Are You Nuts To Want a Twin?

If you have to ask, the answer may inevitably be yes. A hard-nosed cost analysis.

Ill begin with a conclusion: Financially, owning a twin is nuts.

I pay to haul around a lot of extra stuff to support a second engine, total horsepower is divided between two packages which complicates emergency decision making. And unless I continue to take serious dual every six months, Im probably not as safe as Id be in a single.

On the other hand, Ive been in general aviation for 30 years as an owner, instructor and attorney and I know that buying decisions arent always clear-eyed, unemotional examples of piercing analysis. You could argue that buying any airplane makes no sense at all. Make that times two for a twin.

When I mention to other pilots that I own a twin, the reaction varies from oh wow from those who havent gotten past being impressed by a fistful of throttles to you lunatic from those who base their airplane ownership decisions purely on economics.

And therein lies the purpose of this article. What exactly can you expect to pay to operate a twin? Right up front, Ill say this: If youre not thinking in the range of $200 per hour, youre not thinking at all.

We have kept track of every cent spent on our Aztec, largely because my partner, Chuck Truthan, developed the Truthan Aircraft Expense System, a paper-based accounting method for aircraft ownership. We keep it in the airplane and simply record every expenditure for anything right then and there.

A Nice Aztec
Chuck had owned a Cherokee 180 and I had a Cessna Cardinal before we partnered on the Aztec. When I lived in Chicago, the Cardinal was fine for the flying I did but when I moved to western Michigan, challenging weather and the need to cross Lake Michigan regularly lead me to think about a twin. My partners growing family and a similar overwater requirement pushed him toward a twin as well.

Most of my twin time is in Cessnas, while Chuck had obtained his multi rating in an Apache with a gland problem, the Geronimo. He wanted a Piper, I wanted a Cessna. Surveying the market, we discovered that twin Cessna prices had appreciated beyond the buying power of the $70,000 in cash we had available for purchase and both of us were experienced enough to know that wed have to hold 25 percent of our funds in reserve for the inevitable set-it-right, post-purchase repairs.

We settled on a 1969 Aztec, de-iced (not known icing) with radar. The seller agreed on a price of $43,000 but a pre-purchase inspection revealed some shortcomings the seller wasnt willing to fix. The purchase price was negotiated down to $31,000 for an as is, where is deal. We put $10,000 into the airplane immediately to correct deficiencies and considered that sum part of the purchase price.

Bottom line: We had a reasonably sound, well-equipped twin with 2000 hours on each engine, which we intended to fly as long as we could before overhauling the engines. We also realized that we werent maintaining a $41,000 airplane, for if the Aztec were manufactured today, it would probably cost well over a half million dollars. We were caring for a half-million dollar airplane that would have a commensurate appetite for maintenance.

What Reliability?
We soon discovered that a twin isnt as reliable as a single, a memory I had repressed from my days of multi-engine instruction when I cancelled more lessons in twins than I ever did in singles.

Chuck got bit first, spending $373 to repair a starter in Louisville while his family stewed. This was the first of four starters weve put on the right engine for reasons not yet sorted out. Part of the problem seems to be the screwy decision by Piper to use aluminum starter cables. These will be replaced with copper when the budget allows.

My turn came next. The right starter gave up with the family loaded for a Fourth of July trip. Naturally, I couldnt get it fixed on a Friday evening so we turned a 2:30 flight into a 10-hour drive. Beyond all else, the way this airplane has eaten starters has aggravated me.

In the spring of 1996, we noticed some fuel leaks and discovered the connection between the fuel bladders and the wing skin and filler neck wasnt perfect. Chasing down leaks and fixing a shoddy previous repair cost $1388. In April and May, we began our instrument replacement odyssey, beginning with the manifold pressure gauge ($244) and both tach cables, $430 and later a succession of vacuum DGs.

Hydraulic leaks proved to be a constant irritant, something other Aztec owners warned us about. We decided on a three-year replacement plan for the system by simply repairing leaks; $75 here, $175 there. The summer of 1996 brought problems with the tilt control on the radar, costing several hundred dollars to fix. That problem recurred in the summer of 1998. A few hundred more.

Troubles: Times Two
The engines leaked oil. A lot. They ran well, so we were willing to pay for some repairs to avoid overhaul. Fall 1996 brought an oil pump AD; $750 per engine. This was getting expensive. So with 2100 hours on the engines, we pulled them for overhaul.

We simply picked the wrong shop. The nightmare of dealing with Aero Power and George Geisz of Cincinnati was recounted in the August 1997 Aviation Consumer. After months of delay, our second overhauls were done by Blueprint and G & N and both have worked well, with no-questions-asked support from both. We continue to recommend both Blueprint and G & N.

From a cost standpoint, we capitalized the overhauls and for the purpose of keeping track of the operation of the airplane, we calculate $10 per hour per engine and $5 per hour per propeller. At engine overhaul, we did the props, too. None of the blades met spec and although we burned up the phone lines searching, no used blades were available. With new blades, the overhauls cost $6076 per side, plus $370.60 each for governor overhauls.

What did 1996 cost us? Ignoring the cost of engine overhauls, which we capitalized, we spent $17,291.27 on everything, including fuel, hangar, insurance and all maintenance. We flew the airplane about seven months that year and put 87.8 hours on it, amounting to $196.94 per flight hour. Adding $10 dollars per engine and $5 per prop for overhaul reserve, the hourly cost came to $226.94 per hour.

It Gets Better
With overhauled engines hung, 1997 proved to be a better year. But letting an airplane sit is horrible. Lots of things break. But we were relatively lucky. We dropped $250 to fix the Janitrol heater. We also spent lots of time repairing the duct work, which has deteriorated due to age and indifference. Still, the airplane is just plain cold in the winter.

Continual hydraulic leaks caused landing gear problems, mainly slowness of retraction and extension. Because of the screwy design of the system, we had to put the airplane on jacks and retract the gear to check the fluid level. What should be a simple task is not. The relatively primitive design of the airplane has conspired to elevate our costs. For example, it takes one experienced person a minimum of four hours to remove and replace both engine cowlings, without so much as turning a wrench on the engines themselves.

We bought another starter but had very little unscheduled maintenance. In six months, we flew 86.2 hours and spent $19,122.19 on everything except overhaul set-asides. A substantial portion of that was minor work done while the airplane was down for the agony of the engine overhauls. The hourly rate worked out to $221.84. With the extra $30 per hour for engines and props, it was totaled $251.84. Ouch.

Little things can be surprisingly costly. When a tread let go on a recapped tire, the supplier replaced it at no charge. However, we needed a tire right then and dropped more than $300 to buy what was available (a new one) and get it installed on short notice. Overall, were glad we followed the recommendations to use recapped rather than new tires. We now keep a spare tire in the hangar.

In the spring of 1998, the right starter failed again. This time it ruined the ring gear, delaying me for 24 hours. Fortunately, Sky-Tech had a starter to the shop the next morning and G & N had a ring gear that it shipped right away. A few weeks later, the right engine oil cooler split near the end of a flight to Nashville. Fortunately, Chuck was scheduled to be there for several days so the repair time was only an inconvenience.

In mid-July, I had a total electrical failure and diverted to Falmouth, Kentucky. Fortunately, I ran into Omer Lucas of Lucas Air who worked on Sunday to illuminate one of the many problems of aging airplanes. Someone crossed the wiring from the voltage regulator selector switch to the regulators themselves. Still, the problem took long enough to trace that we had to finish the trip via airline. Chasing the problem and replacing one voltage regulator cost $700. We found a used, serviceable second regulator for $120. New ones cost $335.

During the annual, we had to replace a valve in the boot system. Used, it cost $1100. It confirmed my prejudice that more stuff on an airplane is just more stuff to break. Im not convinced that the boots are worth the cost to keep them alive. In my serious freight-flying days, I rarely had to fire the boots. I now think if theres going to be enough ice to require the boots, Ill simply postpone or cancel the trip. Ive come to believe that having boots encourages more boldness than may be wise. By the same token, the hot pad on the windshield is something Ive used several times in light icing; I like the idea of being able to see when landing. Thankfully, the plate has never required any unscheduled maintenance. Allowing for that valve, another ring gear and other minor fixes, the annual cost $8000.

As of mid-July 1998, we had put 97.9 hours on the airplane and spent $19,152.61 for everything except overhaul set aside. $195.63 is the hourly cost, plus $30 works out to $225.63. Overall, the airplane has cost $204.36 per hour out of pocket. Adding the overhaul reserve, the figure is $234.36 for absolutely everything except the cost of the investment money. Considering that the rule of thumb for operating cost of a complex airplane is four times the cost of fuel, which, at $2.15 per gallon, comes to $223.60, were not far off the mark. I think the hourly rate will drop as we fly more frequently, plus, we seem to be getting ahead of the maintenance curve. Then again, Ive been too optimistic before. Insurance costs may drop slightly as Chuck gets more time in the airplane.

So where are we here? We have an airplane with less dispatch reliability than a single, although we anticipate having to delay or cancel fewer trips in the future. However, Im not convinced we have the right-engine starter situation corrected as the newest ring gear already shows wear. Other gremlins will surface, Im sure.

How our considerable hourly costs tradeoff against enhanced safety is an objective and perhaps emotional consideration. Sorting through the NTSB accident data, purely mechanical causes represent a small percentage of accident causes. Overall, the accident rate between fast singles, such as the Bonanza, Cessna 210 and Lance/Saratoga SP, and light twins is essentially identical.

In singles, accidents are more likely to be caused by flight into inclement weather. In twins, controlled flight into terrain, loss of control on takeoff or landing and landing gear problems are the standouts. Interestingly, in a twin accident, a mechanical failure is most likely to be of the landing gear, not the engine. In singles, mechanical failures leading to accidents are more likely related to the engine-propeller.

For twins, about 3 percent of the accidents involve engine failure compared with 8 percent for singles. Given that an engine doesnt know whether its hanging on a single or a twin, the actual rate of engine failure due to mechanical causes is consistent among the statistical universe of engines, so twins have twice the number of engine-propeller failures as singles, per hour of operation.

But when a twin has an engine failure, pilots seem to be doing well in putting them on the ground after the failure. Even a successful forced landing in a single may result in bent metal, so twins probably have an edge in alighting safely after an engine quits. Ive had three power losses in twins, yet havent scratched an airplane. My one power loss in a single resulted in barely making it onto the airport, just past a swamp with tree stumps. Personal experience like this figures into buying de-cisions and tends to offset cost-induced agita.

Two things can ease the strain: I make sure the aircraft is insured for its true value so worries about trying to save the airframe because of financial considerations dont enter into my thinking. Second, I take serious dual instruction every six months, since the accident stats strongly suggest that lack of proficiency is a risk marker.

Overall, because the risk factor of a twin versus a fast single is identical, I try to cut my risks by filing IFR if the weather is at all questionable. I generally will not fly single engine airplane at night in weather or over large bodies of water. Thus, if I want to go, Im more likely to be able to meet my personal safety standards in a twin. Years ago, author Richard Bach was adamant that single-engine airplanes shouldnt be flown at night or in actual IFR unless the occupants wore parachutes. As I age, Im coming to agree with him. In the Great Lakes region, we get lake effect stratus in the winter. It usually tops below 10,000 feet and is often only 3000 feet thick. From October through April, area forecasts are the standard rubber stamp: Light to moderate icing in clouds and precipitation. The ability to climb rapidly to 10,000 feet often means a winter trip can be flown safely and a twin has the climb to scoot through a layer that a normally aspirated single cant match.

We also have large lakes which, even in summer, arent warm. In a nutshell, Ive flown across them enough in singles and I dont want to do so any more, particularly when I have my family aboard. When I go to Chicago, ATC wont assign an altitude above 6000 feet westbound over Lake Michigan. Coming east means either an IFR routing so far south of Lake Michigan that it doubles the length of the trip or crossing the lake no higher than 5000 feet. Thats not too appetizing on one engine.

If I had control of all the variables, would I still willingly pay $225 per operating hour merely for the pleasure of an extra engine? Slim chance. I see nothing fundamentally satisfying in having two engines for no specific purpose. If I didnt have to frequently fly over cold bodies of water or in low IFR with layers of ice, Id buy a Cessna 210. It carries six, with full fuel and some baggage and it has a longer CG range than the Aztec. It also costs about 40 percent less than the Aztec to operate, is faster, handles better and will get into shorter fields.

I dont like having to pay higher ramp fees for a twin when my airplane takes the same amount of ramp space as a big single and weighs only marginally more. Some FBOs seem to think that because youre a twin owner, you should be charged more in general. I keep waiting to see an hourly shop rate posted as higher for twins than for singles.

If youre considering a twin, keep that in mind. And when you sit down with a calculator to run the numbers, dont believe any totals that are lower than about $180 per operating hour. Dont be surprised if you actually pay $225.

When I fly for fun, Ill continue to rent a Super Cub on skis or floats or a Citabria. For getting places, I am sticking with a twin. But I have no illusions about what it costs.

It costs a lot.

Also With This Article
Click here to view “Insurance: A Third Higher Than A Single.”
Click here to view “Twins: Lots of Good Deals Out There.”

by Rick Durden

Rick Durden is an aviation attorney, flight instructor and charter pilot.