"Very nice sandy beach ... but the sea is really far !". French Aeronavale (Navy) Potez 25 TOE. 1934 "Pink Cruise"

[HubertB]

Ok. So I'm in this « Playing in the sandbox » GB. As I love « different » subjects, I could not resist the fun of aircrafts adorned with roundels and « fish-hooks » - the traditional nickname of the French Aeronavale roundels - landed somewhere in the Sahara , like this pic shows.

 

Some background information on this subject, to begin with.

 

France in Africa

 

Since the mid- nineteenth Century, France expanded its empire with a strong focus on Africa. Algeria, then Tunisia were conquered and annexed, and, later, the Moroccan Kingdom became a protectorate.

France also expanded in tropical and equatorial Africa, adding most countries of West Africa to its empire. Thus in the end of 1893, Ensign Aube, on an armed launch, with a handful of sailors, cruised up the Niger, to Kabara, which is the river port of the famous Tumbuctu. He negotiated with local powers the installation of an outpost, but was subsequently killed in an ambush On December 28th of that year. Tumbuctu was conquered militarily a few weeks later by a French Army column, thus annexing Niger. I mention this small part of history, because it is the root of the "Pink Cruise", as I will expose below.

 

By the 30s, France had a strong presence in North, Central and Western Africa, and was working to develop its colonies and link them. Thus throughout the 20s and 30s, France developed a number of routes to criss-cross and mark up the mighty Sahara, which made up the essential chunk of southern Algeria. A route had been developed, where three roads, coming from Rabat in Morocco, Tunis in Tunisia and Alger and Oran in Algeria, merged in the Algerian town of Adrar, in the Sahara, and then went south to Gao, in what was then known as « French Sudan » and is now Mali, from which it forked again towards the capitals of the different African countries under French rule, like, Niamey, Bamako, Dakar, Ougadougou, Ft Lamy or Bangui.

 

The road that crossed the Sahara in south Algeria – the so-called Tanezrouft desert- was established in the 20s, by expeditions of the French Army. About every 50 kilometers, they burried a water reserve, that was signalled by an empty barrel (« bidon » in -French). There were 16 Bidon station overall, but Bidon 5, mid-way between Ouallen and Tessalit, deep in the desert, became the most famous of all. By the 30s, there was a hotel in Bidon 5 (made of the bodies of two coaches) and a petrol station for both cars and aircrafts.

 

 

 

 

But it was not rare to use other means of ensuring the fuel replenishment of aircrafts in the Sahara

 

 

The Black Cruise

 

In the early 30s, the Armée de L'Air (Air Force ) was officially created as a separate entity from the Army.

The then Minister of the Air wanted a major public relations event to both celebrate the birth of the Armée de l'Air, and demonstrate its power.

This is how the « Black Cruise » was conceived : a demonstration of force, and incidentally, an occasion to show the flag in the African colonies.

General Vuillemin, a Great War veteran, and a specialist of Saharian aviation was tasked with organising it.

The Black Cruise thus took 28 Potez 25 TOE, from Paris to North Africa, then French Black Africa, and back to Le Bourget, over a 27 000 kms trip, from November 1933 to January 1934.

The aircrafts had been specially prepared for the event, with some ad-hoc mods.

The Black Cruise was flown by seasoned aviators, from the Air Force predominantly, but also the Aéronavale – the aviation branch of the French Navy. It was a resounding success, and created a lot of enthusiasm and hype at that time.

 

 

The « Pink » Cruise

 

Enters Count Jean de Laborde, vice-admiral of the French Navy, and CiC of French Naval operations for the African area.

Vice-admiral Laborde was a colourful character, excellent seaman, and enthusiast and proficient aviator. He was the first commander of the French aircraft carrier Béarn.

For the record, he later became Admiral but saw Darlan, who had better political connections, be nominated as Minister of the Navy, after which he nourished a serious dislike of Admiral Darlan.

He had also, and did not hide it, a strong enmity towards anything anglo-saxon, which later events, like the British attack on the French fleet in Mers-el-Kebir in 1940 did not help assuage, quite the contrary. In 1940, he remained loyal to the Vichy regime, and was the commander of the Southern region fleet, based in Toulon, in 1942, when « Operation Torch » took place, leading to the Nazi invasion of the « free zone » in Southern France.

It was Laborde who ordered the scuttling of the Fleet in Toulon in 1942, primarily to avoid the fleet joining the Anglo-Saxon forces, as Darlan was prompting him, and secondarily to avoid the seizing of the Fleet by Nazi forces. He was judged and sentenced to death in 1947 for this « act of treason » and his death sentence was later commuted to a prison one, until he was finally officially pardoned by The French President in 1959.

 

Anyway, back to 1934. France was no foreigner to inter-service rivalry, and Laborde did not like the publicity the Armée de l'Air received with the Black Cruise. He wanted the Aéronavale to even the score, and was looking for a reason to do so.

 

In 1934, France decided to install a plaque to commemorate Ensign Aube, in Tumbuctu. Laborde saw the opportunity he wanted. He informed the Ministry that, as the senior-ranking Navy officer in Africa, he intended to attend personally, with his wife, the inauguration of the commemorative plaque. By « mistake », most certainly , the memo to the Ministry failed to imention that he intended to fly to Tumbuctu, in an African remake of the Black Cruise.

 

In November 1934, he thus set up a group of 3 Potez 25 TOE, and took his small squadron from Sidi Ahmed, the Aéronavale airport near Bizerte, in Algeria, to Tumbuctu, with a number of stops, including at the famous Bidon 5. The 6500 km return flight was a success.

 

Laborde was piloting the Potez 25 TOE coded « BZ 65 », and his wife was his passenger. This is because of her presence that Laborde's expedition became dubbed in the records as the « Pink Cruise ». BZ 65 will be my entry in the Sandbox GB. It was, btw, also a "Blue Goose" aircraft, as it was adorned with the 4-star vice-admiral penant on the fin.

In the pic, below, the person in white is Mrs Countess de Laborde.

 

 

 

And this why you can see pictures of French Navy aircrafts deep in the Sahara desert - actually at Bidon 5-, like the one above

 

The Potez 25

 

The Potez deserves more recognition that he got from the aviation historians.

It was conceived as an observation and bombing aircraft. It was an oustanding success in the 20s and 30s, with more than 3 500 built and used by 18 different countries, in Europe, South America, Africa, and Asia.

With a sound biplane conception, a ingenious structure and engine frame, it could be – and was - motorised with about any engine of the 400-600 hp range, whether water-cooled or radial. The upper wing could be set-up in different longitudinal positions to accomodate different CG with different engines. It could even be flown as a monoplane.

The Potez 25 had also a very famous civilian operator, namely the « Aeropostale », which used it on its South American mail lines, as it was one of the few whose celing could allow to cross the Andes. Antoine de St Exupery has made the exploits of Guillaumet, Daurat, Mermoz famous in his books.

The main version of the Potez 25 was the A2, with a W12 Lorraine engine of 450 Hp. This is the version that was exported and built under licence in Poland.

 

 

 

However, for its activities in the colonies, France developed the « TOE » version (TOE for "Théâtre d'Opérations Extérieures", aka Foreign Theater of Operations).

The TOE was somewhat different from the A2, with a main fuel tank of increased capacity, to 450 liters, the adjunction of a 300 supplementary fuel tank, which can be called a Conformal Fuel Tank as it was attached against the flat belly of the A2. In the process, the TOE did like a lot of old men : it gained a fat belly 🤣 !

Another very visible difference of the TOE was an enlarged radiator for operations in hot countries, with two « ears » added to each side of the original radiator, merging in the fairings of the cylinder banks behind them and a revised cowling flaps setting.

 

 

 

The Lukgraph Potez 25 kit.

 

The policy of Lukgraph is to produce progressively the range of significant aircrafts used by Poland in the 30s, and this is for this reason that we have now have a 1/32 scale kit of this important , but neglected, aircraft. Thank you Lukasj !

But, because of this Polish bias, it represents a Potez 25 A2, not a 25 TOE ...

The kit is in line with recent Lukgraph releases, with the major parts in finely casted resin, and the detailing and accessories parts 3D-printed.

We also have a PE fret, and a decal sheet, one for a Polish A2, and the other one for a French Aeronavale A2. So at least, I have French roundels with « fish-hooks » available for my project !

 

 

 

 

The kit is generally nice and accurate, with one caveat : the belly is represented as a shallow V, when it was flat on the original A2.

 

French Aéronavale Potez 25 TOE « BZ 65 » of Jean Laborde.

 

When I set my goal on representing this aircraft, I confess my knowledge of the Potez 25 and its variants was not what it is today, three or four weeks later. And maybe I should have been smarter and choose another subject, now that I know, but I was commited by my order to Lukgraph !

 

So, the Lukgraph kit will need some conversion to be brought to the TOE standard :

1) a new radiator

2) an extended main tank

3) an additional fuel tank under the belly

4) a fairing under the belly from the end of the additional fuel tank to the tail skid.

5) a revised fairing over the two lateral cylinder banks, to blend-in with the new radiator.

6) I found 4 days ago that, as the belly grew fatter, the TOE cowling was revised and made deeper to fair better with the lower main tank located between the UC legs.

 

But, wait, there is more, to get to the TOE as used by Laborde in the Pink Cruise, like :

 

7) an extension of the side fairings over the cylinder banks, to represent the additional water tanks that were added for the desert flights.

8 )The fairing over the passenger location is different from the original one, which had a ring to accomodate the machine guns. see the pic above with Mrs de Laborde on board.

9) « BZ 65 » had an additional headrest fairing for the passenger, no doubt to make it more comfortable for Mrs Laborde

10) BZ 65 was also equipped with an radio emitter and receiver, in the passenger area

11) the standard practice for Aéronavale Potez 25 flying over barren North African regions was to carry a spare wheel, on the left side of the fuselage

12) To make the trip more comfortable for the passenger, the rear strapontin was substituted with a full seat, identical to the pilot one

13) the TOEs for the Black and Pink Cruises had a totally different tail skid, to accomodate for the heavier weights and rough filed conditions

14) and last but least, poring over my documentation yesterday, it dawned on me that the landing gear was different from the Lukgraph kit, which represents the Potez LG as used on the Polish versions, whereas the « Cruises » TOEs had an oleo-pneumatic Messier landing gear !

 

I have been steadily working on designing the required conversion parts in 3D over the last week, but the work is still in progress, and I thought last night than rather than accomodate the v-shaped belly of the Lukgraph kit, on which I would graft the conversion parts, I'd be better off by removing it altogether and then gluing the conversions parts, once I have printed them. So some parts design will be tweaked accordingly.

Here I am as of tonight :

New radiator

Extended fuel tank :

 

Additional belly CFT :

 

Fatter lower cowling :

 

Revised cylinders bank fairings, with extra water tank :

 

Second, passenger, seat :

 

And finally spare wheel :

 

 

I still have to design the rear belly fairing, the new tailskid, the new Messier undercarriage, the radio sets, the passenger position cover and aperture, and do a general overhaul of my design as I rethink through the conversion procedure.

And of course, the plan is to display the finished kit with a few « markers » of the Sahara, like dromedaries (found in 1/32 on the website 3Drifter.com) or a few fuel barrels (which were actually identical to the 70 litres powder kegs of the era, to be in a weight range acceptable for the dromedaries)

 

 

 

That's it for now. Ready, set for playing in the Sandbox !

 

Hubert

 

PS: in case you wonder why I chose the Pink Cruise Potez over the Black Cruise one :

a) the concept of a Navy aircraft in the middle of the Sahara was irresistible

b) the Aeronavale aircrafts were dark blue-grey on top, and light blue-grey on the undersides, which I prefer a lot to the khaki green of the Armée de l’Air

c) i tought it would be easier to cut masks for « BZ 65 » on the sides of the Potez - this last reason being probably a bit spurious

 

[Landlubber Mike]

Very cool choice Hubert!  Love your scratch parts, this is going to be a stunner for sure.

[Peterpools]

Hubert

What an amazing story behind your entry - absolutely incredible research and the CAD/3D conversion is on a whole new level. Looking forward to following your progress on this journey.

 

 

 

[Martinnfb]

Very cool subject choice, would not expect any different from you Hubert. Will follow with interest.

Cheers

Martin

Motivational click for your convenience

 

[PanzerWomble]

Good Lord .......you've gone "all in" on this one Hubert !!

Interservice rivalry, buried water , Laborde taking his wife !!( shades on The English Patient here ), treason , prison and a Lukeagraph obscure model , plus........ added camels 

Salute ! Give this man the prize now !

 

Fascinating backstory which I love. 

[KevinM]

That's a Very pretty Aircraft Hubert and the story was interesting!

[Martinnfb]

This build brought back an old childhood memories of watching the tv show  "LeTemps des as" . I was so little and my Mom was translating. So random. 

[CANicoll]

You win.  

[mark31]

yes thats special navy bird in the sandbox.

You are already underway with the parts.

 

Mark

[HubertB]

Well, guys, just to show how seriously I take this GB theme, I organised a study trip to Marrakech, to get a better feeling of the desert atmosphere and the local hump-backed fauna  .. Please just don’t tell Mrs B. She believes it was for our wedding anniversary 😇…

Joking apart, I will have some virtual (literally) progress to report when I come back on Tuesday. I have gone through some iterative improvements / redesigns of the conversion parts, and should soon be ready to attack the build in earnest …

Oh, and, while roaming the souks, I think I found what could be an interesting 1/32 scale sand fac-simile, in terms of colour and granulometry. And, on top of it, it should smell good 🤣😂🤣 . If it does not work as I expect, I will still have the option to use my « sand » to flavour some couscous or tajine 😋 So, that’s a win-win !

Hubert

[BlrwestSiR]

What an interesting subject Hubert. Something I wouldn't not have known about but for reading the backstory behind your build. 

[KevinM]

52 minutes ago, HubertB said:

If it does not work as I expect, I will still have the option to use my « sand » to flavour some couscous or tajine 😋 So, that’s a win-win !

He's going "Saving Private Ryan" cans and all... have fun.

[Peterpools]

Hubert

Amazing for sure.

 

[HubertB]

VIRTUAL, YET REAL, PROGRESS

So, after my "study trip" in sunny, and dry, Morocco, I have completed this morning the round of designs for the conversion parts. Next steop will to print them, and starting cutting the kit ...

Compared to the screen captures I posted above of some conversion parts designs, I have kept untouched 4 of them, namely the second seat, the spare wheel, the radiator, and the fairing above of the cylinder banks, with the water tanks extensions.

I have modified the main tank enlergement part, following some better pics and a some (bad quality) drawings, and also because I decided that, rather than design the conversion parts around the inaccurate shape of the belly as represented by Lukgraph - a shallow V rather than a flat bottom in reality), I would remove the bottom altogether and add the conversion parts from a flat base. This has led also to more accurate measurements of the true profile of the kit fuselage, and changes to take them into account. For the main tank enlargement, I also took into account the fact that the whole tank was jettisonable in flight on the 1:1 aircraft, and had therefore to clear the undercarriage struts.

Old (top pic) vs new (bottom pic) :

I found a factory drawing for the supllementary CFT, which although heavily pixaleted to the point of being mostly illegible, had enough "good" information and numbers to allow a more accurate redesign. Old onb top vs new on the bottom :

New shape (the difference is more subtle to see) for the new lower engine cowling, with slightly moire depth and revised angle for the carburetor intakes :

Then there were the new parts needed for the conversion.

The lower rear fuselage fairing :

The new rear skid. The oleo-pneumatic Messier skid was a fairly complex contraption compared to the original simple one.

 

The landing gear has been redesigned to represent the oleo-pneumatic Messier, and also to have a more accurate tread (thanks to some technical drwings from Potez I found on-line) :

I next tackled the revised cockpit coaming for the rear passenger, with the gun ring deleted. I then noticed on pics that the pilot coaming had a small hump under the winscreen, when Lukgraph has it flat. So another part of the kit to cut off , and a complete coaming for the two seats to be designed :

Next, and final - so far - is the radio equipment. I struggled to find proper references for the gear used by French aircrafts at the time, but, again, Potez "Notice Technique" about the changes to the Black Cruise aircrafts was of some great help. I just assumed the gear for the Pink Cruise Potez would be the same. The drawings showed an installation with three boxes, spread in the rear cockpit. TBH, the faces have some creative "gizmology" added, as I failed to find accurate references. So here are radio sets 1, 2 and 3.

That's it for now. I now have to get all parts printed.

Next week, I am off to France for a few health checks, so it may be a bit of time before the next update.

Hubert.

[Landlubber Mike]

Very cool Hubert - can't wait to see this come alive!

[PanzerWomble]

 Love this one Hubert , your absolutely crazy but thats all good !

 I so do not want to go down the route of 3D parts, getting to grips with the Silhouette cutter was.... traumatic. 

 

 

[Peterpools]

Hubert

I'm completely blown away. I was born a good 20 years too early.

 

[CANicoll]

Super nice!  Can't wait to see the 3D bits in use.

[HubertB]

The printing is going well, and started building

 

Well, finished with virtual work, and on to the real one. I have done some printing of the designed parts. Gotta say I had to re-learn a few tricks with the exporting of the printable files, and the slicing software.

My first printing trial on Friday did not end well, and it's 125 % operator’s error. When exporting the design file to .stl format, I missed specifying the resolution settings of the .stl files. Silly me, I thought the 3D software would automatically choose the highest resolution, but it didn't.

When imported in the slicer program (Chitubox), I thought that the square wheel was just a dispaly artefact. But it was not ... So, after 10 hours of printing, I ended up with heavily pixelated parts, a square spare wheel, and some parts not printed 🤣 !

Trial #2 yesterday. In the meantime, I found that I could import .obj files in  Chitubox, which worked for all parts but one, for some reason I cannot fathom. That part was exported in hi-res .stl, and I have to say the printing went mostly well !

I just missed adding enough supports for the supplementary conformal fuel tank, so it fell partly off during the printing process, resulting in a misshapen part.

Here are the pics of my printed parts :

 

I am pretty pleased overall. There are a few print lines however, in spite of the 20 micron layer resolution. It looks like I got some slight wobble of the printing platform, but nothing really major here.

The supplementary tank, plus a few fuel drums and the parts I designed for the Cutlass, are in the printer now, so we'll see tonight how this turns out.

In the meantime I started the build, by attacking the cockpit work. The 3D-printed part from Likgraph has been cleaned from the prining supports. I broke two parts in the process, easily reparable. Ànd I have started bending these teeny weeny PE parts ... Did I say they were tiny ?

TTFN

Hubert

 

[CANicoll]

Hubert,

Looks good and I'm envious of your 3D printing skills.  We have a 3D printer here I have access to, but I'm not even sure where to start.  Your progress looks terrific, and those PE parts are definitely TINY.

[HubertB]

So, the third printing trial of the supplementary fuel tank was successful .

I used the printing opportunity to print a dozen fuel drums, that will be useful for the small vignette I intend to dispaly the Potez on.

 

I will leave before dawn tomorrow morning for a 5-days trip to France.

More when I come back, in 10-days time.

Hubert.

[PanzerWomble]

Very fine lines there - not the corrugated stuff you used to see some years back 👍

[HubertB]

22 minutes ago, PanzerWomble said:

Very fine lines there - not the corrugated stuff you used to see some years back 👍

I’m using a SLA 8K resin printer, with 20 microns layers. The resolution you get is absolutely great. But I am moderately happy with the grey resin I am using. I find it has a tendency to blurr the finest details, at least as viewed with a 3x magnification in the Optivisor

Hubert

[Peterpools]

Hubert

As the saying goes; I'm blown away and envy doesn't even come close to your incredible printing skills, surely a whole new world is out there for creating new parts, details and kits. 

Looking mighty good.

[HubertB]

That feeling when you start chopping off an expensive kit …

Ok, some progress to show after a week of health checks in France (all OK, whewww …) and another week of frustration trying to beat a slicing program (Chitubox) into submission …

The kit, with its plain wings, plus my conversion parts, will be fairly heavy. I designed the one piece new undercarriage to be able to insert some metal rods to strengthen it. But, in the printing process, with a resin that is slightly too viscous and I am not totally happy with, the holes designed in the struts got clogged up. And there is no way I could re-drill them, simply because I do not have a set of drills long enough (between 30 and 50 mm needed) with the required diameter - 1 to 1.5 mm.
So i had to redesign my landing gear to separate the struts, so that I could print them in a way that would not clog the holes. (Relatively) easy enough. But then my slicer refused stubbornly and steadfastly to slice and record the resulting file. After fours days of frustration, with multiple software freezes and forced interruptions, five or six un-installing and re-installing the slicing software, a frantic internet search for alternative slicing softwares - to no avail, as my printer, an Elegoo Saturn 2 will only take slice files generated by Chitubox - i decided that the smartest of the two - between me and Chitubox - had to give way 🤣 🤣 …

I have changed again my design, and it seems I can now print it … Let’s wait for the print result, currently under way, with a new resin 🤞

This stalled my progress on the kit. I have nevertheless started assembling the kit, namely the cockpit structure and PE detailings … This PE is really small and requires steady nerves.

Here is where I am as of tonight …

The white bits are my additions, either to replace some I had broken when removing the printing supports, or the racks for machine guns drums in the rear cockpit. I also needed to add supports for the passenger seat.

And then, whilst the printer is running, came the time to start chopping off the kit, to insert the conversion parts. Did you ever get this slight trepidation when you start sawing off bits of and expensive kit 😱 ?

No coming back now. A pic after one half done :

And of coursé after chopping off the second half, I had to try taping my conversion parts :

Some issues to look at. My lower cowling is slightly too long (but conform to drawings) but more importantly I missed a 3 mm cut in the front end, with, as a consequence, a radiator that sits too high, when it is the same height as the original kit part. The cockpit fairing seems to sit too high at the front. I need to check whether it is a design issue to fix, or an adjustment o make to the cut in the fuselage. The main fuel tank extension has already been slightly redesigned, and is on the printer right now. The extra fuel and rear fuselage fairing look ok, although the extra conformal fuel tank has been tweaked to integrate the recess for the rear landing gear struts. The recess was clearly drawn on the factory drawing I had found, but I had not understood its function at the time, and simply overlooked it …

More when there is more to show …

Hubert