by: Paul Cotcher [ ]
The Su-27's Lyulka AL-31F
Those of us that are Russian aviation and modeling fans well know the performance of the Su-27. The now legendary aerobatic performances dating back to the 1989 Paris airshow have become a staple modern airshow "wow." Performing Pugachev's Cobra where the aircraft pitches beyond vertical and returns to flight in the same direction all while retaining stability are a sight to behold and a feat previously not available to jet aircraft.
Performance like this is due not only to the Su-27's design, but also to its powerful engines, the Saturn/Lyulka AL-31F. Given performance like this, shouldn't the engines receive all due attention on your model.
Let's take a look at this offering from North Star, and how they match up against other Su-27 engine updates.
Each exhaust is built from a combination of resin and photo-etched parts. There are nine primary photo-etched, three resin and one white metal parts to each engine assembly. There are an additional 20 plus smaller parts required to each flame holder assembly.
The photo-etched parts are amazingly detailed, and accurate in every detail we can see. Resin parts are well cast and will provide solid structure to the photo-etched parts.
Resin parts are finely cast and feature an excellent rendition of the corrugated inner surfaces of the exhausts. Also noteworthy is that the forward portion of the exhaust is more properly molded in constricting tube (getting smaller in diameter toward the front of the exhaust - toward the nose of the aircraft). I don't believe I've seen this proper reflected on other resin exhausts.
The exhausts are setup to be displayed as open, which is the natural state of the exhausts as the aircraft sits unpowered.
This is perhaps the most detailed set of exhausts that we have seen for the Su-27, however, that comes at the price of very complex assembly.
Building the Exhausts
The pictorial instructions show a 16 step process. Photos are a little dark, but accurately convey the instruction sequence. Looking over the instructions and the parts makes me wring my hands a bit, as I can tell it's going to be tedious work to assemble. The first thing that pops to mind is avoiding superglue for this assembly. Some sort of slower acting craft glue, or even epoxy might be in order.
The major photo-etched parts are keyed to the resin base upon which the engine is built. This will make alignment an easy problem. Two layers of inner petals are added to the resin base. These petals are on a base runner that wraps around the resin with a key that fits in a slot on the resin part. The piece will have to be pre-curled around a dowel or similar round object to facilitate assembly. Petals are bent to shape to match the inner contour of the actual exhaust can. Pay attention to the details of the parts as some have to be folded over prior to wrapping around the resin base.
Once the inner petals are finished the Outer petals are wrapped around the inner petals to finish the exhaust. In all three layers build up the actual exhaust. Each is keyed, so alignment is simplified in this regard.
Once the outer exhaust can is finished turn your attention to the inner exhaust and the flame holder.This is a complex, multi-layer affair as well. Pay attention as two of the layers have small parts that are attached around the edges - ten to each part. This will be tedious, but the parts are notched, so with careful gluing and good tools it looks quite doable. Also note that while the instructions only show three parts being attached to each ring, there are ten slots in the ring and ten parts to be attached to each ring.
Once the rings are ready, these are stacked with the white metal flame holder and then installed in the inner resin exhaust can. This inner exhaust is added to the outer exhaust and the assembly is completed.
Painting should be done in stages as some of the detail will be hard to get to once the assemblies are completed.
Conclusion and Comparison
As I have previously noted, these are easily the most detailed exhausts available for the Su-27. There are many resin sets available from different aftermarket companies. These are nice sets that are good upgrades over crude kit parts. These will be simpler to install and use, but are nowhere near as detailed as this set. If you are into detail, this set is for you, but be prepared to be patient with the assembly!
As the Academy is the only kit currently available in 1:48 scale, we can assume these exhausts are sized for that kit. That said, with the Hobby Boss kit on the horizon, and potentially even other Su-27 offerings coming, we will have to wait to see how this set might fit those kits.
Our thanks to North Star for the review sample, we will put it to good use with the kit soon! As always stay tuned to RedStars for the latest in Russian modeling!