FAA Order 7110.65 Appendix C
could this be the information you are looking for?? The type designator starts with H, i.e. HXA for a/c with indicated air speed of 100 knots or less.
FAA Order 7110.65, Air Traffic Control
Effective February 14, 2008
Includes Change 1 Effective July 31, 2008
Appendix A: Fixed-Wing Aircraft | Appendix B: Helicopters/Rotorcrafts
Appendix C.
Aircraft Information
Specific Homebuilt/Experimental Aircraft
Homebuilt and Experimental Aircraft*
Designator Criteria
Type
Designator
Performance Information**
Climb Rate
(fpm)
Descent Rate (fpm)
SRS Cat.
Aircraft with cruise (indicated) airspeeds of 100 knots or less
HXA
500
500
I
Aircraft with cruise (indicated) airspeeds of greater than 100 knots, up to and including 200 knots
HXB
750
750
I
Aircraft with cruise (indicated) airspeeds greater than 200 knots
HXC
1,000
1,000
I
NOTE-
*Configuration diversity and the fact that airworthiness certificates are issued to aircraft builders, vice manufacturers, necessitates the assignment of generic aircraft type designators based on cruise performance, rather than specific manufacturer and normal descriptive/performance information.
**All performance criteria has been estimated because configuration diversity precludes determining precise aircraft-specific information.