RE: Does your scale model fly realistically ?
 

Clearly there's no "one scale way" for all models to fly...since different full-scales fly differently from one another. There's not too much information in that article (somehow there never is in magazine articles) but it certainly confirms the general reports on the different WWI types, i.e. the SE5 was stable (of course it was with all that dihedral), the EIII was troublesome (duh) and the Camel was quick on its feet (thanks in part to that big rotary).

RE: Does your scale model fly realistically ?
 

I think the article is pretty good. It is trying to be object and shed some light on the Verbage used describe flight of some of the WWI planes. If you can do real analysis you'll get a better understanding of what really is rather that what someone thinks is..

RE: Does your scale model fly realistically ?
 

I think the important point that I got out of the article was that some of the folklore that we have come to accept as fact may not be entirely accurate. For instance, the vaunted climb rate of the DrI may not be supported in fact. That's one thing I've always wondered about, because as an engineer I don't see any reason why it should climb well. As a matter of fact, when I look at a DrI everything screams, "slow climber" to me. Steep, maybe. But not at a high rate.

One of the problems with relying on the comments of period aviators is that few if any of those on record had broad experience with multiple airplane types. So they didn't have any basis for comparison. Every fighter pilot, even those today, thinks that the machine he's currently flying is "the best". That's part of the belief system that enables them to face an opponent who's out to kill them. Also, the information from the period aviators was almost entirely subjective. Neither the knowhow nor equipment for objective testing existed when the aeroplanes were new.

Javier (the owner of the Aeroplane Collection) has been doing some flight testing with sensors that were not available "back when". He intends to write reports on performance and handling of the various machines. I can hardly wait !


Dick

RE: Does your scale model fly realistically ?
 

Well, as someone mentioned here earlier, everything is relative. As far as the DR1 is concerned:

Richthofen himself allegedly said about the triplane: "It climbs like a monkey, but flies like the devil!"

So, I'm guessing this is in comparison to all others he had flown before it. From my own experience, holding up elevator on the rc triplanes I have flown, is like, ......well being in an elevator. They do climb quite profoundly! And so much so that from what I've read historically, they could climb away from a fight.

ZZ.

RE: Does your scale model fly realistically ?
 

I'm not sure I would agree with this. While it's true that they didn't have our current tech gadgetry back then, by all accounts all sides had quite rigorous procedures for evaluating the flight performance of both prototypes and captured aircraft. Sure, it was based mostly on the reports of test pilots, with rather limited "quantitative data," but then even today we don't treat reports by professional test pilots as "subjective." But they also performed quantitative "climb to altitude" tests and certainly had the ability to document and analyze in-flight airflow tests of various airfoils.

But, I do agree that rank-and-file pilots in any given squadron might not be very objective in their aircraft preferences. Pilots (and RC fliers) prefer all sort of different aircraft based on personal (and often not all that logical) reasons. The phrase, it's all relative, is certainly relevant here. Also just like everyone else, pilots sometimes have personal or professional agendas. Ball was involved in development and promotion of an alternative fighter and so was sometimes quoted "bashing the competition," which was the SE5 in which he had scored the majority of his victories.

RE: Does your scale model fly realistically ?
 

If you're not sure you would agree on the subject, please let me help lead you to a more in depth understanding. In the course of my employment as a flight test engineer, I spent many lunch time hours in the NASA tech library, reading old NACA reports from the teens and twenties. I was attempting to gain insight into the technology of the day and to understand how we had gotten to where we are now. Fascinating stuff, and amazing not just for what they knew, but more so for all the things they DIDN'T know.

Don't get me wrong, I'm not diminishing the Prandtl's or the Platz's. They were giants, and people like me are nothing more than their distant heirs. They and their contemporaries started from scratch and set the cornerstones of modern aeronautics. But it took a long time to flesh out the building and it's not done yet.

NACA in that era was cutting edge in it's study of airplane performance, stability, and the man-machine interface. I was really fascinated by the unanswered questions that the experts were asking themselves in the early post-war years. At that time, for instance, researchers were still considering whether simple static stability was desirable for pursuit aircraft. There was consensus that transports and bombers should be statically stable due to the high muscle effort required to manipulate the controls. But there was a strong school of thought that stability would inhibit maneuverability and was less desirable in a pursuit. None of the writings that I found even considered the adverse effect of low or negative stability on the usefulness of an airplane as a gun platform. The folks of that era simply hadn't gotten that far in their thinking.

I know, I know, we have all heard the story of how the F-16 is intentionally unstable in order to improve maneuverability. Not even remotely true. The BARE AIRFRAME is marginally unstable in a few modes, but the flight control system must be considered an integral part of the airplane. And believe me, an F-16 with the flight control system fully operating is one stable sweetheart . If the stability augmentation isn't working properly, that's cause to go home and not attempt to employ the airplane operationally.

Dick

RE: Does your scale model fly realistically ?
 

I just meant to say that it wasn't all just "seat-of-the-pants" opinions on the part of pilots. Using the techniques available to them at the time, designers and test pilots attempted to determine as accurately as possible the performance specs of aircraft. Is it helpful and/or interesting to obtain modern technical data on these old aircraft (or rather the their modern replicas)? Sure. I guess.

RE: Does your scale model fly realistically ?
 

My simple axiom, "you won't get the right answers if you don't ask the right questions". The people asking the questions didn't know what to ask. So the answers were suspect..
Design specs were put together by people who, for the most part, had no idea about what or how to achieve what they wanted. The aircraft designers used their plane designs in competition against other designers... normally the best performer won. A win of the relative best.
As an example when the SE5a first came into service it was considered "too stable". Pilots flying the Neuports wanted nimble so they De-rigged the SE5a. One would think that fighter pilots of the day should know what worked best for them.. but..It wasn't until later that they learned that a sable gun platform was much better than not. Instrumentation of performance was scant at best and very primative. Yes its the best they had but not really very good. This isn't to demean their efforts its just the facts.. and those matter :D

RE: Does your scale model fly realistically ?
 

One of my very favorite passages in an early 1920's NACA report studying the merits of airplane stability was this point (I'm paraphrasing):

1. Should pursuit planes be stable ? (Pros & cons discussed in report)

2. Should training planes be stable ? Probably not. Rationale being that service pilots of the Great War had a much lower survival rate if they trained in a stable airplane. The two most common training planes for the U.S. were the Jenny and the Standard J-1. The Jenny was unstable in some modes and marginally stable overall, whereas the Standard J-1 was really docile. The J-1 graduates apparently didn't fare as well on the front lines.

Now I wonder if the J-1 really failed to train it's students as well or if maybe the Jenny killed all its inept students, leaving only the ones with greater natural talent ?

Dick

RE: Does your scale model fly realistically ?
 

Yes, and those that mattered were what kept you alive.
Nearly one hundred years have passed since those days of aerial combat during the so-called war to end all wars. The technology being used to design aircraft would make those early designers head spin, including Anthony Fokker. However, it seems they had a pretty good idea as to what would work and what wouldn't by the time the war in Europe broke out....no more multi spinning propellers or flapping wing like affairs but to a certain extent some very honest aircraft that by our standards were very limited and slow. They were frail and prone to many failures including structural as well as mechanical but they soon worked past these problems, after all, these engineers and designers were some of the best and brightest of the day and they certainly were not stupid. They were breaking new ground and their legacy continues to this day.
Anthony Fokker was not afraid to push the envelope, mounting three machine guns onto an Eindecker E IV. This nearly killed him as the synchronizing mechanism failed and he nearly shot off the prop. Fokker's later designs vindicated his ideas and soon planes such as the D VII and D VIII continued the dreaded Fokker Scourage.
Anybody who gets out to New York should stop by the Old Aerodrome in Rhinebeck when they have flight demonstrations of those old early pioneers of flight. You can't help but to admire the courage and skill, not to mention nerves of steel, it took to fly one of those old birds and they still fly them.
It would be no mean feat to fly a scale model of Bleriot's number 11 or a Demoiselle at a scale speed but that doesn't mean you shouldn't attempt to get close to it without stalling.
The popularity of those old planes seems to go on and on, after all companies such as Balsa USA who produce 1/4 and 1/3 scale kits are doing quite well and all you have to do is go to any scale warbird event and count the number of WW I aircraft being represented.
I would love to build a D VII or D VIII but don't have the room for even 1/4 scale version.....maybe someday.

RE: Does your scale model fly realistically ?
 

I suspect that would be the case however continuing on to WW II, the North American AT-6 was notorious for tip stalling and snapping when flown by inexperienced students. If I remember correctly, they did manage to get this corrected but not before a number of students were either killed or badly hurt flying them.

RE: Does your scale model fly realistically ?
 

I just have to post this here (recalling the electric vs. gas discussion earlier). Call me old-fashioned, but this just seems silly.

RE: Does your scale model fly realistically ?
 

"Design specs were put together by people who, for the most part, had no idea about what or how to achieve what they wanted. "

Sounds like nothing has changed:-))))))))))))))

Les

RE: Does your scale model fly realistically ?
 

Just think what Reinhold Platz or Mr. Fokker could have come up with if they had computers?!

RE: Does your scale model fly realistically ?
 

During my six flights today I had a chance to carry out some of the practice exercises you suggested.

My normal procedure is pretty much the same as #2. I just get it lined up going straight at full-throttle, then pull back sharply on the stick. With the Saito 62 it goes over the top easily. This wasn't the case with the Saito 56. BTW, I have this idea that maneuvers should always be done "into the wind." But when you think about it that's pretty silly. Can you imagine a full-scale (combat) pilot who would only roll his plane if he happened to be headed the right direction? ;)

I tried a number of variants on this, the goal of which was to have the model just barely "flop over" the top of the loop. At a couple of clicks above idle following a very mild dive, it went up and over without problems but with a "scale" egg-shape. As I've said before, I strongly doubt that WWI fliers worked on doing "round" loops. Eventually I throttled back enough and had so little dive that the model just barely went over and sort of jerked awkwardly at the top. And on one attempt the model fell out of the loop to the side, turning into a sort of hammerhead turn.

Based on every video I've ever seen of a WWI aircraft flying these pilots did not perform "constant speed" loops. And unless you keep constant speed the shape of the loop is very likely to become egg-like. I'm sure I can do perfectly round loops with the model and this powerplant (or sufficient dive)...but why would I want to...since that doesn't seem to be the way pilots did them "way back when?" In short, round loops are only scale for aerobatic aircraft performing in aerobatic shows.

*****

Note: This is how a proper WWI model should look after a day's flying! :D

RE: Does your scale model fly realistically ?
 

The generator pic was funny! I would much rather have a noisy motor moving around in the air than a stationary one in the pits. Yes, the WWI model with all the castor on it is 'scale'! If I was a WWI pilot seeing the Pfalz DIII for the first time I would feel invincible... that airplane just looks 'right'. Reality would prove otherwise especially against an SE pilot who, generally, considered the Pfalz 'easy meat'. The Fok DRI had 'different' flight capabilities relative to its peers, that's for sure. It may not have had any better climb rate but did it at a slower but steeper angle of attack. It's wing profile, especially the rounded nose portion, allowed that. That's what made the Fok DVII so famous, too.

RE: Does your scale model fly realistically ?
 

I really wish Balsa USA would do the Fokkers (DR1 and DVII) in 1/6th scale to add to that line of aircraft. Maybe that would be a better size for you?

I wanted to reply to something ABU had commented about earlier. I truly believe that the Fokker designs ( DVII and EV) were better than anything the Allies had, and not just because of the lack of flying wires that make them easy to model. The fact that they did not need flying wires is why they were better.
The mark of true innovation is the legacy and impact that is had on future designs, the cantilevered wing is certainly one of those. Which stems from the thick airfoil which had multiple benefits. This was important in ushering in the ability to have a monoplane design. Fully sheeted wings to create skin strength, as seen on the EV.
Another thing, the British designs to me did not leave a legacy. By policy they were stuck in the past and no real innovation seemed to occur until Mitchell designed the Spitfire. (and the other designer who did the Hurricane). They had to fight a government policy that only biplanes were to be built through the 1930's.

RE: Does your scale model fly realistically ?
 

Combat flying is not loops or rolls, it is chasing or being chased. Once stuck in a dogfight the only way to survive/win is be the one who turns or loops the tightest. The perfect combat loop would look like a 9. Whatever position you are in, you are trying to make the other stall out by making them over G the plane putting it in a high speed stall. The guy who falls out is at the disadvantage to the other. Camels and Dr1 were the best here, but the problem is someone will loose the day. The tactics changed to try and get high pass through the opponents flight with guns blazing and keep on going. Stable and speed; being able to disengage combat to fight another day. SE5as, DVIIs, Snipes, Spad 13s. The gods of combat were one of two situations. Being able to make a unmatched plane win or be the right guy with the right machine. The average guys were hawk food.

RE: Does your scale model fly realistically ?
 

Deleted duplicate post.

RE: Does your scale model fly realistically ?
 

Well done, Don. We'll make an engineer out of you yet ! At least you show more aptitude as an engineer than I do as a linguist.

All of your observations are right on the mark. Beautiful, round loops take a lot of power, something only modern high powered airplanes or models can do easily. Draggy, slow planes like WWI types really eat up the energy during the upward portion of a loop, scrubbing away airspeed very rapidly. The only way to keep from slowing down while pulling up is to have gobs of power. Once you get slowed down going over the top, the radius of curvature of your loop decreases. Round loops are for modern airshows. Egg loops are for scale WWI type planes.

Notice that I said the upward leg of the loop eats up energy. Engineers and pilots think of energy in all of its forms. Stored up speed and altitude are energy. You can convert altitude into speed by diving. Gasoline is energy, too. But you need a converter to make gasoline energy into speed or altitude energy. The engine is the converter, but it can only convert gasoline into speed or altitude so rapidly. When we talk about a more powerful engine, we're really talking about a faster way to take gasoline out of the tank and convert it into height or speed.

The character of a dogfight changes as it gets closer to the ground. Basically, you have used up all of your height energy and now you can't dive to gain speed for vertical maneuvers. You are limited to more horizontal turns and by how fast you can convert gasoline into speed.

Dick

RE: Does your scale model fly realistically ?
 

Another component of combat flying is the ability to shoot from a distance. Getting closer is risky business and you'd like to avoid spending too much time or concentration getting up close and personal. If you have a gun platform (airplane) that's very accurate, your quarry may never even realize he's in danger until it's too late.

But shooting from a distance requires good guns, good sights, good marksmanship, and a steady platform from which to shoot. When you have a loosey, goosey airplane like an early Fokker or early Nieuport (no vertical stabilizer), you have to shoot from close range. Similar problem as in trying to shoot while riding a galluping horse.

Dick

RE: Does your scale model fly realistically ?
 

I can't argue with this. The later Fokker designs were heading down the right path. Even if the later British designed aircraft, like the SE5a and the Snipe, were just as good, or even better as combat aircraft, those design paths would soon be coming to an end. There just wasn't much more you could do with a fabric covered biplane.

Nevertheless, I do still suspect that the popularity of DrIs and DVIIs at flying fields can be summed up in two words: FUN and EASY. :D

RE: Does your scale model fly realistically ?
 

Well, the DVII was claimed to make a good pilot out of mediocre ones, and great pilots out of good ones. The treaty of Versailles seemed to agree.

RE: Does your scale model fly realistically ?
 

And really what better definition of a great aircraft!

RE: Does your scale model fly realistically ?
 

"You can convert altitude into speed by diving."

Unless you are flying a fully rigged biplane. I once was flying an 84" Stampe (Moth like) that would fly at the same speed at full throttle flat and level, OR, at nose pointed straight at the ground.

Les