Where were the Mexican Quails assembled?

Aeronáutica Agrícola Mexicana SA, known by its initials AAMSA, was set up in 1971 as a joint venture between Rockwell International, which took 30% of the capital, and Industrias Unidas SA, which owned the remaining 70%. Its plant was at Pasteje, and that is where the assembly of the agricultural aircraft the company built under its own designation should be placed. The shareholding split describes the nature of the project well: a US-origin design produced in Mexico, with the North American partner in the minority position.

The variant built in Mexico was designated the AAMSA A9B. There was also an AAMSA A9B-M, an improved version of the A9M with a lowered rear fuselage, a redesigned cockpit and more dihedral on the wing. These were not a few test examples: the Mexican manufacturer produced 101 aircraft under the A9B designation, a figure that makes the Pasteje plant the centre of gravity of all production of this agricultural aircraft.

Not every aircraft of Mexican origin was finished in Mexico. Seventeen were assembled in Laredo, Texas, from Mexican-made components, and that work was handled by Aircraft Parts and Development Corporation. The resulting arrangement therefore had two assembly points for the same aircraft: the main line at Pasteje, responsible for the 101 A9Bs, and a workshop on the US side that received the parts already made in Mexico and joined them together until the aircraft was complete. Anyone looking for the origin of a particular A9B thus has two possible answers, depending on the airframe.