Expectations: Always Too High


No sooner had I posted this week’s video on Pipistrel’s Panthera than a frustrated YouTuber vented his spleen. “Very disappointed with this aircraft. Don’t know why anyone would buy one when it doesn’t do anything better than its competitors.”

Good point. I thought by now that Pipistrel would at least have developed impulse power or some other revolutionary technology of the sort would-be airplane buyers say they want, but wouldn’t actually purchase on the pain of death.

That’s another way of saying lots of people are experts on how to sell huge volumes of airplanes by doing things the established manufacturers just never seem to have thought of. And seriously, the Cirrus success hasn’t been based on anything revolutionary by any means, including the CAPS system which I discussed in the previous blog.

This becomes quite apparent in the cold light of an Excel spreadsheet populated with performance figures of both modern airplanes and some of the great models from the 1970s, such as the V35 Bonanzas or, especially, the Cessna 210. I noticed this when I was plotting the Cirrus data. I had somehow thought of the SR22 as a 180-knot airplane and the SR22T as a 200-knot plus.

The G6 SR22T will reach those speeds above 20,000 feet gulping 17 to 18 GPH. But some owners have told me they actually slum along in the high teens at 15 to 16 gallons and about 180 knots. The SR22, meanwhile, is more like a 170-knot airplane on 16 to 17 gallons. A late 1970s Cessna 210 did a few knots less on 14 gallons. Efficiency wise, the 210 was actually a little better at 1.96 nautical miles per pound against 1.7 or 1.8 for the Cirrus, the point being that Cirrus knocked it out of the park without kicking up the performance much, if at all.

I always figured the Cirrus story was a combination of timing, good marketing, a capable product, yes, the parachute, and that they launched at a time when there weren’t any new 210s being built. Or much of anything, for that matter. Lancair/Columbia/Cessna—I don’t know how else to describe that iteration of airplanes, sorry—had equally capable airplanes but didn’t sustain. I have no idea if the lack of a parachute had anything to do with it. I’d guess that it was more lack of consistent marketing, sales and follow-up.

If I plug the numbers into my spreadsheet, it indeed shows that the Panthera isn’t much faster than the Mooney Ovation, the SR22 or the SR22T down low at reasonable fuel flows. On that, the YouTube viewer was right. He missed that it’s quite a bit more efficient than the other airplanes, except for the new diesel-powered DA50 RG. And having visited Pipistrel several times during the development, I know that a lot of human effort went into tweaking drag and weight at every turn. There wasn’t much low hanging fruit; just tiny berries at the top of the tree. And although it shows, it’s no more revolutionary than the Cirrus was in 2001.

That’s because the range of considerations governing aircraft certification necessarily limit performance and economy across a fairly limited band. On the economy front, Diamond has broken the mold with efficient diesel engines. At my last calculation, diesels had about 10 percent of the propulsion market and while that’s significant, revolutionary it ain’t. And by the way, when freed of the surly bonds of certification, you get something like the Lancair IV or IV-P. Unleashed on the unwashed masses, you’d soon lose track of the craters.

Efficiency may attract some buyers, but it’s not clear they constitute a significant portion of the universe, otherwise Cirrus wouldn’t occupy the top of the sales chart and the bottom of the specific range scale. Obviously, Diamond has carved a niche with its diesel twins and operating cost has been a factor.

What the Panthera really is is another lesson in methodical series of compromises that every airplane design turns out to be. The big one is the engine, the Lycoming IO-540. For a company as obsessed with green efficiency as Pipistrel is, it struck me as an odd choice of an engine. But the compromise was the requirement that the engine be auto-fuel capable and there just aren’t than many big-inch engines that can do that.  

And here, let me tear off a clean sheet of digital paper and sketch my idea. All other things being equal—they never are—my first choice of engine would have been the Continental IO-550-N, the same engine the SR22 has. It’s essentially the same weight as the 540, but an inch wider; hardly a deal breaker.

But the IO-550 series has one important advantage: it’s more efficient. Because of its induction system, the engine runs smoother and tuned with GAMIjectors and lean of peak, it can run at brake specific fuel consumptions as low as 0.39 pounds of fuel per horsepower hour. Lycomings generally run around 0.44 or 0.45. Even at a narrower spread, at say, 170 HP, that’s a little more than a gallon an hour. It’s about 9 percent less fuel consumption.  

If you’re tweaking ounces of weight and massaging surfaces and fittings to trim drag, 8 percent is hardly chicken feed. It’s almost a gift. Also, the IO-550-N has 310 HP—50 more than the IO-540. That would come in handy for high-density altitude operations without turbocharging. Climb performance would be through the roof. I don’t know if it’s too much power for the Panthera’s rudder and weight. (Remember the Lancair’s rudder limiter system?)

If it’s not, it would make the Panthera less of a refined house cat and more of a feral scrapper with an edgy attitude and maybe disgustingly too much power. Hard points as an option. In other words, just the airplane for me. You can always throttle it back if you get scared.

But alas, the compromise nod to auto fuel ruled that out. Sigh. Maybe next time. Add a turbo while we’re at it.

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  1. You might want to consider that Pipistrel is a European made aircraft. Probably the fact that AVGAS is approx. double the price in Europe vs. USA has something to do with the choice of engine. Also, the IO-540 is nigh on bulletproof.

  2. Though avgas is really expensive in Europe or unavailable – mogas at airfields is also difficult with different countries having different standards, and no avgas at big boy airports,also prices and availability of mogas vary wildly from country to country, so I don’t see this aircraft as changing the world for the european market.
    This airframe was designed around the io-390 if it had been allowed to run Mogas which is something that maybe lycoming would have considered 10-12 years ago when this project starting and oil was $100 a barrel –
    Once lycoming knocked them back they were stuck with a slick airframe and no business case.
    Disappointing that they could not have implemented the lycoming del-120 – like the io-390 it runs 210hp for takeoff and by the time you get to 8-10k feet its putting out more power than the IO-540 (unless you keep the io0540 running at 2700rpm) – why did’nt they try it ?

  3. The venerable 210 also provides superior access/egress and comfort, seats six when required, and gets into and out of tight fields with aplomb.

    Imagine a 337, equipped with a pair of IO-550-Ns. “AirStair door!” (channels Homer Simpson). Seriously.

  4. The Panthera powered with a 260HP IO-470 would solve the autogas issues, and set the table for additional, optional powerplants without a lot of engineering changes such as optional engines like IO-520/IO-550-N for those who want the avgas powered feral cat vs the autogas tabby. I have no idea if Continental manufactures new 470’s.

    With Mooney re-trying to open their doors for the umteenth time, Diamond introducing the DA50, and now a third high performance airplane in the current world aviation market will reveal what the true market really is. At this point the G36 is predictable and has a long term following with Cirrus established as the piston single leader.

    We arm-chair quarterbacks are postulating, pontificating, and making predictions the market is established at 300-500 units per year. Now it’s just a question who gets what portion of that pie. With three additional offerings, maybe that pie is larger. If so, by how much?

  5. Price and feature competition for high end piston singles, – the panthera has the cirrus beat on efficiency, looks, and price (hopefully) – and it has a parachute.
    The diamond da50 brings something else to the market – way more efficient, jet fuel, and more comfort than a cirrus.
    The issue that remains difficult to bring prices down, is that major components – avionics and engines are supplied by 3rd parties – this makes it extremely difficult to bring prices down – the only way to reduce costs is to focus on the airframe production and their are no economies of scale there- even if the market blew up to 2-3000 planes a year split across 4 manufacturers the scope for cost reduction is minimal.

  6. Americans are not getting any smaller or any younger. Cirrus is ripe for a new fuselage. At least 10 inches wider than their legacy offering. (An interior-width measurement is misleading, if it fails to account for a center console.)

    While they’re at it, they can relocate the circuit breakers away from their ridiculous extant location. Add a manual pitch trim wheel. Widen the wing-walks. And add a second boarding step and more effective handrails.

    You CAN make a good airplane even better.

  7. With the larger girth Americans have grown to, plus aging population…is the high end piston single market all about low wing airplanes? What if Cirrus offered a high wing, stretched width aircraft without a console into the mix? I am sure Cirrus has, is, and will be looking at that option as Mooney, Diamond, Pipestrel and Textron play low wing, high performance piston single follow the leader.

    Cirrus does have the now mainstream, accepted, GA aviation investment capitol coming from the Chinese. So does Diamond. Sort of the new ” Detroit” for airplanes. Of all of the competitors, only Pipestrel has experience with high-wing aircraft. Think about that kind of market shakeup Cirrus could do, and maybe force Textron to rethink the 210/Cardinal RG line.

    Hey, this is fun speculating with other’s money. No risk to us, we get to arm-chair quarterback each step, and remains to be seen if anyone of us will actually buy something after the dust settles.

  8. All of the GA aerodynamic magic was figured out by the 1940’s and most of the GA piston engine magic was sorted by the early 1960’s. Wanting a little extra in one area (speed, economy, climb, cabin size etcetc) means you are going to give up something in another area.

    Cirrus seems to have figured out the sweet spot for features, capability, comfort and style. They will continue to own this market segment for the foreseeable future.

  9. The first and only time I ever flew a Cirrus, the engine quit. Thank god for the boost switch, whatever that did. I told the owner/student to go have it looked at. The mechanic said something like “oh yea, they do that, fuel vapor lock blah blah”. I stopped listening.

    Also, I couldn’t shake the feeling the interior and panel was modeled after a Toyota Prius. Guess I’m old school, but I like my old airplane smell and some trusty round dials up front.

    Btw, this is merely a case of sour grapes because I could never afford one.

  10. Maybe people just expect a lot more when paying that kind of price for a piston 4 place airplane? A great used A36 or Saratoga is half the price, easier to maintain, and hauls a lot more family stuff comfortably for real family outings.

  11. Even in these comments, Paul. “Why not engine X instead of engine Y?” Bureaucracy and design cost, that’s why. There are multiple reasons GA prices have well outpaced inflation, and a big one is just how outrageously expensive it is to certify an aircraft with the cantankerous and often completely ineffective FAA. Everyone knows that the bigger the bureaucracy the less efficient and more costly it is. Engineering is always expensive, and in certified aircraft the red tape adds significantly to the cost. Making significant design alterations, especially late stage, is a good way to wind up as doomed as Mooney; the product that is so expensive and offers so little for the money that its market is vanishingly small. GA has also been in the realm of diminishing returns for many decades, aside from the only major advance in powerplants; electronic fuel injection and computerized ignition control, taking 30+ years to show up on GA engines after becoming ubiquitous in automotive and industrial applications.

  12. Personally, I think that the AutoFuel route is necessary. The higher octane TEL issues are not going away. I’m surprised that Cirrus has not awakened to this reality. The AutoFuel has essentially the exact BTU value as 100LL and can be produced in obscenely large quantities (without ethanol btw). I applaud Pipistrel for their efforts to use an easily-certified normal engine instead of the higher compression TEL-drinker. Even with our inconsistent supply infrastructure problems, I’m paying $2.66 for E-free AutoFuel this week from a very consistent supplier.