Any rational purpose for Ho-229?

[Rick65]

A question relating to the Ho-229.
Many post war experimental aircraft without tails (eg DH-108, YB - 49 according to some accounts)were killers because of difficulty with pitch control in the pre fly by wire days.
Did the Ho designs (and the Me 163) dodge these problems and if so how?

 

[GregP]

The YB-49 was not in any way a "killer" that had problems with pitch control. It flew quite well. It's cancellation was largely a political move when Jack Northrop refused to sell his company to Consolidated Aircraft.

The DH-108 exhibited bad flight characteristics, as fas as I know, only at high speeds. They were in the process of exploring high Mach number flight at the time and didn't understand it very well. Had they forced themselves to build a supersonic wind tunnel, many men might not have died.

In the few test flights the Ho-229 completed, I am not aware if they ever approached the critical Mach number of the design, and can't say one way or the other. I haven't seen more than about three test flights reported and the typical performance data seen on the internet is usually listed as "performance data taken from manufacturer's estimates," or words to that effect.

So I don't know how fast it ever actually flew and haven't seen any first-hand reports of its handling. Though most of the stuff written about it suggests it handled quite well, I have sever seen any sources quoted for these reports. I suspect it handled fine and never got so fast as to approach divergence from stable flight, but obviously can't say for sure. If the internet data are correct, the crash of the Ho-229 on the fourth flight was due to an engine failure and post engine failure actions of the pilot and not to bad handling. I haven't seen any reports on the other Ho-229 prototypes test flights, but would like to read them if there are any available out there.

I have always liked the aircraft and have often wondered how it would fly if a replica were built and flown today. I am also not aware if enough data still exist to create a replica that is accurate. The replica built for by Northrop may or may not have same airfoil as the Horten birds did, I don't know.

Does anyone out there know if sufficient data exist to build a proper replica? And if so, who has control of the data?

 

[GrauGeist]

A question relating to the Ho-229.
Many post war experimental aircraft without tails (eg DH-108, YB - 49 according to some accounts)were killers because of difficulty with pitch control in the pre fly by wire days.
Did the Ho designs (and the Me 163) dodge these problems and if so how?

The Ho229 had a additional control surfaces that compensated for the lack of a horizontal stabilizer. If you can find a photo of it's wings, you'll see these "flaps" embedded in the wing's surface, just ahead of the aelerons, two per wing - one above and one undeneath. In both the Ho229 and the Me163 (and the DFS194 project), they had oversized aelerons at the extreme trailing edge of the wing to allow for more control. The downside to this, was excessive drag in hard maneuvering.

There were several pioneers in tailless aircraft in the years leading up to WWII and the Hortons and Dr. Lippisch were among them in both tailless gliders and piston powered designs.

 

[Jabberwocky]

I'd think that almost anything (especially a single aircraft) flying at a few dozen feet across the channel would be almost invisible in amongst the ground clutter.

My sentiments exactly.

Luftwaffe fighter bomber raids of 40 or more aircraft (FW 190s mostly, sometimes Do-217s) could evade UK radar technology at the time by flying low level (~50-80 feet) cross Channel approaches, so what made the Ho 229 special in this regard?

 

[professorcurly]

I don't remember where I read this, but I've heard that the Northrop flying wings also ran into problems of the radar operators in the US "losing" them during test flights, for the same reasons as the Horton - a fortuitous shape that served dual purposes. The difference between Northrop and Horton flying wings was also explained to me as being the Horton design traded lift for stability, while Northrop's designs didn't which lead to the different characteristics between them. Grain of salt though, this could be apocryphal information and I don't have the expertise required to determine the benefits and disadvantages of flying wing designs.

 

[Kryten]

Until the advent of flight control computers the flying wing concept was pretty much a dead end, just look at how many different nations and companies tried to develop the flying wing and found it unworkable, the 3 flights of this Horton is hardy enough to draw conclusions as to it's flying characteristics, unless of course you want to believe the Horton brothers were using technology or designs that no one else though of , tested or copied decades later!

 

[Milosh]

Monogram Close-Up #12, Horten 229, has a description of the crash and what should have been done to avoid the crash. An engine flamed out > no engine fire, be sure.

Horten 229 (Monogram Close-Up 12) | Free eBooks Download - EBOOKEE!

 

[stona]

There are various accounts of the accident. I reputable author has even claimed an intentional one engine flight was being attempted which would be incredible given that the total flight time experienced was less than two hours!

I think this may be a mis-interpretation of the report submitted by the Hortens to the RLM that gave the cause of the accident as pilot error during a single engine landing. This remained the official cause of the aircraft's loss.

I don't think a seized turbine shaft is strictly a flame out and seems to be a likely explanation for the engine failure. In any case the result was typical of engine failures on early jet aeroplanes, particularly at low altitudes.

Cheers

Steve

 

[bobbysocks]

it would depend on the actual performance of the ac. i see the plane as more of a bomber or bomber intercept.....

 

[stona]

it would depend on the actual performance of the ac. i see the plane as more of a bomber or bomber intercept.....

The problem with it being a bomber is that it couldn't carry a bomb load greater than some fighter bombers. Pelz was making the same complaint about the Me 410 during 'Steinbock'.

Cheers

Steve

 

[subkraft]

I often think that the myth of the Ho229 overshadows the Horten brother's real achievements. They really did build the most incredibly high aspect ratio flying wings as gliders successfully. My limited understanding of the aerodynamics was that they learnt how to manipulate the degree of lift generated over different areas the wing surface to create some degree of stability.

 

[stona]

My limited understanding of the aerodynamics was that they learnt how to manipulate the degree of lift generated over different areas the wing surface to create some degree of stability.

They benefited from much of the work done by Lippisch and his team, including Hans Jacobs, Willy Hubert, Fritz Kramer, Heinrich Voepel and others I've forgotten, in the very early 1930s. Much of the calculus was done by the Canadian, Beverley Shenstone who was part of the team.
It was Lippisch and his team who first quantified and understood the complex behaviour of delta wings and figured out the differing wing lift pattern and stall characteristics of the basic 'flying triangle'.
The Hortens certainly developed this in their designs throughout the 1930s, culminating in their 'flying wings' of the 1940s. Lippisch of course would develop the concepts in the Me 163.
Cheers
Steve

 

[delcyros]

The bell shaped lift distribution -spanwise- allowed stability for the tradeoff of additional drag (no fly-by-wire required, really). It´s a genuine creative aspect the Hortens introduced beyond the work of Lippish and his team.
How stability would have fared under slip conditions (off-axis angle of attack) and at airpseeds close to the critical Mach would be interesting, but my aerodynamic
understanding tends to guess not so good at all.

 

[bobbysocks]

The problem with it being a bomber is that it couldn't carry a bomb load greater than some fighter bombers. Pelz was making the same complaint about the Me 410 during 'Steinbock'.

Cheers

Steve

i agree. it isnt going to carry much and other ac might even be better suited. but it can get in and out pretty quickly...and of all the uses for that ac...those 2 are probably the best fit. Or as a recon ac maybe.

 

[GregP]

TheNorthrop N9M-B flying wing at the Planes of Fame was created by Jack Northrop and also requires no fly-by-wire. It flies quite well. We don;t know how it would handle at very high speed, but it flies on two 350 - 400 HP Franklins and does just fine at typical cruise speeds and top speed. It has all the improvements done to the other three aircraft in it including pilot-controllable wing slots, ailevators, and all the other improvements.

Ron Hackworth typically cruises it around 180 mph but the top speed is just under 260 mph, where it also handles well.

 

[R Pope]

Perhaps the "purpose" of this and the many other "pie-in-the-sky" German projects had the desired purpose of keeping a great many designers and workers in Germany and not at the Russian front..........

 

[stona]

The Ho 229 was not entirely pie in the sky. As early as June 1944 an initial order for 10 H IXs was made, soon increased to 20.

A typical lack of focus followed. Gotha made changes to the design, at the instigation of Rudolph Gothert and Dr Berthold (Gotha's technical manager), without the approval of the Hortens. They lost control of their own design.
The Gotha P-60 was presented to the RLM as a development of the Horten design but was in fact quite different.

To return to the influence of Lippisch on the Hortens, it is no accident that the first Horten delta glider (Horten I) was named 'Hangwind' which was Alexander Lippisch's nick name.
Reimar Horten tried to pass the H 1 on to Lippisch (at that time in Darmstadt as chief of the DFS' technical department) following a competition at the Wasserkuppe in 1934. Lippisch declined the offer and, with no way to get the glider home, Reimar burnt the glider on site. He later recalled that.

"We didn't want anyone to be harmed by the bad characteristics of the H 1. That's why we destroyed it and would not allow other pilots to fly it."

Some of those 'bad characteristics' still plagued Horten wings ten years later, most notably issues with longitudinal stability and extreme sensitivity to changes in the CoG. The latter in particular would be a serious issue with any practical service type.

Cheers

Steve

 

[nuuumannn]

I suspect the Germans were desperate to come up with something, anything that might help them, regardless of how wacky or less than useful it might have been. They didn't have much option toward the end.

 

[GrauGeist]

The interest in flying wings goes much further back than WWII.

The theory was that if you eliminate the traditional fuselage and tail assembly, you eliminate a major portion of drag. Once you've done this, you'll exponentially increase your range and power-to-weight ratio.

Dr. Lippisch and the Horton Brothers had extensive research backing the Ho229 but by the time the project had been farmed out by the RLM, it's design had been altered quite a bit.

I would certainly not call it a project of desperation and the old story of "if the RLM had actually taken the jet programs seriously at the beginning" applies here. Had they done so, the jet program wouldn't have been desperately shoved into the breech at the last minute, like they were.

 

[GregP]

Not too sure nobody made it work in WWII. Here is the Northrop N9M-B Flying Wing we still fly today at the Planes of Fame in Chino. Notice it does not seem unstable or uncontrollable. In fact, it flies quite well. This puppy first flew in 1942 and flew well.


View: https://www.youtube.com/watch?v=lSf5TX_FcBw

Our airshow is May 3 - 4 this year at Chino Airport. It will fly there in the show if you want to see it aviating.

So did the XB-35 and the YB-49 fly quite well, too. They died a political death, not a technological one. And it didn't need digital computers to fly, though they DID eventually fit a working SAS (stability augmentation system). It was analog, not digital. And solved all the small flight issues. They also fit an SAS to most turbine helicopters and ALL fly-by-wire jet fighters, so it's not like the flying wings were all alone in possibly needing some stability help. The main fix on the YB-49 were the four small fin and rudders that replaced directional stability lost with the loss of the propellers.

But when Jack Northrop would not sell his company to Consolidated for pennies on the dollar, they killed the plane and tried to kill the company over the years, too. Damn near did.