blog: Fitting a smoke system in a Yak 52

by Theo Hendriks G.W.K.,A & P,I.A.

FLAME MAINTENANCE

It started with a smoke system that is designed for Yak52 and can be purchased via Spruce.

The Baggage compartment seems to be the best place, but when I did a bit research with our Russian mechanic, he adviced me to install behind the baggage compartment there used to be 20 Kg of radio equipment that was removed, so no center of gravity problems when installed.

The main problem was how to fill the tank? The only option was to install a filler-cap, so we ordered a filler cap as well. First I tried if it would fit in this space, there was a unused bracket that was in blocking the tank, so it had to be remove first.

To build a bracket that was strong enough, a profile or extrusion and a bend sheet of 2024 T3 alclad is been used. The L shape profiles is standard kit equipment.

Another problem showed up. You are not able to reach the aft screws to secure the reservoir to the bracket.
The plastic “wings” are removed from the screws and installed them with a nut to secure them. Now you are able to slide the reservoir into the bracket and can be secured.


Also a rising bracket was riveted to the lower L shape plate to secure the tank on the top side

An adapter was designed to fit on the tank filler cap so a 2 inch hose could fit. The new filler cap was installed behind the canopy so that the area was as flat as possible and would not cross any beams or ribs on the inside. 3 rivets where removed and 2 countersink rivets where installed in stet, one hole was use to install the filler cap with a screw and nut.


Finally a connection was made between the tank and filler cap with cast iron elbow’s and 2 inch Mil-H 6000 hose. Then I realized that when this tank is overfilled with paraffin or diesel it will leak via the vent line on till the level was equal. To prevent this I installed the vent line over the filler connection.

The Yak has an 24 Volt system and the smoke system is designed for 12 Volt so a converter is added to the kit. Behind the instructor seat is enough open space to install and cool it.

In the wiring diagram delivered with the kit they added the converter before the arming switch, that means that the converter is always active, it has been changed in a way that the arming switch arms the hole system including the converter. The Landing-lights where removed earlier so I used that switch to arm the system. To Activate the system I installed a switch right of the starter-switch (Red) and a LED that comes on when the system is armed. With your hand on the throttle you can reach the switch. A remote switch is installed on the control stick to activate they system shortly.

And Yes !! it does work !!