50 size models usually require 5 or 6cell pack which are quite expensive andwon’t fit into my smaller models. So on theone hand these packs are used less fre-quently and on the other hand due to therelative high cost, one could usually onlyafford a couple of them. The result is thatthese larger models tend to be flown lessfrequently than they should otherwise. Thismakes for a poor investment in my book.

Up to this point, it had appeared thatpower hungry drive systems were the lastword in large EP models and anyonemaking the step will have little choice butto put up with the high investment, con-straints and limitations. When it comes tolarge EPs, I felt like a pig in a slaughter-house but all that was about to changeafter a sneak peek into PA’s crystal ball.

Synonymous with PA’s out-of-the-boxcreativity, I wasn’t at all surprised to hear abouttheir radical approach to their latest flagship,the 58” PA Extra MX. It runs on only two 3S22000mAh packs plugged in series. Humblepacks which most EP modellers already haveand thus gives practically anyone the opportu-nity to step into the 50 class domain without theneed to heavily invest and better still; withoutthe need to make a huge compromise on per-

formance. There was no hidden cost of dedicat-ed chargers or packs and THIS was exactly whatI was looking for.

First ImpressionA year before the launch of the MX, PA sent

me a prototype Thrust 50 and enticed me to giveit a spin. I installed it into my 54” Hyperion Yak54e and thoroughly abused it in the air. Although

my Yak weighed in at 5lb (2.23 kgs), theThrust 50 performed amazingly well. Therewas absolutely no lack of power and it feltvery lively with almost unlimited verticalson the APC 15x8E. Almost a “nitro-like”experience with generous amount ofpunch I might add. My own static benchtest indicated it produced about 1300W ofpower with whopping 10lb of thrust, thusgiving my Yak a 2:1 power to weight ratio,essential for good 3D performance. I washappy to note that an average 5 minuteflight only drew about 1412mAh from my2200mAh pack in spite of pushing my Yakhard. This was like driving an eco-friendlyNOX equipped Japanese super car!

I chuckled at the thought that I couldnever achieve that sort of performancewith my excessively leaned out OS70Ultimate powered H9 Funtana 40 on the

APC 14x4W and 15% nitro back then.It was many months before I received a real

shocker from PA. They said the AUW of theirprototype to be just a tad over 1.5kg ready tofly! I was dumbstruck because I would haveexpected a 58” model even by PA’s standards tocome up to at least 2 kg’s. The initial bench teststats I took earlier happily told me that I will begetting almost 3:1 power to weight ratio with

the MX, something completely unheard ofin a balsa 3D model in any class. Thisappeared like I will be getting to drive anF1 Ferrari pretty soon and I was reallyexcited at the prospect.

It came the day when my review modelfinally arrived and naturally, like a kid onhis birthday, I simply could not wait toopen the box. I was blown away by thesight of the exquisite metallic mango &black finished airframe that came with thecolour matched fibreglass cowl and wheelpants. Predictably, I immediately removedall the pieces from protective plastic bag totake a closer look at the inside.

I was impressed to see that PA has usedconsiderably more carbon fibre in the MXthan its smaller processors I have flown inthe past. It had CF stringers the entire lengthof the fuselage along with CF on the batterytray, wing attachment and cross braces. TheCF landing gear felt stiff and robust, perfectfor rough landings. The MX comes with fullyairfoiled vertical and horizontal stabilizersand factory pre-assembled ailerons built intothe removable two piece wings. There ispractically no hinge gap present.

According to PA’s website this is quitecomplex to produce: the ailerons fit intothe wing trailing edge tunnels and areglued and pre-aligned in the factory.Despite the laborious production of thisdesign, PA decided to produce the aileronsthis way, as it allows perfect aerodynamicflow over the airfoil and results in maxi-mum efficiency of the control surfaces.

I perused the contents of the hardwarepack and I was quick to note the gleamingCNC metal clevises, plastic ball links andCF control horns and the optional CFVortex generators packed separately. I wasthoroughly seduced by the “bling”!

The BuildThough extremely excited at this point,

I forced myself to refrain from building tillI went through the manual. I found themanual to be very comprehensive indeed.It had text complemented with graphicsand time saving tips and I can safely attestthat any modeller (except a completeblind imbecile) would have absolutely noproblems building the MX at a leisurelypace in just three short evenings.

As most parts are already factory pre-built, assembly was quick and easy. I startedthe build with a customary dry fitting of theairframe to check the fit and for any possi-ble covering warp. The fit was perfect andonly once did I need to employ a file to fitthe motor box and some light sanding toline the elevator up. Everything else fittedwithout a hitch and lined up beautifully.

When it came time to commit to glue, Iused 30 minute epoxy as recommended inthe manual. I would recommend sticking tothis for maximum structural integrity; withthe benefit of hindsight, this decision hasnow paid off big time, since all structuralcomponents on my MX are still intact after150 punishing flights to date. This has nowgiven me a lot of confidence to try almostanything in the air without much worry.

The German made ball links and CNCmachined aluminium clevises employedfor the linkages fitted well and providedslop free mechanics. These clevises arenothing like spring clevises. I spent a littlemore time aligning the servo arms andthen filing the CF rods to the preciselength before applying epoxy. Onceassembled, I did a pull test on the assem-bly and it gave me a very confident feelingabout its integrity. It also eventuallyproved to be very robust in flight.

With all the servos installed, I wasamazed at the slop free and direct feel itoffered. Ball links and metal clevises arecertainly the way to go!

With the MX finally built up, I insertedthe battery packs and weighed my MX. Itcame in at an unbelievable 1.76kg! None ofmy previous smaller “super light” 40 size3D models ever came close be below 2kgeven after “cheating” with dry fuel tanks!

With all control throws as per the man-ual, I positioned the battery packs toobtain the recommended “sweet-spot” CGof 118mm and diligently inscribed a markin the fuselage and I was finally set for theweekend’s shakedown.

The ShakedownWith only a very gentle breeze blowing,

it was ideal flying weather for stationarytorque rolls, hovers and to check its preci-sion flying capabilities. With high rates set,I executed a full power rolling takeoff. It

was exceptionally short and MX went verticallyup into a low stable hover transitioning into anice slow torque roll and then moved into a setof slow harrier rolls. Despite it size, the MXseems to float in the air. I was blown away athow stable it felt and I haven’t even trimmed herout yet! I was already grinning from ear to earsince it felt so familiar to the smaller PA modelsthat I have been flying previously. All my priorbig plane anxieties melted away and no longerfelt intimidated by its size. Advancing the throt-tle and putting the MX into a straight and levelflight, I did a series of upright and inverted levelflight and I was really impressed how neutral itfelt and proceeded to try a few 4 point and slowrolls. They were easy to get precise and I mustadmit that I have never managed to do decent 4point and slow rolls on zero expo with highrates prior to this! For a 3D capable model itexceeded all expectations in the precisiondepartment and in my humble opinion wouldcertainly please any IMAC enthusiast.

Switching down to low rates, I explored itsprecision capabilities further and found that iteasily maintained precision flight very well. Itdoes spectacular big air loops and Split-S withthe smoothness that I can only relate to 100ccaerobatic gassers. On the recommended CGthe MX felt very neutral and tracked remark-ably well. There was hardly any correctionneeded to be made to keep on track and gavethe feeling as if flying on rails.

Switching back to high rates, it was nowtime to explore its performance envelope fur-ther and I started with a simple KE manoeuvre.The KE was absolutely coupling free. All that isrequired is a quarter roll and hold the rudder.That’s it! This is what I call “user friendly”! Sincethe KE’s were so easy, I kept flying KE circuitsand alternating KE figure 8’s and then slowingdown to see how slow and stable it holds. Itsreally amazing to see such a big model flyingslow and stable KE’s! The Quantum 65’s silkysmooth throttle response made it very easy tofine tune the altitude while flying slow and low.This also makes it very easy to maintain precisealtitude while hovering down on the deck.Pushing the throttle on the KE, it did a nice bigKE loop with absolutely no tendency to roll outon the down-line. Sweet “Puckerfree” KE loopsas I chuckled to myself.

Getting bolder, I began to advance the throt-

tle more to check its high speed performanceand I was not disappointed. The powerful Thrust50 gave me a distinct sense of invigorating ener-gy, something I missed from the days of flyingnitro models. In spite of using small packs, it isby no means an underpowered lumbering pieceof flying timber but in fact quite the contrary andbeyond all expectations of a typical EP model. Infact it was a completely new flying experiencefor me and I felt revitalized. The rolls were asquick, crisp and precise. It felt very responsiveand alive. Coming in low and fast into a verticalclimb, it showed off a pretty insane climb rate. Itwas is if I had afterburners on and it just climband climb to a point where I had to ease back onthe throttle for fear of flying beyond the radiorange and descended with a rather long drawn,slow KE spin and exited into an inverted eleva-tor and harrier. The inverted slow harriers wereso stable that I felt confident enough to bring itdown low and pop into an eyelevel hover as Iwould with any of my smaller models. Beforelong I must admit that I totally forgot that I wasactually flying a 58” model and in my mind feltas if I am just having fun with one of my small-er models. I did another vertical climb andpushed 3/4 throttle into a very aggressiveblender. Wham and my jaw dropped! Theblender was wild and recovery was as pre-dictable as any of its siblings. With so muchpower on tap, I did not find the need to use allthe power of the Thrust 50 and I happily flewbetween 1/2 to 2/3 throttle most of the time.Having said that, the knowledge of having somuch reserve power on tap felt extremely com-forting. Its definitely as hot as a jar of Jalapeños.

Keeping my flight time at a conservative 6minutes for the maiden, it was time to land andI did a nice long upright elevator into a harrierspot landing. I was thoroughly impressed that ittook the same amount of runway for the roll outas its smaller siblings and equally easy to exe-cute; something virtually impossible with my

54” Yak. As a matter of fact, I have alreadyclocked about 150 flights at the time of writing,and to be honest I have only done 3 conven-tional landings with the MX. The conventionallanding actually felt considerably easier than a.40 size nitro trainer. I am pretty confident thatanyone who has mastered spot landings willonly need a runway no longer than 3m land theMX. Big as it maybe, this baby packs some seri-ous STOL capabilities that are rare on other sim-ilar class models. As such it gives a lot of flexi-bility on where it could be safely flown.

Don’t take my word for it, check out the fly-ing videos in www.precisionaerobatics.com

On subsequent sessions I installed the CFVortex Generators (also known as Side ForceGenerators) and found that it actually enhancesthe stability of harrier and elevators even more.It also gave a bonus of further widening the aer-obatic performance on one CG position. In myopinion, I would strongly recommend installingthe VG’s for anyone who desires flying both pre-cision and 3D on one session.

My TakeThe MX engineering design is by far, light

years ahead of the rest and in my humble opin-ion PA’s brilliant concept for the MX with itsiPAs package represents the absolute panicle inEP technology available off the shelf. Nothingeven comes remotely close to matching thislevel of performance and certainly lives up toits catch phrase:- Beyond the Max!

From what I have experienced thus far, theMX capabilities are only limited by the pilot’sproficiency and creativity behind the sticks. Itspredictable and easy handling coupled withsuperior agility and awesome power makes itan extremely formidable unlimited aerobaticmodel that would easily please intermediatelevel and experts alike. After 150 flights andgiven the artistic license, I would dare say LightYears Beyond The Max.

What really impresses me most is the factthat the MX is only PA’s first attempt in the 50class EP category. Not only did they get it rightthe first time but in fact the MX redefines theentire class and possibly creating a new genrein aerobatics.

DislikesPA went as far as designing their own thumb wing bolts – they look cool but I would

have to say that they felt a tad soft and could easily shear under excessive force. Alsoperhaps the manufacturer could include a paper template to help locate slots for the VGs.The Extra MX and all required set up is available from www.PrecisionAerobatics.com.

Call 02 9558 0443 or email info@PrecisionAerobatics.com for more details.