I feel that the engines in SimplePlanes are in need of a remodle. First, There should be torque for engines along with horsepower. This means we can have powerful, but slow engines or an engine with tons of torque and horsepower. Along with this, there could be different gearboxes. This includes a manual gearbox or an automatic gearbox.

Second of all, there should be different engines with different sounds with shifting noises. This would make engines look and sound more appealing.

Third of all, there should be different sizes for engines. You could have a really small electric engine, a SUV sized engine, or a big rig's huge diesel engine. This would make engines more close to a real one.

Lastly, There should be different amounts of pistons in the cars. So, if you are building a motorcycle, you could have a 2, 4, 6, 8, 10, or 12 piston engines in that motorcycle.

Those are just a few reasons why I think that there should be an update with an "engine Redo".

If you read through all of that, you should get an A in English class.

I've already made a forum post about this,however I had no luck in contacting the devs,so I'll just put it here also as some kind of insurance :P

Is there a command in the XML file which acts the same as Input,but works with a toggle system? I want to know this since I want to be able to extend and retract flaps/airbrakes on the push of a button.

In case I wasn't clear enough,I will give an example:
Let's say I put a airbrake from the gizmos under my wing to act as a flap.I go into the XML file,and instead of having Input="VTOL" I put toggleInput="NextWeapon" so when I press "F" in game,the flap will extend and retract accordingly.

In case this type of function does not exist,I would like the devs to consider adding it,possibly in the next update or small patch,since it could be very useful in many ways.

Explosion-related

Explosion Force should be divertable by certain shapes, which can throw the damage somewhere else without critically damaging the vehicle.
A Vehicle with most, if not all parts with their partCollisionResponse to "None" still has some disconnecting parts even though the link between the parts did not get destroyed. Make sure that only "Default" and "DisconnectOnly" will be affected by the explosion in these ways:
a) For Default, the explosion destroys the part and sends the parts it's connected to flying, if all parts are set to Default, then it will cause the craft to explode and fall apart.
b) For DisconnectOnly, the parts it's connected to will be disconnected from the Vehicle.
c) For None, it depends on the health of the part. If it gets its health depleted, it will explode but do no damage to any blocks in its area(It depends on the health of the nearby parts if it takes x explosions from certain blocks.)
Weapons that can explode should have explosionScale, explosionRadius, and explosionDamage XML attributes.
Explosion sounds that depend on the explosion size need tweaking. That includes the missiles, bombs, the torpedo, and the cannon.
Parts-related
1. If a part is destroyed, the damage it deals to nearby parts should depend on the health of nearby parts and the partCollisionResponse attribute.
2. Parts with a health of 100-below should blow up and disappear.

Fix for potatoes(Credit to Alta2809 for reminding me):
Explosion Physics should be enabled when Physics is set to Medium or High.

(EDIT 1: grammar change)
(EDIT 2: added a fix)