"Pate" Berg was born in Lahti on 23 November 1911.

He received flying training in 1930-31 and was accepted to KadK on 2 June 1931.

He was promoted to luutnantti (lieutenant) on 16 May 1935 and posted to LLv 26 on 31 January 1938.

The LLv 26’s pilots entered in combat for the first time with Gladiators on 2 February 1940.
At 10:40, luutnantti Berg was engaged in combat with a reported six I-153s above Hanko and shot down one of them.
38 IAP reported that they attacked Turku AF base and kapitan Vakkh Teplyakov claimed two Bulldogs in combat. Three more Bulldogs were claimed as shared destroyed on the ground by kapitan Teplyakov, kapitan Sergeyev and starshiy leitenant Ivanov.
Jorma “Joppe” Karhunen described Berg’s first claim during the Winter War (Karhunen was at the time a Fokker D.XXI pilot and flight commander in 1/LLv 24):

"We shared the ice base at Littoinen near Turku in the beginning of February 1940. LLv 26’s Gladiators were flown here after they had been assembled in Sweden.
On the 2nd of February I saw Berg climbing from Littoinen in GL-263. Air raid sirens were screaming in Turku. Time passed and I saw Berg land. He ran toward me and told me:
"I shot down a Chaika (Polikarpov I-153), it crashed on the ice. My own aircraft has hits, can you borrow me a Fokker so I can go and have a look at the wreck?"
As he was very excited about his first kill, I gave him my permission to use one of our Fokkers. Berg took off and returned after some time. Unfortunately he had damaged the Fokkers undercarriage making a harsh landing on the ice, so the Fokker had to be repaired at the state aircraft factory at Tampere overnight."

“A squadron of Chaikas bounced me from the above. I received several hits on my Gladiator, but a fast evasive turn prevented any further damage. I decided to test the manoeuvrability of my new mount and the nearest three-plane Chaika section wanted to fight with me. The rest of them went away.
The Chaikas made a tight turn to try finishing me off again. I made a turn too and I discovered that my GL was able to turn with the Chaikas. I was not even warmed up when I was able to get into a firing position behind one of them. I tightened my turn to the extreme and thus I was able to pull enough deflection and my short burst hit his engine.
The plane I fired on went down towards the ice. His comrades decided to turn for home, and my victim made a landing on the ice. It looked only slightly damaged. I decided to fly back to Littoinen because I feared the hits on my own aircraft might be critical.”

Berg and the eight Gladiators of detachment Heinilä left Littoinen on 4 February and headed for Utti to be a part of 1/LLv 26.

Berg took turns with vääpeli Valio Porvari flying interception missions.

On 18 February, enemy bombers heavily attacked Vyborg. At 11:30, luutnantti Berg (GL-279) destroyed two and damaged one SB out of a formation of forty encountered near Kouvola.
It seems that he had been in combat with bombers from 54 SBAP, which reported that 40 SBs escorted by twelve I-153s from 149 IAP attacked Kouvola. The bombs were dropped at 11:52-11:59. Three SBs were damaged by heavy a/a machinegun fire. 3. and 5. eskadrilyas were attacked over the target by a reported five Bulldogs and nine Fokker D.XXIs. In the following combat, the gunners claimed two Bulldogs, while own losses were limited to two damaged SBs: one piloted by leitenant V. V. Butrim received 22 bullet holes, mainly in the left wing and navigator’s cockpit, and landed safely at own airfield, while the second SB flown by leitenant N. I. Ivanov was forced to land at Kotly airfield, navigator leitenant A. A. Smirnov being wounded in right hand.
The I-153s of 149 IAP reported combat south of the target with two Fokker D.XXIs and four Bulldogs and claimed three victories. Mayor Sergey Plygunov claimed one Bulldog, mayor Leonid Kuldin claimed one Fokker D.XXI and a second Fokker D.XXI was claimed by leitenant Vladimir Litvinenko. Near the target, the fighters met heavy a/a fire, leitenant Litvinenko’s I-153 got 36 holes from the close explosion of a shell. Nevertheless, he safely landed at the own airfield.

On 19 February, luutnantti Berg’s three-strong patrol of LLv 26 was chasing a formation of 32 SB bombers when it was engaged in combat with various I-153 fighters above Sippola at 15:25. One of the enemy fighters was shot down by Berg and another was shared between luutnantti Poul Christensen and vänrikki Lauri Sihvo. The rest of the enemy fighters broke off and headed towards Suomenlahti.
They had been in combat with I-153s from 149 IAP, 7 VA, which reported that at 15:40, seven I-153s and four I-16s were escorting 35 SB-bombers. After bombs were dropped, five “Bulldogs” attacked, with four I-153s responding. I-153 c/n 7142 and 7158 did not return from Sippola. Starshiy leitenant N. Yu. Iyentish and starshiy leitenant V. S. Osipov (CO of the 2nd eskadrilya) became POWs. Leitenant Makarov force-landed at Kotly after lack of fuel while leitenant Semenov returned with 47 bullet holes in his aircraft.

Berg later told about his experience with Chaikas:

“The Chaika has a back armour plate for the pilot so firing at them directly behind with Gladiator’s rifle-calibre guns is useless. Dogfighting them is the best chance to get a Chaika if you are good at it.”

Source SA-Kuva.

At 10:50 on 20 February, luutnantti Berg (GL-280) of LLv 26 attacked a detachment of 30 bombers above Kouvola. He attacked a bomber in the middle of the formation, but this was a mistake, as he ended up in the middle of murderous crossfire from the bomber formation. His Gladiator caught fire and Berg opened the canopy and unstrapped himself to jump. He, however, got stuck when his boot got jammed in the cockpit and he struggled for a few moments, trying to remove his stuck boot and the flames burnt his face before he fell free from his blazing Gladiator. Later Berg heard that the SB he had attacked dived burning into ground. He was hospitalised for the rest of the winter war.
It seems that the bomber shot down by was SB c/n 7/216 of 5./54 SBAP, which was shot down in air combat over Kouvola and crashed at Kattilainen, Ruokolampi. Leitenant Yevgenij Mikhailovich Filonenko was KIA and mladshiy leitenant Vasiliy Yefimovich Kufakov was killed at arrest. Shturman leitenant Mikhail Ivanovich Maksimov was believed to have been taken prisoner after the forced landing on the ice of Gulf of Finland and on 17 July 1940, the Soviet Legation inquired whether Maksimov had been taken prisoner; in fact, he died of wounds on 21 February.
On the same day alikersantti Ilmari Joensuu (LLv 26) shot down a DB-3 over Laatokka (possibly from 54 SBAP).
During the day six SBs and one DB-3 were lost for various reasons.
149 IAP reported that six I-16s and eleven I-153s were escorting 36 SB-bombers to target no. 32 (Kouvola Junction). Finnish fighters intercepted on the return flight south of Utti and mladshiy leitenant Oleg Filatov (I-153) claimed one Fokker and got one hit on his own aircraft. No Finnish Fokkers were lost on this date.

With five aerial victories during the Winter War, he was one of the most successful Finnish Gladiator pilots and a "real" ace with biplane fighters.

After the end of the Winter War, he was posted to LLv 32 on 27 March 1940, as letueen päällikönä (flight leader), flying Fokker D.XXI and on 30 April 1940 promoted to kapteeni (Captain).

After the mobilization on 18 June 1941 he was posted as flight leader of 1/LLv 32, which was based at Hyvinkää and equipped with six Fokker D.XXIs (with Mercury engines) (these were replaced with Curtiss Hawk 75s in the middle of July).

The Continuation War started on 25 June 1941 and Berg continued to act as leader of 1/LLv 32 until 13 August 1941.
He returned as flight leader of 1/LLv 32 on 3 September.

Kapteeni Berg is pointing out a patched bullet-hole on his Curtis CU-533.

He claimed his first victory in the Continuation War at midday on 17 July when he was involved in combat with I-153s from 10 KOAE-KBF, of which he claimed one.

During a sortie between 13:20-15:10 on 1 September, kapteeni Berg (CU-557) and vänrikki K. Karhila (CU-502) claimed a shared balloon over Jääski.

At 10:55 on 3 September, kapteeni Berg’s eight-aircraft strong 1st Flight jumped I-153s from 7 IAP over Siestarjoki. In the ensuing fifteen minutes long combat seven I-153s were claimed. Finnish pilots claiming in this combat were kapteeni Berg, luutantti Veikko Evinen (CU-560), vänrikki Kyösti Karhila (CU-566), vänrikki Sakari Alapuro (CU-553), vänrikki Jaakko Hillo (CU-558), ylikersantti Uuno Alppinen (CU-556) and kersantti Jaakko Kajanto (CU-570).
Vänrikki Karhila described the combat:

At 10:55-11:05 hours. On a surveillance mission we met 5-6 I-153s. I saw one break off to the sea. I was about 1,000m higher. I caught it easily and got by surprise behind its tail. I opened fire from 20m off and the plane caught instantly fire and crashed in the sea. My plane was CUw-566.”

On 19 September, kapteeni Berg’s eight-plane 1/LLv 32 engaged five MiG-3s of 7 IAP over Ohalatva between 13:20-13:30 and destroyed four them with the fifth as a probable. Finnish pilots claming in this combat were kapteeni Berg (three MiG-3s), vänrikki Kyösti Karhila (CU-560) (1 probable), ylikersantti Uuno Alppinen (CU-566) (one shared) and kersantti Jaakko Kajanto (CU-558) (one shared).
Berg recounted:

“At about 3,000 m altitude I saw among the clouds at first four enemy aircraft flying to the opposite direction. I took a diving turn and went after them. Just after coming out of the cloud I saw a bit lower one I-17 only 200 m away. I fired at it and it started smoking instantly and went down diving on its back. I followed the others, which still numbered as four. I opened fire on the nearest, when it pulled down to left pulling up again. I followed and fired when it started to smoke. At the same time two more (Alppinen and Kajanto) came to fire at it. I radioed that there are more on the left side and turned to left to look for a new target. To the left I saw right down to the surface two I-17s, which banked to the left and continued thereafter to south. I caught quickly one of them, which was remaining behind. When I fired at it, it began bank to the left, I pulled after it firing every now and then, getting closer all the time. When I got the bursts even a couple of times ahead of hit, it suddenly flipped to the left crashing. The I-17 was easily caught by the CU. My plane was CU-563.”

On 30 October, 1/LLv 32 was transferred to Nummela to neutralize the Red air forces which was operating from Täcktom airfield, Hanko.

On 1 November, kapteeni Berg’s pair of 1/LLv 32 tried to lure the Russians into combat over Hanko. Berg and ylikersantti Uuno Alppinen (CU-563) claimed a shared I-16 from 13 IAP-KBF, which crashed into the ground. Despite the Finnish top cover pair, the Russian top cover swarn downed the Finnish lead aircraft, killing Berg.
It seems that the Soviet ace starshiy leitenant Vasily Golubev and starshiy leitenant Gennadiy Tsokolayev of 13 IAP-KBF shot down Berg. The war diary of 13 IAP-KBF described the combat:

“At 14:43 [Moscow time] two I-16 planes took off from Täktom airfield. The pilots of the pair were starshiy leitenant Gennadiy Tsokolayev and leitenant Ivan Tvogorov. A while later another pair began their take-off, but the Finnish artillery began to shell the airfield, when only one I-16 piloted by starshiy leitenant Vasily Golubev managed to get airborne while his wingman had to interrupt the start. A moment later two I-153 aircraft took off piloted by starshiy leitenant Aleksandr Ovtsinnikov and leitenant Grigoriy Semyonov, but they did not participate in the whole combat. Two Spitfires attacked Tsokolayev’s pair from the sun. Tsokolayev dodged with a steep bank and managed to avoid the attack, while Tvogorov’s aircraft received hits and became damaged. The wounded pilot was able to bring back his aircraft to the airfield, but it broke up in the landing. In the meantime, Golubev attacked the Spitfire from the sun, which had harassed Tsokolayev and shot it down. The downing was shared between Golubev and Tsokolayev.”

At the time of his death, Berg had claimed 5 biplane victories and a total of 10 victories, scored on 100 sorties.
During his career, he was awarded with the Vapauden Risti of the 4th Class.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1940
1	02/02/40	10:40	1	I-153 (a)	Destroyed	Gladiator II	GL-263	Bromarv	LLv 26
2	18/02/40	11:30	1	SB (b)	Destroyed	Gladiator II	GL-279	Kouvola	LLv 26
3	18/02/40	11:30	1	SB (b)	Destroyed	Gladiator II	GL-279	Kouvola	LLv 26
	18/02/40	11:30	1	SB (b)	Damaged	Gladiator II	GL-279	Kouvola	LLv 26
4	19/02/40	15:25	1	I-153 (c)	Destroyed	Gladiator II	GL-279	Sippola	LLv 26
5	20/02/40	10:50	1	SB (d)	Destroyed	Gladiator II	GL-280	Kouvola	LLv 26
	1941
6	17/07/41	11:00-12:00	1	I-153 (e)	Destroyed	Curtiss 75A	CU-553	Kilpeenjoki	1/LLv 32
	01/08/41	13:20-15:10	1	Balloon	Shared destroyed	Curtiss 75A	CU-557	Jääski	1/LLv 32
7	03/09/41	10:55-11:10	1	I-153 (f)	Destroyed	Curtiss 75A	CU-551	Rajajoki	1/LLv 32
8	19/09/41	13:20-13:30	1	MiG-3 (g)	Destroyed	Curtiss 75A	CU-563	Ohalatva	1/LLv 32
9	19/09/41	13:20-13:30	1	MiG-3 (g)	Destroyed	Curtiss 75A	CU-563	Ohalatva	1/LLv 32
10	19/09/41	13:20-13:30	1	MiG-3 (g)	Destroyed	Curtiss 75A	CU-563	Ohalatva	1/LLv 32
	01/11/41	14:00-14:05	½	I-16 (h)	Shared destroyed	Curtiss 75A	CU-570	Tvärminne	1/LLv 32

Biplane victories:5 destroyed, 1 damaged.
TOTAL: 10 and 1 shared destroyed, 1 damaged, 1 shared balloon destroyed.
(a) I-153 from 38 IAP, flown by Leitenant Bedarev, shot down and taken POW.
(b) Probably claimed in combat with SBs from 54 SBAP, which only suffered two damaged bombers.
(c) Claimed in combat with I-153s from 149 IAP, 7 VA. The Finnish Gladiators claimed two aircraft and Leitenant Iyentish and Leitenant Osipov were shot down and taken POWs while a third I-153 was damaged.
(d) Possibly SB c/n 7/216 of 54 SBAP.
(e) Claimed in combat with I-153s from 10 KOAE-KBF.
(f) 1/LLv 32 claimed seven I-153s. 7 IAP lost three I-153s, 235 ShAP one I-152 and 153 IAP one I-16.
(g) 1/LLv 32 claimed five MiG-3s. 7 IAP lost two MiG-3s and 153 IAP one.
(h) Claimed in combat with I-16s of 13 IAP-KBF. Leitenant Ivan Tvogorov managed to land his damaged fighter.

Sources:
All aces of Stalin 1936-1953 – Mikhail Bykov, 2014
Black Cross/Red Star Volume III - Christer Bergström, Andrey Dikov and Vlad Antipov, 2006 Eagle Editions Ltd, Hamilton, ISBN 0-9761034-4-3
Hävittäjä-Ässät (Finnish Fighter Aces) - Kalevi Keskinen, Kari Stenman and Klaus Niska, 1994 Apali, Tampere, ISBN 952-5026-00-0
Ilmavoitot, osa 1 - Kalevi Keskinen and Kari Stenman, ISBN 952-99432-8-8
Ilmavoitot, osa 2 - Kalevi Keskinen and Kari Stenman, ISBN 952-99432-8-8
LeR 2 - Kalevi Keskinen and Kari Stenman, 2001 Suomen Ilmavoimien Historia 17, ISBN 951-98751-0-7
LeR 3 - Kalevi Keskinen and Kari Stenman, 2001 Suomen Ilmavoimien Historia 18, ISBN 951-98751-1-5
Red Stars 5 - Baltic Fleet Air Force in Winter War – Carl-Fredrik Geust, Samuil Tirkeltaub and Gennadiy Petrov, 2004 Apali, Tampere, ISBN 952-5026-31-0
Red Stars 7 - Talvisota Ilmassa - The Winter War In the Air - Carl-Fredrik Geust, 2011 Apali Oy, Tampere, ISBN 978-952-5877-04-5
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
Suomen Ilmavoimat part III – 1941 – Kalevi Keskinen and Kari Stenman, 2007, ISBN 978-952-99743-1-3
Suomen sodissa 1939-1945 menehtyneiden tiedosto
Talvisodan taistelulentäjät - Joppe Karhunen kindly provided by Tuomo Lukkari
Additional information kindly provided by Alexey Andreev and Andrey Dikov.