In February 1940, mayor Kuldin served in the 149 IAP, which was equipped with Polikarpov I-153s and I-16s.

On 18 February, enemy bombers heavily attacked Vyborg. At 11:30, luutnantti Paavo 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 leytenant 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 leytenant N. I. Ivanov was forced to land at Kotly airfield, navigator leytenant 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 Kuldin claimed one Fokker D.XXI and a second Fokker D.XXI was claimed by leytenant Vladimir Litvinenko. Near the target, the fighters met heavy a/a fire, leytenant Litvinenko’s I-153 got 36 holes from the close explosion of a shell. Nevertheless, he safely landed at the own airfield.

On 21 February, Kuldin damaged an I-16 at landing.

Kuldin ended the war with 1 biplane victory.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1940
1	18/02/40	11:52-11:59	1	Fokker D.XXI (a)	Destroyed	I-153		S Kouvola	149 IAP

Biplane victories: 1 destroyed.
TOTAL: 1 destroyed.
(a) No Fokker D.XXI was lost on this day.

Sources:
All aces of Stalin 1936-1953 – Mikhail Bykov, 2014
Soviet Aces 1936-1953
Soviet Fighter Pilots 1936-1953 - Mikhail Bykov
Suomen Ilmavoimat part II – 1928-40 – Kalevi Keskinen and Kari Stenman, 2006, ISBN 952-99743-0-2