Discovery Air Defence Services

Discovery Air Defence Services (formerly Top Aces), a subsidiary of Discovery Air, is a defence contractor based in Pointe Claire, Quebec. Working with the Royal Canadian Air Force (RCAF), they offer advanced training to the Army, Air and Navy branches under the Contracted Airborne Training Services (CATS) program.

Founded in 2000, it consists of three former Canadian Forces pilots experienced with CF-18 fighters and jet trainers like the CT-155 Hawk II.

The company signed a $94-million contract with the CF in 2005, supplying jet trainers in 2006. It has 17 Alpha Jet trainers, 8 of which are based with 3 Wing at Bagotville, Quebec, the remainder are based at various fixed locations across Canada such as 4 Wing Cold Lake in Alberta, Victoria IAP in British Columbia and Halifax IAP in Nova Scotia. In late November 2011 it was announced that the interim CATS contract had been extended until June 2012 with an option to extend to June 2013.

The jets will travel to other training sites:
 * CFB North Bay
 * CFB Trenton
 * CFB Comox
 * Ottawa Airport
 * Halifax Airport

Fleet
The Alpha Jets were initially purchased by the German Luftwaffe. They were sold to Abbatare Incorporated of Arlington, Washington and resold to Top Aces.

Unlike the BAE Hawk trainers, the Top Aces jets do not have any RCAF markings and are not included in the RCAF aircraft inventory. Some Alpha Jets retained the Luftwaffe paint schemes but a few have been repainted in desert or northern camouflage.

As of 22 April 2013, the fleet consists of 26 aircraft.