McDonald was promoted to Acting Pilot Officer on probation on 25 November 1939 (gazetted 19 December 1939).

Acting Pilot Officer McDonald was graded as Pilot Officer on probation on 24 August 1940 (gazetted 29 October 1940). This rank was confirmed on 25 November 1940.

McDonald was posted to 112 Squadron on 20 September 1940 and took part in the Greek campaign with this unit.

On 4 December, Flight Lieutenant Lloyd Schwab, Flying Officer R. J. Bennett, Flying Officer Richard Acworth (who was promoted to Flying Officer during the day with effect from 29 August 1940), Pilot Officer Leonard Bartley, Pilot Officer Jack Groves, Pilot Officer McDonald, Pilot Officer R.H. MacDonald, Sergeant G. M. Donaldson of 112 Squadron left Sidi Haneish to ferry Gladiators to the Royal Hellenic Air Force. Four fighters were to be handed over to the Greek while the other four would remain on attachment to 80 Squadron with the attached pilots.

Twelve of the sixteen 112 Squadron pilots that had left for Greece on ferry flights returned to Sidi Haneish in a Bombay on 7 December. The pilots were Flight Lieutenant Lloyd Schwab, Flying Officer Richard Acworth, Pilot Officer Leonard Bartley, Pilot Officer Jack Groves, Pilot Officer McDonald, Pilot Officer R. H. MacDonald, Sergeant G. M. Donaldson, Flight Lieutenant R. J. Abrahams, Flight Lieutenant Joseph Fraser, Flying Officer Edwin Banks, Flying Officer Homer Cochrane, Pilot Officer Alfred Costello. The other four pilots remained in Greece (Flight Lieutenant Charles Fry, Flying Officer R. J. Bennett, Pilot Officer R. H. Smith, Second Lieutenant H. H. Geraty) attached to 80 Squadron.

During the morning on 4 March 1941 five Italian warships identified as two cruisers and three destroyers, sortied down the Albanian coast and commenced shelling the coastal road near Himare and Port Palermo, under cover of a strong fighter escort of G.50bis and CR42s from the 24^o Gruppo C.T. The flotilla actually comprised of the destroyer Augusto Riboty, the torpedo boat Andromeda and three MAS boats.
An immediate strike was ordered by RAF units, 15 Blenheims being ordered off. Nine 211 Squadron aircraft and five from 84 Squadron (a sixth failed to start) were led to the area by Squadron Leaders Gordon-Finlayson and Jones, escorted by ten Hurricanes, followed by 17 Gladiators, 14 from 112 Squadron and three from 80 Squadron. Four 80 Squadron Hurricanes led by Flight Lieutenant 'Pat' Pattle flew on the starboard flank of the bombers, with four from 33 Squadron to port, and two more above as ‘weavers’. At 15:00 the warships were seen ten miles south of Valona, and the Blenheims went in to bomb in line astern; several near misses were seen, but no hits were recorded.
At this point six G.50bis dived on the Hurricanes, shooting down V7801 in flames; 24-year-old Warrant Officer Harry J. Goodchild DFM (RAF No. 517435) was killed. It seems that the Italian fighters did not see the bombers, for they reported only single-engined types - ten ‘Spitfires’, three ‘Battles’ (obviously Hurricanes) and 20 Gladiators. Once the Blenheims had completed their run and were on their return flight, Pattle ordered the Hurricanes to hunt in pairs over the warships, where a number of Italian fighters were seen. At once a lone G.50bis attacked Pattle and his No 2 - on this occasion Flying Officer Nigel Cullen - but Pattle promptly shot this down and watched it spiral into a mountainside just north of Himare. At this moment a second Fiat ‘jumped’ Cullen (Hurricane V7288) and he was not seen again; his aircraft crashed near Himara, and the Australian ‘ace’ was killed.
Pattle flew on towards Valona, and was attacked by another lone G.50bis which he reported went into the sea south-west of Valona harbour after a brief combat. He then became involved with a third such fighter over Valona harbour and claimed to have shot this down into the sea in flames on the west side of the promontory. Nine CR.42s were then seen below and he dived on these, reporting that one went into a spin with smoke pouring from its engine; he claimed this as a probable. Sergeant Edward Hewett was also heavily engaged, claiming one G.50bis shot down near Himara and three of eight CR.42s near Valona. The only other claim by a Hurricane pilot was made by Pilot Officer William Vale, who claimed another G.50bis.
Meanwhile the Gladiators, led by Squadron Leader H. L. I. Brown, tangled with a reported ten G.50bis and five CR.42s. Flight Lieutenant Joseph Fraser led the third section after some G.50bis which entered clouds, but he claimed one shot down and a second shared with Brown, Pilot Officer Jack Groves and Pilot Officer McDonald. Flying Officer Richard Acworth was about to attack another when he came under fire himself and was driven down to 2000 feet. He got in a few deflection shots, saw smoke issue from his opponent’s engine before being attacked by another, and thus only claimed a probable. Flying Officer Edwin Banks attacked a G.50bis which went into a spin; as he saw a parachute in the vicinity he also claimed a probable, and two more such claims were made by Flight Lieutenant Charles Fry and Sergeant 'Paddy' Donaldson, while four more aircraft damaged were claimed by Groves, Brown, McDonald and Flying Officer Homer Cochrane.
In return the 24^o Gruppo pilots claimed four Gladiators, one ‘Spitfire’ and one ‘Battle’ shot down. Sottotenente Nicolo Cobolli Gigli of 355^a Squadriglia, who was flying a CR.42 on this occasion, and Sergente Marcello De Salvia of 354^a Squadriglia were both shot down and killed, while Tenente Francesco Rocca of the latter unit was wounded. No losses by other CR.42 equipped units have been discovered. Cobolli Gigli and De Salvia were both awarded posthumous Medaglia d’Oro al valor militare.

During the afternoon of 13 March Squadron Leader H. L. I. Brown led 14 Gladiators from 112 squadron and six of 33 Squadron's Hurricanes off from Paramythia for an offensive patrol over the Kelcyre area. Approaching Kelcyre at 15:30 on an altitude of 17,000 feet an estimated 14 S.79s were seen - aircraft from 104^o Gruppo B.T. - with an escort identified as 20 G.50bis and 20 plus CR.42s.
Three of the Hurricanes attacked the mass of fighters, followed by the Gladiators, and many individual dogfights ensued. Squadron Leader Brown attacked the leading fighter of a flight of three, but it evaded him successfully. He then got on the tail of another, which turned and dived and eventually crashed; he claimed a G.50 and another damaged. Flight Lieutenant Joseph Fraser attacked a CR.42, which had not seen him. He reported that it burst into flames and crashed near Bousi. Two more were claimed destroyed by Flying Officer Homer Cochrane and Pilot Officer Jack Groves, while Pilot Officers Neville Bowker and McDonald each claimed a probable CR.42.
The Gladiators reformed, then spotted about 30 more CR.42s with 38^o Stormo BR.20s. Seven of Flight Lieutenant Charles Fry’s ‘C’ Flight pilots went after the bombers, while Flight Lieutenant Fraser’s ‘A’ Flight tackled the fighters, claiming seven more shot down. Fraser attacked a CR.42, which flick-rolled and dived away. He followed it down and got in two long bursts after which the enemy aircraft levelled off and lost speed, with the pilot slumped forward in the cockpit. The aircraft then dived vertically into the ground north of Corovode. Fraser then climbed back up to 8,000 feet and got on the tail of another CR.42 firing at it continuously until it burst into flames and was destroyed. Fraser’s own aircraft was badly shot up, as was that of Pilot Officer Groves (after having claimed a second CR.42 and one damaged), but both managed to get back to base. Flying Officer Cochrane claimed two more CR.42s while Pilot Officer P. C. L. Brunton and Flying Officer E. H. Brown each claimed a CR.42.
The ‘G.50bis’ seem to have been 22^o Gruppo Macchi MC.200s, 11 of which accompanied 18 CR.42s from the 160^o Gruppo over the front. The Italian pilots claimed four Gladiators and one Hurricane shot down, losing just two CR.42s flown by Tenente Gualtiero Bacchi and Sottotenente Enzo Torroni (both from 375^a Squadriglia), but no MC.200s. It seems that Capitano Vittorio Minguzzi claimed a probable Gladiator in this combat.
Although no claims were made against the bombers on this occasion, several were in fact hit and damaged, a number of crewmen being wounded.
In his combat report Fraser commented that the CR.42 pilots always tried to flick-roll when attacked.

McDonald was promoted to Flying Officer (war subs.) on 24 August 1941 (gazetted 4 November 1941).

He was posted from 112 Squadron on 7 November 1941.

On 24 August 1942, McDonald was promoted to Flight Lieutenant (war subs.) (gazetted 15 September 1942).

McDonald was mentioned in dispatches on 14 January 1944 (gazetted 11 January 1944).

McDonald ended the war with 1 shared biplane victory, this one being claimed while flying Gloster Gladiators.

He remained in the RAF after the war.

Flight Lieutenant McDonald resigned his commission on 17 July 1946, retaining the rank of Squadron Leader (gazetted 26 July 1946).

Claims:

Kill no.	Date	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1941
	04/03/41	1/4	G.50 (a)	Shared destroyed	Gladiator		Valona-Himare area	112 Squadron
	04/03/41	1	G.50 (a)	Damaged	Gladiator		Valona-Himare area	112 Squadron
	13/03/41	1	CR.42 (b)	Probable	Gladiator		Kelcyre area	112 Squadron

Biplane victories: 1 shared destroyed, 1 probable, 1 damaged.
TOTAL: 1 shared destroyed, 1 probable, 1 damaged.
(a) Claimed in combat with G.50bis and CR42s of the 24^o Gruppo C.T. RAF claimed seven G.50bis destroyed, four probables and four damaged, three CR.42s and one probable, while losing two Hurricanes. 24^o Gruppo C.T. lost two CR.42s and got one damaged while claiming four Gladiators, one Spitfire and one Battle. No losses to G.50bis have been found.
(b) Claimed in combat with MC.200s from 22^o Gruppo and CR.42s from 160^o Gruppo. 112 Squadron claimed 10 CR.42s destroyed, 2 probables and 1 damaged and 1 ‘G.50bis’ and 1 damaged without losses. The Italian pilots claimed four Gladiators and one Hurricane shot down, losing two CR.42s flown by Tenente Gualtiero Bacchi and Sottotenente Enzo Torroni (both from 375^a Squadriglia), but no MC.200s.

Sources:
Ace of Aces: M T StJ Pattle - E C R Baker, 1992 Crécy Books, Somerton, ISBN 0-947554-36-X
Air war for Yugoslavia, Greece and Crete - Christopher Shores, Brian Cull and Nicola Malizia, 1987 Grub Street, London, ISBN 0-948817-07-0
Shark Squadron - The history of 112 Squadron 1917-1975 - Robin Brown, 1994 Crécy Books, ISBN 0-947554-33-5
The Commonwealth War Graves Commission
The London Gazette
Additional information kindly provided by Csaba Becze and Carlo Minguzzi.