First Flights Report

Great Planes 33% Pitts

by Bob Pastorello

Updated 01/12/2003

Update 6/2 - Finally had some time to really play with the Pitts following the wing/cabane modification.  The Cabane fix is absolutely reliable, and my wing is still extremely solid.  Had a few really good "trim" days, and here's what I've learned.  This Pitts, like SO many others has pretty hard adverse roll couple with rudder; that is, Left rudder produces Right roll, and vice versa, so knife edge has to be flown.  Or choose a LOT of mix, and I haven't done that.  Also on knife edge, negative pitch with rudder is pretty hard...I'd say in the neighborhood of 15 -18% or perhaps more will be needed.  BUT - those are the ONLY negative attributes.

    The POSITIVE attributes are that it is ROCK solid, VERY predictable recovery in all attitudes, is VERY smooth, and tracks like it is on rails.  Aileron-only rolls are VERY straight (unless you're really at slow cruise airspeed, then rudder is necessary).  Snaps and ANY variety of tumbles; Lomcevaks, Crossed Snaps, Knife Edge snaps, a maneuver I created called a Pinwheel, ALL of the tumbling maneuvers are simply OUTSTANDING.

    I put THIS Pitts through every conceivable maneuver that I know, and throughout the power envelope...NOTHING has vibrated loose, or broken, or even accumulated any slop.  Clevises and pushrods are as solid as new, and I probably have 15 VERY vigorous flights on the bird now.

    There are some changes to mine in the timeline; First, the ZDZ 40 is ADEQUATE and very Scale-like performance overall, but only about 2 1/2 vertical rolls from a level, cruise speed entry line/pull up.  I am NOT after "speed", but after "authority", and that means I need REAL vertical.  Second, the stock tailwheel steering is FAR, **FAR** too sensitive if you fly off paved surfaces.  It is extremely easy to be too fast on the landing and get a squirrel uncaged in a heartbeat.  I have reduce my tailwheel travel by using a much longer steering arm.  We'll see how that goes.

Update 4/13 - Took the time to check all the control travels, as the ailerons seemed slower than I prefer, so I thought I'd dial 'em up.  Well, I found that I had dialed IN some differential, which likely was causing the barreling I saw, particularly in vertical up and down rolls.  So, I re-measured EVERYTHING. Here's my current setup, and I'll update after I fly it....No matter how sure you are of stuff, it is ALWAYS a good idea to recheck when things seem unexpected (like the barreling I observed, and the need for so much rudder work in rolls = DUH!)

First flights took place today, April 12, 2002.  In between thunderstorms, with a variable-direction, gusty wind about 10-15, I decided to chance it.  Just couldn't wait any longer.

As expected, assembly at the field was the typical crawling around, hoping you don't drop screws and fumbling where you can't see type of operation.  But it didn't take long...I was pleasantly surprised.  The test of THIS will be in August!!!

After assembly, came range check...the JR R649 PCM receiver couldn't have been more solid....in fact, at the limit of my field, (that's my standard collapsed antenna distance), the range was the SAME - Engine Off or On!!!  That was sweet to know.  Rock solid.  Did all the wiggling, range testing, throttle up/down, etc., everything was fine. 

I have to mention, for those who are ZDZ 'disbelievers', that this 40 purrs like a kitten and pulls like a farm mule.  The ProZinger 20 x 10 revved up nicely, the 40:1 Redline synthetic mix worked, and just a minor tweak on the low end, and we were good to go.  To check it, I left it solidly secured (I ALWAYS do that), engine running, and walked back to the pits with my Tx to get my tray/neckstrap.  It just kept on ticking....Of course, when back at the starting line, I just whammed the throttle forward, she went right up to max rpm and stayed there solid.  No surging, spitting, anything.  VERY nice....sorta comforting for the "First Flight"....

Having NO logical reason to delay longer, I pointed the beauty about 45 degrees cross wind, expecting some weathervaning on rollout for takeoff.  Smoothly advance the throttle, and had to DRIVE the rudder...but only at first.  [Word of advice here...the stock tailwheel steering is enough to get an inexperienced person in trouble...of course, if you're inexperienced, you have NO business trying a Pitts anyway, right??] As she picked up speed, I was able to back off the rudder a lot, and she tracked straight down the runway, just a touch of crosswind rudder, and just a little up to keep the tail down.  After about 60', full throttle, I pulled her off, and needed only a little bit more right rudder on the climb out.

Engine purring, J&A muffler singing, I did the first few circuits, just feeling her out.  Solid.  Slightly heavy to the touch compared to lighter monoplanes, but it IS a Pitts, after all!  I needed about one beep of right aileron, about 3 down beeps of elevator, and 2 of rudder (confirmed after flight 4 that those settings brought the controls to their neutral, so the plane is pretty straight).  After the trim was in, I did some loops, half-cubans, aileron rolls, and played with different airspeeds [NOTE: She likes her life played FAST!!  Most of the clean looking stuff got really nice near full throttle; slower, and you REALLY know how much drag there is!] Decided to do a couple of snaps, and found out it is really easy to bury the elevator.  The stall is crisp, and the rudder/ailerons most effective, but if one overpulls the elevator, she'll mush down and lose airspeed so fast you think someone hung a drag chute out!  Did a few hammerheads, vertical rolls, a few 4 points and 8 points, and realized that the Pitts, as wonderful as it is to fly, DOES need to be "driven"...it is NOT a "point and click" sort of bird.  There is proverse roll couple, which speeds up the rolls when using rudder correction, so you have to back out of the aileron for the last third of a slow roll to get a smooth rate.  That's a little tricky.  

Knife edge is a SLIGHT belly pitch, with a little adverse roll (right rudder knife tended to roll out to the canopy), but I didn't mess with it today.  It will be fine.  The small rudder is misleading; it has PLENTY of authority....Oh, BTW - ALL throws and CG were set up exactly per instructions, dead stock.

Anyway, after about 6 minutes, the knees settled a bit, and I think my heart rate got below 130, so I thought about landing...well....it's a Pitts.  First pass was the far-too-slow-way too-much-flare bounce-diddy-bounce of yesteryear!  Such a rookie thing to do....but it was okay.  Only about three small bounces, and it was okay.  And didn't groundloop.

Post flight, I checked EVERY nut, bolt screw, pushrod, clevis, etc. and found NOTHING amiss.  My hats' off to Great Planes, they did this one right.  Refueled, I decided to just press on and get some more flights.

As the sky was threatening, and the wind coming up, I decided to just play around, and found it is a REAL blast.  You could call it a "tumblebug", if you wanted to.  She snaps, inside, and out, and does the prettiest tumble on a 45 degree upline you'd ever care to see.  Just gorgeous, and ends up level, flying out...really pretty.  Cross-snaps bleed off airspeed like the real one, and the windup at the bottom of an Immelman is something to be proud of...in all, I'd have to rate this one as just about the best scale-like bipe I've flown.  It is very responsive, works exactly like GP said it would, and meets my expectations.

This airplane would do FINE in Basic through Sportsman, and with a little more punch, Advanced.  But one better be skilled on the ol' rudder, pal....she needs it everywhere, just like the real one!  I am a VERY proud papa, and this one will get used a lot!

Some photos -

Right Side View	Left Front Quarter	Left Rear Quarter
Right Front Quarter	Top Left Quarter

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