SNCASE SE.1500 Series

[Drasleon 226]

 

 

 

Hello everyone, for my first suggestion I would like to tell you about the SNCASE SE 1500 and its derivatives for LeO 451.

 

 

 

Part I, History

Spoiler

1945 ,On the ruins of the defeated Third Reich, the allies sent teams to study and recover as much German war technology as possible.

The French were no exception. Within their expedition, there was a group detached by the french air force. Among them, Michel Decker, head of the section STA/ES (Service Technique Aéronautique / Engin Spéciaux (: Aeronautical Technical Service / Special Machinery in english) was responsible for the study and recovery of German missiles and rockets.

On his return to France, Decker decides rather than copying and rebuilding German weapons, it is better to draw inspiration from them to create new ones.

For this he created an important program, covering all categories of missile.

-AA for Air-Air

-AS for Air-Sol (« Sol »mean «Ground » in english)

-SA for Sol-Air

-SS for Sol-Sol

-CT for Cible Télécommandée ( remot-controlled target)

 

Then he sent this program to all the French aeronautical companies of the moment.

The quickest to react was Louis Marnay, head of the SNCASE aircraft design office. As he was in charge of the Cannes factory, reopened but empty, he could use it to work in the greatest secrecy.

Marnay proposed a glider, simple to manufacture and use, capable of being dropped from an airplane.

But what airplane? The choice fell on the old LeO 451, which had been manufactured by the SNCASE before the war and of which there remained a large stock recovered from the Germans.

 

Note that this was not the first time that the LeO 451 was used to test flying bombs. Indeed, in 1938, Maurice Hurel and Jean Turck worked together to create the BHT 38 (Bombe Hurel Turck 1938). It was a remote-controlled flying bomb. His tests were halted by the defeat of 1940. As for its patent, it was recovered by the Germans during the war and served as inspiration for the Henshel HS 293 flying bomb.

Following the invasion of the Vichy free zone, the two men joined De Gaulle's Algeria and went back to work on behalf of the allies. After creating a jammer against the HS 293, they rebuilt their BHT which they tested again on LeO and Glenn Martin.

Their experiments never knew industrial production but the two men were still active within the SNCASE and Marnay had only to knock on their door to associate them with his project.

That's what he did with Jean Turck.

 

Even before the STA had approved his proposal and placed an order with him, Marnay and his teams got down to work to create their first glider, the SE 1500, which gave his family his name.

A total of 118 SE 1500 and derivatives were created. These machines flew between 1946 and 1957

The SE 1500 never saw operational use. However, the SE 1500 family can be divided into three categories :the experimental gliders, the CT and the AS (with the SE 1500 (1st generation), the SE 1520 and the SE 1530).

It is this last category that interests us.

 

 SNCASE SE1500

Spoiler

They are the first born of the series of which they gave their names.

An initial order (N°614/DTI/STA) was placed with SNCASE by the STA on April 14, 1946.

The specifications were as follows:

 

-The glider's natural stability after separation from the LeO 451 had to be such that altitude had to be maintained for at least 20 seconds without special equipment.

 

-Explosives of 10 to 250 kg were to be used at distances of 10 to 200 meters

 

-The construction had to be representative of a 15 to 20 ton aircraft (never respecte)

 

The first prototype had been built and had already made its first flight (November 7, 1946) dropped from LeO even before the STA signed its contract (February 7, 1947).

 

And here I am going to clear things up once and for all : The SE 1500 (first generations) are NOT flyings bombs. These are gliders equipped with a bomb bay. The triggering system of the bomb was original to say the least. The bomb was connected to the glider by a cable (its value could vary between 10 and 200 meters as provided for in its specifications). When the cable stretched, the bomb exploded.

 

But what kind of explosives were on board ? The answer was given to us by the second flight which almost cost the life of the crew of the LeO. The SE 1500 dropped at 4000 meters went into a spin and crashed without exploding. The LeO 451 pilot, reassured by the stability of the explosive, approached the crash.It was then that the yellow liquid of Melinite exploded and the aircraft returned to base heavily damaged.

 

Note that this is not the only accident recorded: another time the glider, once released, reassembled the left engine and skirted the cockpit before descending in a spin towards the sea. An examination on the ground showed that the glider had scratched the propellers. It took time for the engineers to correct the multiple flight problems.

 

Ok : but what was the payload of bombs?

We do not have a precise answer to this question but we can make an estimate. According to specifications between 10 and 250 kgs. The first prototypes weighed a total of 557 kg, 110 kg more than on the plans. And here again, the SE 1500 has dimensions comparable to its cousin the SE 1530, whose explosives payload capacity is known to be between 350 and 500 kg.

 

But what about its speed?

 

Again we do not have a precise answer but we can have an estimate thanks to a note of February 1951 about the parachute of an SE 1510. The SE 1510 is an experimental glider. Designed to study glider performance and on-board technology. This version differed from the first SE 1500 by adding a rudder, autopilot and remote control (gave by Turck). It also included a parachute in order to be recovered and reused. However, the note mentions that the parachute used was « not made to recover a 500 kg body at 500 km/H ».

 

A total of 26 SE 1500s were produced. This is the most produced version of the series.

 

Lenght 5 m

Wingspan:4,343 m

Diameter : 0,70m

Weight :557 kg

SE 1500 production line, note the bomb bay on the glider

  SE 1500 n°22, note the bomb bay and SNCASE symbol.

 

 

 

Introduction to the SE 1520 and SE 1530 flying bombs

Spoiler

Following the success of the SE 1500 and SE 1510, the STAE placed a new order with SNCASE for 10 SE 1520 flying bombs the 20 April 1949 This time, they are indeed flying bombs supposed to explode on impact and no longer glider bombers. With theses 10 SE 1520, are also commanded 10 SE 1530. The SE 1530 differ from the SE 1520 by the addition of the SEPR401 liquid rocket (to increase the impact speed).

In addition 10 SE 1521 and 10 SE 1531 are ordered. These models belong to the category of experimental gliders and differ from the SE 1520 and SE 1530 respectively by the removal of the explosive charge and the addition of EFA parachute and MAP deployable skid in order to be recovered and reused.

 

All these machines recover the technology on board the SE 1510 and are equiped in addition to altimeters and contact anemometers to trigger parachute drops or flight commands. Finally a servo motor from V1 is added.

Another modification which is not mentioned on the document but visible on the photos is the placement of the wings on the same plane unlike the SE 1500.

In addition, the wingspan increases from 4,343m at 4,35 m.

 

Finally a contract is signed with the STAE was passed on November 6, 1948 (N°2238/48).

Sadly if the SE 1521 and the SE 1531 flews 23 and 3 times respectively, the SE 1520 and SE 1530 never flew. With the disappearance of the heavy bombers in the Air Force, these machines no longer had an operational future. For this reason all pictures that you would be looking at will be pictures of SE 1521 and SE 1531

 

However, we have the proof that the SE 1520 and SE 1530 were built. The note of 17 July 1954 (AT 33/54) requests the modification of 5 SE 1520 to SE 1523

The note of 25 July 1955(1400 GTC/30) requests the modification of the 5 last SE 1520 to SE 1502 M for the navy.

For the SE 1530,the note of 2 June 1953 (AT 164) requests the modification of 7 SE 1530 to SE 1522. The note of 17 july 1954 (AT 31/54) requests the modification of 2 SE 1530 to SE 1523.We don't know what happened to the last SE 1530 and we don't know if it was actually built.

Note that its rival from the same AS 10 program, the Breguet 910 suffered the same fate.

 

 

When at SE 1502, SE 1522 and SE 1523, they are all CT( remot-controlled target)

 

SNCASE SE 1520

Spoiler

This is the bomb for which we have the least direct information. We can however deduce them from its twin brother the SE 1530

Like him, we can estimate the explosive load to be between 350 and 500 kg.

For flight performance, we know that an SE 1521 dropped at an altitude of 450 m flew at a speed of 260 km/h. However, we can expect it to also reach the speed of 500 km/h of its cousin the SE 1510.

23 test flights were carried out on SE 1521

 

Lenght 5 m

Wingspan:4,35 m

Weight :557 kg

Diameter : 0,70m

Explosive charge:350kg at 500 kg

Max Speed : 500 km/h (estimated)

260 km/h at 450 m

 

 

SE 1521 during the test: the red and white coloring is to help find the device after dropping

 

 

SNCASE SE 1530

Spoiler

For this machine this time, we have information revealed by Michel Decker himself (watch source)

It is he who gives us the value of the explosive charge mentioned above.

While giving us a description of the device, he shares two important pieces of information

 

1: the main (and only) difference with the SE 1520 is the addition of a SEPR41 rocket, the same as on the SE 4100 another AS machine from SNCASE. This nitric acid rocket gives the bomb for a duration of 10 seconds a thrust of 1250 kg

 

2: Regarding the second piece of information, it may be subject to debate because it may pose a very small problem of balancing in the game: The practical range of the missile which can be dropped at a distance of ... 50 km from its targets. However, we can relativize by pointing out that Decker does not give us information on the altitude of the carrier aircraft for this range to be reached. In any case, I leave you to meditate on this information.

Only 3 test flights were carried out on SE 1531.

 

Note that the S1530 is 50 cm longer than the SE 1500. This is probably due to the rocket protruding behind.

 

Lenght 5,50 m

Wingspan :4,35 m

Diameter:0,70m

Explosive charge:350 kg At 500 kg (Mélinite)

Pratical Range: 50 km

 

LeO 451 with SE 1531

 Note the rocket SEPR41 on this picture.

 

 

Finally why add SE 1500 series in War thunder?

Spoiler

- Revaluing and (re)discovering the LeO 451

- Armament made in France

- Ability to perform «surgical attacks» at high altitude

-Give a new challenge to enemy fighters who would have fun intercepting them.

- Excellent potential for future naval battles

- Primitive Drones at 3.0

- Completely unique gameplay especially with the SE 1500 (first in the series)

- With the SE 1500: for the ultimate pleasure of dropping a bomber from another bomber (yes I know, say like that, it gives a headache).

- For the Fun of course !!!!!!!!!

 

 

Sources:

Spoiler

For my sources,

My main source is a pdf document by Philippe Jung, historian and former member of Cannes Aérospatiale (among others, I leave you his CV: http://www.cannes-aero-patrimoine.net/mediawiki/index.php?title=Philippe_Jung)

Concerning the document in question, it is the synthesis of its presentation at the 45th Congress of "the Astronomical Federation" in Jerusalem in 1994 and resulting from its association "Cannes Aéro Spatiale Patrimoine"

caspea_PMEX___001_SE1500.pdf

Interview with Michel Decker on « Aviation Magazine » of 1st June 1952

https://gallica.bnf.fr/ark:/12148/bpt6k53231046/f6.item

 

https://gallica.bnf.fr/ark:/12148/bpt6k53225953/f20.item

 

Finally, I got this document from the internet

TdB42.pdf

This is a newsletter of the members of the "Lyon Society of Aviation History and Aeronautical Documentation".

It is from this document that the photos of the SE 1521 (and one photo of SE 1531) come to me

 

 

Edited May 5, 2022 by Drasleon

[leroyonly 4,310]

Open for discussion. 

[Drasleon 226]

7 minutes ago, leroyonly said:

Open for discussion. 

 

Thanks you very much 

[Drasleon 226]

Well it seems that with the royal update, I finally have the opportunity to dust off this suggestion.

Now that we have a Lancaster Mk.7 in the French tree, we also have a potential new carrier aircraft in the tree.

 

From the information I have on the 10 S Lancaster, it could carry 2 SE 1500 series machines one behind the other.
However it seems that historically, this one only carried remote-controlled targets (including the SE 1503 and SE 1523)
But knowing that SE 1520 were modified in SE 1523, the use of this type of device (SE 1520 and SE 1530) in games on the Lancaster Mk 7 does not seem so innapropriate to me.