Gorgeous looking pair of wings.

KW

That's a convincing argument, if it were needed, to choose the Evo over the Meridian and Jetprop. Did you build a similar comparison of the -42 against the -135, and compare the -42 at 135's speed to the -135? I also wonder how the Epic would compare with its beiiger engine?

Ashley

That's a convincing argument, if it were needed, to choose the Evo over the Meridian and Jetprop. Did you build a similar comparison of the -42 against the -135, and compare the -42 at 135's speed to the -135? I also wonder how the Epic would compare with its beiiger engine?

Ashley

Thanks, and I'm looking forward to another spreadsheet.
Ashley

Don't know all of the Epic numbers but it should be somewhat close.

Thanks Gerry, those extra seats are expensive. They buy you more range though - particularly when a couple of seats are empty.

They are. Almost double the cost for those two extra seats. I'd be interested to see just how much more range there is with the Epic. I guess I failed to add that part into this spreadsheet, lol.

Looking at the spreadsheet. It looks like the Epic and my Evo setup will have roughly equivalent range at top speeds. Not knowing what each airplane will do fuel burn wise and TAS at economy cruise I didn't want to attempt adding those in without better numbers.

I updated some numbers and added range as well as nm/gal.

Slow the Epic down to EVO speeds and I be the fuel burn will be very similar. I see a difference of 10-40 knots depending on phase. That costs a lot of fuel. It really speaks to the capability of the Epic lugging around 2 more seats.

i love this spreadsheet, thank you for making this....very helpful, i want an EVO in the future- but i'm enjoying my fixed gear lancair for now

after running some numbers with my weekly commute flight of 250nm- the evo WILL cost more, that answers one of my itching questions

We can get an idea of the effect of slowing the Epic using Gerry's spreadsheet and EPIC's specs, http://epicaircraft.com/aircraft/pricing-specifications

First, high speed cruise fuel consumption claimed by Epic is a little less than that Gerry used. Plugging in 60 instead of 66 gph and keeping all else the same gives the Epic a range of 1223 nm with 45 mins reserve. (Epic claim 1385 nm range with that reserve.) The Epic would take 3 hrs 50 mins, Gerry's 42 Evo would arrive at 1223 nm 6 mins later with 28 mins reserve; a 135 Evo with the same 185 gall capacity as Gerry's 42 would come in 22 mins after Gerry with 34 mins reserve.

Slow the Epic to 265 kts and the manufacturers claim 40 gph. Plugging those into Gerry's spreadsheet gives a range with 45 mins reserve of 1566nm. 196 gals are used for the trip. Neither Evo can stretch that distance at the speeds we're discussing.

Going back to to 1223nm and keeping the Epic at 265 kts, unsurprisingly it comes in last at 4 hrs 35 mins; it could fly another 1 hr 18 mins. Gerry's EVo 42 would come first at 3 hrs 54 mins, with 28 mins reserve. The Evo 135 would finish the course in 4 hrs 18 mins. The Evo-42 uses 165 gallons, the other one gallon less.

The numbers vindicate Gerry's choice of the 42 over the 135. The Epic has substantially greater range at a speed that's comparable with the high-speed cruise of the Evo135, but it's still burning 20% more fuel.

In modifying the numbers for the Epic, I didn't change fuel consumption of speed during descent. If I change the speed to 265 kts and simply keep the rate of consumption the same as cruise, the 1223 nm trip takes 4 min more and the reserve increases to 2 and 7 mins. The 45 min reserve range is then 1585 nm, which makes the 1650 nm claimed by Epic seem very reasonable.

Ashley

I used 66 gph for the Epic in cruise because that's essentially what had been reported to me by someone that built and flew the planes. Maybe it's not accurate however, it's fairly typical for manufacturers to overstate their performance capabilities. Also, that's essentially what my brother's PC-12 burns (444 lbs/hr = 65.4 gph).

Just a point I'd like to make. 28 minutes of gas is not very much gas at all. I think it would be quite foolish to try and make a 1250 NM trip and plan to arrive with that little fuel. Its important to remember that alot of the numbers that are put out on each airplane, are in fact not actually attainable when you fly with the decent amount of caution that is needed to operate an airplane safely. I am not trying to say anything negative about the aircraft at all, just that it is important to remember these issues when discussing different airframes.

At top speed the ranges of all three airplanes are close, and the time taken for Gerry's airplane to complete the distance is very close that of the Epic; not so much for the slower Evo-135. The fuel used by the Epic is considerably more than the other airplanes. The only point of the spreadsheet is for comparison. I didn't think anyone would consider it for planning purposes.

Gerry, sure, all companies are optimistic when they give numbers. I assumed your numbers came from Lancair and were equally likely to be optimistic so thought it fair to use Epic's numbers for their airplane. Similarly, I gave the Evo-135 the same fuel as your Evo-42.

Ashley

Actually, my numbers for the Evo come from RDD, and people flying them, not Lancair. The numbers I used for the Epic also came from RDD and people flying them. Also, as stated above, my brother has a PC-12NG. Even though the planes use a different PT6-67 engine they are both 1200 hp so I figured the fuel burn would be similar.