DU and A in case of the bullet piercing the fuel tanks the gas is injected
into the tank over the fuel level and lowers the risk of igniting the fuel
vapors in the tanks. In V and its later versions all five rubber fuels are
filled with the special polyurethane foam which absorbs the fumes. Therefore, we can deduct that these two bottles on the left of the reduction
gear only belong to the versions A, D and DU! Although they are painted
in red, they are also wrapped with silver, electrically heating cover. The
original Zvezda’s instructions unfortunately don’t address this.
Main reduction gear covers on D version can be opened into almost horizontal position as opposed to certain angle on V version due to the
possibility of EVU installation. Both hydraulic blocks and auxiliary unit
AI-9V are identical for both version, just in D version the engine sucks
the air through the louvers in the right cover but because debris collected in this location and birds attracted to nest there when the aircraft
were parked for longer time, starting with DU version the air intake is
routed throughout the grille opening located on the tail end next to the
SARPP-12DM emergency recorder. Therefore, in D version we will not
find the air suction duct in the tail boom when the starting engine cover
is opened. The area under L-166V-11E above the gear case is identical
only in the aircraft lacking this installation there is not wiring inside the
cover. Now let’s move on to peek at the landing gear, radio section and
the tail boom interior.
The TV3-117 and TV3-117V engines do not differ from the outside.
Unlike the V version, where the air intake for the Ai-9V auxiliary power
unit is routed through the tail via the grille at the SARPP-12DM emergency
recorder, the D version has the intake directly at the power unit on the right
side of the fuselage. Also shown is the retrofitted L-166V-11E.
Tailend of the V version with air intake
grille for AI-9V unit.
The D version does
not have it.
The red cylinders of the fire protection system are located on the right side of the reducer on both the D and V versions.
INFO Eduard - November 2021