flow versus a diversion of air to the scat tub and oil cooler.
So I am thinking there is another approach (have I said I am NOT and A&P?). Instead of mounting our oil coolers on the firewall, what about a baffle mount? It would force more air flow to remain inside the baffle compartment and would still give good airflow over the oil cooler. Anyone have insight on that approach?