Tuesday, August 7, 2012

Parkzone Albatros D.Va WWI BNF–Build and Flight Review

Update 8/3/12:  Also see Parkzone Albatros 3D


Update 8/7/12:  Like all Parkzone 40 inch-class foamies, the wing mounts are already loose.  Added the usual thin foam weather stripping.  Opened the whole bottom half of the plane again.  I shoulda put the foam tape on the bottom wing roots during the initial build, but I thought maybe this time would be different. 

Nope.  Lucy pulled the football away, again.

Additionally, the bottom wing is developing cracks at the underside root.  Granted, I’m flying the plane harder than most, but the thin chord was so obviously under-designed as pointed out in my pre-flight review. 

Horizon Hobby is falling to a distant last place regarding general quality and also quality control.  The 1/2 price-or-less Chinese makes are heads and shoulders above Horizon’s overall build quality and even farther ahead on value delivery. 

Original article follows:


INTRO

Some might not notice, but with very few exceptions the airplanes I review all have one thing in common: they are classics.  This build and flight review is no exception...

flying_thumb2_thumb
SPECS
-
Wingspan: 42.3 in
- Overall Length: 35.0 in
- Flying Weight: 43.4 oz
- Motor Size: 480-size 960Kv Brushless
- Servos: 4 digital servos (installed)
- Prop Size: 10 x 8 (included)
- Speed Control : 30-Amp Pro Switch-Mode BEC
- Recommended Battery: 3S 1800mAh 11.1V LiPo (included)

FEATURES
- Construction: EPO (Spongy Z Foam)

REQUIRES
- Radio:  4 channel 
PAID
$340 MSRP
$249.99 Street
+ $20 tax
= $270
ESC failed before second flight.
Horizon wants $120 in total to/from shipping to replace it.
= $390 as purchased and warrantied
WOW!

PLANNED UPGRADES
- None  (Update 8/3/12:  Also see Parkzone Albatros 3D)


ON THE GROUND
 
UNBOXING
As usual, the Albatros comes nicely packed in a very large Horizon Hobby box compared to most planes its size. The plane arrived in good shape.
 box
The most surprising thing about the unboxing is the number of parts.  The Albatros “Bind-N-Fly” (not!) ships in, count ’em, 66 pieces. 
 
parts

Plan on 2 hours of awkward assembly.  BNF, yeah right!! 
Liars.

On top of the high parts count, assembly is overly complex, fussy, frustrating, risky and time consuming. 
 
Example, none of the screws fit properly, and the delicate airplane needs to be manhandled to force them in.
 
One would hope that the instructions would at least be helpful.  One would be wrong.  The instructions are some of the worst I’ve seen, and the assembly order makes for maximum difficultly handling the pieces as they go together for absolutely no reason.

Example:  The tail is put together last, making it very difficult to manipulate the rest of the plane, but it doesn’t depend on having the wings together first, not in the slightest.
 
What a chocolate mess!   Yuck!
 
APPEARANCE / FIT N FINISH

No doubt, the Albatross is a great looking foamie once completed. 

I like PZ’s chosen colors and they are really vibrant in the air.  The details like the plastic and foam engine façade, plastic wing struts and guns are a nice touch. 

motor
Z foam and its delicate finish is always a letdown.  For some reason, Horizon EPO models are more susceptible to dings and fingernail scratches, and the paint peels too easily. 

If you crash-proof with leading edge tape, like I do, the delicate finish gives you one opportunity to get it right.  Once the tape touches the paint, pulling it back removes the paint.  I expect a better more durable finish at this price point.  Horizon needs to copy better, cheaper Chinese builds.

The wing supports are fussy to install, the tongues being a little too large for the grooves, needing to be gently forced.  And the landing gear assembly is eye endangering; the long metal hooks have to be fashioned into a flailing contraption of piano wire, plastic covers and screws.  Juggling it into place without turning your new bird into a scratch-n-dent special is an exercise in patience.  For that matter, wearing safety glasses will help keeping both of your eyes from becoming a scratch and dent special, too.  

I’m too impatient for these BNF things, I wish there was a way to buy a plane that would bind to a radio and fly.  You know, just fly.  This is one of the more frustrating kit planes I’ve assembled in a while.

BUILD QUALITY/SETUP
Build quality is a low point.  The plane turns out pretty plasticy, with needlessly complicated Rube Goldberg landing gear.   Any mishap to this baby is going to do some serious damage to a ton of tiny customized parts. 
 
The Albatros D VA seems to achieve a new point low within Horizon Hobby’s “rip off the customer by selling lots of overpriced parts” business model.  You can feel the propensity to beak as you stress the plastic pieces to get the plane together.
 
A typical, but Abatros-magnified Horizon Hobby kit plane annoyance is that none of the 25 or so screws fit right, you have to bear down very hard with your best screwdriver to get the screws to seat properly, raising the Spector of badly breaking the plane before it ever takes off.
 
Some of the screws, particularly the landing gear axle assembly screws, don’t hold their pieces together tightly even after they bottom out in their easily strippable plastic anchors.  And speaking of those custom molded cheap plastic anchors, the manual makes a big deal out of noting the left/right designation, but the L/R parts are utterly identical and completely interchangeable.  It’s like some control freak designers simply wanted to force you to follow their direction, even though the plane’s assembly and build complexity is off-the-charts random.

The wings are lightly reinforced on the bottom sides with what appears to be a thin fiberglass insert, PZ T-28 style.  I guess carbon is too expensive for a $250 model.   Hmmm. 
 
The bottom wing root is clearly too thin to survive most combinations of stick actuator and wind miscalculation.  It almost broke a few times due to the fact that the bottom wing was attached (and re-attached and reattached to re-open the plane) before the tail was assembled for no good reason.
 
1/3rd to 1/2 price Chinese builds use copious carbon fiber and plywood embedded in their wings and fuselage, the Albatros has none of either material present but plenty of need.
weakrootIMG_7437

The bottom wing root is too weak due to the flimsy nature of Z foam.  Add the rear notch for the gear and the bottom wing attach point is an accident waiting to happen.

The battery connector leads are so thin, you’ll swear the Albatross uses a small 2-cell.  The electrical components are absolute junk.

The EPO foam is less sturdy than really good modern day China EPO.  Horizon’s “Z Foam” is heavy on marketing and low on performance.  It is flimsy, somewhat delicate and too susceptible to finger print indents/crushes.  The Albatros’ thin foam wing attach points really emphasize the flexible nature of the foam’s integrity. 

The final assembly is fairly heavy and lifting from the top wing center point, the only natural handle hold, easily crushes/dents the top surface of the wing. 

The optional steerable tailwheel is a nice touch.  The last thing I need is another skid.

In the end, assuming you arrive at the end in one piece and with your wits intact, the plane looks pretty nice, if not a little “too puffy” for scale.
 
I made the mistake of waiting til I was almost ready to drive to the field to fire up the electrical system for the first time; I should have done it the night before, but I chose sleep.  I plugged in the battery expecting to set a little sub trim and expo, check the servo directions and drive off.   Bzzzzzt! 
 
Bzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
The first thing that was odd was the ESC arming, it took about 30 secs after battery power was applied to tweedle the E-Flite ESC song – a red flag. 
 
The second problem, this one huge, was that the elevator servo’s stubby little 3” wire lead (could the manufacturer cut cost corners in any worse way than that??) had pulled out of the Rx when I Velcro'd it in the tight slot next to the ESC.  Stupid me, I didn’t notice.  With any other plane, I wouldn’t have to write about something so simple, but with this assembly nightmare, the entire lower half of plane had to be dissembled, pushing the cheap plastic screw anchors to the limits and marking up the foam with flailing landing gear piano wires, again.  Crap.
 
I took my time even though winds were dead calm, and disassembled the whole bottom apart without breaking the thin foam wing root, yay.  I even managed to get it back together without stripping the 10 involved plastic screw anchors.  15 minutes of PERFECT flying weather later, I powered the electrics back up.
 
Elevator good.  Rudder bad.  Same thing!  You gotta be kidding me.
 
Re-opened the bottom of the plane; this time hurried.   15 minutes and a few hurried dings later, all the electronic leads were seated and, now, zip tied.
 
Running full bore on the ground produced 22.7 Amps and 265 Watts.  Well within the range of the 30 amp “Pro” (more on that later) ESC.  If not weak.
 
After all the assembly and re-assembly and re-re-assembly, I noticed the bottom wing’s front attach point was loose, allowing the Angle of Attack to shift up/down slightly.  I thought it might be my fault from opening and re-opening the plane, but it was actually just a loose mating between the two pieces of hard plastic designed to form the front lower wing mount.  I inserted a slice of thin cardboard from inside the battery access door and tacked with CA.  Fixed.
 
Finally.  Ready to drive out for the maiden.  One hour of precious calm winds, lost.  Uhg!  Now that’s the way to piss off your customers.
 
In finished form, this plane is effectively a one-piece build.  Taking a wing off is too painful, time consuming, and damaging.
 
GROUND ISSUES
  1. Extraordinary build complexity while “binding to fly”
  2. Too many custom plastic parts seemingly designed to break, forming HH’s usual but ill-advised cash flow model
  3. EPO foam is not as strong as other makes; foam surface is too spongy and dents too easily; paint is too easy to peel and mars easily.
  4. No reinforcement in the foam fuselage; only thin fiberglass strips under the wings.  No carbon fiber. 
  5. Single horizontal stab screw goes into a plastic brace that isn’t glued to anything, both could just fly off.
  6. The lower wing roots are too weak where notched for the landing gear.
  7. It is way too difficult to access the interior.
  8. Servo leads are too short (3”) and want to pull out of the Rx.
  9. The ESC battery connector wires are too thin gauge for safe 20-30 Amp operation.
  10. The instructions are useless. 
  11. Many different screw sizes are provided but never distinguished in the manual.
  12. The assembly diagram blow-out is too small and jumbled to discern how the landing gear is supposed to go together.
  13. The assembly diagram blow-out is too small and jumbled to discern how the optional tail wheel attaches and should be routed. 
  14. The tail wheel installation requires cutting foam.

All of this can be figured out with trial and error, at least you won’t get stuck.

Frustrating assembly is an understatement!  “Bind-N-Fly” is an outlandish marketing lie.  This model is a BNFU.
 

IN THE AIR
 
grass1
BLUF
A delightful slow flyer--while trundling in the heart of its envelope—but displays significant vices when moderately pushed.

START/TAXI/TAKEOFF
The significantly nose heavy stock setup wants to bounce the tail wheel up off the ground, so full back stick while taxiing is a must.  The optional tail wheel (the other option is a scale skid) works well.
 
Operating from a manicured grass field would be easy if it weren’t for the tendency to nose-over the mains.  CG is already an issue. 
 
GENERAL CONTROL
Once airborne, the fiery red plane proves to be a great slow speed floater, its seeming purpose in life.   There is enough double-wing area to mostly counter a pretty high weight and build density.
 
My first maiden turn was to the left and I immediately noticed the tail sag low in the turn.  Thinking I needed left rudder trim, I input a few clicks.  But now the plane wanted to yaw and roll a little to the left when wings level, so I entered some right aileron trim.  Then, when wings level, the old German seemed to slip a bit sideways through the still-calm morning air.  Hmmm.
 
Soon, I realized the Albatros didn’t need any of my trim inputs, except maybe a tiny bit of wing-leveling aileron trim.  What I initially perceived as yaw misalignment was actually a surprisingly severe affinity for adverse yaw, combined with an ineffective vertical stab.
 
Holy Moly, the yaw axis is all over the place.  Precise left/right directional control feels like steering a Porsche while cuffed with a Slinky. 

I decided to land part-way through the maiden so I could take out the trim and visually re-establish the center point on the rudder and ailerons, then try again.  After that, the plane’s unruly yaw coupling at least made sense.
 
Maiden (My HD video camera is arbitrarily limed to 10 min clips):
 
BALANCE & AEROBATICS
As stated, the CG is too far forward by design.  The 3S 1800 mAh spun the insufficient 480 for over 10 minutes, so there is an opportunity to lighten the nose with a 1200 to 1600 mAh 3-cell.  There is also some ability to slide the battery into the fuse so it hangs off the back of tray, but it is clearly not designed for that.

My second flight with a 1250 mAh 3S had to be aborted before takeoff, as the ESC failed on the second electrical power up.  The motor initialized and beeped, servos repositioned, but no arming tweedle or servo responsiveness to the Tx.  ESC was toast after one lazy sortie!   Luckily it waited until the next ground power-up to glitch.

Albatros aerobatics were, well, interesting.  That’s actually good in my book.  The plane has no lack of flight character.  But realistically, that character is a combination of (mostly) simple Parkzone design gaffs and (less so) genuine WWI flavor.
 
The first flaw is the forward CG, making the beginning of each glide a hurried re-trimming exercise.  That increases stall speed noticeably above optimum for the airframe, and speeds landing touchdown while limiting the amount of flare you can squeeze out before dropping a wing and the nose pretty hard. 
 
Design miss.
 
The second flaw is massive adverse yaw with severe roll-to-yaw coupling.  See maiden video, 7:10 mark.  It reminds me of flying the A-10, where high mounted motor mass limits the number of continuous axial aileron rolls to about a half a roll before the plane is wobbling uncontrollably due to the dumbbell effect. 
 
The major roll-to-yaw coupling could be a genuine Albatros trait, but if so, it is sufficiently wild to have warranted an RC implementation re-tune.   The nose hunts all over the place.  Differential ailerons would help, as would some AIL—>RUD mixing, as would a bigger or longer horizontal stab. 
 
Design miss.
 
The third flaw is aggravated stall behavior.  The most fundamental cause is the portly weight.  Barring a lighter more powerful re-engine (easy to imagine since the brick E-flite 480 is weak and power hungry) some aerodynamic mitigation is in order.  The unpredictable wing and nose drop, and the wacky kick-in-the-rear yaw instability needs to be addressed with some copious washout.  More washout, at this late juncture, is probably best induced with a few clevis-turns of up-aileron on both sides.  
 
Design miss.
 
Taking the plane’s vices as they are, aerobatics are still plenty of fun and you can easily blame the flailing craft on it’s WWI roots, even though the real cause is its modern-day RC designers’ aerodynamic stupidity. 
 
Loops:  The super cheap 480 power system (at this price??) is too weak to pull up from cruise to get over the top without a near-apex slop fest slide off.   Start from a slight down hill entry with a head of steam, then love your eggs—no choice—maybe the plane should have come with bacon.
 
Rolls:  These make a great demo footage for Aero 101 Lesson 3, “Introduction to Adverse Yaw.”  Coordinate with hard pokes of pro-rudder during the erect (uh…. huh huh, I said hard, poke, and erect) portions of rolls and then abruptly reverse the rudder to counter-roll during the inverted portions.  Great practice for normal adverse yaw control, but crazy exaggerated.  But still, kinda fun, and I like the challenge of executing an axial roll with this yaw axis weeble wobble.
 
Other Recognizable Maneuvers:  Good luck!

POWER SYSTEM
Cheap.  Weak.  Easy on the battery in an absolute sense, but inefficient for the heavy motor weight and low thrust production. 
 
E-Flight “Pro” ESC corner cutting limits your safe power-increase options due to the itty bitty battery wires.  Shameful quality. 
 
ADVANCED HANDLING CHARACTERISTICS
AHC is not really possible, beyond wallowing through unruly stalls with the tail feathers tracing uncommanded Figure 8’s.
 
APPROACH & LANDING
Easy.  No issues beyond a mild struggle to hold up a heavy nose in transition to flare and flare.  Keep her flying all the way to the ground.

IN-FLIGHT ISSUES
  1. Ineffective vertical stabilizer design (could be scale but could’ve also been fixed without impact)
  2. Crazy adverse yaw is actually kind of fun. Higher than desired weight increases stall speed.  Still goes slow.
  3. Forward CG.
  4. Pot-luck stall behavior—usually wing rock resolving into a right-wing-low nose-low side slip with increasing right auto rotation.  Yeesh, careful!

OVERALL
All that said, the Albatros is still a delightful floater with a light battery.  Easy to handle and very relaxing to fly when semi slow and consciously rudder-coordinated.  You have to fly the tail around, heli-style.
 
Gorgeous lines and brilliant colors.  I like the pilot scarf fluttering in the wind, even if it was copied from the old Great Planes Tri-decker pilot.

Plenty of simple RC design vices could, very generously, be called “WWI personality.”   But this bird will almost certainly bite a beginner with its swashbuckling yaw divergence and nasty stall behavior.


GRADES

Appearance: A+
Some’ll hate it.  I love it.  Brilliant in low angle sunlight.

Aerodynamics: C-
Lovely floater when manually coordinated in heart of the airspeed envelop.  Otherwise, pretty unruly.  This is one airplane where AS3X would’ve made real money, but the Parkzone dudes were too dim to figure it out.

Power System: D+
Cheap.  Weak.  Heavy (even with a plastic case?!).  Inefficient.  Arguably, character is true to period.

Build Quality/Durability:  F
Horrendous (dis)assembly.  One piece when finished. Class trialing component quality.  ESC dead on second sortie power-up.

Value:  F
$270 for an ARF (sold as BNF/PNP).  But mine was $390 to pay the to/from shipping charges quoted by Horizon to replace their junk ESC with another POS.  Is this some new-fangled “junk for gold” program? 

Overall Grade: F
“Pretty” is where the fun stopped.