Pavel Kel'in was born in Vladimir in 1913.

He joined the Red Army in August 1935.

Leitenant Kel'in took part in the Soviet-Finnish Winter War of 1939-1940 flying Polikarpov I-153s in 149 IAP.

149 IAP was formed on 31 January 1940 at Pushkin based on elements from 38 IAP and was attached to VVS SZFr. Reinforcements was received from 25 IAP (16 I-16s for 1st Eskadrilya), from 51 IAP (14 I-153s for 2nd eskadrilya arrived on 14 February 1940 from Leningrad) and from the Air Force Academy (VVA) in Moscow.

On 1 February, 149 IAP moved to Vejno west of Lake Peipus (Chudskoye ozero).

At 15:00 on 26 February 1940, 149 IAP was involved in combat over Kouvola when starshiy leitenant Viktor Vilchik claimed a monoplane (Fiat?). Leitenant Kel'in and leitenant Aleksandr Salov claimed one Fokker each (both flying Polikarpov I-153s). Leitenant Begrov and starshiy leitenant Pindyukov shared a fighter ”equipped with open radial engine” (this is clearly referring to a Fiat).
Urgently needed on the front, LLv 26 used only ten days in Fiat training before the baptism of fire. Luutnantti Olli Puhakka (FA-4) took his pair to combat bombers and fighters south of Kouvola. Over Pyhtää, he claimed one I-16 and his wingman vänrikki Kauko Linnamaa (FA-9) claimed one probable DB-3 (from 1 AP). Puhakka also claimed a damaged I-15bis over Kotka during the same combat.

When Germany invade the Soviet Union on 22 June 1941, leitenant Kel'in served in 92 IAP, flying Polikarpov I-153s and MiG-3s.

On 25 June, he crashed with his aircraft.

He left 92 IAP in October 1941.

In March 1942, he was posted to 426 IAP, flying LaGG-3s with this unit.

On 16 May 1942, he was wounded and hospitalised.
After this, he left 426 IAP.

On 20 September 1942, he was posted to 3 GIAP, flying LaGG-3s and La-5s with this unit.

On 22 February 1943, he was presented to the title of Hero of the Soviet Union, but did not receive it (he was awarded the Order of the Patriotic War, 1st Class, instead)

Kel'in was severely wounded in a flying accident on 30 May 1943 and died the day after.

At the time of his death, Kel'in was credited with 1 biplane victory and a total of 12.
These had been claimed during around 200 combat missions.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1940
1	26/02/40	15:00	1	Fokker (a)	Destroyed	Polikarpov I-153		Kouvola	149 IAP
	1941
	01/09/41		1/2	Fw 189	Shared destroyed	Polikarpov I-153		N Begach	92 IAP
	1942
2	30/03/42		1	”Me 115”	Destroyed	LaGG-3		Ramushevo	426 IAP
3	01/05/42		1	Bf 109	Destroyed	LaGG-3		Sherebut’	426 IAP
4	01/05/42		1	Bf 109	Destroyed	LaGG-3		Sherebut’	426 IAP
	03/05/42		1/2	Ju 88	Shared destroyed	LaGG-3		Pola station	426 IAP
5	09/05/42		1	Bf 109	Destroyed	LaGG-3		Pola station	426 IAP
	11/05/42		1/2	Ju 88	Shared destroyed	LaGG-3		Byakov - Demidovo	426 IAP
6	02/12/42		1	Bf 109	Destroyed	La-5		Krasnyy Pakhar'	3 GIAP
7	07/12/42		1	Ju 52/3m	Destroyed	La-5		Krasnyy Pakhar'	3 GIAP
8	07/12/42		1	Ju 52/3m	Destroyed	La-5		Krasnyy Pakhar'	3 GIAP
9	12/12/42		1	Bf 110	Destroyed	La-5		Vodyanskiy	3 GIAP
10	12/12/42		1	Bf 109	Destroyed	La-5		sovkhoz Krep'	3 GIAP
11	12/12/42		1	Bf 109	Destroyed	La-5		Chelikov	3 GIAP
	1943
13	22/02/43		1	Ju 87	Destroyed	La-5		Alekseyevka	3 GIAP

Biplane victories: 1 and 1 shared destroyed.
TOTAL: 12 and 3 shared destroyed.
(a) Probably claimed in combat with Fiat G.50s from LLv 26, which claimed 1 destroyed I-16 and 1 damaged I-15bis without losses. 149 IAP claimed 4 destroyed enemy fighters without losses.

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