The Citation 525 Series initial aeroplane was the Citation Jet. The CJ1 model is a variant of the Citation Jet with upgraded avionics. The CJ1+ model is a variant of the CJ1. The CJ2 was a new model (525A) in the 525 Series, which was derived from the CJ1 and featured a stretched cabin and higher payload capacities, better range, higher max. operating ceiling, as well as a standard six club seats configuration. The CJ2+ model is a variant of the CJ2 which featured further improved avionics as well as the implementation of FADEC. The CJ3 was another new model (525B) in the 525 Series, which was derived from the CJ2 and featured a further stretched cabin and was the first model to incorporate the integrated Pro-Line 21 Avionics Suite to include the FMS-3000 and the Electronic Flight Bag which were also used in the later manufactured CJ1+ and CJ2+ aircraft.

CJ: Standard Flight Instrument Configuration Consist of an integrated Honeywell SPZ- 5000 Flight Guidance System (IFGS). Standard FMS is the KLN900.
CJ1, CJ2: Standard Flight Instrument Configuration consist of Rockwell Collins Pro Line 21 Integrated avionics Processing System (IAPS). Pro Line 21 can support different FMS systems with the UNS-1C/K as standard.
CJ1+, CJ2+, CJ3: Basic avionics is supplied by Rockwell-Collins and includes fully integrated flight instruments, flight guidance and communication / navigation systems. Collins Pro Line 21 system manages the electronic instrument and engine displays, the autopilot and flight guidance system. The standard long-range navigation system is the Collins FMS-3000.

The CJ4 is a Twin Turbo-jet aeroplane, with 2 pilots’ seats and a maximum 9 passenger seats. Two Williams FJ44-4A turbo-fan engines with Full Authority Digital Engine Control (FADEC) power the aircraft. As the only aircraft in the CJ family, the CJ4 features swept wings, as well as a second MFD.
The CJ4 received its first Type Certification in March 2010, under FAA CFR Part 23 Commuter Category.
M2 and CJ3+:
The M2 and CJ3+ include a Garmin G3000 Flight Suite, winglets and minor interior modifications. Size, gross mass and aerodynamic characteristics of the M2 and CJ3+ are similar to other C525 variants. The M2 is based on the CJ1+ with upgraded avionics and aerodynamics, whereas the CJ3+ is based on the CJ3 with upgraded avionics.


Serial Numbers:
Citation Jet: 525-0001 – 0359 CJ1: 525-0360 – 0599 CJ1+: 525-0600 – 0799, excl. 0685 M2: 525-0800 – and on, incl. 0685
CJ2: 525A-0001 – 0299 CJ2+: 525A-0300 and on
CJ3: 525B-0001 – 0450, excl. 0057 CJ3+: 525B-0451 and on, incl. 0057
CJ4: 525C-0001 and on