Operational Order No. 13

Saturday, 18 October 1941

1941-10-18

S E C R E T. 21 SQUADRON OPERATIONAL ORDER NO. 13. COPY NO...8.... ( Ref: Bomber Group Op. order No. "A" 129 ) DATE: 18. 10. 41. MAP REF: Tobruk 1 : 500000 and Target Map D./8 LIST OF APPENDICES: "A" INFORMATION. Derna L. G. is 5 miles due South of Derna. It is situated on the escarpment, some 900 ft. above sea level. Latest information is to the effect that most aircraft are likely to be found on the Northern and Eastern sides of the main L. G. The disused petrol store and the large hangar at North West corner of the L. G. make excellent recognition points. Briefing by C. O. and S. I. O. INTENTION. High level attack by 9 aircraft. EXECUTION. (a) List of aircraft and crews see appendix "A" (b) o/c "A" Flight will provide 6 aircraft o/c "B" Flight will provide 3 aircraft (c) Time of starting up 0700 hours. (d) Time of take off 0715 hours. (e) Route: Fuka point 300 degrees, 305 miles. 230 degrees, 60 miles to Derna. (f) Formation: Flights in Squadron "Vic". (g) Flying Instructions: As soon as in formation, climb to 12000 ft. in rich, 2200 r.p.m. at 25" boost. When 50 miles from target, climb to 18000 ft., and form line astern. (h) Photography: 3 Verticals and 3 oblique cameras. (i) Attack: At 10 miles from target, if no fighters seen, leader to dive to 15000 ft. and release, nos. 2 and 3 to follow and release at 15500 ft. and 16000 ft. respectively. Then dive, into line astern and head South at 10000 ft. When well clear, cruise in lean at 17000 r.p.m. at 26" boost. Formation must be kept. (j) Return: As per Bomber Group order "A" 129, via L. G. 110. (k) Landing order: Order of take off. ADMINISTRATIVE ARRANGEMENTS. (a) All aircraft must carry full capacity fuel and oil. (b) All magazines and pans to be fully loaded. (c) Each aircraft will carry full bomb load i.e. 8 X 250 lbs. Fuse N. ( inst ). (d) All necessary desert equipment. INTER COMMUNICATION. W/T Officer. ACKNOWLEDGE. .....L Saunders.....Lt. For O. C. 21 Squadron.

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Original page(s): 84

Transcriber's Notes

Phase 2: Technical Expansion (The "Transcriber's Notes") Glossary of Terms * 21 SQUADRON S.A.A.F.: No. 21 Squadron, South African Air Force. During October 1941, the unit was a critical medium bomber component of the Western Desert Air Force (WDAF) operating Martin Maryland aircraft. * BA-BH (MARTIN BALTIMORE): The R.A.F./SAAF operational code for the Martin Baltimore medium bomber. While 21 Squadron became synonymous with the Baltimore (BA-BH) in 1942, during the October 1941 period, they were equipped with the Martin Maryland, the direct technical precursor utilized for high-altitude interdiction. * C. O. / S. I. O.: Commanding Officer and Squadron Intelligence Officer. * DERNA L. G. / SATELLITE: Derna Landing Ground. This was a vital Axis airfield complex on the Cyrenaican escarpment, utilized by the G.A.F. (German Air Force / Luftwaffe) and I.A.F. (Italian Air Force / Regia Aeronautica) as an advanced base for frontier operations. * FUSE N. (inst): Nose Fuse (instantaneous). These fuzes were selected for surface-level targets to ensure the 250 lb General Purpose (GP) bombs detonated immediately upon impact, maximizing blast and fragmentation against unarmored aircraft and logistical structures. * L. G. 110: Landing Ground 110, an Allied forward operating or refuelling strip in the Western Desert. * MC/GP (MEDIUM CAPACITY / GENERAL PURPOSE): Standard Allied ordnance designations. For this raid, the Marylands were ordered to carry a full capacity load of 8 x 250 lbs General Purpose (GP) munitions. * MET: Meteorological data. Precise MET conditions were essential for the high-altitude transit at 18,000 feet and subsequent visual bombing runs over the Derna escarpment. * R.P.M. / BOOST: Revolutions Per Minute and manifold pressure (measured in inches of mercury). These refer to the power settings for the Maryland's Pratt & Whitney engines; "rich" mixture for combat maneuvers and "lean" for fuel conservation during the return flight. * W/T: Wireless Telegraphy (Morse code radio communications). Operational Context Operational Order No. 13, dated 18 October 1941, details a coordinated high-level strike against the Derna Landing Ground. This location was of paramount strategic importance as the primary advanced hub for Axis air power in Cyrenaica, providing Rommel's Panzergruppe Afrika with air cover and interdiction capabilities against the besieged Tobruk garrison and Allied supply lines. The raid was part of the Desert Air Force’s broader attrition campaign intended to degrade Axis air strength and logistical sustainability prior to the launch of Operation Crusader. Targeting the Northern and Eastern sectors of the L.G. specifically aimed to destroy dispersed German and Italian airframes on the ground, utilizing recognizable features like the large Northwest hangar and a disused petrol store as visual aiming points for the horizontal bombing run. Execution Constraints The mission profile dictated a long-range unescorted sortie of 9 Marylands. Execution required a specific climbing profile to 12,000 feet in "rich" fuel settings before a final climb to 18,000 feet 50 miles from the target. The attack was planned as a staggered altitude drop (15,000 ft, 15,500 ft, and 16,000 ft) to saturate the target area while providing vertical separation for the flights. A significant tactical constraint was the threat of Luftwaffe interception; the order mandated that the formation immediately "form line astern" and dive to 10,000 feet if fighters were observed, using high speed to egress southwards. The technical requirement for 3 vertical and 3 oblique cameras emphasizes the necessity of Battle Damage Assessment (BDA) to confirm the neutralization of Axis airframes. Furthermore, the return leg via L. G. 110 highlights the fuel endurance limitations of the Maryland when operating at deep-penetration distances from the squadron’s home base at LG 21. The document, signed by Lt. L. Saunders, stands as a formal directive for a high-risk mission against one of the most heavily defended and strategically vital airfields in the North African theater. 86 Phase 1: Verification & Extraction Identity Check: 18.10.41.