Schalk van Schalkwyk was born in 1913 and was from Cape Town, South Africa.

In February 1940 he was posted to 1 SAAF Squadron.

In May 1940 Captain van Schalkwyk was serving as flight commander in the squadron. This unit was at the time equipped with Hawker Hurricanes and Hawker Furies.

On 5 August nine Gladiators led by Captain van Schalkwyk arrived at Khartoum from Egypt to take part in the East African campaign.
At first they were held by Air Commander Slatter to assist in the defence of the Sudan.

In August he was promoted to Major.

At 14:50 18 September, three Gladiators of 1 SAAF Squadron took off from ‘Azaza, to patrol in the Càssala area. Two CR.42s climbed up to challenge them around 16:00. The South Africans got in first, Major van Schalkwyk claiming one and 2nd Lieutenants John Coetzer and John Hewitson (N5852) claiming a second shared; one CR.42 was seen to spin and crash while the other was chased to its airfield at Tessenei, where it was reported to have crash-landed.
2nd Lieutenant Hewitson reported in his logbook a dogfight with two CR.42s over Kassala. One retired while the other apparently fell out of control. He fired 1000 rounds of ammunition during the combat. The South African Gladiators landed at Khasm-el-Gírba at 17:15 without having sustained any damage.
The manner of combat described by Hewitson suggests that this episode coincides with one described in the notes of Lieutenant Andrew Duncan’s notes on 1 September, and reported as such by other sources, but without confirmation from the Italian side. This should therefore be the first combat between CR.42 and South African Gladiators on the Eritrean-Sudanese front.
Italian Bulletin No. 101 seems to confirm the battle, noting that "Blenheim and Wellesley escorted by Gloster-type fighters" had been intercepted over Càssala. The same document claims one ”Blenheim shot down in flames and another probable” and admits that only one Fiat ”hit [its] engine in combat [and] landed regularly [at] the field [of] Càssal””. The use of Gladiators as bomber escorts was probably a simple inaccuracy in the Bulletin, which nonetheless attests to their presence. There is no explicit mention of fighter combat in the document, nor is there any indication of the names of the Italian pilots involved in the action, although it is known that a section of the 412^a Squadriglia was stationed in Barentu in September, including at least Tenente Raimondo Di Pauli and Sottotenente Fiorindo Rosmino.
Tenente Di Pauli, when he returned from captivity, reported that he had been shot down in combat on 16 September 1940, that he had parachuted and suffered minor shrapnel wounds to his lower limbs. However, apart from this precise testimony of the pilot, there is no other evidence to confirm this shooting. In fact, there is no trace of it in the afore-mentioned bulletin, which reported the regular landing of one of the fighters on the field of Càssala, even if its engine was hit, nor has the corresponding form for recording flight accidents been found so far. Such a shooting would also contradict the testimony of Tenente Leone Concato who, on the following 4 October, explicitly identified SergenteMaggiore Ottavio Bracci as the first pilot of the Squadriglia shot down by the enemy and his fighter as the first aircraft lost in combat. The above, and the precise testimony of 2nd Lieutenant Hewitson, who merely reported an enemy aircraft "apparently" out of control and another that had escaped - without noticing any of the enemy pilots parachuting - suggest that the engine-damaged CR.42 was piloted by Tenente Di Pauli, who nevertheless managed to disengage and land regularly at Càssala despite the damage. On this occasion, he pilot may have suffered minor leg injuries.

On 20 September Major van Schalkwyk with Second Lieutenants Leonard le Clues Theron and Andrew Duncan strafed Tessenei airfield. A Ca.133 was reported damaged on the ground.

On 1 October he became CO of the squadron.

On the 6 November, the British forces in Sudan launched an offensive to capture the Italian fort at Gallabat as well as occupy Metema, which was just across the frontier. All that the RAF could provide in way of support was six Wellesleys, two Vincents, six Gauntlets, ten Gladiators (drawn from ‘K’ Flight and 1 SAAF Squadron) and four Hawker Hardys (from the Rhodesian Air Force). The Wellesleys were first into action bombing Gallabat, with the Gladiators requested to over fly the area in large formations. Three Gladiators of ‘K’ Flight arrived over the advancing troops at low level. They were patrolling to the east of Metema when a formation of an estimated six or seven CR.42s from 412^a Squadriglia led by the unit commander Capitano Antonio Raffi attacked them from out of the sun. The Gladiator pilots were taken by surprise; 24-year-old Flight Lieutenant Kenneth Howard Savage (RAF no. 37483) (L7614) was shot down and killed while Pilot Officer H. B. Kirk (K7969) was forced to take to his parachute; neither pilot saw their attacker. Pilot Officer Kirk was wounded in the leg and became a PoW. Pilot Officer Jack Hamlyn evaded the initial onslaught but his aircraft (L7612) was badly damaged and he force-landed, returning later on foot. These three victories were claimed by Capitano Raffi, Tenente Niso Provinciali and Sergente Pietro Morlotti.
Meanwhile, Major van Schalkwyk (N5855) of 1 SAAF Squadron had also taken off from Azzoza, but on arriving over the front was also attacked by the CR.42s. Observers on the ground at once rang the strip at ‘Heston’ to report the lone Gladiator in combat with eight opponents, and despite thick mud caused by an unexpected downpour during the night, Captain Brian Boyle at once took off, arriving just in time to see the commanding officer’s Gladiator going down in flames, the pilot taking to his parachute with his clothes on fire; he did not survive. Immediately Boyle was also attacked, bullets entering the cockpit and wounding him in hands and legs; desperately he fought on until the engine of N5852 stopped, and he had to crash-land between the lines. Boyle was brought in by Indian troops and sent by ambulance to Wadi Seidna where he was hospitalised for some weeks. He was subsequently warded a DFC (1 SAAF Squadron’s first) on 7 January 1941 for his gallant action in going single-handed to van Schalkwyk’s assistance.
It seems that Captain Boyle was credited to Sottotenente Fiorindo Rosmino.
Capitano Raffi reported that four victories were claimed as a result of these engagements, but Sottotenente Rosmino’s aircraft was hit and he returned with his parachute pack riddled with bullets.
Van Schalkwyk survived the crash but was badly burned. He died of his wounds the following day.

He is buried at Keren War Cemetery.

At the time of his death van Schalkwyk was credited with 1 biplane victory.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1940
1	18/09/40	16:00 ca	1	CR.42 (a)	Destroyed	Gladiator II		Càssala area	1 SAAF Squadron

Biplane victories: 1 destroyed.
TOTAL: 1 destroyed.
(a) 1 SAAF Squadron claimed 2 destroyed CR.42. 412^a Squadriglia only suffered 1 damaged CR.42 with the pilot (Tenente Di Pauli) WiA.

Sources:
Aces High - Christopher Shores and Clive Williams, 1994 Grub Street, London, ISBN 1-898697-00-0
Aces High Volume 2 - Christopher Shores, 1999 Grub Street, London, ISBN 1-902304-03-9
Dust Clouds in the Middle East - Christopher Shores, 1996 Grub Street, London, ISBN 1-898697-37-X
Gloster Gladiator Home Page - Alexander Crawford.
I Cavalieri Erranti - Ludovico Slongo, Stefan Lazzaro, Eugenio Eusebi, Michele Palermo and Danilo Ventura, 2023, ISBN 978-88-87952-37-7
Springbok Fighter Victory: East Africa Volume 1 1940 – 1941 – Michael Shoeman, 2002 African Aviation Series No. 11, Freeworld Publications CC, ISBN 0-958-4388-5-4
The Commonwealth War Graves Commission
Those Other Eagles – Christopher Shores, 2004 Grub Street, London, ISBN 1-904010-88-1