Brewster Buffalo dive speed and handling

[Wmaker]

playing aero babysitter

Bweehehehehhe...   

Glad I wasn't drinking anything.

[Stoney]

Well, like I say, I thought better climb rate was a pretty dead indicator of better better thrust-weight.

Don't use the term "thrust to weight" for propeller aircraft.  "Power to weight" is the proper comparative term.  In jet engines, maximum thrust is constant regardless of speed, whereas in a prop aircraft, thrust varies with speed.

And, climb rate is an indicator of excess power, not thrust-to-weight or power-to-weight. 

[WMLute]

Good point and no I didn't film it BUT the Brew had just finished turn fighting with another plane and I had a good alt advantage AND had been in level flight for a bit so I am ASSUMING that I had more E.

It is possible the Brew had just dove and dispatched it's opponent quickly and was holding more energy than I had thought.

I just found it "odd".

I am a fairly good judge of E states and can usually tell these things but for the Brew I tend to be off on my "guess" by a good 500' constantly.

I could have just been wrong on this occasion as generally I don't have a problem fighting and killing 'em.

[dtango]

Uh, actually in this case I don't really understand.

Ok, first, how I define a zoom climb for our purposes-Straight vertical, or darn close to it. The wings are unloaded or close to unloaded at this sort of angle. The way it usually gets down in combat. I can easily see how the Brewster might climb better at 120mph IAS than the D40, even though the D40 climbs better at its Vy. But I don't think we are talking about an angled climb when we speak of vertical performance generally, we are talking about maneuvers that involve pointing the nose at the noonday sun until one of you runs out of airspeed. Lighter wingloading would seem the Brewster's only performance advantage over the D40. In this case, I don't see why lighter wingloading would come into play as an advantageous factors, cause like I say, the wings are unloaded anyway.

Most of my post above didn't really address wing-loading.  Let's assume your 90 degree zoom climb case.  With that because sine(90)=1 our forces in the direction of flight resolve to:

F = T - D - W

As you see the greater the weight the more it counteracts thrust thus weight has an impact.

In reality it's a great deal more complicated than that.  I can toss out generalizations and simplifications to try to make the point more but in the end I think that only leads to more questions that can only be resolved by much more in depth modeling of it all which I do not have the time or patience to do.

This is the sort of climbs where people are finding Brewsters with lower initial airspeeds chasing them up for surprisingly long amounts of times.

Too much conjecture.  It's very likely that these "people" are experiencing "Tango's 1st Law of Air Combat - you can't defy aerodynamics" meaning if you don't understand and factor in the aero nuances you'll end up with nasty surprises.

Well, like I say, I thought better climb rate was a pretty dead indicator of better better thrust-weight. And I thought top speed was a good indicator of thrust versus drag for the airplane at low AoA. An airplane zooming straight up is at low AoA, in fact like I say, its unloaded. As for weight, isn't weight unimportant except as it relates to thrust? Same thing with drag? So I still can't see why the D-40 doesn't hold all the cards in vert performance against the Brewster.

Already answered in this post and above but let's focus on your drag statement here.  The plane with a higher level speed probably has the lower drag coefficient (but not necessarily because it could be just offset by an overload in thrust).  However the absolute value of drag for the faster airplane could be even higher than the slower aircraft.  For instance take the P-47D40 vs. the lowly B-239.  Knowing that at level flight T=D here's what we get at sea level:

plane   bhp   p.e.   mph   drag
47d40   2600   0.8   340   2294
b-239   1000   0.8   280   1071

So in this case absolute drag of the faster airplane is higher.  Aero is full of nuances like these.

Signing off for awhile guys.  Headed to Belton TX!

[Muzzy]

If a noob may be allowed to voice an opinion:

The brew was the biggest surprise for me in AH.  I took one up simply because I was having a crappy day in the arena and thought it might be fun for a few seconds (before I got shot down again).  By the end of the day I'd found some interesting things.

1. I could turn inside just about anything. (Not a surprise after I'd read Soda's evaluations).

2. In a low altitude furball i could follow enemy aircraft in climbs and get good shots as they came over the top and dived. I would loose them as they picked up speed, however.

3. The gun package was adequate enough for my purposes.

4. People tended to ignore me in fights, which was a wonderful advantage.

5. I can't catch anything.

I'm also finding that building alt, while still useful, doesn't help me that much because the Brew really doesn't gain much speed in dives and low speed just seems to be where it handles best.  So I actually look to get pounced, so I can bring the fight into the low-speed turnfight where the Brew excels.  I would never take this bird into a base cap situation, but when you don't have time to build altitude it's a great little plane to fly.  The major problem I have is that you have to let the enemy come to you.  That said, I got more kills in the Brew then I did flying any other ride.

-Muzzy