Why companion instead of BH4

[Bissetg]

? it’s just physics. I didn’t say I can land shorter than you, but for a given pilot the 150lb or so lighter aircraft has less energy to lose so all things being equal it will require less landing roll.

[Battson]

I was kidding Grant

[kestrel]

The extra 540 weight on the nose pulls the airplane down making it land better!

[Battson]

^ He gets it - braking authority

[500AGL]

I keep hearing that a 180hp 2500lb airplane want work but the 172 has been doing just that for years! Sure you aren't going to be bush flying at high density altitudes at that weight but it should be totally fine for airport to airport work.

A 172 isn't a 4 place aircraft. At least not with any fuel, or any DA, or any performance. It's a great two person airplane.

What's the disadvantage to the 540?... mainly the investment cost on a larger aircraft. You won't build a 4 place as light as a Companion, even the bare fuselage weighs a bit more, as much as it appears the same, it's not quite. Fit up a 4 place and drag it around the sky, and you may find the 540 burns very very similar gph at the same speeds. A 90hp cub burns more per hour than a 180hp bearhawk at the same speed.

As always with EAB aircraft, every builder, owner and pilot have their own vision, mission, and satisfaction level. I've been caught looking for justification for my vision and rational before, but I've learned that if the path you choose is the one you want, then don't ask for justification, just do it. If you are truly on the fence, then listen to both sides and understand each position.

pb

[Battson]

You won't build a 4 place as light as a Companion, even the bare fuselage weighs a bit more, as much as it appears the same, it's not quite. Fit up a 4 place and drag it around the sky, and you may find the 540 burns very very similar gph at the same speeds. A 90hp cub burns more per hour than a 180hp bearhawk at the same speed.

Never say never I am pretty sure Colin's first Bearhawk 5 came in lighter than the average 4-place / Bravo -540's. I take your point, although where there's a will

I think you nailed it with the mission and personal preferences stuff, we can only speak for our own wants and needs.

On a side note, I do look at companies like Murphy, Glasair, and many others before them which diversified out into many aircraft models, before crunching back down to just one or two. There seems to be a happy medium for the "average" kitset aircraft company. Not everyone can be Vans Aircraft... I am sure Bearhawk Aircraft is way above average!

[svyolo]

They are literally the same airplane which is why I am asking. The only difference is that they removed the baggage door, moved the baggage bulkhead forward and adjusted the engine mount length. It literally says Bob didn't see a point in redesigning the airframe for the Companion. I keep hearing that a 180hp 2500lb airplane want work but the 172 has been doing just that for years! Sure you aren't going to be bush flying at high density altitudes at that weight but it should be totally fine for airport to airport work.

There was no Companion available when I ordered my B kit. I always intended to build mine primarily as a 2 seater. With the availability of the Companion, I would make the same choice as you are suggesting for the same reasons. Same cost to build, same cost to fly, almost exactly the same performance, but I can carry more including two more seats when I need it. Even if the Companion was a bit nicer to fly, I would make the same choice. Others might prefer the better perceived flying qualities.

I did buy a 540, because it is cheaper and simpler than a turbo 4. I did want the altitude performance.

[gregc]

Fit up a 4 place and drag it around the sky, and you may find the 540 burns very very similar gph at the same speeds. A 90hp cub burns more per hour than a 180hp bearhawk at the same speed.

pb

I'm building a Companion and I haven´t added anything to this thread since I think your are 100% right in saying "choose the one you want" and do it. But, I can´t resist the fuel burn issue since I see this a lot. It seems like you are saying: fuel burn for 540 = 360 < C-90 (at some speed). Even a clapped out, draggy, running rich 90hp cub is not going to exceed 6gph by much. If you guys are getting that with a 540, please let me in on the secret sauce recipe .

[Grum.man]

I haven't tried 6 gph but my Questair Venture will do 170kts all day long on 8 gph with the IO-550G! I've always heard the 540 was a guzzler though.

[jaredyates]

I find that 6gph works for putting around with a light load, but 7 works better with a full cabin. 18"/1800rpm on the 540 should get close?

[kestrel]

I think the analysis works until the Bearhawk was built heavy enough and the Cub flying slow enough that the Bearhawk is "on the back side of the power curve". Weight does lead to a minimum power setting. Assuming that everyone is light enough and/or flying fast enough to be on the front side of the curve, the comparisons hold up pretty well. ...or to put it another way, the engines are all reasonably close to the same efficiency so power and mixture settings are more relevant than displacement or number of cylinders. ...all else being equal.

[Battson]

It seems like you are saying: fuel burn for 540 = 360 < C-90 (at some speed). Even a clapped out, draggy, running rich 90hp cub is not going to exceed 6gph by much. If you guys are getting that with a 540, please let me in on the secret sauce recipe .

Yes, a larger engine is more efficient than a smaller engine, all other things being equal - because there is less friction.

Comparing a Cub to a Bearhawk is hard for fuel burn, because the Bearhawk is dragging a much larger skin area and cross-section through the air.

That being said, the IO-540 Bearhawk can fly with Super Cubs for the same fuel burn rate the Super Cubs get at a given airspeed, in spite of those disadvantages! It requires running the IO-540 aggressively lean of peak.

Of course, if the Cubs went lean of peak too - they would burn less than a Bearhawk -540 ever could, but they would also be going a lot slower. For a given airspeed and fuel burn rate, the larger engine should always be more efficient. In the case of the Bearhawk, it is so much more efficient, that is can overcome the considerably larger drag forces acting on the Bearhawk 4-place or Bravo fuselage without using more fuel than the Super Cub, for a given cruising airspeed.

[TimTall]

I tested this last week! I fly regularly with a couple 150hp supercubs and a Murphy Radical. I can burn less fuel for a given airspeed than they can. Cruising with them at a blistering 98 mph I can get my fuel flown down to 5.5gph. I'm running very lean of peak to do it running in the 15-20% power range.

At that power setting it's almost impossible to make little speed adjustments with the throttle. I use the mixture for subtle power changes instead. In still air I'm getting better gas mileage than my truck at that fuel burn!

Engine temps get pretty low pretty quick at that speed so I usually don't do it for too long but it is definitely possible.

[500AGL]

I'm building a Companion and I haven´t added anything to this thread since I think your are 100% right in saying "choose the one you want" and do it. But, I can´t resist the fuel burn issue since I see this a lot. It seems like you are saying: fuel burn for 540 = 360 < C-90 (at some speed). Even a clapped out, draggy, running rich 90hp cub is not going to exceed 6gph by much. If you guys are getting that with a 540, please let me in on the secret sauce recipe .

As noted by others, what I'm saying specifically is that an O-360 in a Patrol, burns less than a C-90 in a Cub, at the same speed. (Same in a Husky for that matter. You have to run more throttle in the cub, and less in the Patrol. Under 5 gph at 85-90 mph, and pushing closer to 7 gph in the cub) I've proven this myself more than I wanted to, because I was driving the Cub.

I am not saying that a xx-540 will beat a C-90.

But it's not hard to accept 9-10 gph in a 540 for a speed that requires the O-360 to be the same, or very very close. If needed, would you buy 1-2 gph more to have 260-300hp available at your disposable than 180 hp? If so, the buy-in cost is truly the only difference. (FYI, while I can fly at 125 mph in a patrol at 8 gph, to fly at 150 requires 10+)

For argument sake, it can be said that if you drive your 540 equipped airplane like you would fly with a 180 hp 360, the 540 will last a long time because you're not working it to full capacity. But, that's a divergent topic for another venue.

Muddy or clear, it's more info and opinion.
pb