Andy Ellison and Julian Beckett review the .46 and .90 size models - 5/1/11
3D - It’s everywhere! 3D this, 3D that, a shock flyer epidemic, heli’ fliers trying to implode their expensive machines, dethermalising tails on slope soarers, reverse pitch props on indoor electric models - what next? Free flight duration prop’ hanging?
I’ve dabbled in the past, but sometimes without actually realising it! I used to spend hours copying Hanno Prettner’s Sandown Park tricks with my Wot 4 back in 1983. I’ve even owned one or two of the early ‘dedicated’ toys, but never really found one that I was happy with. Truth is, if you’re a 3D-capable pilot it’s not always easy to learn new tricks and manoeuvres unless you have the right machine. If you’re having to battle with the airframe you’re on to a loser from the start. That said there are many dedicated models available these days, and most of the aerodynamic issues are being addressed. With high-torque 3D servos being developed and propeller manufacturers increasing diameters and shallowing pitches in their new 3D prop’ ranges, it seems that a revolution is well and truly here.
Whilst I’ve never been one to jump on the bandwagon with trends, when Graham gave me the opportunity to get my hands on a new 3D toy I was very keen - rapture and double delight when two arrived on my doorstep! It’s no surprise that Seagull’s Harrier is named after the manoeuvre, it’s one that the manufacturers claim they will do particularly well. The model comes in two sizes, the 481/2” (1230mm) span Harrier 46 and the 611/2” (1565mm) span Harrier 90, the latter being slightly more favoured by discerning 3D pilots. Mind you, it seems the smaller models are just beginning to really break through and, who knows, they could be the next ‘big thing’.
Not wishing to be too greedy I dragged my old mucker Julian in for the ride. He’s well into 3D flying and can draw the odd round of applause from the indoor ‘Shockie’ crowd when he has to. He’d also just ousted a useless 3D airframe, which meant that he had all the required gear for the bigger Harrier.
There were a few things that struck the pair of us when looking over the models. Firstly they’re not the prettiest aircraft around, but that’s what functionality gives you.
There’s no fin; bags of side area, with the rudder slipped into the back of the deep fuselage. However, the main thing that hit us was the sheer quality of the kit. The build is very, very good and the Ultracote covering is simply the best we’ve seen on an ARTF - a credit to whoever specified it. One minor problem that the covering job does bring to light is that you have to stop and think for a moment before you pick the model up, as it’s quite difficult to find a non-squidgy grip point.
Another item of note is the practicality of having a two-piece, plug-in wing. Transportation is a breeze compared to some of the stuff we’ve dragged around over the years. The wings are joined by two quite large aluminium tubes and retained by wing bolts through the fuselage sides. These are easily accessible as the whole of the front fuselage top decking lifts off.
The instructions are a bit of a curate’s egg. Well-illustrated and broken down into the most basic steps, but it really doesn’t need a page and a half to tell me how to apply cyano’ to an aileron hinge followed by another page and a half to describe the same operation on the elevator hinges!
The hardware pack is very complete, and despite Julian’s misgivings about the strength of the horns they proved to be more than up to the job when we tried to wreck one. There are some long and unsupported 2mm wire pushrods that tend to whip a bit under load, and they’re really not conducive to the longevity of the model - especially so on the big Harrier. As mine were already bending on the bench I decided to sleeve them with 4mm carbon tubing; this way I could still utilise the supplied fittings rather than changing them all to 3mm. Julian upgraded this area of his model as well, employing some scraps of carbon and some Pete Tindal fittings. Believe me, as supplied the pushrods really could cause the model to crash - if you decide to build a Harrier then corrective action must be taken!
Since the instructions advocate cyano’ for locking everything in place, there was a distinct lack of locking nuts or spring washers. However in reality you’ll need to get something off once in a while, and if everything’s cyano’d up you’d have a problem! An alternative method of locking things down is required, as vibration (from four-stroke engines in particular) will soon have things dropping off all over the place.
Aside from a few cosmetic differences (the large one has a wire-braced tailplane and no spinner whilst the smaller one has a big shiny red spinner) there really is nothing between the two other than size.
‘Building’ is a term loosely used in ARTF circles, perhaps ‘fitting out’ is more appropriate - and there’s not much fitting out required with the Harrier; once you’ve glued in the tail feathers the rest is a formality. With three servos to fit in the rear, wiring can become a rats nest if you’re not careful. To this end a simple paper tube up the back end keeps things neat and tidy under the see-through covering.
There was some misalignment in the pre-fitted captive nuts on my undercarriage and Julian’s bulkhead bolts were a full 12mm out of place for the ASP 1.20FS he was using. After checking that he’d not done anything stupid with the motor mount (like hang it upside down or something), he took corrective action and altered the thrust line for the cowling, avoiding that ‘Concorde on approach’ look. The cowling is much simpler to dress for a four-stroke motor than a two-stroke. Mine was going over an Irvine .53 and although still tidy it ended up looking like a piece of gorgonzola with small holes all over the place for access.
The tail wheel screws to the bottom of the fuselage with a tidy fitting, clamping it to the underside of the rudder for steering. A set of tidy looking spats cover the main wheels, though these had to be dressed out to allow the wheels to spin freely. Moving within, the simple tank arrangement is very easy to fit snugly under the removable fuselage top, and there remains lots of space to fit the NiCad and the receiver battery pack. I do wish that the removable top had been supplied with some kind of canopy flooring to hide the gear under that big clear bubble, in fact, at a later date I’ll cover the underside with something suitable.
All that’s left to do after this little lot is apply the (simply awful) decals. They’re printed onto a semi-clear sheet that clashes with the covering in the most horrid way. Best to cut most of it out if you’re going to use them. Oh, and it will also say ‘Harrier’ in 8 places on your model as well as silly things like ‘No Step’ if you decide to use them all. Fortunately, Julian has a vinyl cutter and binned the lot in favour of his own brand. I stuck with a couple or so for the photo shoot but they’ll be coming off again in short order, I can tell you!
The secret of easy 3D often lies in good propeller selection. After trials Julian opted for a 13 x 4” APC on his four-stroke, whilst I settled for a 121/4 x 33/4” APC on the Irvine .53 (this prop’ was originally developed for control line stunt use). Anyway, nothing left to do now but fly. I’ll let Julian report on the ‘90, I’ll chip in afterwards with anything noticeably different for the ‘46.
FLIGHT REPORT - HARRIER 90
“The take-off roll is very short. Pretty much as expected and totally understandable with that big, stump-pulling four-stroke up front! Note that using low rates for take-off and landing is to be advised before slipping it into ‘crazy frog’ mode when you’re safely airborne.
“You’d expect that a model with barn doors for flappy bits would be all over the shop in an instant, but the reality is very different. She feels very graceful on the sticks and is capable of regular aerobatics on low rates - something many devoted 3D models often struggle at! This is a good starting point to build a relationship with the airframe and get a feel for the things to come. You’ll quickly realise that there isn’t a stall as such, it’s far more likely that you’re going to upset it by using too much elevator throw and messing up the tail than suffering anything wing-induced. With all that side area, knife-edge flight is a real gimme; on high rates very small knife-edge loops are a real hoot to perform, with those around you cringing as the model simply shrugs off the manoeuvre.
“I tried various mixes, and herein lies the real secret of mental manoeuvres. Snap flap didn’t work as well as I thought it might, with the model getting a little cross with me when pulling lots of elevator in really tight loops. Reflexing the wing to the point of ‘dethermalisation’ is a better way to go in order to achieve effortless harriers etc. I started out at 10% spoiler but eventually settled on 20% with application coming via a mixer switch. This reflex makes the model rock steady in the harrier, both upright and inverted, with the tail well down beyond the 50 - 60° from horizontal. It’s great fun to traverse the patch with only the tail wheel touching the ground!
“To achieve a nice ‘flop’ into inverted harriers and parachutes meant moving the C of G further back to around 200mm from the l.e. root; but I now have to land the model with 1/4 down elevator!
“This rearward C of G permits the execution of much crisper entry into most 3D tricks, but I had to max out the elevator throw to get it right on the money, which caused concern as even with all the bracing wires, the tailplane was visibly waffling in the prop’ wash. For this reason I avoided my favourite cringe inducer, the blender, lest I be faced with the first tailless Harrier shortly after...
“The extra size of this larger model gives the pilot more time to think, and more time to admire the crazy attitudes that it can be coaxed into. My favourite is a short vertical climb into an inverted flat spin - if the entry is just right the model will rotate on the spot for as many revolutions as the pilot dares, without descending. It looks particularly cool to fly out of this bizarre manoeuvre in high alpha knife-edge!
“The model’s size took some time to get used to. She’s really big at close quarters and a little intimidating if you’re not very confident with low-level, ‘in your face’ hovering. Following a couple of good flights on a nice calm day I was able to tap the rudder on the ground at my feet, with a seriously juicy hand catch for dessert!
“Landing is quite easy but the model does have a tendency to hit the floor tail first. A blip of power is often required at this point to stop you dropping vertically and splaying out the undercarriage.”
FLIGHT REPORT - HARRIER 46
Much of the above flight report applies but obviously with its lower wing area and slightly higher loading the smaller model is less inclined to ‘kite’ around. Whilst the tail is unbraced it doesn’t seem to suffer the wobbles of the bigger machine and, in terms of power, the Irvine .53 is about as small as you’d want to go for satisfactory vertical performance and safe hovering on what turns out to be quite a heavy model. Even on the shallow pitch prop’ it could better benefit from a mini-pipe of some sort.
A more powerful and slightly larger four-stroke like the Yamada .63 would probably be ideal, or possibly the higher end range of the O.S. 70 Surpass series.
Anyway, the model requires a slightly longer take-off run than its bigger brother, this possibly being due to the tail wheel holding the back end up and obstructing the rotation a little. Despite misgivings at first about the suitability of standard servos on a model of this type, they handle the flight loads perfectly well.
She flies quite slowly with a shallow pitch propeller and you’ll not experience flutter if you can nail the linkages. At the other end of the speed range it’s entirely possible to make the model fly like a pig if using excessive control throws or switching to 3D rates in the wrong attitudes. However, if you can get your head around the amount of switch flicking required for proper 3D, then always deferring to a ‘safe’ mode before flying away will help when you get the model into a little trouble. The model is very draggy, which is quite desirable, but you don’t want to be hanging around too long with a dead-stick motor. Make your decision quickly and get it down onto the patch to avoid damage arising from running out of ideas and altitude all at the same time.
Whilst the tail on the larger model could be a bit stronger (particularly with the requirement that they both have for lead at the back end to optimise the centre of gravity for 3D flight) we were both very pleased with the models.
As you’ll know, 3D flying is very popular right now, and if you want to cut your teeth on a suitable aeroplane, both Julian and myself thoroughly recommend the Seagull Harrier. With the smaller model having a street price of around £90 and the bigger version only £30 or so more, it really is hard to fathom how they do it for the money. Distributed throughout the UK by J. Perkins, any model shop worth it’s salt should be able to get you one very easily indeed.
DATAFILE - Harrier 90
Name: Harrier 90
Model type: High performance 3D ARTF
RRP: £153.99 (Dec 2010)
Wingspan: 1565mm (61.5'')
Length: 1690mm (66.5'')
Wing area: .72 sq.m. (7.75 sq. ft.)
All-up weight: 8 lb 2oz
Wing loading: 17 oz / sq. ft.
Rec’d engine range: .91 two-stroke or 1.20 four-stroke
DATAFILE - Harrier 46 (no longer in production)
Wingspan: 1230mm (48.5'')
Length: 1445mm (57'')
Wing area: .46 sq.m. (5 sq. ft.)
All-up weight: 6 lb 6oz
Wing loading: 20 oz / sq. ft.
Rec’d engine range:.46 - .52 two-stroke or .52 - .72 four-stroke
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