Timo Starkloff

After being a bit lazy during summer, I resumed working on plans and CAD again. Not much to do with the P.1091, I increased the tail a bit and also the angle of incidence. Otherwise it's "just" sorting parts and rework text and explanations. Nethertheless it takes some hours of work. It still is an unusual model and much fun to fly. A month ago I had to change motor and esc. The previous one with around 180 W got too hot one day in summer. Now the motor is capable of up to 25A according to the datasheet, although only short duration. I'll try to fly not at maximum power for long periods. There is not much cooling for a small motor inside the fuselage. But center of gravity and accumulator position is perfect and a heavier motor would make changes necessary for my model. Timo

Yesterday I saw a B-25 flying low level over our company in Heilbronn, Germany. Sitting at the computer a few minutes before end of work, heard an unusual noise and saw the familiar twin tail and two radial engines from behind. Thinking about taking a picture with the smart phone I just opened the windows to listen to the engine sound. Got small and vanished very quick. Absolutely unusual sight in our region! Timo

Just found a picture of a colourful one ? https://sv.wikipedia.org/wiki/Fil:J_22_Röda_Blixten_på_flygvapnets_25-årsjubileum.jpg Timo

Yes, of course, Graham. A building thread would be fine ? There are several simplified EPP versions flying in Germany, built for EPA aircombat contests. I also remember pictures of more detailed ones in 1/12 scale, built by Swedish aircombat pilots for WWII class. https://www.rc-network.de/threads/eine-einfache-aber-konkurrenzfähige-epa-einmot.722578/ Timo

Thanks for the nice building log ? It's already twelve years ago since my first and last visit to the Yeovilton museum when visiting a friend nearby. What a great collection! Timo

Pictures published ?

Another highlight was the turbo jet bicycle from Dom ?

A highlight for me is the mass formation flight of the PC-7s. Built as a simple design from EPP in 1/6 scale, very light and realistic in flight, it's one of the few group projects I think which really worked out well with around 40 models built and flown.

A week ago was the annual meeting in Huttwil, Switzerland for models built after plans or own design. Last year was cancelled due to covid-19 but this year restrictions were relaxed just in time for the small event. It is different to normal airshows since Saturday is traditionally the day for the model builders and pilots to meet. Sunday is the airshow part for spectators. Main goal of this nice meeting is getting in contact with others and discussing and exchanging ideas in a tranquil atmosphere. The models always range from a few grams to several kilograms, built from all kind of materials. Timo

Last weekend there was the meeting for plan & self built models in Huttwil, Switzerland. Last year it was not due to covid so this time much more people than usual appeared with a great range of models. If there's interest, I'll post some pictures in the events thread. With my 1091 I've had a great formation flight with an Yokosuka Ohka someone built after my FMT plan of the same 1/12 scale. 180 cm compared to 45 cm. It wasn't easy to follow that small plane but the yellow colour helped a lot. Right to the airfield is a steep slope which provided me with perfect conditions to fly the P.1091. Low level flying over the airfield combined with soaring along the nearby ridge. I'm still undecided if I should test increasing wing angle to improve gliding angle, but it already is a fine flier. A bit weak on hand start and a long gliding path even with flaps deployed, but otherwise unsual looking and flying fine. Timo

Nacelle covers are attached, the extension on the inner sides is missing, yet. A quick check for the looks was necessary ? Timo

Wing attachment of gun camera and cartridge collector is complete with a magnet and pins. The nacelle cover will be used as an air inlet to the motor. Small size, but better than nothing. Timo

The nacelles inlet and outlet is a typical Petter design. Looking very easy, but changes shape from front to rear, slightly bent and following the curve of the nacelle. I sanded it from balsa two times and decided to make the four of them from glassfiber. Balsa parts are vacuum formed the quick & dirty way, afterwards filled with Reliefco 300 ceramic (which is nice and easy to be sanded to perfect shape), once again vacuum formed and these parts are now used as a mold for glassfiber parts. Now only the lengthened exhaust for the inner nacelle sides is needed (to prevent exhaust fumes going to the air inlet on the wing leading edge of the original). Timo

I would be happy if there wouldn't be so much work left to do, Simon ;-) The fuselage tail is finally closed.

Last preparations for the cartridge collector and gun camera. It took a while to get the proper shape from photographs (drawings were not accurate). And then I had to make some corrections since the airfoil thickness of my model is not perfectly scale and their height shouldn't be too different. Timo

I decided to use a leftover nose wheel as tail wheel, as previously planned. So I can close the fuselage tail. A small hatch will be installed, slightly bigger than planned for access to the tail wheel, linkage and tail wiring. The nacelles still need the air intakes & exhaust cover. Actually it's made from several layers of 3 mm balsa. It will be useful as an cooling air inlet, although small. I haven't decided yet if I use them as a template for glassfiber parts. Timo

More small tasks: installing the ESC switch and preparing the installation for the nacelle plug connection to the wing. Timo

The horizontal stabiliser is covered with Oratex, aftwards I resumed work on the nacelles. Due to too strong magnets and the flat shape of the hatch (difficult to grip) I changed to a classic hatch opener. The brushless controller got a plywood plate to be attached to. The motor is attached to the aluminium plate for better stability due to the huge spinner and lower temperature through higher mass. Timo

Time to resume work again on the Whirlwind ? Actually it's covering the horizontal stabiliser and installing magnets for attachment. Timo

The 109s needed a replacement spinner. After testing several options, the 3d printed one from my brother worked best. After all, it’s a bit like Easter eggs painting ? Timo

Finally I have the first really good inflight pictures of the 1091 ? I keep using the 3S3000, start is easy, flying is fine and reliable with the current settings even in different wind conditions. Still looking very unusual ? Spring and thermals can come. Timo

Cold and windy but dry at least, so more test flying yesterday and today. As expected it wasn't perfect flying in rough conditions. I had problems finding a good elevator trim, being either too high or too low. Either too much sink rate or loosing too much speed when turning into the wind. I also found out that the ESC voltage regulator has problems with the increased butterfly flap. 3A should be enough for six small servos, but this time I used digital servos on the wing and that could be the reason. There's a chance that they need high current at the same millisecond. And Kavan fast'n'eze hinges are more stiff than the traditional ones. Another task to optimise. This morning I made several small changes. I increased angle of incidence a little bit by adding layers of tape to the fuselage. I moved elevator linkage to the inner hole of the servo horn. I also moved that servo and resoldered the clevis on elevator side to get a straight wire which is moveable with small force. Finally I put a light 3S3000 accumulator inside, COG a bit more forward than yesterday. Still more aft than originally calculated but that helps for finding thermals. Accumulator position is now perfect on the center of the accumulator board and easy accessible from the hatch, so that estimation was good. Flying was different right from the start. The little up and down after hand start was away, just a perfect straight acceleration at a light upward angle. Flying was smooth despite the once again windy conditions. Only landing took full concentration. I had to land down the slope on the narrow grass patch with unsteady wind. Decceleration was too high at first, adding power for a second then lead to a long glide path at the same angle as the slope. So half butterfly once again to bring the model down while working on all rudders to keep the 1091 straight. Maximum deflection is fine since rolls and loops are possible, but for the next flight expo on aileron and rudder is zero and only 10% on elevator. So now I'm coming to the point where I can recommend building this model without bad feelings. More flights willl follow, of course, but it seems I'm on the right track. Finding good settings for a new model is always interesting, especially in this case with many servo functions and the double role as motor and glider plane. With scale models you have to make the best from what you have, no chance to alter the original design too much. Timo

Cold and a bit late, but otherwise perfect conditions today for some real test flights. I changed the center of gravity a bit to get to the optimum point. I think two positions for low and strong wind will be suitable with the small tail. And I increased the butterfly deflection to decrease the glide path on landing (which is quite long). Further I optimised servo movements a bit. Several short flights and landings showed good flying characteristics. There's a little upwards tendency on an otherwise easy hand launch, which is just minor but I want to check that another day. Otherwise no flaws, although I think flying in rough conditions will be more interesting. Forward cog could help, of course. Glide angle is superb and I'm looking forward to good thermal conditions. Rolls are fine and loops and circling can be really tight. Aileron reaction supported by flaps is good, rudder a bit weak and has to be increased, elevator is fine but can be optimised, too. Stall tests on both cog positions were satisfying and better than expected, just the nose is going down and speed quickly regained. No tendency to flip over one side. The AG35 airfoil is definitely a fine one. Easy to built with flat bottom surface. Easy handling, good performance. Timo

Thanks everyone ? No flying weather recently so I started adding panel lines. Timo