30 OCTOBER 2011

Several months ago an early-20s young man approached me, asking if I would teach him to fly in his own air-plane. Before agreeing, I in-

quired as to what type and model of aircraft he owned. His reply was, “I don’t own it yet, but I’m travel-ing to the West Coast to look at one this weekend.” To protect the inno-cent, and in this case, the not-so-innocent, I won’t divulge the type and model here. It was a classic tail-wheel aircraft powered by a Conti-nental engine.

I asked if he had done a prepur-chase inspection, and he had not. Rather, he mentioned that a good friend who flew tailwheel airplanes was making the trip with him and would look it over. If the purchase was made, they would fly the plane back to Wisconsin. I strongly suggested he have a thorough prepurchase inspec-tion done by someone who knows that type of aircraft. I even offered to help locate a reputable A&P/IA who could do the inspection. But he was quite self-assured that he and his friend would be able to handle ev-erything. After all, the current owner had provided him with photocopies of the logbooks and at least a dozen photos of the airplane, and it sure looked good in the photos.

Five days and 17 hours of flight time later, the two fellows arrived at Hartford with the “new” airplane. The next day we began flight train-ing in the aircraft. The first problem encountered was with the pull-type starter—it wouldn’t engage. I pulled it through by hand and didn’t hear

any rubbing or grinding noise, so I started the engine by hand-propping. I suggested we have the local A&P look at it at flight’s completion, which the owner agreed to do.

After starting and ensuring we had a good oil pressure indica-tion, we began to taxi around on the airport ramp. I like to have stu-dents learn ground handling by doing some figure “8” maneuvers before taxiing to the runway. The

aircraft had what appeared to be a relatively new Scott 3200 tail wheel installed. While attempting to do the “8’s,” we found the tail wheel did not properly respond. Full rud-der application, assisted by a lot of brake pressure, was required to get the airplane to turn as desired. I then suggested that we have the A&P check out the tail wheel, too.

Following 15 minutes of taxi prac-tice, we made our way to the runway. Flight systems were checked along with a magneto and carb heat check. All seemed to be normal. We aligned the aircraft with the runway center-line, established our diagonal line of sight, smoothly moved the throttle to full power, and began the takeoff. Once airborne the airplane would barely climb, and this was a 60º day

with a 10-mph breeze on our nose. I again suggested that we do some checking when we get back on the ground and find out which prop was installed. The new owner had been told it was a cruise prop and to not to be alarmed at the slow rate of climb.

After reaching a safe altitude for conducting air work, I suggested we trim the airplane for level flight and run it at full power. This would tell us what indicated airspeed we were getting, as well as the maximum in-dicated rpms. Neither seemed to be correct. For this aircraft we should be seeing 115 mph and 2575 rpm, but we were only getting about 90 mph and 2350 rpm. I then suggested we include a GPS and an electronic tach checker on our next flight to deter-mine accuracy of the airspeed indi-cator and tachometer.

After completing the flight, we hangared the airplane and began a more thorough review of the log-books. They indicated that the prop installed was a cruise prop. How-ever, after the A&P removed the prop spinner skull cap, we found that the prop was a climb prop, not match-ing the logbook prop installation en-try. The engine logbook entry also showed that the cylinder compres-sion was good on all cylinders, but one was a little less than the other three. Further checking found that this cylinder had been less on the previous three compression checks.

The next day’s flight included a GPS check along with a tachom-eter check. The airspeed indicator was correct but the tachometer read about 125 rpm slow.

BY Steve Krog, CFI

THE Vintage Instructor

Buying an airplane andletting emotion control the decision

But he was quite self-assured that he and his friend would be able to

handle everything.

VINTAGE AIRPLANE 31

It was time to put the plane in the shop and do some serious checking, as well as correct the pull-type starter and tail wheel. The A&P found the pull-type starter arm to be so badly worn that it couldn’t depress the starter solenoid button. Thankfully, he had a good used starter arm and replaced the worn arm. Now the pull-type starter would engage; one problem cured.

Before inspecting the tail wheel, the A&P next used a borescope and looked inside the weak cylinder. Af-ter the inspection, he just shook his head and stated the cylinder had to come off, which he did. The finding was even worse than expected. Two rings were broken and one ring was completely missing. The cylinder wall was badly worn and the wrist pin caps had cut deep grooves in the cylinder wall. It was junk. Did the last owner forget to install one ring, or was it ground up and scattered throughout the entire engine? A short ground run followed by removing and inspecting the oil screen during a prepurchase inspection would probably have iden-tified this problem!

The oil screen was removed, but there was no sign of metal particles in the screen. So the mystery deepens. Was the missing ring ever installed?

The A&P then recommended re-moving the other three cylinders for a close inspection. While waiting for the owner to give the okay, the A&P turned his attention to the tail wheel problem. Two problems came to his immediate attention. The Scott 3200 tail wheel was not approved on this aircraft without first install-ing a heavy-duty leaf tail spring. This modification had never been done. Further, the leaf tail spring was bent, preventing the tail wheel from proper travel and unlocking as it was meant to do. Either a new smaller tail wheel was in order, along with a new leaf spring, or the heavy-duty leaf tail spring assembly would need to be purchased and installed.

Due to the potential for addi-tional airframe stress the “new” tail wheel may have created, the A&P closely inspected the tail section of

this aluminum-frame aircraft. No stress cracks were found, but signifi-cant amounts of surface corrosion were discovered. It was not enough to yet make the aircraft unsafe, but it was enough so that the corrosion would need to be dealt with to pre-vent further deterioration. Again, this could easily have been spotted in a good prepurchase inspection.

The owner agreed to have the A&P treat the corrosion as well as purchase the proper leaf tail wheel spring assembly to accommodate the Scott 3200 tail wheel.

Following some discussion about the engine, it was agreed to pull the remaining three cylinders. Close inspection indicated that at one time the cylinder walls were rust-covered. The rust was scraped clean, but there was a lot of pitting found in the walls. These cylinders had ap-proximately 800 hours’ time since new. A complete top overhaul was agreed upon, and the cylinders were sent to a nearby engine shop.

Unfortunately, this new airplane owner/student pilot has learned and experienced a very expensive and valuable lesson. Lack of knowledge coupled with a strong emotional pull toward this particular airplane has caused him a great deal of ad-ditional incurred expense, extended downtime, and plenty of frustra-tion. And much of this could have been prevented.

Being directly involved with three different classic aircraft type clubs, I get calls almost daily from individu-als about to buy an airplane. Here is what I suggest to them:

• First, are they familiar with the type and model of aircraft they de-sire to purchase? If not, definitely obtain outside assistance before making the purchase.

• Next, do your best to remove the emotional desire to purchase this airplane. This can be very dif-ficult, but there are other aircraft of the exact make and model out there. Don’t get attached to the first one you think looks good.

• Make arrangements for a pre-purchase inspection. I can usu-

ally provide them with one or two names of individuals in their geo-graphic area who could perform the inspection. I strongly recommend prepurchase inspections!

• Conduct a title search. If buying an airplane out of your geographic area, this is a must. One does not want to find out, after money has been exchanged, that a lien has been filed and not satisfied on this airplane. It will prevent getting a clear title until the lien is satisfied.

• Contact the FAA to obtain a CD containing all of the FAA recorded files on this airplane. This will usu-ally take about 10 days. One may find these records do not coincide with the aircraft logbooks, especially if the logbooks have been “lost” and new logs have been created.

• Contact an insurance company to get a quote on this type of aircraft.

What do they require for flight time to obtain coverage? Costs can be significantly greater from one type of aircraft to another. Don’t be surprised after the purchase.

• Locate a qualified instructor to assist with getting checked out in the airplane.

If these questions and checklist items can be answered satisfactorily, and the aircraft is found to be both legal and mechanically sound, then by all means move forward with the purchase and begin enjoying the pleasure of general-aviation flight.

Don’t do like my student did, and find out how expensive an aircraft can be after the initial purchase!

To request a CD of the aircraft records from the FAA, visit its web page at:

http://aircraft.faa.gov/e.gov/ND/Or you can write to the FAA at:FAA Aircraft Registration Branch, AFS-750P.O. Box 25504Oklahoma City, OK 73125-0504Phone: 866-762-9434You can also find them on the Internet at www.faa.gov.The cost generally is $10 per CD; rarely is there more than one CD for the air-craft. The records have been scanned and saved as PDFs.