{"id":630,"date":"2025-08-26T13:37:46","date_gmt":"2025-08-26T12:37:46","guid":{"rendered":"https:\/\/wordpress.familie-lahme.de\/?p=630"},"modified":"2025-08-27T15:44:23","modified_gmt":"2025-08-27T14:44:23","slug":"rc-modelling-bo-209-monsun-by-graupner","status":"publish","type":"post","link":"https:\/\/wordpress.familie-lahme.de\/index.php\/2025\/08\/26\/rc-modelling-bo-209-monsun-by-graupner\/","title":{"rendered":"RC Modelling: BO 209 Monsun by Graupner"},"content":{"rendered":"\n

The B\u00f6lkow Blohm BO209 “Monsun” is a 2 seated small aircraft first mentioned in 1967.
You can find all data about the manned version on Wikipedia<\/a>.<\/p>\n\n\n\n

Graupner came with several builds of the plane starting 1971 with a rubber band driven propeller as a free-flight version.
Over time semi-scale models with a wingspan of 1600mm and 920mm were added.<\/p>\n\n\n\n

I got mine with 920mm wingspan back in 2002. It was not my first RC model, but the one I own the longest time, and the one with the most “refurbishing” done over time.<\/p>\n\n\n\n

Those days I was (and mainly am still) a fan of Graupner. So I did also purchase a Graupner remote control of series FM4040 and FM414. They came in a bundle with trainer setup.
Unfortunately I never had the chance in those days to get a buddy at my side to train me, so I had to start from scratch.
In these days the regulation of RC flights was not at that level it is today and there was no really limitation, where to fly what. So with the total absents of any experience, I went down into the valley on a nice parking lot with about 100 x 25 m surrounded with trees up to 30m height. Yep, the one you don’t want on your first flight.
So long story short, after a short takeoff I had a hard turn and -how do you say that, “dropped a wing”.<\/p>\n\n\n\n

These were my first minutes in flight with my brand new BO209.<\/p>\n\n\n\n

But it would not be me, if this had been the end.
Rebuilding the plane was quite a pain as it came as ARF and no plans were attached, so I had to strip down every part, try to puzzle it and make a drawing to rebuild each of it. It took me about a month before I got all back in place. I was ready for the next attempt.<\/p>\n\n\n\n

This time I had managed to get in contact with a model airfield a few km offside. But again I learned some lessons. Starting on grass was a pain for that plane. So I had to throw it be hand. With a little hassle I managed to get it stable and it was up in the air. Unfortunately I had replaced the small battery which was a 6 cell 500mAh NC with a slightly heavier 7 cell NIMH. This made it fast to fly but also needed some speed to land. The result was on landing I completely detached the gear and the nose.
Those were my second few minutes in the sky with that damn thing.<\/p>\n\n\n\n

Time has past by and she is still my little favorite.
From the original model is not much left, as I have “upgraded” her in a manner to get her in shape, where I can handle it. After braking the wings several times I have build new one from scratch. 180mm more wingspan (now 1100mm) and a flat profile of type Clark-Y<\/a>.<\/p>\n\n\n\n

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The once single aileron with the full length of the wings have been replaced by a more scale like 2\/3 Flap and 1\/3 aileron.<\/p>\n\n\n\n

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The engine has switched from a 30W Speed 400 to a 180W brushless and the battery has gone Lithium with a 3S and 2200mAh. The nose wheel has become controlled and from the once 650g she has gained some weight and is now with nearly precise 1000g. Her flight time can go up to 20 minutes.
All in all she flies really well now. Don’t get me wrong, she is not that smooth rider she was intended to be in her very first days. She can go fast and does crazy things sometimes and needs a well known hand when landing. But she can also go smooth and slow if the air is calm and suits for nice picture shots in the sunset.<\/p>\n\n\n\n

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Future plans:
Honestly she is a bit dirty at the time and I really would like her to get a better look. But with each flight you get some scratches and all the effort of getting a clean cover goes in seconds. I really need to rebuild the canopy, because it is broken and glued all over. This needs some special work as You don’t get spare parts from it anymore and my working place is currently very limited.
The idea of doing sail tows is still on my mind and I do have some weight left over. There is about 50gr of lead in the nose, that could also fit into a 240W engine. We will see.<\/p>\n","protected":false},"excerpt":{"rendered":"

The B\u00f6lkow Blohm BO209 “Monsun” is a 2 seated small aircraft first mentioned in 1967.You can find all data about the manned version on Wikipedia. Graupner came with several builds of the plane starting 1971 with a rubber band driven propeller as a free-flight version.Over time semi-scale models with a wingspan of 1600mm and 920mm…<\/p>\n","protected":false},"author":2,"featured_media":649,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"[]"},"categories":[49,50],"tags":[54,52,51,53],"class_list":["post-630","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-modelflug","category-monsun","tag-aircraft","tag-graupner","tag-monsun","tag-rc-flight"],"_links":{"self":[{"href":"https:\/\/wordpress.familie-lahme.de\/index.php\/wp-json\/wp\/v2\/posts\/630","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wordpress.familie-lahme.de\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wordpress.familie-lahme.de\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wordpress.familie-lahme.de\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/wordpress.familie-lahme.de\/index.php\/wp-json\/wp\/v2\/comments?post=630"}],"version-history":[{"count":6,"href":"https:\/\/wordpress.familie-lahme.de\/index.php\/wp-json\/wp\/v2\/posts\/630\/revisions"}],"predecessor-version":[{"id":678,"href":"https:\/\/wordpress.familie-lahme.de\/index.php\/wp-json\/wp\/v2\/posts\/630\/revisions\/678"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wordpress.familie-lahme.de\/index.php\/wp-json\/wp\/v2\/media\/649"}],"wp:attachment":[{"href":"https:\/\/wordpress.familie-lahme.de\/index.php\/wp-json\/wp\/v2\/media?parent=630"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wordpress.familie-lahme.de\/index.php\/wp-json\/wp\/v2\/categories?post=630"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wordpress.familie-lahme.de\/index.php\/wp-json\/wp\/v2\/tags?post=630"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}