Horton Ho 229
Horton Ho 229 Flight Characteristics
Probing the Secrets of one of the most Enigmatic Designs in Aeronautial History
This is the story of the development of Horten Ho 229 (aka Ho IX)R/C model kit currently for sale on wingsontheweb.com. The Ho IX isnot an ordinary aircraft, and the development of the model was farfrom ordinary as well.
- Recreate the 'Mysterious Bird' Horten with dense mechanical detail exceeding expectations of small-scale models! THE 4 MAIN POINTS OF 1/72&1/144 Ho 229. This SWS kit builds two models in 1/72 and 1/144 scales based on the unfinished “Ho IX V3” prototype, recreating what a finished Ho 229 might have been like if used in actual combat.
- Horten Ho-229 flying wing was first in many achievements once it was introduced in the late days of WWII. For its time it was beyond revolutionary and you Probably the most sophisticated aircraft of the Second World War comes from Germany. The best scale model representing it comes from Japan.
Horton Ho 229 Flight Characteristics Probing the Secrets of one of the most Enigmatic Designs in Aeronautial History. This is the story of the development of Horten Ho 229 (aka Ho IX) R/C model kit currently for sale on wingsontheweb.com. The Ho IX is not an ordinary aircraft, and the development of the model was far from ordinary as well. The Horten Ho 229 V3 is the only extant example of the world's first all-wing jet aircraft. Built in Germany during World War II, the Horten Ho 229 promised spectacular performance. Horten 229, Ho 229, Horten229.org Horten 229 V3 now on public display at the Smithsonian Udvar-Hazy Center This website was established in 2017 - raising money to attach the wings.
Work began in June of 2006.I entered this project with some experience flying 'model' flyingwings such as the Zagi. The Horten shares some properties with thesemodels, but there are also some differences. A well designed flyingwing will handle much like a conventional plane in most flight modes.
I spent some time with a Combat Wing powered by an electric motor. This model flies well with its wing fences in place. It's fullyaerobatic, and is capable of a much tighter turn than a conventionalplane of the same size and weight. This is also true of the Horten.
Where the flying wing suffers is in precision maneuvers such asmult-point rolls. Here the lack of a vertical surface is adisadvantage. I spent some time flying the Combat Wing withits wingtip fences removed. Surprisingly, it was quitemaneuverable as long as the wings were kept within 45 degreesof the horizontal in level flight. If an axial roll wasattempted from straight and level flight, the model would'fall off' when the wings became vertical and dive.Barrel rolls were possible however.As long as positive Gs were maintained, the lack of yawcontrol was not a problem.
Ho 229 V1
I started by building a 66' span prop powered Ho IX, similar inlayout to the full size Ho IX V1. At first I fittedit with a tractor motor and prop. The motor was smalland didn't really produce enough power for this model.
The model flew, but control did't seem right. It seemedto be fighting against attempts to control it. Therewas much debate over the causes. In the end I decidedto try a more powerful motor. The new power setupchosen was more appropriate for a model of this size.
The next test flight was spectacular! After a shortforward surge, the model pitched up vertically anddid several summersaults in the air! Fortunatelydamage was minor, but I was mystified at what couldcause such gross instability.
At that point someone kindly chimed in online andoffered the observation that all successful proppowered flying wings are pushers, and that theturbulent airflow generated in the prop wash was guaranteed to cause problems with a flying wing.
Armed with that knowledge, I set about convertingthe model to a pusher. I chopped off the aft portion of thebat tail and made a firewall capable of supporting themotor.
The result was dramatic! The model now flew perfectly.Now finally I were able to explore the flight envelope of this plane.The pusher Ho IX exceeded my expectations. It handled betterthan the combat wing in fact. It tracked better, stability wasnoticeably better. Knife edge flight wasn't quite possiblestill, but the thickened center section of the Ho IX givesit a surprising amount of inherent yaw stability. I've heardthat of all aircraft designs, the Ho IX comes theclosest to modelling the flight of a bird. The thickenedcenter section and the gradual tapering thickness of thewings is part of this I'm sure.
On to EDF
The ultimate goal was to design and build an EDF poweredHo 229 V3. I contacted Arthur Bentley and he was happy tohelp as he is a fellow Horten addict. I purchased hisHo 229 drawings and scanned them into CAD to use as abasis for the design.Horten Ho 229 Restoration
Precision Scale?
There were many who didn't think an exact scale modelwas the best approach. Some said that the EDF units withscale inlet ducts would not be powerful enough. Otherssaid that the original airframe design would not dowell at lower Reynolds Numbers. To all of these people,my question was, 'Have you tried it???' I never gota good answer to that, so I proceeded with my plan.
I had a feeling that the naysayers may at leastbe partially right about the power produced by thecurrent generation of EDF units. However, thistechnology is advancing very quickly. I had littledoubt that much more powerful systems would soon beavailable with the same boresize. (this is alreadytrue, by the way, only a little more than a yearafter the maiden flight of my first EDF Ho 229)
Since I planned to make tooling for a fiberglasscenter section, the duct bore and geometry wasa decision that needed to be made early and once.
Construction of the Second Model
Horten Ho 229 Flying Wing
I began by making a center section plug. Some thoughtI was crazy for spending months making permanenttooling for a design with unknown flying characteristics.In my darker moments I wondered if they were right...But I pushed on driven mostly by faith in the Hortenbrothers and their genius. I somehow knew deep downthat the model would fly well. This wasn't completelyblind faith as I had been flying the pusher for sometime and the Ho 229 V3 is very similar in all butpropulsion.
When the first center section parts came out of themolds, I completed construction of the first EDFmodel in the gearless configuration for bungeelaunch.
By this time Heiner Skroblin had joinedthe RCSCALEBUILDER.com discussion and he offeredsome advice. He was among those who doubted thatan exact scale model would fly well, however.
Heiner also mentioned using extensions on the exhaust tubes,but all the way up to the maiden flight of thefirst EDF model, he never said they were mandatoryor what would happen without them.This turned out to be a very fateful omission...
Gliding Tests
Flight testing of the EDF model began withgliding tests off the bungee. These were mostlysuccessful, but many 'bounce and flip' landingswere experienced which were puzzling at the time.Flying the model gearless and lightweight (withoutfans and motors), there was no damage involved,but this behavior was still puzzling. I nowunderstand that this is caused by touching downwith too much airspeed. If the aircraft is notslow enough to stall, it will bounce up andsometimes flip over. The trick is to hold itlevel as long as possible, continuing to feedin 'up' elevon until with full 'up', it fallsto the ground. The model will 'float' on theground effect for quite some distance beforethis proper touchdown can be achieved, so alarge field is a must for landing it properly.
After many successful glide tests, it was timeto try powered flight. At the heavier weightwith fans, motors and batteries installed,a much higher tension on the bungee wasrequired. For a seven pound AUW, 35 lbs onthe bungee was found to give a good boostfor powered flight.
On the first flight, 3/4 power was appliedas the bungee reached its limit. The planeimmediately became unstable. It was alsotoo high and too fast to bring her down,and not high enough to try to turn aroundand land without power. So, I tried togain control but to no avail. She bankedto the vertical and dove into the ground.
I later found out from Heiner that othershad experienced similar results when attemptingto fly without extension tubes. Why he didn'ttell us this *before* the maiden flight, Istill don't know.
Horton Ho 229 A-0
The Third Model
The crash of the first prototype was verydisappointing. The center section wascompletely destroyed, but the outer wingpanels were repairable. A new centersection was prepared and joined to therepaired outer wing panels. Extensiontubes were carefully installed on theexhausts, long enough to make sure thatthe exhaust air flow was well above theboundary layer of the wing.This model was finally flownsuccessfully on March 29, 2007. It was agreat relief to see it fly. The firstflight went very well. Control responsewas excellent, power seemed more thanadequate. It was certainly fast! Landingwas a challenge, as it always is withthis model. I had to go around oncebecause the first time I was comingin way too hot. It flipped over onlanding because I didn't slow it downenough, it took time to develop theproper technique. There was some minordamage to one of the elevons, but Iwas nonetheless overjoyed that shefinally flew!
The ROG Version
As most of the people interested inthis model wanted to install retracts,I next set about building an all newmodel that would feature retracts,flaps and drag rudders. As always,I was determined to model thesefeatures in as close to scale fashionas possible.The drag rudders were constructedjust like the full size in layout,size and operation. These werethe most difficult and time consumingof all the control surfaces to construct.
To prepare for flying the ROG EDF model,I fitted the pusher prototype withlanding gear. I first tried to modelthe full-size Ho 229 V3 landing geargeometry with its resulting nose-highstance. This proved to be unworkable.The model lifted off prematurely,causing a bouncing takeoff that washard on the nerves! Landing likewiseinvolved a lot of bouncing. The AOA(angle of attack) was clearly toogreat.
I shortened the nosegear tobring the incidence of the wing tonear zero, just a degree or two ofpositive incidence. This turned outmuch better and I logged many flightswith the pusher Ho IX in this configuration.Takeoffs were sometimes difficult.Sometimes the model would want to veerin one direction or the other on thetakeoff roll. With the drag of thelanding gear, landing speeds weremore managable and the model had lesstendency to 'float' near the ground.Flight time was greatly reducedhowever.
Horten Ho 229 Flying
Soon the 82' EDF ROG model was ready for flight.I found a huge parking lot for the test flightswhich had plenty of room for error. It turnedout that the problemswith takeoff in the pusher model were much worsein the larger EDF version. On the first flightattempt, the model seemed to dig in on the nosegear.It veered sharply, flipped over and skidded on itsback! I thought that the nosegear may be binding,so I soldered some washers on the axleand tried again. Same result! The model wasgetting beat up now and I was getting frustrated.
Horton Ho 229 At Smithsonian
Consulting with some experts, I found out thatthe original Horten aircraft used 'up' elevon ontakeoff. On the next attempt, I pulled the stickback fully from the start of the takeoff roll.The result was dramatic! Nice smooth, straighttakeoff roll. Liftoff was a bit abrupt, I had toease off the stick once airborne. But it worked!I have since learned that this takeoff techniqueis also used in other tailless aircraft such asthe Avro Vulcan and F4D Skyray.
With these changes the ROG version of the modelperformed flawlessly. The first successful flightswere in June of 2008. So, a full two years wasspent in development. It has been a difficultbut very satisfying project. Along the way I meta lot of great people and had a lot of fun.I'll never regret having taken on the project.In the end my decisions concerning the projectwere vindicated. The Ho 229 is not without itsquirks, but none of them are due to basic design.An exact scale model therefore has no disadvantagesthat I've been able to discover. All of theproblems encountered were inherent to the basicnature of this type of aircraft.
Horten Ho 229
The Horten brothers deserve a lot of credit.Some say the Ho 229 is overrated. That maybe true. It was not without its flaws. It was,however, an amazing achievement considering thetime it was designed and built.
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