In October 1936 he went to Spain, arriving on 13 October, as a member of the first group of volunteers to fly in the Spanish Civil War, using the nom de guerre ’Julio’.
In Spain, he commanded the first units of Soviet fighters.

In November of 1936, Pumpur's unit consisted of about 50 I-15s and I-16s fighters.

He took part in the first operations with the I-15 in Spain on 4 November 1936 over Madrid.

Starshiy Leytenant Pavel Rychagov was slightly wounded on 16 November and during his recovery, the Escuadrilla Palancar was commanded by Pumpur. The two detachments were in turn led by Yevgeniy Yerlykin and Starshiy Leytenant Georgiy Zakharov.

By 9 December, he was credited with 2 Ju 52/3ms.

Pumpur left Spain on 11 May 1937.
During his time in Spain he claimed 2 and 3 shared victories flying the I-15.
He also flew the I-16 in Spain.

On 4 July 1937, Pumpur and Konstantin Kolesnikov (posthumously – KIFA 12/05/37) was decorated with the Gold Star of the Hero of the Soviet Union and the Order of Lenin for their performances in Spain.

During the first months of the Sino-Japanese war the losses of the Chinese Air Force was extraordinarily high and in September 1937 (long before the first official grant of a credit of 50 million dollars in March 1938) there was a Soviet resolution to deliver 225 combat aircraft on credit to China. Among the type supplied were 62 I-15bis, 93 I-16s and 8 UTI-4s. This was the beginning of the secret “Operation Z (Zet)”, envisaging not only the dispatch of aviation equipment, but also the tours of Soviet volunteers for participation in battle.
In China the Soviet fighters received new nicknames and the I-16 was known as ’Lastochka’ (Swallow) and the I-15bis as ’Chizh’ (Siskin).

In September the first Chinese pilots were sent to Lanzhou for the new fighters, long before they arrived in China.

The Chinese delegation returned to Stalin on 14 September 1937 with a request for Soviet volunteers. Soon the Komissar of Defense K. E. Voroshilov received an order to assemble the best volunteer aviators and send a squadron of I-16 fighters (31 aircraft and 101 men) and a squadron of SB bombers (31 aircraft and 153 men) to China. At this time a Soviet ‘eskadrilya’ consisted of 31 aircraft in 3 ‘otryady’, each otryad was having 10 aircraft. The remaining aircraft was for the commander. Two or more eskadrilyas equaled a ‘brigada’. During 1938 the ‘eskadrilya‘ was redesignated to ’polk’ (regiment), while the ‘otryad’ was redesignated as an ‘eskadrilya’. The strength or structure did not change, only the names, though later the regiments began to organize with 4 to even 6 component squadrons, while the squadrons themselves became 15 aircraft formations.
A ‘southern’ route was prepared for the bombers. It was planned to send the aircraft in crates to Alma-Ata, assemble them there, and ferry them the rest of the way to China by air. The itinerary, beginning in Alma-Ata, passed through Kuldzhu (Yingying), Shihe, Urumchi, Gucheng (Qitai), Hami, Anxi, Suzhou (Jiuquan), Liangzhou (Wuwei), and concluded in Lanzhou on the Huanghe River. The first commander of the ferry route was the already well-known NII-VVS test pilot Kombrig A. Zalevskii. The base at Alma-Ata was commanded by Kombrig Alekseev. At the series of Chinese aerodromes along the route there were also organized airbases with Soviet ground personnel, including meteorologists, radio operators, and maintenance technicians. At Urumchi the chief of the base was Moiseev, and then A. V. Platonov, at Gucheng - A. V. Politiken, at Suzhou - Glazyrin, at Liangzhou - G. I. Baz’, and at Lanzhou - V. M. Akimov.
The first bombers, ten SBs, were shipped from Moscow on 17 September. They were followed by another 16 aircraft on the 24 September and on 27 September five more. In all, 31 aircraft, which were the full complement of a bomber squadron, were sent dring September.
For fulfilment of the “special government assignments” the selected voluntary Soviet fighter and bomber pilots assembled from across the country in conditions of the strictest secrecy from the middle of September and through the first ten days of October (‘Operation Zet (Z)’). Many of those who were chosen at first believed that they were headed for “the Spanish corrida”, but their long road led to “the Sino-Japanese tea ceremony”.
Fighter pilots sent from all districts for the Far Eastern special aviation units were inspected by the “Spaniards” Kombrigs Ya. V. Smushkevich and Pumpur. Many veterans from the 9 OIAE (Independent Fighter Squadron) were chosen but also some fresh pilots, including Dimitriy Kudymov, Korestelev, Bredikhin and Viktor Kuznetsov. From the 32 OIAE of the Pacific Ocean Fleet six were chosen, among them Aleksey Dushin, S. Remizov and Manuilov. In the command staff of the air group several test pilots were included; among these was A. N. Chernoburov.
Airmen for the bombers were selected mainly from units of the 1st Army of Special Designation. From there arrived 22 SB crews, five for the TB-3s and seven for the DB-3s. The last aircraft type, having just appeared as the “super-new” aircraft in Soviet bomber aviation, had not been gathered to hand over to the Chinese. At first they were to be used as fast transports for servicing the ferry route itself. Each DB-3 could carry 11 passengers or equivalent cargo. Transport TB-3s and the old civil ANT-9 were also used alongside them on the route in the beginning to transport specialists and cargo.

From 31 October Kombrig Pumpur commanded the southern route. Learning of the flying accidents in the Kurdyumov group (Kurdyumov was killed on 28 October), he changed the already set flight date for the second group of I-16s. This group consisted mostly of Far Easterners from the 9 and 32 OIAEs. Pumpur began to train the pilots intensively for flights at maximum altitude, with landings in almost inaccessible places in the hills, and limited landing strips. The pilot Korestelev, who nosed over on a short landing strip in the mountains was removed from flight status, and was almost returned to his unit, but his comrades displaying bravery, stood firm. This group stood out for its preparedness.
Supplementary TB-3s were required in the transport role because the DB-3s kept having accidents and crashes. While returning from Lanzhou to Kuldzhu, Group Commander Kayuk made a mistake and crashed when he flew into a gorge. Only two in the tail of the airplane survived; a passenger, colonel Zhuravlev, and the flight mechanic Talalikhin. They reached Kuldzhu after a month wearing their flying boots and fur gloves!

A group of nine I-16s flew out from Alma-Ata at the beginning of December 1937, led by Kombrig Pumpur. (Later another commander of the route, Kombrig A. Zalevskii also sometimes escorted ferrying groups in an I-15bis, which he often flew to Hami for instruction of inexperienced pilots who frequently nosed over the I-15bis while landing). The group flew to Lanzhou without any incidents. There they turned the I-16s over to the Chinese and returned to Alma-Ata in a transport aircraft for a new group of machines. As the volunteer Dimitriy Kudymov remembers, after the second successful journey Pumpur requested this group to continue in the role of ferry pilots, but then taking pity on them, let them go to war anyway.
The Chinese pilots Tun, Lo and Li (flying Hawk IIIs) led the group on to Shanghai.
Unfortunately the Soviet volunteers remembered at best distorted names of the Chinese, more like nicknames; and in Chinese sources the family names of Soviet are not understood either, and are written in ideographs, and therefore it is practically impossible to establish for certain the interaction between Soviet and Chinese pilots in the vast majority of cases. But in the given situation, it is known that the leaders were the new commander of the 4th PG Lee Kuei-Tan, the commander of the 21st PS Teng Ming-Teh, and his deputy Le Yi-Chin. From the moment of arrival of this group at Shanghai were busy with the Japanese, and by the beginning of December the entire group had been deployed together with Chinese fighter units at Nanking.

The late 30’s and early 40’s were times of great purges in the Soviet Union. There were two waves of purges in the VVS RKKA. The first was in 1937-1939 and ended when Beria took command of the NKVD after Jezov. 5616 officers from the VVS were purged during this period and of these only 892 returned to service.
The second purge against the VVS RKKA started in April 1941. At least 18 high air force commanders were arrested under false accusations of a conspiracy against Stalin made up by the NKVD. The conspiracy was supposedly led by General Kiril Meretskov (a veteran from Spain), who had been chief of the General Staff (August 1940 – 14 January 1941). Pavel Rychagov was arrested on 24 June 1941. Other arrested included the Commander of the PVO General Pulkovnik F. M. Stern (a veteran who had served in Spain, Lake Khasan, Khalkin Gol and Finland - as commander of the Air Force of the 8th Army), the deputy commander of the General Staff Yakov Shmushkevich (arrested on 14 June 1941), the deputy commander of the VVS RKKA Academy Kombrig F. K. Arzenuchin, the chief of Staff VVS P.O P. S. Volodin, the Commander of the VVS Moscow Military District Pumpur (who had been fighter commander in Spain 1936-1939) and several others. All of them were badly tortured during the NKVD questioning.
When German troops closed in on Moscow during the autumn of 1941, government and political institutions were evacuated. 300 high ranking Soviet officers in prison in Lubjanka were executed by the NKVD due to lack of transportation but the group of 18 high VVS commander were evacuated earlier to Kuybyshev (now Samara). However to order for execution followed them and Rychagov (together with his wife; Mayor Maria Nesteryenko - commander of independent aviation unit) was executed on 28 October 1941. Other executed this day included Shmushkevich, Stern and Laktyonov. Pumpur was executed on 23 March 1942.

At the time of his death, Pumpur was credited with 2 biplane victories.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1936
1	??/??/36		1	Ju 52/3m	Destroyed	I-15		Spain
2	??/??/36		1	Ju 52/3m	Destroyed	I-15		Spain
	??/??/3?		1	Enemy aircraft	Shared destroyed	I-15		Spain
	??/??/3?		1	Enemy aircraft	Shared destroyed	I-15		Spain
	??/??/3?		1	Enemy aircraft	Shared destroyed	I-15		Spain

Biplane victories: 2 and 3 shared destroyed.
TOTAL: 2 and 3 shared destroyed.

Sources:
Air Aces Home Page - Jan Safarik
Air War over Spain - Jesus Salas Larrazabal, 1974 Ian Allan Ltd, Shepperton, Surrey, ISBN 0-7110-0521-4
Polikarpov I-15, I-16 and I-153 Aces - Mikhail Maslov, 2010 Osprey Publishing, Oxford, ISBN 978-1-84603-981-2