Bleriot XI

[Birgir]

Now the wing is fixed and testing can go on. This time I used 10x5 prop and 425 gr lead.

The model still needs a bit up elevator to keep level and could also do with more speed. Later I tried 10x6 and 400 gr of lead but dropped a wing turning too soon and broke the landing gear. I ‘ve already started to fix that.

The flight in this video taught me to leave the phone in the car while flying.

B.

Edited By Birgir on 19/08/2017 22:14:50

[J D 8]

FLAMBARDS BLERIOT rolling

[J D 8]

After a long wait my Bleriot took to the sky once more.

More info and pics soon.

[Birgir]

Grate news, looking forward to more pics

B.

[Jon H]

I missed these posts until today. The model looks good in the air but i think your elevator rate it a bit too high. If you have a load of expo in it remove that as well as that could be the reason its porpoising on the landing approach. It also looks a tad tail heavy but you might get away with that if the rates are lower.

For propellers, dont use more than 5'' pitch as its thrust you need for that model and not speed. The higher pitch will give you greater speed, but only if there is enough thrust to overcome the drag of the model. If 10x5 is revving out well then try 11x5 as the next step.

[Birgir]

Thanks Jon, I will keep this in mind.

Here is a video that John might like 😊

**LINK**

B.

[Don Fry]

Birgir, I would also leave the CG alone for the moment, and reduce the elevator throws a bit. Get used to it first, now it flies.

[Jon H]

Posted by Birgir on 12/10/2017 17:12:53:

Thanks Jon, I will keep this in mind.

Here is a video that John might like 😊

**LINK**

B.

ooo nice. You sure got that 30 sounding good

[john stones 1 - Moderator]

Posted by Birgir on 12/10/2017 17:12:53:

Thanks Jon, I will keep this in mind.

Here is a video that John might like 😊

**LINK**

B.

Magic

[J D 8]

That is a nice video Birgir.

Despite having the model ready at the end of last year things have conspired [mainly weather] to keep it on the ground until last Sunday which was cloudy but flat calm,Ideal conditions to test an edwardian era aeroplane.

This model was built some 40 years ago for the filming of flying shots for the TV series Flambards along with a number of other models and full size ground running replicas by David Boddington and his team. Model built by George Swallow I belive.

I had intended to add more detail and four stroke motor to the model but on discovering it's history decided to keep it as original as possible including the fitting of a Webra 60 from the 70's although with a modern carb and a home made exhaust to fit in the engine bay. I dont think any silencer was fitted filming they just dubbed on old engine sounds afterwards.

For the first take off I held in full up as I opened up the motor but pressure from the long tail on the skid half way down the fuzz made a good anchor in our rather soft strip but on its release she rolled away and rose into the sky with little input from myself. Soon I had to throttle back as it was climbing steeply,there was no shortage of power.

These early aeroplanes tend to be one speed machines with their lifting tails,to much speed and they start doing strange things [ not a problem for early airmen with the limited power availble at the time] A couple of circuits and motor in for a smooth touchdown. Brill

Had five more flights and as other clubmembers arrived they said they could not belive that the Bleriot could fly so slow and stay in the sky.

I tried a stall high up at low power but all it did was keep going in a nodding flight,It sometimes wallows in a turn but nothing to worry about.Shutting down to tickover results in more of a parachute decent than a glide.

[J D 8]

Up and away

[J D 8]

Fly past

[Jon H]

very nice

[Birgir]

Looks grate and very well balanced in the air

[Birgir]

Thanks Donald, I like your advice.

I will hold back on changes and practice with 10 x 5 and 425 gr.

The problem is though that the flying season is probably over here in Iceland for this year.

B.

[Birgir]

Hi

Yesterday I managed to do one flight with my Bleriot. I went back to 10 x 5 prop and 425 gr of ballast. I also reduced the elevator throw about 25%.

The take-off went very well, strait into the wind (4-5 m/s) and I managed the model better than before, did a couple of circles and a figure eight.

Then the dreaded landing approach. When flying my trainer, I usually glide in on half a throttle and then reduce the power to let the model loose height.

When trying the same approach with my Bleriot it looks like I reduce the power too much and too soon and it ends in a kind of “drop down” landing and a broken landing gear.

I notice that John talks of “motor in for a smooth touchdown” on the landing approach.

I would sure like to hear a better explanation of this approach and how to land a Bleriot with under cambered wide wings and a marginal powerhouse.

All comments are welcome.

B.

[Denis Watkins]

Fly to the ground

Is the best way

Maintain flight until the wheels are just about to touch down

Then throttle off

[Don Fry]

From a look at your video, it looks like you are flying it in using the elevator, and it looks like it's going a bit fast.

Try this, at a bit of hight. Cut power, and progressively feed in feed in up elevator. So you get slow, controlled flight. Also try putting more up elevator so it stalls, which is too much elevator. And note the sit of the aircraft when it was controlled, and mentally note the stick position because this is your approach / landing speed. Have a good look at the sit of the machine, because it's easier to see this than estimate speed when it's coming towards you.

Now still at hight, with the elevator at the slow flight position, try increasing power, don't move the elevator. As you increase power, the decent rate reduces, then halts, and the it started to climb, all at the same, approach / landing speed.

Have a good think about what this means. Throttle controls hight. Elevator controls speed.

Then the landing approach becomes, reduce power, adopt approach / landing speed with up elevator, and don't move the elevator. Vary power to put the thing down where you want it. Just as it's touching down, a bit more up elevator produces perfection, with moter to tick over.

How slowly, how near the stall you approach varies from aircraft to aircraft. Yours I would guess needs a bit of margin, because it's a high drag shape, and will slow quickly and get you in trouble.

[J D 8]

Hi Birger, I too found that cutting power to far back resulted in a steep glide [ if you can call it that ] angle.The large wing area, wire bracing,open structure result in a lot of drag I do not have a lot of movement on the elevator being so far back [ compaired to a modern aircraft ] it has a lot of leverage.My model has the later normal type elevator not the all moving tips.

Have found that for general flying around I am mostly just using the rudder and throttle.

As Don says I found it best to control the approch with the throttle only using the elevator to round out at touchdown. Cheers John.

[Jon H]

Dons method has its merits for sure and I use power to control the decent of my WWII models as they typically don't like high angles of attack. I flew my Nieuport 17 today and again a cut and glide approach will not work, it needs to be flown in with power then held off only the last few inches. From your earlier video it looks like you are trying to hold off about 3 or 4 feet too high. You should fly it down to the ground. To practice, just do low passes at normal flying speed and just get them lower and lower until you effectively touch down. As is a low pass, not a landing, the throttle will remain quite constant so its one less thing to think about

[Don Fry]

Mind you Birgir, I suggest you do, say a hundred landings with the trainer trying out the options. Because the Bleriot is too beautiful to experiment with.

[Birgir]

Thanks for this

I think I’m beginning to understand the task at hand and getting a better understand of the problem.

I’m used to land my trainer using the throttle to control the decent, (i.e. elevator – speed, throttle – height) but the trainer is trimmed for level flight at ca. 60% throttle. And a proper decent at about 40 - 50% throttle.

The Bleriot isn’t trimmed properly at all. I fly it at full throttle using the elevator to maintain height. This is the first thing I must change.

My limited experience with the Bleriot tells me though that I have a very narrow band of throttle change to play with, much narrower than in the case of my trainer.

So, next flight the task is to trim for levelled flight at something less than full throttle. Full throttle should then increase height and something less should cause levelled decrease in height.

Because of the narrow band in throttle change, it is possibly wise to install throttle curve in my TX. For example, setting 50 – 75 – 90 at 25%, 50% and 75% stick position resulting in the last 10% of throttle change spreads over the top 25% of stick movement.

When this trimming is accomplished I should be able to practice a few low passes hopefully resulting in a smooth landing in the end.

I would welcome any views and warnings about this approach.

​B.

[Jon H]

I think you should not worry about the throttle curve at this point. If the model is out of trim you don't really stand a chance no matter what the throttle is doing.

Another thing is that this model will probably fly a great deal slower than your trainer and you are probably flying it too fast. This will cause a significant pitch up (as seen in your video) which you then hold down with the elevator stick and the trim. The problem is that when you slow down to land the model will try and dive into the floor and could be the cause of your porpoising approaches.

I think it was Don who recommended trying to work out how slowly the model will go. This is a very good idea as you can find the stalling speed, then open the throttle another 10-15%, then re trim the model for this speed. Once you have done that just leave it alone and fly it at that power setting pretty much all the time.

When it comes to landing, you will have a model which is going to fall slowly if the speed comes off, and climb if power comes on. You can then land as was described earlier.

[onetenor]

Many full size also need flying on as it was called . i.e. power on landing

[J D 8]

My Bleriot flys much slower than anything else I have,it climbs on full power, at cruse it flys level and at lower setting it decends.As noted before with no power decent is steep but not that fast,just so much drag.

Monsieur,s Bleriot and Morane gave us what today is the standard piston plane set up, engine at the front,wing and pilot in the middle,stabilizer at the rear. However their aircraft were very much experimental in the early days of aviation and their designs very much a compromise to get airborne with the low power heavy engines available at the time. Wings tend to be stubby and broad, nose rather short,long fuselage with lifting tail and a more reward c of g. These features do tend to lead to a flying machine that has one comfortable flying speed,any more it climbs and less it wants to decend.

Follow Jon's suggestions above and I think you will have a nice flyer. Good luck John.