Koolhoven Flying Boat Projects

Hi all,

here is a two pages shows the Koolhoven flying boat projects with the
Ontwerp 1151,can any body add more Info.

http://i811.photobucket.com/albums/z...psbd1e1b62.jpg

http://i811.photobucket.com/albums/z...ps94f457a0.jpg

wel een erg duidelijke verwant van de do 24

That's right J.weel,

and please note there is two projects,one has three and the second
has two engines,but unfortunately,no drawing to Ontwerp 1151.

The upper drawing was indeed relased in response to the MLD requirement that led to the Do 24, in competition with the Fokker B.5. I don't believe it was a proper design, just a publicity stunt. In any case the small Koolhoven company couldn't actually build such an aircraft. They also drew a 100-tonne transatlantic flying boat in 1932...

the question is not if they could bild it
but why they dit not
some say Fokker could not bild a plane with an aluminium hull
but the b5 dus have an aluminium hull

Well, Fokker never built the B.5. Certainly the Navy trusted Dornier better.

The Koolhoven drawing by Justus van Hattum does not represent an actual design in my opinion. Even if they made such a design, yes, I'm saying the small Koolhoven company could not have built it. Building single-engined steel tube aircraft without major design flaws was didfficult enough for them.

Het schijnt dat Justus van Hattum op een wekelijkse basis van Frits Koolhoven een tekening moest maken voor een nieuw 'project'. Je moet hier inderdaad vraagtekens zetten bij de haalbaarheid.
Overigens had Fokker ook als ik het goed heb een ontwerp voor een 3-motorige vliegboot.
Het is uiteindelijk de Do-24 geworden!

Er zijn veel van dergelijke tekeningen, ook eentje van een aangepaste FK-52, uitgevoerd als laagdekker (dus niet meer als dubbeldekker!). Die tekeningen waren toch wel bedoeld voor publiciteitsdoeleinden, lijkt me.

Hi all,

I think the Koolhoven could have a capability to build a large aircraft,and may
be they concerned by those projects,but Netherland Government saw the Fokker
could do it better,and for 100-ton project,I agree with you,that was far away from Koolhoven capacity,because it was a giant.

There was one Koolhoven seaplane (and it looks I have the propeller at home). Hope you can see the picture below? Type:

N.V.I. F.K.34

Navy scout and fighter, 1925

http://members.ziggo.nl/henrikaper/k...s/nvi-fk34.jpg

Nice find Hans023.

Citaat:

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Oorspronkelijk geplaatst door Hans023

There was one Koolhoven seaplane (and it looks I have the propeller at home).

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Citaat:

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Oorspronkelijk geplaatst door hesham

Nice find Hans023.

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And so the rumour was created that somewhere in the Netherlands a Propellor from a Koolhoven seaplane has survived. :unsure:

Hans023 has in the meantime learned that his propellor can only handle 80hp instead of the 500hp from the Koolhoven seaplane :wacko:

a small reminder
it seems some people stil thing bilding a steel tube hull with a wooden wing was ols and low tec
the al metal messersmit and spitfire are complex and better

THEY ARE WRONG
altho the messersmit and the spitfire are faster than taking the Fokker D21 and
The G1 in its original decine was G1 was just as fast but stronger as a wapons platform and more reliabole

The D21 was not capabole of keeping up on speed on the BF 109
but it did turn faster
and it was the only type of fichter that was aprofed to pull 9G in anny way
both the bf 109 and the spitfire could not
even new restored spitfires are not alouwed to go beond 6 g in pulling force
if the pilot dus pull more the whole airframe needs a very ecspensive inspection

after the war private pilots could buy a ww2 warplane fore a smal buc
and they were juced fore airobatic manouweres
those pilots soon found out the metal planes were no good juce of that
they broke apart
the best airobatic airplanes like the walter exstra are bild with a steel tube frame
and a wooden wing

wood has a constand stress strength
and is stronger a pound as aluminium and steel

a metal wing wil get weaker after every time it flexses
a wooden wing wil not it wil be just as strong in 50 jears of when it was bild
as long as it dus not rots away

Te koop: stokpaardje

Hesham: there was another seaplane by Koolhoven, if you can't find it on the sites I can search it for you and send it.

Pim: indeed! Now being puzzled if numbers in front of 80PK were sanded away (like other letters missing), or on what very early -max 80HP- plane the prop was used for (see* big prop dimensions.., I could imagine one needs wide 25,5 cm blades for a seaplane to have most pull power at low speed to get out of the water..). Would you know a Koolhoven expert who can recognize this prop? Thx, Hans

*
Gewicht 9 kg; spanwijdte 250 cm; 8 gaten rondom gat van rond 6,5 cm; de kern is rond 18 cm en 10 cm dik; bladbreedte max 25,5 cm.

Citaat:

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Oorspronkelijk geplaatst door Hans023

Pim: indeed! Now being puzzled if numbers in front of 80PK were sanded away (like other letters missing), or on what very early -max 80HP- plane the prop was used for (see* big prop dimensions.., I could imagine one needs wide 25,5 cm blades for a seaplane to have most pull power at low speed to get out of the water..). Would you know a Koolhoven expert who can recognize this prop? Thx, Hans

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Big propeller + 80hp = slow turning rotary engine

Clerget 7Z
Le Rhône 9C
Thulin A ( licence Le Rhône 9C )
Gnome Lambda
Oberursel U.O ( licence Gnome Lambda )

So save to say no Koolhoven propeller

Ho ho Pim: I just bought some Koolhoven books and the prop was hanging for more then 70 year above a bar at Nieuwenhoorn, only 25 km's away from Koolhoven plant Maasvlakte: clear evidence it's a Koolhoven prop!
:-))

Serious: thanks and thanks also in advance for possible more help. I will search about these engines in what planes and behind what props they were used. But given only 80 HP (if correct), I guess it must be planes before 1915-25. The finding of (1 prop in Alkmaar 2 weeks ago and) an identical prop so close to Maasvlakte: still possible a young Koolhoven plane? (K. used some Gnome's)

"Only 25 kilometers away is........is clear evidence".

Dit ontgaat het me volledig, en meer.

dat heet humor Tracker, daarna het "serious" (maar blijf vragen als onduidelijkheden)