Here is a good outline for your BC LOR: (I serve in SOF so somethings may not be applicable)
It is with great pleasure that I personally recommend RANK XXXX to be selected to become a 153A Rotary Wing Aviator.
RANK XXXX is a highly intelligent Non-commissioned Officer/Soldier and has always demonstrated the utmost character and professionalism consistent with our ARSOF Attributes and the Army Values. RANK XXX continually accomplishes all assigned tasks above standard and has achieved accolades while operationally deployed. The United States Army would highly benefit from investing in RANK XXX by enrolling him/her into Warrant Officer Candidate School. His/her growth and development as an outstanding NCO have provided him the key leadership qualities, moral courage, and common sense essential for becoming a successful Warrant Officer. In conclusion, RANK XXXX also possesses the intelligence, fortitude, aptitude and drive to become a technical and tactical subject matter expert in the field of Aviation as a Rotary Wing Aviator. I whole heartedly recommend RANK XXX for acceptance as a 153A Rotary Wing Aviator.
And here's for your company commander:
I strongly recommend RANK XXXX for entry into the Flight Warrant Officer program. RANK XXX has served in [INSERT UNIT] for [TIME]. During this time, RANK XXXX has done [INSERT ACCOLADES, ACHIEVEMENTS, DEPLOYMENTS, ETC]
RANK XXX has displayed a high level of maturity and leadership ability. He/she has shown the ability to work at levels above his/her grade and should be placed in positions of greater responsibility. RANK XXX is a winner and a leader. He/she is able to adapt to any situation and rise to the occasion. He/she has the mental, physical, and interpersonal skills to succeed in any position he/she is put in. I am confident he/she will succeed as an Aviation Warrant Officer.
NOTE: I was a first time select with these LORs. Make sure you highlight your achievements. I've been told the board weighs these two LORs heavily since they're the ones that work closest to you and have had time to evaluate your leadership abilities.
Let me know if there is anything else I can do to help. Good luck!