Anton Kovalevskii was born in 1909 (some sources say 1908).

He attended the Orenburg School for Military Pilots.
He was a detachment CO in the 1st LBAE MVO Moscow Military District.

Kovalevskii went to Spain with the first group of Soviet fighter pilots, arriving on 29 September 1936 and using the nom de guerre ’Kasimir’.
In Spain he served in the Escuadrilla España flying Nieuport Ni-H.52s and Lorie 46s.

In November, he became part of the Escuadrilla Rychagov and leader of an I-15 patrulla.

By 9 December, he was credited with one He 51.

In January 1937, two Chato flights commanded by Yevgeniy Yerlykin and Kovalevskii flew south to Malaga. A third Soviet pilot, Yemel’yan Kondrat, was also a member of one of the flights, but the remaining five pilots were Spanish.

Over Malaga at 12:00 on 1 February, Starshii Leitenant Kovalevskii (Escuadrilla Rychagov) got on the tail of a S.81 and started to fire. Smoke and flames erupted from the bomber but as he started to pass over the top of the bomber, one of its gunners were able to fire into the belly of his I-15. The fighter started to smoke and crashed into the ground killing the pilot.
The S.81 was also reported as lost.

Kovalevskii is buried in the local cemetery of Malaga.

He was decorated posthumously with the Order of the Red Banner on 2 February 1937.

At the time of his death, Kovalevskii was credited with 3 biplane victories.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1936
1	??/??/36		1	He 51	Destroyed	I-15		Spain
2	??/??/3?		1	He 51	Destroyed	I-15		Spain
	1937
3	01/02/37	12:00	1	S.81	Destroyed	I-15		Malaga area	Escuadrilla Rychagov

Biplane victories: 3 destroyed.
TOTAL: 3 destroyed.

Sources:
Air Aces Home Page - Jan Safarik
Air War over Spain - Jesus Salas Larrazabal, 1974 Ian Allan Ltd, Shepperton, Surrey, ISBN 0-7110-0521-4
Polikarpov Fighters in action Pt. 1 - Hans-Heiri Stapfer, 1995 Squadron/Signal Publications, Carrollton, ISBN 0-89747-343-4
Polikarpov I-15, I-16 and I-153 Aces - Mikhail Maslov, 2010 Osprey Publishing, Oxford, ISBN 978-1-84603-981-2
Soviet airmen in the Spanish civil war 1936-1939 - Paul Whelan, 2014 Schiffer Publishing Ltd, ISBN 978-0-7643-0