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DEVS: Is the BLC system modeled


ff4life4
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Is the Boundary Layer Control system modeled on the DCS Mig-21.

 

The only mention in the manual of it is in the general design of the Mig 21. This system is not mentioned in the landing system. It could have a huge impact on aircraft handling if its properly simulated.

 

 

If it is modeled, where are the ports exactly. And is there any specific controls for the system.

 

Thanks Devs

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Throttle idle?

 

Generally: http://en.wikipedia.org/wiki/Blown_flap

 

No my throttle was at 55% (on the control indicator)

 

I have attempted a landing with the BLC switch in the down position (default is up) and the plane seemed to behave more liked I expect and the landing worked. Can someone clarify what happens when the switch is up or down and how that affects the plane descending?


Edited by stray cat
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BLC system increases lift by promoting laminar flow over the wing/lifting devices. The result is that it reduces the AoA experienced by the wing, and increases lift (you can see this effect on the AoA indicator - it reduces by approximately 2 degrees in the case of the MiG-21 when the system is operating).

 

A stall is because the air flow is disturbed, and separates from the surfaces. This flow seperation is turbulent, and adds drag as well.

 

Best regards,

Tango.

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Stray cat: Landing in the Fishbed at 55% throttle is an excellent way to conserve fuel for the ministry of state defense - not only does your litre count go down for this approach, but you won't spend any fuel on the next trip after crashing the aircraft! :)

 

I rarely move under 75% throttle for an approach. The Fishbed won't punish you for reaching threshold at 350-60-70 kmh, so stay fast and stay safe. =)

 

At the rest: Should this switch be manually toggled if flaps can not be lowered or during windmilling approach (p.164 in manual)?


Edited by scaflight
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If the switch is up, does that mean the system is on or off? The tooltip is confusing. Also what other things need to be set for the system to work?

 

 

Manual says:

7. Maximum permissible airspeed for going around with BLC system

operating is 360 km/h.

 

Aircraft would sink by

25 - 30 m due to

automatic

disconnection of BLC


Edited by stray cat
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This contradicts what? BLC is only active with flaps fully extended. If you go faster than 380 km/h, the flaps would be pushed up by aerodynamic forces which causes the BLC to turn off. To prevent that and the associated altitude loss, you must restrict speed on go around to 360 km/h.

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75-80% is about right for approach in the MiG-21.

 

While looking around the cockpit I saw that the throttle has 4 labels pertaining to the approximate throttle position. In the English Cockpit version the second to last setting says "LND" in English (not sure what it says in Cyrillic Lettering) and the approximate throttle position is around 80%

 

Bottom line like the previous poster said before, 360-380 Kmh on final is OK, the Chute will stop you (unless you cut the chute early) in plenty of runway. The key is a proper flare attitude and wings level with minimal sink rate.

 

Cheers

[sIGPIC][/sIGPIC]

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75-80% is about right for approach in the MiG-21.

 

While looking around the cockpit I saw that the throttle has 4 labels pertaining to the approximate throttle position. In the English Cockpit version the second to last setting says "LND" in English (not sure what it says in Cyrillic Lettering) and the approximate throttle position is around 80%

 

Bottom line like the previous poster said before, 360-380 Kmh on final is OK, the Chute will stop you (unless you cut the chute early) in plenty of runway. The key is a proper flare attitude and wings level with minimal sink rate.

 

Cheers

 

In Russian cockpit that "LND" label is labeled as "СПС" - "SPS". It is strange how there is SPS switch but on throttle it's labeled as "LND".

 

5773188806_30bfb9e60a_z.jpg

 

Real world manual actually mentions when landing not to go beyond BLC stop. That is if you plan to land with BLC system active and not end up as a big fireball on the runway. :)


Edited by ObvilionLost

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In Russian cockpit that "LND" label is labeled as "СПС" - "SPS". It is strange how there is SPS switch but on throttle it's labeled as "LND".

 

5773188806_30bfb9e60a_z.jpg

 

Real world manual actually mentions when landing not to go beyond BLC stop. That is if you plan to land with BLC system active and not end up as a big fireball on the runway. :)

 

Try flipping that SPS switch while going 350 kph will full flaps.

You'll notice the difference... :)

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