On 11 June 1937, after a month’s sick leave, teniente Manuel Aguirre López led a patrulla of four I-15s, flown by teniente Fernández de Velasco and sargentos Manuel Zarauza Clavero and Francisco Montagut Ferrer. Whilst attempting to deliver reinforcements to government fighter units operating in the Biscay area, all four pilots were forced to land at the French airfield at Parme, in Biarritz. The aircraft were seized but their pilots were allowed to return to Spain.

The autumn of 1937 saw the establishment of the Grupo N^o 26 (I-15) and on 9 October 1937, capitán Juan José Armario Álvarez was appointed CO of the Grupo, which initially comprised three escuadrillas with 15 aircraft each.
The Soviet 1^a Escuadrilla was led by Kapitan Yevgeniy Antonov and operated from Sagunto and Sabadel airfields, while teniente Gerardo Gil Sánchez headed up the Spanish 2^a Escuadrilla (capitán Chindasvinto González García had handed over command to his deputy, Gil, to act as an interim CO). Both operated on the Aragon front. The Spanish 3^a Escuadrilla was formed at Figueras under the command of teniente Juan Comas Borrás, which initially flew defensive patrols over the Catalan coast. The unit’s initial cadre of pilots consisted of Leopoldo Morquillas Rubio, Miguel Zambudio Martínez, Juan Olmos, José Redondo Martín, Antonio Britz Martínez, Rafael Sanromá Daroca and Antonio Nieto Sandoval-Díaz. Later, they were joined by José María Campoamor Peláez, Elías Hernández Camisón, Montagut, Jesús Pérez Pérez, Alfredo de Albert Porcar and José Puig. Many of them were surviving pilots from the Northern front and later in the month the unit operated from Reus airfield.
Capitán Armario initially flew with the Soviet patrulla of the staff flight of the Grupo N^o 26, often accompanying Starshii Leitenant Stepanov.

In December, sargento Montagut served in the 3^a Escuadrilla of the Grupo de Caza N^o 26, which was equipped with Polikarpov I-15s.

On 28 December, 16 fighters from Grupo 2-G-3 clashed with nine I-15s and 12 I-16s directly above Teruel. Nationalist pilots were credited with shooting down four ‘Curtiss fighters’ and a Rata for the loss of Antonio López Sert (3-87) of Escuadrilla 1-E-3 (reportedly to small-arms fire). Teniente Carlos Bayo Alessandri (2-E-3) attacked a Chato head-on, scoring some hits. He made a second attack from astern and the enemy fighter began to lose height and crashed behind Republican lines near Villastar. Alférez Javier Allende Isasi (2-E-3) claimed two I-15s while alférez Jorge Muntadas Claramunt (2-E-3) claimed the fourth I-15 and alférez Manuel Vázquez Sagastizábal (1-E-3) claimed the I-16.
It seems that at least the 3^a/26 (I-15) was involved in this combat and they claimed four CR.32s during the day. The CO of the unit, teniente Juan Comas Borrás claimed two CR.32s while sargento Montagut and Rafael Sanromá Daroca claimed one each.
The Republicans admitted the loss of teniente José M.^a Campoamor Peláez, who fell with his burning I-15 in the vicinity of La Muela, while two other aircraft returned to base damaged.

On 21 February 1938, all the serviceable Polikarpovs took off to try to oppose Nationalist bombers during the Battle of Alfambra.
At 10:20, Miguel García Pardo and Javier Allende Isasi of 2-G-3 took off on a routine reconnaissance flight over the Teruel front. There they discovered 20 I-15s and a similar number of I-16s in combat with a few Bf 109Bs. When García Pardo and Allende Isasi went to the assistance of the Messerschmitts, the German pilots failed to recognize them as allies and opened fire on them. They beat a hasty retreat, calling into battle another formation of Fiat CR.32s before continuing with their reconnaissance.
The new formation compromised 24 CR.32s of the XXIII Gruppo ”Asso di Bastoni” led by Maggiore Andrea Zotti. The pilots included the Spanish capitán Carlos Haya González who, after attending his mother’s funeral, arrived by car in Bilbao just as the group was about to take off. Despite Commander Zotti’s opposition, he insisted on taking his place in the formation.
At 11:04 over Teruel when they spotted about 40 Republican fighters split in three formations with I-15 “Chatos” at 3,500 and 4,000 meters, and I-16 “Moscas” at 5000 meters. The Republican fighters were already in combat with 17 Bf 109s. Zotti immediately chased them, and sent part of the Gruppo to attack the “Chatos”, which tried to evade as they were over Republican lines. At Puebla de Valverde, the “Moscas” intervened, but they were faced by the rest of the XXIII Gruppo, which at the end claimed two “Chatos” and a “Mosca” destroyed. One of the I-15s was claimed by Franco Lucchini of the 19^a Squadriglia. In attempting to destroy an I-15 that was attacking another aircraft of his squadron, Carlos Haya González approached too close and collided with the I-15, falling to his death. It seems that this was sargento Francisco Viñals Guarro (I-15 CA-013) of the 2^a/26, who managed to return despite the almost total destruction of the rudder (according the Republic bulletin, it was teniente Manuel Orozoco Ovira, of the 4^a/26, who collided with Haya). Viñals’ I-15 was found to have a shattered aileron, badly damaged upper port wing and missing cockpit door and gunsight. Viñals’ promotion, recommended by the coronel Jefe de Fuerzas Aéreas and the Minister of National Defence, Indalecio Prieto, was effective from 22 February. The order was gazetted in the Diario Oficial issue No 47, which noted, ’For his heroic conduct in yesterday’s combats near Teruel, sargento del arma de aviación Francisco Viñals Guarro is promoted to teniente.’
Juan Lario Sanchez witnessed this combat. Haya fell near Puerto de Escadiòn, and was posthumously awarded with a Medaglia d’oro al valor militare.
The German pilots of J/88 claimed seven I-16s when 1 staffel claimed three near La Pueblé (Leutnants Fritz Awe, Hans-Karl Mayer and Erich Woitke) and 2 staffel claimed four near Sarrion and Teruel (Unteroffizier Herbert Ihlefeld, Leutnant Edgar Rempel, Unteroffizier Kurt Rochel and Staffelführer Oberleutnant Joachim Schlichting).
It seems that the Bf 109s had been in combat with twelve I-16s from 2^a/21, which suffered three wounded pilots and one killed in combat with Messerschmitts and Fiats over Teruel in the morning while reporting 18 enemy aircraft downed (daily total?). Leitenant Aleksey Denisov (I-16 CM-034) claimed one Bf 109 before being shot down and had to bail out wounded. Leitenant Boris Adil’gireevich Takhtarov was wounded and badly burned when his aircraft (CM-123 or CM-239) caught fire after being hit by Bf 109s and he had to take to his parachute. When he jumped his parachute opened early, and on the way down the Germans tried to strafe him, but his comrades prevented them (he spent 35 days in the hospital and then returned home). The third wounded pilot was Andrey Belov. Leitenant Viktor Sergeevich Troshkin was killed while flying CM-032.
General Rojo advised Prieto, the Minister of Defence, that the Air Force had carried out three operations during the day, and that during the last of these they had been involved in a large-scale combat with the Nationalist Air Force. He later advised Prieto that according to information from Jerica (the Air Force’s command centre) five German aircraft – later stated to be five Bf 109s, seven Fiats CR.32s and one twin-engined aircraft had been destroyed. This message included the information that the ace pilot, Carlos Haya, who was reputed to have carried out the night attack on the War Ministry in Madrid, had been killed in this engagement. Their own losses were quoted as two I-16, which failed to return to base and two others, which were damaged and whose pilots were injured. Sergeant Manuel Orozco Ovira, who managed to fly his aircraft back to base after its tail had been destroyed, was recommended an award for outstanding bravery and skill.
The I-15s from the 2^a/26 claimed three and two probable CR.32; these were claimed by Teniente Leopoldo Morquillas Rubio (CO) (1 probable), J. Mora Fauria, sargento Francisco Viñals Guarro, Fernando Villins León (1 probable) and C. Zuazo Garre. Montagut from the 3^a/26 claimed a Bf 109 while an unknown pilot from the 4^a/26 claimed a CR.32. An unknown I-16 pilot from 1^a/21 claimed a CR.32.

Miguel Zambudio Martínez (CO 3^a/26) was promoted to capitán on 1 October.
Later in the month, Zambudio was replaced as CO by teniente Antonio Nieto Sandoval-Díaz, with teniente Montagut serving as his deputy.
The escuadrilla included José Santander Menéndez, Esteban Corbalán Marín, Sánchez López, José Falcó, Joaquín Tremosa Arnavat, Álvaro Muñoz, José Garre Solano, Alfredo de Albert, Mario Cuesta, Antonio Britz Martínez and Rafael Belda.

Montagut ended the Spanish Civil War with 2 biplane victories.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1937
1	28/12/37		1	CR.32 (a)	Destroyed	I-15		Teruel area	3a/26
	1938
2	21/02/38	11:04-	1	Bf 109	Destroyed	I-15		Teruel front	3a/26

Biplane victories: 2 destroyed.
TOTAL: 2 destroyed.
(a) Probably claimed in combat with 2-G-3, which claimed 4 I-15s and 1 I-16 for the loss of 1 CR.32. The Republicans claimed 4 CR.42s with the loss of 1 I-15 and 2 damaged (unknown units).

Sources:
Fiat CR.32 Aces of the Spanish Civil War - Alfredo Logoluso, 2010 Osprey Publishing, Oxford, ISBN 978-1-84603-983-6
Fighter Pilots Of The Spanish Republic (Vol. 1) - Rafael A. Permuy López, Historica 36/39 no. 1, ISBN 84-87314-89-9
Soviet airmen in the Spanish civil war 1936-1939 - Paul Whelan, 2014 Schiffer Publishing Ltd, ISBN 978-0-7643-0
Spanish Republican Aces – Rafael A Permuy López, 2012 Osprey Publishing, Oxford, ISBN 978-1-84908-668-4