expl
Member
Recently I obtained ASSO-3 and started general checks and some overhauls.
First, some general overview:
Model designed year 1993 (this particular build year 2014)
Many kits sold and build (I've been able to find on the internet I-6xxx, I-4554, I-4671, I-4762, I-4827, I-5385, I-8303, I-B458, D-MASO, and one from France with no registration).
Might be it would be possible to obtain drawings of the aircraft via this forum?
Mine is I-B458, recent photo.
Some questions to the ASSO owners (if any).
Although ASSO-3 has ~12 m2 area, and rather "thick" profile, stall speed seems quite high - IAS shows 75-80 km/h with flaps (and two persons on board)... That is a lot!
I haven't concluded that yet, as pitot system seems to be leaking... However - it is very similar to what GPS is showing.
Flaps design.
The flaps are not designed properly.... They overload the wing structure in some places.
Undercarriage design
The area welded in several spots, and not the whole diameter.
Perfect place for the cracks to appear (and they do, as in the image below)
Wing-spar interconnection:
First - metal "sheets" are attached via 5mm (class 10) bolts (8 of them)
The bolt itself is enclosed to 7mm steel tube(within the spar), therefore the total diameter for shear force in wood is around 7 mm/per bolt.
However - as the momentum at this point is very high - around 16 tons in total (at +6g, which is typical calculated "breaking" load) - 7 mm does not look like sufficient...
Anyway - as it looks OK after 100+ hours of flying (wood is not weared/loosened), and there are many other ASSOs flying....I am probably wrong with the calculations.
Second: the interconnecting bolts (20 mm - black ones) are not not close-tolerance type, therefore due to normal wear - they could loosen up quickly.
First, some general overview:
Model designed year 1993 (this particular build year 2014)
Many kits sold and build (I've been able to find on the internet I-6xxx, I-4554, I-4671, I-4762, I-4827, I-5385, I-8303, I-B458, D-MASO, and one from France with no registration).
Might be it would be possible to obtain drawings of the aircraft via this forum?
Mine is I-B458, recent photo.
Some questions to the ASSO owners (if any).
Although ASSO-3 has ~12 m2 area, and rather "thick" profile, stall speed seems quite high - IAS shows 75-80 km/h with flaps (and two persons on board)... That is a lot!
I haven't concluded that yet, as pitot system seems to be leaking... However - it is very similar to what GPS is showing.
Flaps design.
The flaps are not designed properly.... They overload the wing structure in some places.
 | The flaps are driven by the car windshield motor. |
 | The original gear (above) as only 50 degree movement angle (the flaps are deployed in 1-2 seconds, which is way too fast) It will be re-made with larger gear, to increase the angle and reduce the force required. |
 | The end-rod lever will be drilled into the lower location, to reduce the force. |
 | However, the force - required to push flaps out will remain very high due to extremely short leverage. Unfortunatelly - it is impossible to simply re-design it. |
 | The wing-body interconnection, has round pin which does not distribute the load and wears out quickly... In addition, the pin is steel, and the rod - titanium... They are .... welded(!!) together. Miraculously - titanium and steel "weld" held 100+ hours... |
 | Crazy design: all ASSO 3 has flap-rod going straight through the rib...  |
Undercarriage design
The area welded in several spots, and not the whole diameter.
Perfect place for the cracks to appear (and they do, as in the image below)
Wing-spar interconnection:
First - metal "sheets" are attached via 5mm (class 10) bolts (8 of them)
The bolt itself is enclosed to 7mm steel tube(within the spar), therefore the total diameter for shear force in wood is around 7 mm/per bolt.
However - as the momentum at this point is very high - around 16 tons in total (at +6g, which is typical calculated "breaking" load) - 7 mm does not look like sufficient...
Anyway - as it looks OK after 100+ hours of flying (wood is not weared/loosened), and there are many other ASSOs flying....I am probably wrong with the calculations.
Second: the interconnecting bolts (20 mm - black ones) are not not close-tolerance type, therefore due to normal wear - they could loosen up quickly.
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