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I would like to focus on two examples of a prewar antique aircraft—a restored 1938 Aeronca Chief with up exhaust and a 1939 Aeronca (Stick) Chief. The information and procedures will apply to most any prewar antique aircraft.
Aircraft Systems Engineering with a History Lesson
The first question is what the heck is an up exhaust? Well, some early versions of Aeroncas employed an up exhaust, the exhaust manifold extended upward outside the engine cowling then back down inside where it then entered the heating manifolds before exiting the bottom of the engine cowl. Each side employed one for carburetor heat and another for cabin heat. You would think the exhaust manifolds being longer would be much quieter buty it’s not—not a all.
Early versions of Aeroncas employed an up exhaust, the exhaust manifold extended upward outside the engine cowling.
The Stick Chief refers to the aircraft controls that employ a stick as opposed to a yoke.
The Stick Chief refers to the aircraft controls that employ a stick as opposed to a yoke. And why would anyone do that, you ask? In the late 1930s, then President Rosevelt, put the country on a war footing and declared the US would need 25,000 pilots. He was informed by the Navy and Army Air Core that they had neither the aircraft, personnel nor facilities to undertake the effort. To that end, civilian flight schools were pressed into service with several military officers overseeing civilian flight instructors. This was the beginning of the cadet pilot program.
The aircraft employed to meet the demand had to meet several requirements, one being the use of a control stick in place of a yoke or wheel. This was done to give the primary students the feel of flying military aircraft. There are only several Stick Chiefs still around. Records indicate this one was used as a primary trainer for about 2,000 hours.
Best $20 I Ever Spent on My Aeronca
If you would like to know where your airplane has been and who did what to it, look up its N-number on the FAA website (aircraft.faa.gov) and find the offer to access all records. Any aircraft that’s over eighty years, has been modified/ repaired/restored more than once. Your antique aircrafts airworthiness certificate was not issued by the FAA as the Department of Commerce was the governing body at the time. Your airworthiness certificate most likely is dated sometime in the mid-1950s. They made up for that when they came into existence.
Pilot’s Operating Manual/Handbook
Unfortunately, there are none. Aeronca and most aircraft manufacturers from that time felt it was unnecessary or that all the information contained on instrument marking and data plates was sufficient for operating the aircraft. While there are several “handbooks” around, they do not contain the source of the information or there is a lot of opinion on how things work. With that in mind, you’re going to have become a flight test engineer and create one yourself from a reliable source.
Log on to the FAA’s Dynamic Regulatory System website (DRS) and find the Type Certificate Data Sheet, then locate the aircraft you are operating. That section lists everything about the aircraft and variations on the model and engine, including propeller and weight and balance information along with airspeed limitations.
Those Wonderful Folks at Continental and Sensenich
Continental provides engine publication information on its website where you can find information for the A-65 Operation Manual, Maintenance Manual, Overhaul Manual and Parts.
Sensenich Wooden Propellers
Both aircraft employ Sensenich wooden propellers. All information on the care and feeding is listed on their website easily downloaded for your maintenance manual. For any additional information, contact them in person. When it came time to changing mine, it was not in bad shape but just looking tired. After placing a new one on my Stick Chief, we considered using the old one on the 1938 Chief. Sensenich recommend sending it back to them for evaluation. They would recommend one of three things:
- It was no longer serviceable and was only good as firewood or hung over a fireplace with a clock mounted in the center.
- It was servable and could be restored and refinished good as new then quoted a price.
- Recommend buying another new one.
The second one was selected and, on special order, the 1938 Sensenich decals were added. So just how old was the propeller in question? Their records indicate it was manufactured in 1956.
Where Can One Find Parts For an 80-Year-Old Airplane?
Be wary of used parts with an unknown history. Chances are they are no better than the parts you are removing.
The FAA is Here to Help
The FAA published Advisory Circular 23-27 (Parts and Materials Substitution for Vintage Aircraft). This AC provides guidance for substantiating parts or materials substitutions to maintain the safety of old or out-of-production general aviation aircraft where parts or materials are difficult or impossible to obtain.
In brief it covers two things. You can make or have made the parts you need. If you do, so you must employ contemporary practices and materials. A great example of this requirement would be that initially the wooden parts were held together by a glue that was a fish oil base which tended to crystallize and lose its adhesiveness. The fabric covering was Irish Linen covered in flammable doping process.
The original plans and drawings also called for something called “fish paper”, which I think was a brand name as opposed to the actual skin of a fish. The fish paper was like a heavy stock paper and was varnished over bulkheads structures as a reinforcement. At any rate, I am sure Aircraft Spruce does not carry it.
So, there is no Original Equipment Manufacturer (OEM) around to contact for parts? Well, there is one. There is a small rubber pad located under the tailwheel leaf spring. The OEM is a company Fabreeka, which was subcontracted to Aeronca in the 1930s. They still can provide you with that part and as the OEM so you will not need to employ AC 23-27.
Being your own Flight Test Engineer.
Some figures are going to change for each aircraft so you, as the PIC, are going to do some flight test engineering. Like any good flight test engineer, you can easily gather it together from online sources and actual flight tests and publish it in your own pilots and maintenance handbook(s). With this information and your experience flying the aircraft, you can also easily organize a check list to employ when operating the aircraft.
Flight test fuel consumption test: each time you fly keep track of the time and amount of fuel you buy to fill the tank. As the fuel quantity indicator consists of a wire on a float, it’s a good idea to know and keep track of your fuel consumption rate. The mixture control is usually conspicuous by its absence on these aircraft. The A-65 burn rate is between three and four GPH (mine is 3.1).
The oil consumption rate is given by Continental as 1/3 cup per hour. Again, changes will indicate problems. There is no oil filter, unless it was added as a field modification. The A-65 utilizes a metal screen filter. This is a must-check item on every 25 hour oil change.
If you want to gain real insight and experience in maintaining the care and feeding of any aircraft antique or modern airplane, find a maintenance shop where they allow owner assisted annual/repair.
They will put you to work on your airplane as an apprentice mechanic. The experience you gain will be the best insight to maintaining your aircraft you can ever obtain from books.
Congratulations you are now a flight test engineer.
- Flying and Maintaining Prewar Aeroncas: A Guide for Antique Aircraft Owners - March 31, 2025
- Flying during the pandemic and my approach to LAX - November 10, 2023
- No good reason to fly, but this is why I do - March 3, 2023
Re: 1st paragraph
I left the ranch in February 1942 to attend the Army Air Corps sponsored ‘civilian’ aircraft engine overhaul school at Reedley Jr. College in Reedley, California. The course was an ‘Off Reservation’ extension of the Post Schools at McClellan Field in Sacramento.
There at Reedley, I studied the basics of aircraft engine mechanics under the supervision of Chauncy Reynolds, a WWI veteran fighter pilot. Our class work included disassembly, inspection, reassembly and test-stand run-ups of a selection of WWI and 1920’s/1930’s engines. I remember, particularly, the Gnome/LeRohne Rotary, the Curtiss OX-J’s, a 180 Hisso, a Liberty V12 and a Packard V-1500 12 cylinder engine. An assortment of 4-cylinder Continentals & Lycomings rounded off the collection.
Upon completion of the 10 week course, we were transferred to McClellan Field where we were billeted in the ‘tar-paper’ barracks (shacks) of the Army Basic Training facility known as “Splinter City”. There we were given an additional 4 weeks of “Advanced Instruction” in aircraft engine maintenance & overhaul. At McClellan, we had our first exposure to the more modern engines used by the Army Air Corps. they were the Allison V-1710, the Rolls Royce Merlin and an assortment of Pratt & Whitney and Wright engines.
My brother was a mechanic in the 8th Air Force in England and France.
Re: His Aeronca
While a student at Northrop Aeronautical Institute in 1947/48, I became involved in the initial organization of the Northrop Glider Club. As the first paid-up member ($35.00) I received my first glider flight behind the then National Champion Glider Pilot John Robinson. We bought & recovered a surplus Leister Kauffman sailplane. We would trailer it out to Rosamond Dry Lake near Lancaster, Ca. (Rosamond is now a part of the USAF Experimental flight Test Base at Edwards, Ca.) There we would launch it using a 1941 Oldsmobile Hydramatic four door sedan and 3000′ of 1/8″ diameter mild steel wire. We were able to tow to 2,100+’ altitude across the dry lake bed. It was an exciting experience for everyone. On one occasion we had a visitor arrive in a Cessna. He was soon to be famous as the first man to exceed the speed of sound, the man was Captain Chuck Yeager.
I got carried away with sailplaneing & when I saw a surplus Aeronca TG-5 3-place glider for sale in the Los Angeles Times, I borrowed enough to make the $125 purchase price of the glider. It was never to be as a glider though. It took me from 1948 through 1951 to convert it into an Aeronca L-3B/O-58 65 hp. liaison version. By the time it was completed & licensed (N68759) I was working at Norton AFB in San Bernardino. It gave us many happy flying hours using sailplane soaring techniques we would work the prevailing updrafts along the San Gabriel Mountains & the San Bernardino Mins. On occasion we would fly out to the desert thru the windy & infamous Cajon Pass to El Mirage Dry Lake where the Southern Calif. Glider Club had regular soaring competitions.
My memorable experience at El mirage was a day when the dry-thermals (read that ‘dust devils) were everywhere. I decided to see how high I could get the Knocker to go using some dust devil lift. It was unbelievable, as I took-off, I spotted a giant ‘duster’, flew into it tangentially & spiraled tightly to the left. My variometer, rate of climb indicator, topped-out at the max & I was on my way to 14,600′ before deciding to cut the engine to conserve fuel. The military spec. service ceiling on the L-3 was 7,500′. I was almost twice that & higher than I have ever flown since in an aircraft of my own. After cutting the engine (a 65 hp. Continental), I soared between 14,000′ & 10,000′ for 45 minutes w/o power. It was an
experience of a lifetime. These numbers were verified by a recording barograph that I had constructed from a weather balloon radiosonde.
On other occasions we would visit my first wife’s family (& my own) up in Fairfield. In a 75/80 mph knocker,
it was about a 7 1/2 hour flight up & 7 hr.. back, with little tail wind.
Cajon Pass was always an interesting if not exciting experience. It is known for the infamous Santa Ana winds that funnel thru the pass on occasion. The ride up the canyon required sailplane techniques to avoid the worst of turbulence & downdrafts. Going up-canyon was always itchy’ but on the return from the desert side we would thermal soar to as high as 10,000′ & ride across the pass in smooth air. After clearing the rough air we had a lot of altitude to bleed-off so it was ‘full carburetor heat on’ & a rapid power-at-idle approach to the San Bernardino Airport. Many days when the prevailing wind was up-slope, we would ridge-soar the San Bernardino Mountains to Lake Arrowhead & beyond to Big Bear Lake. On days when the North wind would come up, it could be quite rough which would take the fun out of the day.
The two highest peaks in the area were Mount Baldy@ 10,500′ at the east end of the San Gabriel Range & Mount San Gorgonio @ 11,485′ at the East end of the San Bernardino range. Both of these became easy targets for the L-3. Initially, I kept the L-3 at the old Fontana airport North of Fontana on North Highland Ave. It was a short hop up to the flank of ‘Baldy’. I would top-out over ‘Baldy’ at around 11,000′, head back to Fontana, turn-off the magnetos & glide to a dead-stick landing. It was no great feat to go into Fontana ‘dead-stick’ as there were two 4000′ runways so I could set up to land on the far runway & if a bit short I would land on the near runway.
Those were the days when flying was very informal with no traffic controllers, or traffic for that matter, to interfere.
Alas, the end of the knocker came at the hands of the infamous Santa Ana wind. One night a 75 mph wind (Cajon Zephyr) roared down the pass & swept away my beloved L-3 along with many others parked at the old San Bernardino Airport. The tie-down ropes broke & it flipped up & over twisting a wing, breaking the main spar, landing upside down. I sold it for $250 to a guy who wanted to restore it. Lost track of N68759 & to this day I do not know what ever became of it.
Thanks for sharing. Nice story and experience.
love to read your story, as i have refurbished my 1939 up-stack Chief, NC23971. This chief came into family about 1950.
My Dad and Uncles had two 39 chiefs , NC23907 had up exhaust, and were use in the CPT program training during WWII.
Note, CPT is “Civilian Pilot Training”, which is on the contract Uncle Joe signed, training Navy ROTC students out of Miami U, oxford, Ohio. I came across NC31977 and bought it last yr, which Hogans bought new in 41, put some 800hrs on it first 10 months.
I was hoping you’d explain the rationale for up-stacks…haha
Aeronca fly in this year 2025, Middletown, Ohio.
A couple of comments. The yellow Chief photo is the post-war 11AC Chief which never had a stick option. Secondly, the stick option was pre-war, not due to the war. A salesman for Aeronca had a customer who said they would buy a Chief if it had a stick. He reported it back to Aeronca engineering, and they quickly drew up the plans to add a stick to the control system. As the article noted, it really never sold, so the option was quickly dropped from the sales brochures. Finally, for safety purposes, we plan for 4.5 gallons per hour with the A-65 usually. 3.1 is closer to taxi fuel burn. The A65 manual has a fuel burn vs. rpm graph. Many owners use a calibrated stick for the fuel quantity, which is more exact than the gauge.