.First off fantastic mod, I've had a ton of fun messing around with these new parts, secondly are you planning on adding any new engines? There is several kinds that haven't been made in any other mod. If you had the ambition you could try making: A variable cycle engine: A variable cycle engine is a jet engine that can change its bypass ratio, allowing it to act like a low bypass turbo fan at low speeds, and a turbojet or. ramjet at high speeds. A well designed variant could go at least mach 4.2, and possibly mach 5. https://en.m.wikipedia.org/wiki/General_Electric_YF120 .https://en.m.wikipedia.org/wiki/Variable_cycle_engine A super conducting electric prop or ducted fan: An electric prop that would have three times the thrust, half the energy consumption, and one third the weight of a normal electric prop. If you made it a ducted prop/fan, it would produce even MORE thrust, aswell as being 95 percent more effecient at high speeds. If you were to make this, I'd would recommend making it able to rotate for use in vtol applications. It would be able to attain much higher speeds than a conventional prop and have instant acceleration due to the electric engine. .http://www.gizmag.com/go/7459/ .https://en.m.wikipedia.org/wiki/Ducted_fan Vtol pulse units: small pulsejets used for vtol operations. (Sorry there isn't much more to say about them) https://en.m.wikipedia.org/wiki/Pulse_Ejector_Thrust_Augmentor Futuristic RATO boosters: RATO boosters were used by the military to drastically reduce the needed runway length of aircraft, simply thrust in a can. You could make a very high performance version of this to allow planes to perform sub orbital hops, very short or vtol take offs, and ability to brake the sound barrier and get through the transonic speed region at low altitudes. .https://en.m.wikipedia.org/wiki/JATO Motor jet or high performance turboprop: a high performance turboprop can have 15000 shp (shaft horsepower) and be capable of flight well over 600 mph, the tips of the blades break the sound barrier, making these the loudest aircraft engines ever created (the american sonar system designed to detect submarines could hear russian turboprop from miles away). High performance turboprops also have the fastest subsonic acceleration of any modern aircraft (Russians would fly their tu95's near the stall speed of NATO fighters, and then accelerate rapidly causing NATO fighters to have to use after burners to catch up, using all theur fuel). A motor jet would also be interesting as it has all the bonuses of a propeller and a jet engine (high top speed, short take off, effecient) but could be relatively heavy. .https://en.m.wikipedia.org/wiki/Motorjet .https://en.m.wikipedia.org/wiki/Kuznetsov_NK-12 Racing radial engine: a high performance radial engine producing 3000-6000 horsepower (the racing plane "rare bear" produces 4000 horsepower and can go 528 mph at sea level). This would be SO cool to have in a mod, it doesn't necessarily fit in with the rest of the engines but it would definitely add to the game. The sound of these engines is the coolest engine noise I know of. They look great (with all the chrome exhaust pipes, counter rotating propellers, and bright paint schemes) .https://en.m.wikipedia.org/wiki/Rare_Bear .https://en.m.wikipedia.org/wiki/Radial_engine