42 Squadron RAF, Greg’s future squadron, moves the 4½ miles (7 km) southwest from Trèzennes (aka Trezennes or Triezennes), just outside Aire-sur-la-Lys to Rely, Pas-de-Calais, on top of the low chalk hills to the southwest.
42 Squadron’s move WNW from Trèzennes to Rely, Pas-de-Calais, shown on a modern map (courtesy Google). Click for a larger, zoomable map (opens in new tab)
It was no doubt the continuing westward advance of German forces in Operation Georgette that occasioned the move to Rely, although by 25 April 1918 the line had practically been held some 6½ miles (10½ km) to the east of Trèzennes. For more on Georgette and the Spring Offensives in General, see:
Three flights today: the first in an RE8 around the aerodrome – with an intriguing entry (‘Vacuum Control’) in the Remarks column – and two further afield flying in formation and on a compass course.
Log book entry
Date: 25.4.18
Hour: 2.50
Instructor: –
Machine type and No.: RE 6647
Passenger: –
Time: 45 m
Height: 4500
Course: Aerodrome
Remarks: Vacuum control
Date: 25.4.18
Hour: 5.55
Instructor: –
Machine type and No.: DH6 7670
Passenger: –
Time: 55 m
Height: 2000
Course: Marlboro. Swindon. Aerod.
Remarks: Formation
Date: 25.4.18
Hour: 1.10
Instructor: Lt Gowler
Machine type and No.: RE 3551
Passenger: –
Time: 50 m
Height: 2000
Course: Compass course (Wootton Basset, Chippenham &
Devizes. 5 forced landings)
Remarks: DUAL
Vacuum Control
So what was the ‘vacuum control’ of the first entry (but not the first flight) of the day? I’m grateful to Duncan Curtis, who has provided this authoritative explanation:
‘Vacuum Control’ relates to a feature on some aircraft/engines, whereby the carburettor/s were equipped with vacuum controls. The vacuum control feature allows the pilot to adjust engine mixture for altitude: on early engines no adjustment; then on some engines manual adjustment; and finally all engines gained automatic adjustment via vacuum bellows (post-WW1). For service types equipped with these engines (of which the RE8 was one), the pilot had to demonstrate correct operation prior to graduating ‘B’ on his operational type.
Requirements to graduate ‘B’ (from Higher Instruction), referring to Vacuum Control in point 8. Click for larger image. Credit: Duncan CurtisA page from the RE8 parts catalogue showing that Claudel and BB carburettors were fitted with vacuum control. Click for larger image. Credit: Duncan Curtis
[Topic updated 25 September 2018]
Formation Flying
The second aerial event of the day was some formation flying on a circuit from Yatesbury to Marlborough to Swindon and back, a distance of some 30 miles (48 km):
Yatesbury-Marlborough-Swindon flight shown on a modern map (courtesy Google). Click for a larger, zoomable map (opens in new tab)
Cross Country
The third entry in the log book, but actually the first flight of the day, was a cross-country compass course under dual control with Lt Gowler as instructor. The course was a 34 miles (54 km) circuit from Yatesbury to Wootton Basset to Chippenham to Devizes and back.
Yatesbury-Wootton Bassett-Chippenham-Devizes cross country route shown on a modern map (courtesy Google). Click for a larger, zoomable map (opens in new tab)
In a remarkable military achievement on Anzac Day 1918, British and, particularly, Australian forces retook Villers-Bretonneux from German forces who had taken the town the previous day, in the Second Battle of Villers-Brettoneux.
Although this action was in the Somme sector before Greg arrived in France, an oblique aerial photograph of Villers-Bretonneux found its way into his collection. It’s being published today on Anzac Day in honour of the events 100 years ago:
Oblique aerial view of Villers-Brettoneux from the North East. Click or tap for larger image (opens in new tab). Image credit: Greg’s War Collection.
For comparison, here is a broadly similar, contemporary view generated from Google Maps:
Villers-Brettoneux on Google Maps. Click or tap for larger image (opens in new tab)
For more about the Second Battle of Villers-Brettoneux on 24 and 25 April 1918, see the new ‘Setting the Scene’ article:
