The FAA definitions and notification requirements have changed:
(a) Class 1—Model Rocket means an amateur rocket that:
(1) Uses no more than 125 grams (4.4 ounces) of propellant;
(2) Uses a slow-burning propellant;
(3) Is made of paper, wood, or breakable plastic;
(4) Contains no substantial metal parts; and
(5) Weighs no more than 1,500 grams (53 ounces), including the propellant.
(b) Class 2—High-Power Rocket means an amateur rocket other than a model rocket
that is propelled by a motor or motors having a combined total impulse of 40,960
Newton-seconds (9,208 pound-seconds) or less.
(c) Class 3—Advanced High-Power Rocket means an amateur rocket other than a
model rocket or high-power rocket.
https://www.nar.org/?s=faa
Flying Class 1 rockets requires no notification or waiver and generally includes low and mid-power models. Class 2 are high power rockets that require notification and waiver applications. Class 3 - Space X ?
This chart that summarizes the NAR/Tripoli certification levels and federal limits is a handy reference:
View attachment HPR_metric9c.pdf
