The Pitot and Stall sensors are positioned to allow minimum disturbance from things such as prop wash or other localised airflow.
On large aircraft this is on the forward fuselage.
For aircraft with nose-mounted engines this is not as easy so outboard on a wing is where they go.
Piper must have found that the left wing is less prone to disturbance so it was all packed in that area. Since most of the small Piper twins have build commonality with the single version the sensors were kept in a similar place.
The Navajo has the stall warning fitted to the right wing for something different.
Last edited by 43Inches; 15th Oct 2013 at 06:00.