- June 20, 1924 - attending flight school, taught by Lt. A. Zarins
- April 10, 1925 - soloed on LVG #27
- 1926 - responsible for the training of one section of Aviation Regiment conscripts (32 members).
- 1931 - transfers to the Naval aviation unit.
- Acquires the nickname "Bumba" ('The Bomb')
- Sept.9, 1934 - Participates in the Aviation Festival at Riga/Spilve.
- July 5, 1936 - Participates in the Aviation Festival at Liepaja.
- 1936 - the Naval aviation unit is resolved, and Karklins is transferred to the 8th Reconnaissance Squadron of the Aviation Regiment.
- July 31, 1938 - Participates in the Aviation Festival at Liepaja.
- August 28, 1938 - Participates in the Aviation Festival at Lutrini.
- September 11, 1938 - Participates in the Aviation Festival at Jelgava.
- 1938 - serves as Commander of the naval aviation school at Liepaja.
- 1939 - serving with the reconnaissance squadron stationed at Liepaja. Rank: Lieutenant
- October 29, 1939 - Karklins transfers the Squadron's motor launch "Lidaka" to Riga.
- June 1940 - (Soviet occupation) - Karklins is responsible for finding new quarters for the Aviation Regiment personnel and flight school.
He arranges for both groups to move to the Match Factory in Bismuiza, and oversees the transfer. His assitant during this process, B.Andersons,
describes Karklins as having an "optimistic nature".
- 1940 (Soviet occupation) - passes medical inspection and deemed suitable for service in Soviet aviation.
- 1944 (German occupation) - serves with the Latvian Aviation unit (NSG 12) of the German Luftwaffe, and is assigned to the first Squadron. Rank: 1st Lt.
- 1944 (German occupation) - On one occasion, while ferrying an aircraft from Gulbene to their base at Vecumi aerodrome, Karklins and another pilot were attacked by
a Soviet fighter plane. Karklins flew at treetop height and used various ground objects for cover to escape successfully, but the other
airplane was shot down. Karklins was awarded the Iron Cross for his actions in this incident.
- August 12, 1944 (German occupation) - dies in action on an especially stormy night flight in the vicinity of Smiltene. He failed to return from the night mission and, a few days later,
German pilots reported seeing aircraft wreckage in the woods. When a party was sent to investigate, they found Karklins plane and he had died in the crash. On August 27 he was laid to rest in Bralu Kapi, Riga.
Note: There were two aviators named "Janis Karklins" in Latvian aviation, both served at some point with the naval section, and it
is likely that some of these biographical details are confused between the two of them. Note also that one of these men, I believe
the one which first joined the naval squadron, had two crashes with Fiat CR.1 aircraft - one on November 8, 1928 and the other on
June 12, 1931.
- Briedis, E. Latviesa Stasts, pg. 77, 135
- Bruvelis, E. Latviesu Legionari, pg. 200, 204
- Bruvelis, E. Latvijas Aviacijas Vesture
- Daugavas Vanagu Menesraksts, 1969 No.2 pg. 18 [Rucels]
- Daugavas Vanagu Menesraksts, 1970 No.3 pg. 18
- Daugavas Vanagu Menesraksts, 1975 No.1 pg. 14, 17
- Daugavas Vanagu Menesraksts, 1979 No.4 pg. 15, 16, 21
- Hazners & Berzins (ed) LKOPKL Vol.7 pg. 22, 27*, 33, 39, 73
- Kadets No.4 pg 31
- Latvijas Kareivis, Sept.5, 1934
- Latvijas Kareivis, Sept.11, 1934
- Loza & Ozolins, Latviesu Lidotaji Vol.2, pg. 11, 18, 19, 42, 81
- Muiznieks, J Putnu Cels, pg. 26, 43, 58, 65, 77, 88
- Silgailis, A. Latviesu Legions, pg. 226
- Sparnota Latvija, No.41 (Nov 1937) pg.316, 318
- Sparnota Latvija, No.50 (Aug 1938) pg.603, 605, 606
- Sparnota Latvija, No.51 (Sept 1938) pg. 631, 633
- Sparnota Latvija, No.52 (Oct 1938) pg. 667
- Sparnota Latvija, No.53 (Nov 1938) pg.709
- Sturtivant & Page The DH4/DH9 File pg. 265