CASR

-
Canadian
Defence Policy,
Foreign Policy,
& Canada-US
Relations

-

In Detail
——
 IMP –
the CF18
Incremental
Modernization
Program

——

by Allan Ng
M.Eng., P.Eng.

 

CF18 Index

In Detail Home

CASR Home

Canadian Defence Procurement  –  December 2003

The CF18 Incremental Modernization Program  –  In Detail

Allan Ng reviews DND's CF18 fighter aircraft modernization plan  (Part 2)

Details, details,  ...  the Nitty-Gritty Behind Boeing's ECP 583

Engineering Change Proposal 583 includes the addition of the following:

Raytheon AN/APG-73 multi-mode radar
The AN/APG-73 is a development of the original AN/APG-65. The APG-73 has all of the modes available to the earlier radar set but with triple the processing speed and memory capacity, and the addition of Terrain Following and Terrain Avoidance modes.  The latter features are critical for any ground attack missions. For air-to-air missions the APG-73, unlike the APG-65, is capable of guiding state-of-the-art AIM-120 AMRAAM active homing missiles.

The APG-73 is now a mature radar system  –  having entered US service in 1994 – and is standard on later model F/A-18C and on the new F/A-18E/F Super Hornet. (There is some irony in the APG-73's late entry into CF service, this radar having originally been a joint US-Canadian development.)   A possible future upgrade to the radar is an option that will allow the APG-73 to produce high resolution radar ground maps useful for ground attack missions or for reconnaissance. [1]

BAE Systems AN/APX-111 Combined interrogator and transponder
Also known as IFF (Identification Friend or Foe), this device is used to determine whether any electronically-interrogated aircraft are 'friendlies' or unknowns. (Depending on the rules of engagement,  any unknown tracks could be declared to be 'hostiles'.) Basically, the interrogator portion of the APX-111 demands the correct coded response from a targeted aircraft. If that interrogated aircraft is also fitted with an APX-111, the transponder will send back an appropriate coded signal to the interrogator. Signals are only sent to interrogators the system recognizes.  In other words,  the APX-111's transponder will either identify itself as 'friend' or it will not respond at all.

The APX-111 transponder unit is also compatible with civilian mode S functions and, presumably, mode C.  Both modes are required for flight in civilian airspace. The AN/APX-111 will bring the CF18 up to current NATO standards for combat identification and will allow the AIM-120 AMRAAM missiles to be used out to their maximum range while reducing the risk of 'friendly-fire' incidents. The CF18 was already equipped with a transponder but, by combining the function of both interrogator and transponder in one unit, APX-111s save weight and volume. [2]


[1]  For more on the AN/APG-73 multi-mode radar set, see the Raytheon website.

[2] For more on the AN/APX-111 IFF/transponder, see the BAe Systems website.


<   Part 1  —  Not Your Father's Hornet
>   Part 3  —  ECP 583 (Cont)  Radio and Mission Computer