Because that would add several million dollars to the airplane's price. An angle of attack sensor (the sensor MCAS relies on) for a small, twin-engine private j

Because that would add several million dollars to the airplane's price. An angle of attack sensor (the sensor MCAS relies on) for a small, twin-engine private jet can cost nearly $50,000. The ones in the MAX cost a lot more. Even if cost wasn't an issue, space and weight are. There are just so much stuff you can tackle on the fuselage or inside the engine cowling before it starts affecting the airplanes ability to fly.