Mirage F1 - Does anyone knows what the french acronym ADF stands for?

[Rudel_chw]

On the manual this engine system is translated into english as SRL, which stands for "Slam Relight Lighting" ... it's a device that allows the throttle to be directly moved from any part  of its dry quadrant, to any part of the AB quadrant.  But the instrument panel indicator light for it says "ADF", nor SRL ... hence, my question, what does ADF stands for?  Thanks for any info on this   

 

Edited July 28, 2022 by Rudel_chw

[Zeagle]

I would assume "atutomatic detonation failure" ("défaillance de la détonation atutomatique",  or "fallo de la detonación atutomática" )? Or maybe "apply directly to forehead"....I 'm about 65% sure it's one of those.

Edited July 28, 2022 by Zeagle

[Gallus]

Hello,

If the device you describe allow you to go from iddle to full after burner with no delay in throttle mouvement then ADF could stand for Allumage Dans la Foulée which mean ignition directly following (sorry for the rough translation).

Edited July 28, 2022 by Gallus

[Rudel_chw]

Thank you both, but I need to be more certain about this, as I’m editing a training mission for the F1 and I’d like to add more background information to each item. I have the manual of the real F1, but it’s in english as it’s for the South African version, will try to get the french version, to be sure. 

[ARM505]

I'm amazed the SAAF version isn't in Afrikaans.....we could have thrown yet another language into the mix!

For some historical perspective, the old SADF (South African Defence Force, now called the SANDF or 'South African *National* Defence Force because reasons) looooooooved to translate literally everything into Afrikaans. I know, I was in it. I wish I could find the translation list we had for every technical aviation related term into Afrikaans. Same in the Navy. And of course the army, which normally didn't need anything translated into Afrikaans because in the army everything was already in Afrikaans.

[Zeagle]

I was just kidding Rudel. I have no idea what that means...

 

[Flappie]

On 7/28/2022 at 8:30 AM, Gallus said:

Hello,

If the device you describe allow you to go from iddle to full after burner with no delay in throttle mouvement then ADF could stand for Allumage Dans la Foulée which mean ignition directly following (sorry for the rough translation).

I've just found a Facebook post from 2020 about the Mirage III. It says ADF means "allumage dans la foulée" indeed.

Quote

L’allumage de la PC ‘’dans la foulée’’ ADF. Ce dispositif simplifie la tâche du pilote qui peut déplacer la manette à volonté sans avoir à attendre la stabilisation du régime au PGSEC avant d’allumer la PC.

It reads:

"ADF" afterburner ignition. This  feature makes it easier for the pilot by letting him move the throttle as he desires, without the need to wait for engine speed stabilization at dry thrust before engaging the afterburner.

https://hr-hr.facebook.com/groups/643827295701575/permalink/3039875229430091/

[Flappie]

@Rudel_chw  I've just found an even better source of information here, about the ATAR+: http://www.aeromed.fr/AEROMEDN59.pdf , page 14.

It reads:

This modification was interesting. It consisted in adding to the ATAR 9K50 a true ADF (allumage dans la foulée), just like the one from the Mirage 2000 M53 engine.

It might be necessary at this point to explain how the good old ATAR 9K50 afterburner sequence worked, before comparing it to the ATAR+ sequence. To sum it up, the pilot needed to wait for the 9K50 to almost reach its dry thrust nominal speed engine before initiating the afterburner sequence (figure 1).

With this modification,the afterburner sequence could be initiated in anticipation, well before the dry thrust nominal engine speed (figure 2). Anybody who worked with afterburner-equiped engines knows that igniting fuel in a nozzle strongly reduces the pumping margin because of thermal obstruction [overpressure] if the compressor compression rate is not maintained to a more or less constant level.

Regulation anticipates the afterburner sequence by controlling the nozzle opening. This can be observed on combat aircraft during takeoff. If the nozzle stays closed, the engine will pump and risk a compressor surge, and it won't be able to give the expected thrust boost, a source of disappointment for the pilot. If the nozzle is opened too much, the engine won't ignite.

This ATAR+ modification was only working below 27.500 feet (more or less) because this information was transmited to the engine by the aircraft air data computer. The trick was -among other things- to trigger overspeed (engine speed going from 8400 rpm to 8900 rpm - this was used over M 1.4 until then) as soon as the throttle was moved to the afterburner position, which allowed the engine to meet the proper afterburner conditions 3 to 5 seconds sooner.

 

The author was a test pilot who worked on this ATAR modfication for the SAAF Cheetah.

But I guess the principle is the same for our Mirage F1 ADF. Actually, he says this modification was tested on a Mirage F1AZ.

Edited July 30, 2022 by Flappie

[Flappie]

The article was split in 2 PDFs. The next one talks about the ATAR+ testing in South Africa. Very interesting!

http://www.aeromed.fr/AEROMEDN60.pdf (page 11)

In this one, we learn that the Cheetah ATAR+ modification was never implemented (although its evaluation had proven satisfactory).

Edited July 29, 2022 by Flappie

[Rudel_chw]

Thank you so much, @Flappie .. I know that these little details are not a big deal, but a great part of the enjoyment that I get from a full fidelity module is the learning of all of its intrincacies and quirks, and the information you provide is just what I was looking for .. thanks again 

 

Edit: I don't speak french, but google translate helps a lot  thanks for the magazines

Edited July 29, 2022 by Rudel_chw

[Flappie]

You're welcome. I enjoyed the time I had looking for this information! I wish I knew this test pilot. He knows how to tell stories!

An interview of the guy: https://www.aerocontact.com/videos/4187-meet-the-a320neo-first-flight-crew-etienne-miche-de-malleray