original Bearhawk 4 place vs the model B

[augman40]

Are there any noticeable operating characteristics of the original 4 place Bearhawk vs the model B? STOL performance cruise.... ?

[Nev]

If ever there was a thread with the potential to erupt in a cloud of fur and feathers.......

Essentially you would be looking at isolating the effects of all other components besides the wing (and any other differences between the A & B model).
Any two aircraft for comparison would need the same VG's, tires, brakes, engine, power settings, flap fairings (not included in the B model kit), aileron reflex, propeller, aircraft weight, wingtips, CG, aerials and parasite drag contributors, ISA conditions etc. Then the airspeed position error on both aircraft needs to be properly established.

Cruise

As with most aircraft, the Bearhawk can cruise at a range of speeds - largely dependent on engine power output and whether Lean of Peak or Rich of Peak.
For comparing Cruise performance you're realistically going to be choosing a particular airspeed, then measuring and comparing fuel consumption at that airspeed.

STOL

Aircraft STOL performance is largely dependent on the power on stall speed with optimum landing flap.
Due to the high Angles of Attack approaching the stall, Airspeed Indicator position error can be large (and non-linear).
This often leads to very low Indicated Airspeeds being displayed near the stall.

Other factors effecting STOL performance are:

• Aircraft weight has a large and exponential effect - (the V² contribution of the dynamic formula).
• CG is important - a mid to slightly aft CG gives a lower stall speed.
• VG's make a measureable difference.
• Braking

However, anecdotally, one of the largest determinants of overall STOL performance is pilot technique.

This is all a very roundabout way of saying....."it depends".

[augman40]

Im saying Same pilot same engine same conditions. Dude flys the A model hops out and jumps into the B model, Whats the difference?
ps. thanks for the reply NEV

[Nev]

I haven't noted any observable performance differences.

[jaredyates]

I think what Nev is saying, and what I would say, is that the difference is small enough that it would likely be overshadowed by other differences between the airplanes. Nobody has built two otherwise identical planes with and without the mods to do the tests.

[tailwind]

There may not be differences in flight characteristics but if I remember correctly I think you will find that the main spar is a little higher.

[rodsmith]

The B wing has a thicker airfoil (1" at its thickest point) so it had to be raised slightly to maintain cabin height/door clearance.

[Bissetg]

My understanding is that the B model wing has a better characteristic at the stall, a lower tailplane incidence and better aerofoil shape giving a sniff more speed.

If the point of your question is, I have the option to buy an A Model or a B model, my answer would be that the A model with VGs is an excellent machine, the B model is slightly more excellent but possibly not noticeably so to a lot of folks.

My B model is the perfect plane for me, would I be happy with an A model with VGs? Damn right I would be!

A Bearhawk isn’t a wonder plane in the sense that it is still subject the the laws of physics, but for what I do it’s ahead of anything else I’ve tried for versatility, performance and running cost by a country mile.

My advice is just buy it whether it’s an A or a B.

[jaredyates]

There is much big-picture wisdom in this post.

[jaredyates]

I would like to have more information to answer your question, and it is on my to-do list to gather more data. We have a model-B now and used to have an original. I hope to get to it this fall, and if anyone wants to help ride along and scan for traffic, they'd be welcome, and that might motivate me to get it done sooner. Getting good data requires selecting smooth enough conditions, having reasonably accurate instruments, and putting in the time. Lately the rest of life has been getting in the way. Anecdotally, I do find the Model B to yield faster speeds at equivalent fuel burns, though we seldom ran the 360-powered original quite as hard as we do the 540, and the differences are more pronounced as speed increases.

As for pitch authority derived from the new tail, I think CG matters most. The new plane has an extra 100 pounds up front and I can definitely feel it. It would be interesting to ballast it to match the CG of the old plane, and see if the pitch feel is different. We have loaded it for travel (high gross and aft CG) but haven't done light weight aft CG tests.

The short version is that you really need apples to apples to be able to answer your question, but it is really hard to create apples to apples.

[Camflyer]

I would be glad to ride along!
We met last year at tripple tree. We live just outside of York

[augman40]

It seems that if everything needs to be apples to apples and this and that, there's not much difference between the two models. So that's cool. Thanks for everybody's input without diving into the weeds too deep.

[Nev]

Thats my assessment, they're both good aircraft.
As the kitset product evolves Mark is adding some refinements and that is probably more noticeable.

[jaredyates]

It seems that if everything needs to be apples to apples and this and that, there's not much difference between the two models. So that's cool. Thanks for everybody's input without diving into the weeds too deep.

We've been estimating 5 percent or so advantage in cruise speed. It's up to you to decide what is small. A 5 percent reduction in fuel burn across 1000 hours is 600 gallons of fuel or around $3000. The small things become relevant at scale.

[augman40]

Great point.