Buying a Decathlon

[Solari]

I'm in the market for a decathlon. An ad was posted recently for a 2012 ACA Decathlon located near me that has my eye.

It appears that the aircraft has been used almost exclusively for aerobatic training since new. Both the airframe and engine are at 1200+ hours.

Is there anything I need to watch out for with a Decathlon that has been used extensively for aerobatic training? I'm sure that puts a relatively high toll on the airframe and engine even if it's flown within limits, and I would assume student pilots have made mistakes. Any info on potential problem areas would be greatly appreciated... I'm hoping to avoid any big ticket maintenance items in the first few years.

 

[BB57]

I'm in the market for a decathlon. An ad was posted recently for a 2012 ACA Decathlon located near me that has my eye.

It appears that the aircraft has been used almost exclusively for aerobatic training since new. Both the airframe and engine are at 1200+ hours.

Is there anything I need to watch out for with a Decathlon that has been used extensively for aerobatic training? I'm sure that puts a relatively high toll on the airframe and engine even if it's flown within limits, and I would assume student pilots have made mistakes. Any info on potential problem areas would be greatly appreciated... I'm hoping to avoid any big ticket maintenance items in the first few years.

Honestly, I'd pass on that one. A 2012 Super Decathlon will probably be in the $175,000 -$200,000 range and if not, ask "why?".

It's got 1200 plus hours of apparently almost steady acro use. The TBO is just 1600 hours. Flown right side up most of the time it's a 2000 hour engine. However with the thermal stresses and gyroscopic loads from a steady diet of acro flight, it might not even make TBO. That's a large expense on the horizon and the sales price needs to reflect the cost of an overhaul in the very near future.

The current operator has been making money with it, so the big question is why are they selling it? I'd suspect they are concerned about the upcoming overhaul and/or other deferred maintenance that makes it more economic for them to sell it.

Realistically, you can find a Super D fully restored around the same time that 2012 was made, with a low time engine and prop for around $80K-85K. For example, this one was rebuilt in 2011. It has the same dated Airtex interior (right down to the fabric and colors) as my 7KCAB, and has wood spars, and steel rather than aluminum gear, but otherwise it's not giving up much of anything to a 2012 and has probably been abused a lot less. The $100K or so you'd save on the purchase price buys a lot of fuel and maintenance. You could have it re-winged with new ACA metal spar wings painted to match and still save $70K. Add new aluminum gear and you'd still be $62K ahead.

https://www.barnstormers.com/classified-1602561-1978-Bellanca-Super-Decathlon.html

Back in the day fabric on the belly used to be an issue, lasting only about 400 hours of acro when the design was new. However, changes to the formers and tapes have more or less eliminated the issue. Still, check the fabric carefully in high stress areas.

Fuel tanks historically have not stood up well to snap rolls and they require removing the fabric over the tanks to replace them. Look carefully for any indications of fuel leaks that might indicate replacement is looming.

Take a close look at the fuselage fabric and underlying tubing around the main gear. Decathlons and Citabrias can take a beating in this area from student landings. Cross check to ensure that the gear do not look bent and that each wingtip is the same distance off the ground. If the gear look symmetrical side to side but the wing tips are at different heights on level ground, something is bent in the fuselage tubing, and it's an expensive fix.

 

[Bob Turner]

Agree. If you have the bucks for a 2012, find a restored and overhauled 1978, and put the many, many $ saved toward annual spar inspections and new avionics.

I would go for the aluminum gear mod, but not for metal spar wings. Those machined lift strut fittings scare me.

 

[Big Ed]

I'm gonna take the opposing view on this.

There are a finite number of airworthy Decathlons out there. 800 or so, I believe. The odds of finding a perfect aircraft with no concerns at a fair price is nearly zero, unless you buy from the factory, and IMO the factory price is not fair. If you want to not buy a plane, you will always find a reason to scare you away. If you want to buy a plane, just make sure it is priced correctly to address your concerns.

Every Decathlon in the fleet has been used for aerobatic training. That is what they are designed and sold for. Is it possible you will find one owned by a little old lady who only flew it for $100 hamburgers on Sunday? Maybe, but I doubt it, and then you would need to be concerned about the engine sitting.

I would have zero concerns about 1200 hours of aerobatics. I would be a LOT more concerned about an airplane with 40 years of unknown usage history than an 8 year old plane where you know exactly what it has been doing. I would also have less concern about a trainer used in a school environment with competent instructors supervising proper technique, as opposed to some yahoo backyard fighter pilot overstressing it because he learned from the internet.

I do concur the engine is probably ready for a rebuild, but that's not a reason not to buy. Just make sure you add $20-$25K to your budget and make sure the price reflects it.

The other two big concerns are addressed. 8 year old fabric and paint should be in great shape. And you got metal wings. So your only unknown is the engine. Price it as a worst case known and make the deal if you can afford it.

 

[Bob Turner]

That is what is great about this place. We can politely disagree.

I bought my 1977 Dec in 2003 - great cover, lousy interior, 1000 hr. engine and prop. $42K, and it needed a $3000 prop hub. I added an interior and a glide slope receiver, and since then have had very few problems. I did re-do the mags in 2017, and both fuel pumps have been rebuilt. This year I rebuilt the brake masters. It did get aluminum gear, and I think they were well worth the effort and expense.

So, at least in 2003, it was possible to buy a near perfect 26 year old airplane. And except for the engine, it is still near perfect. An engine overhaul would put me at the $80K invested point. Unless I do it - I might be able to overhaul it myself for $20K. I would want an AD-free crank . . .

 

[Big Ed]

The notion of a "restored" older plane is very appealing. But there are not many out there. And you are going to pay for those, because restoration is not cheap. That assumes you are even getting a true restoration, as opposed to a Strip-IRAN-Recover.

Far more planes are like the one I just bought: 40 year old aircraft with original fabric and paint, perhaps a recover in the last 20 years or so, and the owner is nursing it along. Many are going to have some kind of minor accident history, like a prop strike due to noseover or overcontrolling a wheel landing. Many are going to have vague flying histories once you get back past 20 years or so. In all likelihood the original owner and mechanic of a 1970's aircraft are dead.

I got a hell of a deal on mine, $45K, but I also got an engine that sat for several years, a wood spar with unknown accident history (though logs are clean), a 40 year old cover job with more patches than Maverick's flight jacket, and who knows what condition the steel tubes are in. A factory restoration with metal spar wings would run 75-100K. A strip and recover with wood spars would run 25-50K. If you find an aircraft under 100k, you are probably getting the latter. Over the next 5 years I expect to recover the fuselage and rebuild the engine . I am still mulling my options on the wings and spar. I prefer wood spars, and I definitely prefer the price, but the resale market does not.

 

[Hiperbiper]

Added to the "expensive things to check" list should be the prop...depending on type/model the inspections can be costly.

 

[BB57]

I d

The notion of a "restored" older plane is very appealing. But there are not many out there. And you are going to pay for those, because restoration is not cheap. That assumes you are even getting a true restoration, as opposed to a Strip-IRAN-Recover.

Far more planes are like the one I just bought: 40 year old aircraft with original fabric and paint, perhaps a recover in the last 20 years or so, and the owner is nursing it along. Many are going to have some kind of minor accident history, like a prop strike due to noseover or overcontrolling a wheel landing. Many are going to have vague flying histories once you get back past 20 years or so. In all likelihood the original owner and mechanic of a 1970's aircraft are dead.

I got a hell of a deal on mine, $45K, but I also got an engine that sat for several years, a wood spar with unknown accident history (though logs are clean), a 40 year old cover job with more patches than Maverick's flight jacket, and who knows what condition the steel tubes are in. A factory restoration with metal spar wings would run 75-100K. A strip and recover with wood spars would run 25-50K. If you find an aircraft under 100k, you are probably getting the latter. Over the next 5 years I expect to recover the fuselage and rebuild the engine . I am still mulling my options on the wings and spar. I prefer wood spars, and I definitely prefer the price, but the resale market does not.

The bit in bold sounds good in theory but the reality is that you'll get back between $0.30 and $0.50 for every $1.00 you put into a rebuild.

Let's look at a real world example and look at costs to rebuild, versus sales prices for the rebuilt aircraft.

I paid $60K for my 7KCAB last winter with a 2007 rebuild, ACA metal spar wings and spades, and 154 SMOH, 154 hours on a new prop and a rebuilt exhaust. The wings with spades and heavy front struts will run around $30K painted and ready to hang. An overhaul on a IO-320-E2A will run about $25K. A new prop is $5K and a rebuilt exhaust is about 1.5K. That's a total of $61,500.

In the case of my 7KCAB, the previous owner lost about $3K in total after paying for a major overhaul, new prop and exhaust system ($31.5K total) that he put into an aircraft that he purchased for $30,000. He also ended up paying $1600 on the agreed upon annual (where I covered the first $1K in lieu of a formal pre-buy and I did my own on site inspection and identified some critical items to be addressed in the annual).

The owner before him, spent about $18K on ACA wings, and $15K on the rest of the rebuild in 2007. He retained the old interior, but the airframe itself was well done. I have no idea what he paid for the plane originally, but he clearly 'lost' money when he sold it in 2014 with a run out engine making metal. How much he "lost" arguably depends on how much he flew it in that seven year period.

-----

My goal in selecting a 7KCAB to purchase was to find one with recent fabric and a low time engine, that would not need any major money poured into it for several years. That's basically what the OP said he is looking for with the exception that he's looking for no major maintenance for "the first few years".

So far, I'm on track. The oil analysis reports keep looking good and I've put about $2,800 into the aircraft since I bought it. That includes mostly expected improvements and/or known deficiencies like an engine analyzer, a vertical card compass to replace the broken wet compass, new belts and shoulder harnesses, and new tires and tubes. The only unexpected issues I've had were an already adjusted to its limits transponder, which I replaced with a used transponder from the shop that attempted to recert my old one, and a broken brake clevis. Normal stuff on a 53 year old aircraft.

-----

If I had money to burn, I'd look at a gently used 5-10 year old aircraft. But as it is, I've got less than $63K spent in total as opposed to $150K to 200K and that money I didn't spend up front (and the interest it is earning) will pay for a lot of future maintenance and improvements on my solid, reliable, nice looking, $60K aircraft.

 

[Bob Turner]

Older Decathlons have the old Hartzell HC-C2YR-4BF. If the hub AD has been complied with, you should be ok. I don't know anything about the 3-bladed or MT props.

 

[Big Ed]

... the reality is that you'll get back between $0.30 and $0.50 for every $1.00 you put into a rebuild.

I agree with everything you say. You clearly bought well. But planes that fit your description are hard to find. Your statement above explains why. People know they are going to lose money on a rebuild, and they are going to lose money on metal wings. So they don't do it, not if they have an expectation of selling in the near future. Restored Decathlons with metal wings and low time engines for a reasonable price are pink unicorns.

The OP's plane could be a very good buy. It all depends on price. The reduced value of the high time engine is easy to compute, and easy to fix. The rest of the plane checks all the boxes for someone who just wants to fly.

His main concern was "is 1500 hours of aerobatic training too high for the airframe". IMO the answer to that is no.

 

[Solari]

Thank you for the thoughtful replies everyone. It is very helpful to get all of this insight and hear your opinions. Something appealing to me about the newer planes is the normal category gross weight increase. This will be my only airplane and I plan on using it for the occasional xc. The extra 150 lbs will help a lot if I bring a passenger with me - I like to be by-the-book when it comes to weight and balance. I've seen a couple older restored and upgraded decathlons with the gw increase, but they are few and far between.

One new piece of information - the plane had an over-G event in its first few hundred hours. I don't yet know all of the details, but I'm told that it was thoroughly documented and that repairs and inspections were coordinated with the factory. Is this something I should be significantly concerned about? Anything I would need to pay extra attention to during the pre-buy? I imagine there are older planes out there that have blown through limits and not reported it, so at least I feel like I have a good idea of what I am buying.

It also had a minor prop strike. This seems pretty common based on the ads I've seen.

The price is very competitive. A pristine 2012 would be out of my budget, which makes this one very tempting.

Thanks again for the help!

 

[Big Ed]

I'm not an A&P or IA, so take my opinions with a large bag of salt grains.

IMO, as an aerobatic aircraft gets older, the odds of it having an over-G event approaches 100%. The question is whether those events were reported and addressed. I would bet 95% are not. The pilot resets the meter and tells nobody. So would you rather have a known event that was IRAN, or would you rather have unknown, unrecorded events?

Keep in mind an aerobatic airplane rated for 6 G must be engineered to withstand 9 G. I believe the structure must be failure tested to that load as part of certification. They literally turn the airplane upside down and stack sandbags on the wings until it breaks. So the fact that your plane has been recorded as going past 6 G is not some inherent blemish. Like I said, I'll bet mine has too, I just don't have it logged.

Having said that, the entry is going to be in your logs forever. It will affect resale value. I would certainly read the logbook entries closely, ask an IA for advice, and perhaps call the factory for an opinion. It's not a show stopper, but should be priced into the deal. Sounds like it is.

As for the prop strike, good luck finding a plane without one. Especially a taildragger. Most especially a Decathlon. Put it this way. I have flown 4 Super Decathlons. 3 of them have prop strike history, either a taxi nose-over or over-corrected wheel landing. That includes the one I bought last month. There are well established tear down and IRAN procedures for prop strikes. As long as that was done correctly by a reputable engine shop, I would have zero concern about that. Again, as long as it is priced into the deal, which it sounds like it is.

The gross increase is very nice. At 1800 pounds max gross, I can carry a passenger and 12 gallons. With just myself and a full tank of gas, I am over gross at takeoff. Never mind my aircraft will climb to pattern altitude by the end of the runway. If you fly a wood winged Super D, you have to get comfortable with the fact that you are going to be over gross. If that bothers you, then grab the metal winged bird while you can.

(sidebar: I read somewhere that gross weight was in part determined by a drop test. The aircraft was loaded with weight, raised 6 feet, and dropped on the gear. When the prop touched, they subtracted a buffer and that was the gross. Or something along those lines.)

 

[BB57]

Yes, the gear comes into play as well, and a gross weight increase involves both the wing spar and the landing gear. I believe ACA moved to the current aluminum gear in 2004 and IIRC you need both for the GW increase.

Since I plan to teach in my 7KCAB, the ACA metal spar mattered, just from the standpoint of being able to be "legal" in the event something happens.

I agree that an airplane like a Citabria or a Decathlon really doesn't care if it's 50 or even 100 pounds over gross - just don't land it hard if you *are* over gross weight. My impression is that Decathlons tend to be flown on in three point wheel landings rather than full stall landings where the tail arrives first and the main wheels drops several inches to the pavement - and being over gross weight is probably what makes those tail first arrivals unpopular and/or ill advised.

There's no such thing as a minor prop strike. Any strike that bends or damages a blade requires a tear down of the engine. The good news is that insurance will cover it - if the aircraft is insured - if the aircraft has been continually insured against all risks, that's a plus.

I also agree over G events, as well as over speed events probably go unreported most of the time. As noted the design G limit has to be at least 1.5 times the certified G limit, so unless it was massively over G'd, it's not an issue. In terms of overspeed, the limiting factor on the Citabria and it's 162 mph Vne is the windshield collapsing. The Decathlon has the brace down the middle for that reason, but my understanding is the 200 mph Vne was lower than planned for the rest of the structure, and just not worth redoing the windscreen to get a higher Vne. So in both cases, if the wind shield didn't collapse, it's probable that nothing else was bent or over stressed. Still, the aircraft should be checked if it occurs.