Part 61 schools have it easier: students are trained to the standards outlined in the Federal Aviation Regulations. The FARs list what areas of operation and topics will be covered, including the minimum number of hours required for each area. All flight schools can offer training under Part 61 without obtaining special FAA approval. However, they must comply with the statutory requirements under the CFR (code of Federal regulations) and train pilots to the standards of Part 61. Overall, Part 141 schools offer a better choice for the student helicopter pilot.
If you want to fly professionally and you can afford it, it is recommended that you plan training full time for your helicopter ratings. Training full time ensures that you do not have to re-learn skills lost during the intervals between your lessons. This means you will have to give up your day job and spend about eight months to a year in school. It is possible to complete your training on a part time basis but it will take you a lot longer.