Best Avanti or Viper jet?

[Declan]

I'm looking to get a sport jet.  The main three contenders seem to be the Freewing Avanti, FMS Avanti or the E-Flite Viper 90mm.  I'm edging towards the Freewing Avanti as it's about £150 cheaper and being only 80mm should be a bit easier on the batteries.  I like the look of the FMS Avanti as it's physically bigger I think, so easier to see in the sky.  E-Flite seems good and I like the brand but the white and red scheme I fear will be a bit obscure in the sky at certain angles, especially with our frequent grey skies.  

Anyone got any thoughts on these, good or bad.  Or have I missed another contender?  I'm not keen on the look of the futura.

[Colin Carpenter]

I have the FMS Avanti earlier version on 4s. Standard Sebart blue /red/white scheme.  Flys a dream but needs high C lipos and a dry grass strip otherwise won’t get off. Landings are straightforward ! Unfortunately because I go out at 9 am when grass is always wet it’s been in its box for last few years. 😭😭😭Colin

[RICHARD WILLS]

Im not a jet expert , and I like the Avanti as my friend has one , but the Arrows Marlin is excellent for a first time jet . 

The big bonus is the price of the model at only about £165 plus you can use all the 4s batteries that you already have . (I use my regular 3300s) 

Secondly , if you do stack it (they move quick and will roll in just as fast ) its not going to break the bank . 

Down side is : no retracts , but I have fitted some to mine and modified it to a Hawk . Why not see if Colin will part with his early Avanti ? 6S Batteries are pricey . 

Edited April 9 by RICHARD WILLS

[Declan]

Nice paint scheme, looks amazing!  I have an Arrows Marlin already so I'm looking for something a bit bigger.  I've been using my 2600 batteries in it but I must try the larger 3300s.  I haven't yet because I thought they might be too heavy but I will give them a go.

6S, lol, they're not cheap.  I must have more money than sense!  Still, you can't take it with you.....

Edited April 10 by Declan

[Ron Gray]

FMS Viper Jet, imo one of the best EDFs available. Freewing Zeus is also nice to fly but the white / blue colour scheme can make the model invisible in some lights. Both can easily drop a wing if flown too slow and the elevator on the Zeus can be blanked by too much flaps.

Edited April 10 by Ron Gray

[Konrad]

Since you asked. To save you from having to read the rest of this post, I will tell you that the best sport jet today that runs on 800 gram to 1Kg batteries is the FMS 90mm Avanti with Thrust Vectoring (TV). Nothing comes close!

 

Some general comments on sport Jets. As a general rule the FMS/E-Flite are just one step ahead in quality and manual set up than the Freewing brand. True there isn’t a nickels difference but that difference is in favor of FMS. Much of this can be traced to the electronics Freewing servos are still just this side of junk! Freewing’s manuals are atrocious when it come to set up values.

 

About batteries I like the Roaring top brand as they are a bit more robust than my current favorite  brand the SMC HVv2.  The SMC with the ability to be charged to 4.3v is a game changer when it comes to EDF, just don’t allow then to get hot! This means to never allow the voltage to drop to bellow 3.3 under load. and keep a lot of air flow moving to keep them cool!

 

As I own or have owned most of the jets mentioned I will say that If you don’t want TV the best sport jet is the 90mm FMS/E-flite Viper! Again nothing comes close in a Non-TV 90mm model. You can do so much with the jet in the air and with your set ups.

 

An honorable mention is the Freewing Zeus but it has a lower aspect ratio wing. This is fine, even great, if that is what you want. There are a few flaws with the Zeus. 

*First is that there is far too much gray is the current livery. Freewing must be doing this so you will crash more often and buy replacement models!

*Second the cooling air into the battery compartment is wholly inadequate! Add some cooling ports to the front doors and make a cooling hole above the front retract.

*Third the battery tub is far too weak. Add some 1mm x 6mm pultruded carbon on each side of the tub near the top

*The elevator servos are not up to the task. Upgrade them with high quality 17gram servos. (I don’t think Freewing models are worth spending more than the cost of the E-Max servo). 

*The manual CG location is a bad joke. I fly my Zeus with the CG 15mm(?) aft. That is the model will just sit on the tail ready to fly. This means there is no ground control with the nose wheel. To put more weight on the nose I shim the forward side of the retract mount 0.5mm to tilt the rear mains aft. At this CG (balance on the leading edge of the LG trunion block) I land with full flaps 90°. There is no blanking of the elevator nor do I need any flap to elevator comp. The reports you might read of elevator blanking actually are real, but this is because at the manual's CG the nose is so heavy that the elevator can’t keep the nose up at landing speeds!

I moved my elevator push rods in one hole towards the servo output shaft. I set my high rate to be the mid rate value shown in the manual for the first flight.

Here is some of my experience with the Zeus. It crashed as a result of failed elevator servos. I was flying out 3 of my leftover charged batteries in rapid succession. i suspect the elevators servos over heated from effectively running hard for 20min straight. I have 4 sets of batteries left over so I bought another replacement Zeus, it has that much potential!

https://www.hippocketaeronautics.com/hpa_forum/index.php?topic=27635.0

 

The Freewing 80mm Avanti is actually a bit bigger than the 90mm Zeus. On the same 8cell batteries I like the 80mm Avanti ever so slightly over the Zeus. The problem is that Freewing does NOT offer the 80mm Avanti as an 8 cell set up!

Issues with the 80mm Avanti are much the same as the 90mm Zeus. 

*That red and gray livery are invisible in any gray sky! The new yellow Avanti is much better in this regard.

*The new tighter fitting front doors choke the cooling air to the batteries.

*The CG in the manual is way to far forward in the manual and the manual elevator throws are way too high.

The fixes are much the same as the Zeus.

https://forums.modelflying.co.uk/index.php?/topic/60007-avanti-s-freewing-80mm-upgrade-to-8-cell/&tab=comments#comment-1027056

 

Moving to high performance sport scale jets.

The best currently on the market is the Freewing 80mm T-33. It flies a lot like the old Bridi Kaos series of sport pattern ships.

The set up issue are typical Freewing in that there is 3oz of nose weight in the nose that needs top be removed. Cut the nose off at the front panel line and dig out that balance slugs. This allows you to then use an 800gram plus battery. (I love the Top Models 6250 6 cell in the nose of my T-33s). CG isn’t too far off in the manual but I am aft of the manual.

 

The next best 80mm scale performance jet is the FMS 80mm Hawk. This is the only jet I can knife edge loop with the stock systems.

Like most jets it comes set up way too nose heavy. I had to remove the gyro and cut the foam away hitting the front wing hard point mount to allow the battery to be moved aft to reach my CG with the Roaring Top 6250 battery.

* I hate the gear doors

* All three of my Hawks are very poor in the inverted flight. I need 80% forward stick. This leads me to think I’m nose heavy but the rest of the flight profile indicated a very neutral CG.

 

I like the larger 80mm jets but would like to move them over to low amp draw 8 cells when practical ( I often use the 80mm JetFan with HET motors) to accomplish this. All 90mm jets should be running 8 cell low amp draw set up for any sport jet. As you can often get 8 cell set ups with the 90mm this is what I purchase.

 

If you have any other questions about the 800g to 1Kg battery sport jet please ask.

[EvilC57]

15 hours ago, Konrad said:

* First is that there is far too much gray is the current livery. Freewing must be doing this so you will crash more often and buy replacementmodels!

Interesting you should say that, I recently bought an FMS Futura 65 in grey & yellow (they also come in grey/red and grey/green), and I find it incredibly hard to see in anything other than bright sunshine. I’m on my second one now because I crashed the first due to disorientation when flying it under a dark and cloudy sky. I also have one of the little Arrows Viper 50mm EDFs, which even though it’s smaller and faster, I find easier to see because it’s mainly white.

[Konrad]

There is a reason to the madness, sales! 

[Declan]

On 14/04/2025 at 15:42, Konrad said:

If you have any other questions about the 800g to 1Kg battery sport jet please ask.

Konrad, thank you for the detailed reply which I'm just picking up now.  I had removed the Freewing Avanti from the list once I'd worked out the total cost from Motion RC with import duty and VAT added.  

The FMS Avanti does look nice and at my age the way it stands out in the sky is very important!  I like E flite as I've got a couple of their models and I like the quality and general setup.  The Viper in white and grey does worry me flying in our downcast skies.

I'm nowhere near ready for the thrust vectoring option as I'm new to EDF's and trying to get my eye in with an Arrows Marlin.  Flying it is no problem but I've found landings a bit challenging as I like to bring my prop models in very slow and gentle.  I think I need a bit of a technique change and fly the model down a bit more.  So no real rush on purchase as I'm not really ready for it TBH.  

[Konrad]

Wow, that’s a huge change in direction from the 80mm/90mm to the 64mm models. 
 

if viability is a key concern do think about staying with the bigger models. 
 

but if you are keen on the 64mm I think this offers the best value. That Bee livery is easy to see. 

Yes, most jet land best with the nose brought up and the sink rate controlled by throttle (power). In full size flying we are taught that the elevator controls speed and the throttle controls altitude. 

The L-39 can land with both landing approaches the shallow fly it on or the high alpha power on landing. 
 

Maybe the Freewing L-39 might be good for you. I have no experience with this jet. 

[Konrad]

Why is the Freewing offering subject to more of a tax burden than FMS/E-Flite. 

[Declan]

Konrad,

5 hours ago, Konrad said:

Wow, that’s a huge change in direction from the 80mm/90mm to the 64mm models. 

I have the Arrows Marlin already, it's my first EDF.  I'm hoping to step up to the larger models.

5 hours ago, Konrad said:

Why is the Freewing offering subject to more of a tax burden than FMS/E-Flite. 

The freewing Avanti is a Motion RC model and they are based in Europe.  This makes them subject to import tax and VAT.  

[Konrad]

This is that Brexit fall out? If taxation is the issue then FMS is by far the better choice. Like I said before, just on the merits of the product line FMS Is ever so slightly the better product brand.

 

I strongly recommend the upgrade to the 80mm/90mm model (800g to 1000g batteries).

 

You should be able to land the Marlin like a jet (nose high with 20% to 30% power on). Once you are comfortable with that move on up the bigger and dare I say often better flying models.

 

I like the FMS Avanti as the wing planform helps with high alpha flight. Also if you want you can upgrade to TV with little added cost.

 

Yes, the FMS Viper can do high alpha but just not as nice. But the Viper does "normal" flight aerobatics a bit better than the non-TV Avanti.

 

Again if you can swing it, the FMS Avanti set up with TV is the best. You can and should be able to turn on and off the TV. I land with the TV off.