Wrong start-up procedure?

[Redglyph]

Given the "aircraft moving forward" issue and the unclear power sources during the start-up procedure, I have tried three different methods.

 

In summary,

(1) follows the RAZBAM manual, without battery

(2) directly switches battery ON

(3) directly switches battery, transfer and alternators ON

 

-> (1) and (2) yield an audio warning when the engine starts, and the aircraft moves forward

-> (3) follows the leaked (French) Mirage 2000-C pilot's flight manual, and seems better

 

There are other issues like the status lights and especially the starter pump which misbehaves.

 

Here are the details below, I think the actual procedure needs clarifying, and the little quirks in warning lights should be addressed.

 

I had a look at a video of the M2M Mirage, but it seemed very fancy (even though it's supposed to have been validated by guys from the French AF, but I'm not sure it's about this part), so I didn't push the comparison further.

 

See also the thread on the manual.

 

Finally, there is the stable values of RPM and Tt7:

> N down and stable at 49%

> Tt7 down and stable at 650 °C

 

Shouldn't these be 47-48% (close enough), and 480 °C (ref. manual pp. 9, lectures courantes, ralenti au sol)?

 

========================================================= METHOD 1

 

- parking handle raised

- vent/ignition on D or G

 

> audio warning

- audio warning reset

 

> BATT, HUILE, B.P, BP.G, BP.D, HYD.1, HYD.2, HYD.S, PARK

** error: TRN, ALT1, ALT2 should be ON

- engine fuel pump L and R ON

 

> BATT, HUILE, HYD.1, HYD.2, HYD.S, PARK (-B.P, BP.G, BP.D)

** error: B.P light should be ON

** actually, B.P switches off when either BP, engine fuel L or R is ON

** error: TRN, ALT1, ALT2 should be ON

- either starter pump ON, or open the engine start cover

- wait for B.P OFF

 

> BATT, HUILE, HYD.1, HYD.2, HYD.S, PARK

** error: TRN, ALT1, ALT2 should be ON

- click on engine start for 1 second

- wait for N >= 10%

 

> BATT, HYD.1, HYD.2, HYD.S, PARK (-HUILE)

** error: TRN, ALT1, ALT2 should be ON

- throttle on idle

 

> BATT, ALT1, ALT2, HYD.1, HYD.S, PARK

** error: TRN should be on, HYD.1 should be off

> audio warning at N=20%

- audio warning reset

 

> Tt7 climbs to 800 °C

> N climbs to 75% and aircraft moves forward ~50 cm

> N down and stable at 49

> Tt7 down and stable at 650 °C

 

> BATT, ALT1, ALT2, HYD.1, HYD.S, PARK

 

- main battery ON

 

> TRN, ALT1, ALT2, HYD.1, HYD.S, PARK

 

- electric power transfer, alt 1, alt 2 = ON

 

> HYD.S, PARK

 

========================================================= METHOD 2

 

-(?) main battery = ON

> audio warning

- audio warning reset

> TRN, HUILE, B.P, BP.G, BP.D, HYD.1, HYD.2, HYD.S

** error: ALT1 and ALT2 lights should be ON

- parking handle raised

 

> TRN, HUILE, B.P, BP.G, BP.D, HYD.1, HYD.2, HYD.S, PARK

 

- vent/ignition on D or G

- engine fuel pump L and R ON

 

> HUILE, HYD.1, HYD.2, HYD.S, PARK (-B.P, BP.G, BP.D)

** error: B.P light should be ON

** actually, B.P switches off when either BP, engine fuel L or R is ON

- either starter pump ON, or open the engine start cover

- wait for B.P OFF

 

> TRN, HUILE, HYD.1, HYD.2, HYD.S, PARK

 

- click on engine start for 1 second

- wait for N >= 10%

 

> TRN, HYD.1, HYD.2, HYD.S, PARK (-HUILE)

 

- throttle on idle

 

> audio warning at N=20%

- audio warning reset

 

> Tt7 climbs to 800 °C

> N to 75% and aircraft moves forward ~50 cm

> N down and stable at 49

> Tt7 down and stable at 650 °C

> ALT1, ALT2, TRN, HYD.1, HYD.S, PARK

 

- electric power transfer, alt 1, alt 2 = ON

 

> HYD.S, PARK

 

========================================================= METHOD 3

 

- main battery = ON

> audio warning

- audio warning reset

- electric power transfer, alt 1, alt 2 = ON

 

> HUILE, B.P, BP.G, BP.D, HYD.1, HYD.2, HYD.S

 

- parking handle raised

 

> HUILE, B.P, BP.G, BP.D, HYD.1, HYD.2, HYD.S, PARK

 

- vent/ignition on D or G

- engine fuel pump L and R ON

 

> HUILE, HYD.1, HYD.2, HYD.S, PARK

** error: B.P light should be ON

** actually, B.P switches off when either BP, engine fuel L or R is ON

- either starter pump ON, or open the engine start cover

- wait for B.P OFF

 

> HUILE, HYD.1, HYD.2, HYD.S, PARK (-B.P)

 

- click on engine start for 1 second

- wait for N >= 10%

 

> HYD.1, HYD.2, HYD.S, PARK (-HUILE)

 

- throttle on idle

 

> ALT1, ALT2, TRN, HYD.1, HYD.S, PARK

> audio warning

- audio warning reset

 

> Tt7 climbs to 800 °C

> N to 75% (aircraft does not move)

> N down and stable at 49

> Tt7 down and stable at 650 °C

 

> HYD.S, PARK

Edited January 10, 2016 by Redglyph
added some colours to make it easier

[Redglyph]

Further comment on this aircraft moving. Here it's obviously dependent on the start-up method, (1) and (2). It also depends on the throttle, probably, I've seen many videos where people put the throttle quite far, it seems we lack the IDLE position of this throttle, and a STOP position (although there is a stop button...).

 

Otherwise, no, those aircraft don't move when the engine is starting, that would be dreadful and terrible design :D

 

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[Redglyph]

No opinion on this? :)

[atonium83]

You said that the aircraft don't move when start up in reality, that's right. But in DCS when you've finished the start up procedure and start the taxi, you need to put your throttle at 15 or 20% for moving your plane forward..... In the real plane, there is a parking break for this case, because with throttle at 0% the plane move forward.... This feature is not implemented on the Razbam M2KC..... Maybe one day ?

[Redglyph]

There's a parking brake, and if you don't use it the aircraft will move during start-up, no matter which method above is used. Are you saying it should move even after start-up, with throttle at zero?

 

The point of my post is the starting procedure though :)

[Nealius]

Catch is, even if you engage the parking break the aircraft will move if you don't have BATT and ALT1+2 on.

[atonium83]

There's a parking brake, and if you don't use it the aircraft will move during start-up, no matter which method above is used. Are you saying it should move even after start-up, with throttle at zero?

 

The point of my post is the starting procedure though :)

 

During start up the N power climb to +/- 60% then reduce, so at this time parking break is very useful. But AFTER the start up, Parking break is ON because the plane will go forward. For the TAXI the pilot doesn't need to push the throttle, the plane move by himself with throttle at zero.

 

I'm back on the topic :p For you, during start up, the plane doesn't have to move ? I've got a friend working at Luxeuil AFB in France, he told me that one day a M-2000-5F (same start up procedure and same engine than C version) pilot forgive the parking break and his plane have moved forward by 5 or 6 meters in few seconds... I think that the problem on the Razbam plane is the bumper of the nose gear, is too flexible...

Edited January 9, 2016 by atonium83

[Redglyph]

During start up the N power climb to +/- 60% then reduce, so at this time parking break is very useful. But AFTER the start up, Parking break is ON because the plane will go forward. For the TAXI the pilot doesn't need to push the throttle, the plane move by himself with throttle at zero.

 

That'd be interesting to get the same behaviour then (BTW, here I saw N going up to about 75% during start-up).

 

I'm back on the topic :p For you, during start up, the plane doesn't have to move ? I've got a friend working at Luxeuil AFB in France, he told me that one day a M-2000-5F (same start up procedure and same engine than C version) pilot forgive the parking break and his plane have moved forward by 5 or 6 meters in few seconds... I think that the problem on the Razbam plane is the bumper of the nose gear, is too flexible...

I suppose you meant "forget" and not forgive, unless there was a grudge against the parking brake for not being strong enough ;)

 

I'm saying it shouldn't move when the parking brake is engaged, but Razbam's model does depending on the start-up procedure (as Nealius summarized above). I doubt that on the real plane using such or such source of power should have any influence on the initial thrust.

 

But I'm mainly saying that a clarification on the starting procedure itself is needed, and some fixes on the warning lights as well.

[Nealius]

Taxi handling needs to be improved as well. As atonium83 said, it seems the plane should roll at idle thrust. I imagine that's common for fighters.

[Azrayen]

Shouldn't these be 47-48% (close enough), and 480 °C (ref. manual pp. 9, lectures courantes, ralenti au sol)?

Perhaps, perhaps not: we got a newer engine (M53-P2) than the one described in the leaked manual (M53-5).

 

Catch is, even if you engage the parking break the aircraft will move if you don't have BATT and ALT1+2 on.

Actually, one ALT is enough.

Or the TRN (main converter) with no ALT.

 

This suggest that PARK BRAKE needs alternative current to work (in DCS at least).

[edit] looks like it shouldn't, another bug to report (but a minor one, no hurry) :)

 

++

Az'

Edited January 9, 2016 by Azrayen

[Buzzles]

FYI, method 1) of starting without battery is incorrect and a debug feature, I asked :)

http://forums.eagle.ru/showthread.php?t=157011

[Rlaxoxo]

There's a parking brake, and if you don't use it the aircraft will move during start-up, no matter which method above is used. Are you saying it should move even after start-up, with throttle at zero?

 

The point of my post is the starting procedure though :)

 

The Hydraulic Switch should be turned on In order for Parking brake to actually Brake and Hold the Aircraft in place

 

Otherwise It's gonna move

[Redglyph]

FYI, method 1) of starting without battery is incorrect and a debug feature, I asked :)

http://forums.eagle.ru/showthread.php?t=157011

Good to have confirmation of this. I'm not entirely sure how the pumps of two hydraulic circuits are powered - I believe one is driven by the engine, but in any case there must be quite a load on the battery, the alternators should be able to take over as soon as possible.

 

The Hydraulic Switch should be turned on In order for Parking brake to actually Brake and Hold the Aircraft in place

 

Otherwise It's gonna move

 

What switch do you mean?

 

There's a check valve anyway, you wouldn't want the Mirage to move when it's off ;)

[atonium83]

 

What switch do you mean?

 

 

At the right of the PCN (INS) you have one switch for Hydraulic system ;)

[Redglyph]

Perhaps, perhaps not: we got a newer engine (M53-P2) than the one described in the leaked manual (M53-5).

That'd change things, indeed :)

 

Actually, one ALT is enough.

Or the TRN (main converter) with no ALT.

 

This suggest that PARK BRAKE needs alternative current to work (in DCS at least).

[edit] looks like it shouldn't, another bug to report (but a minor one, no hurry) :)

 

++

Az'

 

No, it would have been a very bad design choice if it needed alternate current ;)

 

Are you sure about TRN only? Where would it get its current from?

 

That clarifies the beginning of the start-up procedure, and a possible fix on the brake even though one shouldn't start with the battery alone.

 

Then there are the other matters of:

• several (I think) incorrect warning lights, mostly with the wrong procedure admittedly, yet still incorrect
  
• B.P. behaviour
  
• when to switch off BP and ignition / vent
  
• possible venting behaviour in case of emergency abort
  

The last two were mentioned in another thread for the manual (post), but it's related to this start-up procedure as well.

[Redglyph]

At the right of the PCN (INS) you have one switch for Hydraulic system ;)

 

The emergency hydraulic pump? No, I don't think it's necessary for the parking brake in normal conditions. This pump only takes over when the pression in circuit 2 drops below 160 bars.

[atonium83]

The emergency hydraulic pump? No, I don't think it's necessary for the parking brake in normal conditions. This pump only takes over when the pression in circuit 2 drops below 160 bars.

 

Yeah but at this time this is the only Hydraulic switch in the cockpit, Hydraulic system is not 100% implemented yet....

[Redglyph]

Yeah but at this time this is the only Hydraulic switch in the cockpit, Hydraulic system is not 100% implemented yet....

 

Then I'm not sure what you or Rlaxoxo mean, the only hydraulic-related switch is the emergency hydraulic pump. There are obviously some quirks, so there's something implemented but not entirely finished.

 

Another observation is the HYD.2 warning light, you see it switch off when the engine's RPM increases above the initial 10% since the engine is driving the pump. But the aircraft lurches forward a few seconds after, and in two stages - first you see the parking brake working and it lowers its nose, then it moves forward. Even though there's obviously enough pressure in the circuit.

[Azrayen]

No, it would have been a very bad design choice if it needed alternate current ;)

I'm saying this is how it works now in DCS. I'm not saying this is how it should work. ;)

 

Are you sure about TRN only? Where would it get its current from?

Same answer as above :)

 

Regarding how it should work (based on RL aircraft):

Parking brake works with hyd pressure from the emergency accumulator (fed by hyd system 2). It doesn't need electricity.

 

If emergency accumulator has no more pressure, and the engine isn't running, then you may re-built pressure through the electrical pump (switch on the right side, needs CC from battery or TR). And if you want to check for pressure (hyd jauges), then again you need electricity.

[Redglyph]

I'm saying this is how it works now in DCS. I'm not saying this is how it should work. ;)

 

 

Same answer as above :)

Oh. OK :)

 

Regarding how it should work (based on RL aircraft):

Parking brake works with hyd pressure from the emergency accumulator (fed by hyd system 2). It doesn't need electricity.

 

If emergency accumulator has no more pressure, and the engine isn't running, then you may re-built pressure through the electrical pump (switch on the right side, needs CC from battery or TR). And if you want to check for pressure (hyd jauges), then again you need electricity.

That's pretty much what I thought, but first I assumed the parking brake was engaged when the aircraft ... is parked, so before starting it up, or that there would be enough static pression to use it, which might not necessarily be the case. After all, that's what chocks are for.

 

Anyway, what I meant is, isn't the TRN powered up by the AC, either of ALT 1 or ALT 2 turbines? Or it could be powered up by ground power, but I took care to ask the chief to switch it off ;) So that's something that's probably not correct, and from what you say, "how it works now in DCS", I understand you see it like that too.

 

To be complete, I tried method 2 with TRN alone and ground power OFF, that worked (no lurches, behaves as method 3). I also tried method 2 with emergency hydraulic pump on from the start, it didn't change anything (nor should it) and the plane moved forward, crushing the leg of one of the ground staff unfortunately.

 

In fact, it looks a little bit as if the parking brake needed AC and were on circuit 1, that would be consistent with the warning lights.

 

Let's wait for those bits to be worked out by the dev team then :)

[Toertchen]

The emergency hydraulic pump? No, I don't think it's necessary for the parking brake in normal conditions. This pump only takes over when the pression in circuit 2 drops below 160 bars.

 

Thats what i found:

http://forums.eagle.ru/showthread.php?p=2629803

[Redglyph]

Thats what i found:

http://forums.eagle.ru/showthread.php?p=2629803

 

Very interesting! From another Dassault manual? Is there any chance I could download it somewhere?

[Toertchen]

Very interesting! From another Dassault manual? Is there any chance I could download it somewhere?

 

It is from BEAD-air about an accident with a Mirage 2000 D.

I don't think they changed anything on the parking brake system between C and D.

 

https://www.google.de/url?q=http://www.defense.gouv.fr/content/download/105609/1032382/file/Rapport%2520public%2520BEAD-air-A-2008-006-A.pdf&sa=U&ved=0ahUKEwiQtOPH65_KAhXBpA4KHa8_BngQFggNMAE&usg=AFQjCNEY635SVHoI7nIi_rMyHxZYAOp1OA

[Redglyph]

Thanks! Didn't know those were public, there are some interesting technical details.

 

Ah, who hasn't forgotten to release the handbrake at least once in their life ;)