Day: January 29, 2025

The French Cruiser Submarine FS Surcouf (NN-3) Part II – Besson MB.411 Floatplane and Other Details

The French Cruiser Submarine FS Surcouf (NN-3) was designed with a hanger to carry a single floatplane for scouting purposes. The design chosen was the Besson MB.411, only two of which were produced. Here we see the first production aircraft disassembled on the deck of Surcouf.
Another view of the MB.411 from the same series of photos, this time taken from Surcouf’s conning tower, showing the wing markings. In the foreground is one her three Canon de 37 mm Modèle 1925 anti-aircraft guns.
A final perspective from pierside. There was no catapult, the aircraft was hoisted to and from the water using the ship’s crane. The MB.411 could be assembled and ready for flight in 20 minutes.
An MB.411 without fuselage codes taxiing. The MB.411 was a two-place design with both the pilot and the observer provided with an open cockpit and their own windscreen. Note the generator on the aft fuselage to produce electrical power.
The same aircraft being hoisted out of the water. The airframe was a mix of wood and metal with canvas.
The first production aircraft coded “HS-73” was delivered to Surcouf in June 1935 and was aboard for sea trials in the Caribbean in September. The photo shows the second production aircraft which replaced the first in July 1938 and was coded “7S4-8”.
The second aircraft was put ashore in the Summer of 1940 when Surcouf departed England for convoy escort duties in the Caribbean. The Royal Navy took over the MB.411 and assigned the name Petrel. Here is the second production aircraft in Royal Navy colors being operated by 765 NAS. She eventually became unserviceable due to lack of parts. The first aircraft was in France at the time of the surrender and was written off.
Advocates of The One True Scale often point out that “everything” has been kitted in one medium or another, at least as far as aircraft go. While not absolutely true, you cannot disprove the statement using the MB.411. Despite there being only two operational examples of the type, Fly released a new tool kit this year, and is the second manufacturer to produce a kit after a company named Dujin.
A pair of photographs showing Sucouf’s crew lounging in the sun wearing pith helmets. Note the outline in the deck casing where the crewmen are laying on the main deck. These deckplates are removable, revealing stowage for a 4.5-meter whaleboat intended for boarding actions. This allowed the submarine to evaluate the nationality and cargo of merchant ships which she encountered. Surcouf had space to carry up to 40 prisoners or survivors, a unique capability.
Another view looking forward. Note the lookout in the extendable crow’s nest, another unusual feature for a submarine. Her designers appear to have had few reservations when it came to incorporating novel capabilities.

Surcouf Part III here: https://inchhighguy.wordpress.com/2025/02/05/the-french-cruiser-submarine-fs-surcouf-nn-3-part-iii-portsmouth-navy-yard-overhaul/