Petr Kozachenko was born on 14 June 1914, in the small village of Korosten in the Zhitomir region, Ukraine. After school, he went for three years in evening schools for workers education and when he was 20 years old, he entered the army in June 1934, graduating from Odessa Military Aviation Pilot School in 1936.

As a volunteer, he joined the Chinese forces against Japan in one of the first group of volunteers to be sent there in July 1937. During fights over the Uchan Province he claimed 11 shared enemy planes while flying I-16s. He continued to serve in China until May 1938.

In 1938, he was awarded the Order of the Red Banner for his achievements in China.

It seems that starshiy leitenant Kozachenko served in 38 IAP at the start of the Winter War.

Kozachenko was posted from 38 IAP to 4./25 IAP on 21 January 1940 to set up the eskadrilya with Polikarov I-153s. This unit operated over the Karelian Isthmus.

Between 16:15-17:15 on 2 February 1940, ten I-16s and three I-153s from 25 IAP led by assistant CO Bushev fought with 18 Finnish aircraft over Imatra. The returning Soviet pilots claimed eleven Fokker D.XXIs and one two-seated fighter shot down without losses!
Participating (and claiming) Soviet pilots were kapitan Bushev, mladshiy leitenant Polupan, starshiy leitenant Yakov A. Antonov, starshiy politruk Aleksandr Ivashkin (I-16), major Aleksandr Ketov (I-16), leitenant Smirnov, Denisov, starshiy leitenant Smiryagin, starshiy leitenant Sviridenko, starshiy leitenant Nikolai Zybin (I-16) and starshiy leitenant Kozachenko (I-153).
It seems that Kozachenko also claimed the two-seat fighter (Fokker C.X) and according to some sources this is the only claim he was credited with.
The only claim in this combat that can be verified is that the Danish volunteer Luutnantti Fritz Rasmussen of LLv 24 was shot down and killed in Fokker D.XXI FR-81 over Rauha.

On 19 February, starshiy leitenant Kozachenko (CO 4./25 IAP) and starshiy leitenant Grigoriy Sokolov intercepted twelve Finnish Fokker D.XXIs over Hamina and in the ensuing combat claimed four of them shot down (two each).
According to some sources, these four claims were credited as shared between the two pilots.
These claims can’t be verified with any Finnish losses.

Before the outbreak of the Great Patriotic War, he was promoted to major.

On the first day of the war with Germany, on 22 June 1941, Kozachenko and his group of I-153 aircraft of the 249 IAP (249th Fighter Regiment) flew ground attack missions against German forces at Lubera city (near Zytomierz).

Commanded by kaptain Aleksandr Ivanovich Khalutin, the 249 IAP was credited with 25 aerial victories for the loss of 10 planes and six pilots from June to October 1941 (when the unit was withdrawn from combat to be re-equipped with the LaGG-3s).

On 16 July, he claimed a He 111 over Samgorodok.

On 31 July 1942, he became commanding officer of the regiment, leading it over the North Caucasus Front.

In the spring of 1943, the regiment moved to the South Front and saw action over the Kerch Penisula.

At this time, his regiment was instructed to organise "free hunting missions" on German Ju 52/3m transport aircraft. During one of these "free hunts" on 28 February, Kozachenko was seriously injured after shooting down two Ju 52/3ms when he was hit in his left arm and stomach. He was able to return to base, but after landing he remained in the cockpit until his comrades helped him out and he was admitted to hospital for some weeks.

On 15 February 1943, he was decorated with a second Order of the Red Banner.

Major Petr Kozacheko received the Golden Star of the Hero of the Soviet Union and the Order of Lenin on 1 May 1943 (no. 999).
At this time, he had flown 155 combat missions and taken part in 26 air combats.

He was decorated with the Order of the Patriotic War 1st Class on 14 April 1944.

In the summer of 1944, he returned to duty in the rank of popolkovnik, commanding the 163 GIAP, which the 249 IAP had become. The regiment was now operating over the Crimea area on the 2nd Ukrainian Front.

On 13 August 1944, he was decorated with the Order of Aleksandr Nevskiy.

With 163 GIAP, he also saw action in the skies over the encircled German troops near Minsk. His Regiment operated as part of the Soviet 4th Air Army on the 2nd Belorussian Front. Frequently, his regiment was ordered to cover special versions of the Petlyakov Pe-2 during very important reconnaissance missions. These Pe-2 reconnaissance crews put great faith in Kozachenko's cover, and named him "Daddy" (in Russian - "Bat’ka").

He received a third Order of the Red Banner on 23 February 1945.

In March 1945, the 2nd White Russian Front fought near Gdansk and Gdynia.

On 18 March 1945, "Daddy" Kozachenko was killed in a mission while escorting reconnaissance Pe-2s over Danzig (now Gdansk). His La-5 was hit by anti-aircraft fire and started to burn. The last words heard from him over the radio were "I'm hit, going for a 'Taran'!" (Air-to-air ramming attack).

At the time of his death, Kozachenko was credited with 5 biplane victories and a total of 15. These were claimed during 369 combat missions and around 45 air combats.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	??/??/3?		1	Japanese a/c	Shared destroyed	I-16		China
	??/??/3?		1	Japanese a/c	Shared destroyed	I-16		China
	??/??/3?		1	Japanese a/c	Shared destroyed	I-16		China
	??/??/3?		1	Japanese a/c	Shared destroyed	I-16		China
	??/??/3?		1	Japanese a/c	Shared destroyed	I-16		China
	??/??/3?		1	Japanese a/c	Shared destroyed	I-16		China
	??/??/3?		1	Japanese a/c	Shared destroyed	I-16		China
	??/??/3?		1	Japanese a/c	Shared destroyed	I-16		China
	??/??/3?		1	Japanese a/c	Shared destroyed	I-16		China
	??/??/3?		1	Japanese a/c	Shared destroyed	I-16		China
	??/??/3?		1	Japanese a/c	Shared destroyed	I-16		China
	1940
1	02/02/40	16:15-17:15	1	Fokker D.XXI (a)	Destroyed	I-153		Rauha	4./25 IAP
2	02/02/40	16:15-17:15	1	Two-seated fighter (b)	Destroyed	I-153		Imatra	4./25 IAP
3	19/02/40		1	Fokker D.XXI (c)	Destroyed	I-153		Hamina	4./25 IAP
4	19/02/40		1	Fokker D.XXI (c)	Destroyed	I-153		Hamina	4./25 IAP
	1941
5	16/07/41		1	He 111	Destroyed	I-153		Samgorodok	249 IAP
	1942
6	01/11/42		1	Bf 109	Destroyed	LaGG-3		W Kirovo	249 IAP
	1943
7	08/01/43		1	Bf 109	Destroyed	LaGG-3		W Mineral'nyye Vody	249 IAP
8	28/02/43		1	Ju 52/3m	Destroyed	LaGG-3		NE Khan'kov	249 IAP
9	28/02/43		1	Ju 52/3m	Destroyed	LaGG-3		E Prikubanskiy	249 IAP
10	12/11/43		1	Bf 109	Destroyed	LaGG-3		Bulganak	249 IAP
11	13/11/43		1	Bf 109	Destroyed	LaGG-3		Katerlez	249 IAP
12	16/11/43		1	Ju 87	Destroyed	LaGG-3		Height 114,2 (Crimea)	249 IAP
13	19/11/43		1	Ju 87	Destroyed	LaGG-3		Adzhimushkay	249 IAP
14	25/11/43		1	He 111	Destroyed	LaGG-3		Yenikale - Baksy	249 IAP
15	04/12/43		1	He 111	Destroyed	LaGG-3		Lake Cherkasskoye	249 IAP

Biplane victories: 5 destroyed.
TOTAL: 15 and 11 shared destroyed.
(a) 25 IAP claimed 11 victories but only Fokker D.XXI FR-81 of LLv 24 was shot down and the pilot KIA.
(b) Not verified with Finnish records.
(c) Not verified with Finnish records.

Sources:
All aces of Stalin 1936-1953 – Mikhail Bykov, 2014
Black Cross/Red Star Volume I - Christer Bergström and Andrey Mikhailov, 2000 Pacifica Military History, ISBN 0-935553-48-7
Black Cross/Red Star Volume II - Christer Bergström and Andrey Mikhailov, 2001 Pacifica Military History, ISBN 0-935553-51-7
From Barbarossa to Odessa: Volume 1 – Dénes Bernád, Dmitriy Karlenko and Jean-Louis Roba, 2007 Ian Allan Publishing Ltd, ISBN 978-85780-273-3
Red Stars 7 - Talvisota Ilmassa - The Winter War In the Air - Carl-Fredrik Geust, 2011 Apali Oy, Tampere, ISBN 978-952-5877-04-5
Rumanian Air Force: The Prime Decade, 1938-1947 - Dénes Bernád, 1999 Squadron/Signal Publications, Carrollton, ISBN 0-89747-402-3
Sovetskiye asy - Nikolay Bodrikhin, 1998 kindly provided by Ondrej Repka.
Soviet Aces 1936-1953
Soviet Fighter Pilots 1936-1953 - Mikhail Bykov
Stalin's Eagles - Hans D. Seidl, 1998 Schiffer Publishing, ISBN 0-7643-0476-3
Stalin's Falcons - Tomas Polak and Christhoper Shores, 1999 Grub Street, London, ISBN 1-902304-01-2
Suomen Ilmavoimat part II – 1928-40 – Kalevi Keskinen and Kari Stenman, 2006, ISBN 952-99743-0-2
Voenno-Istoricheskiy Zhurnal, No. 3, 1983 kindly provided by Yuri Shakhov
WWII Ace Stories - Dariusz Tyminski
Additional information kindly provided by Ondrej Repka and Yuri Shakhov