Yakovlev Yak-3 (VK-107A)

[Naughty_17 69]

[Ottobon 19,137]

Quick question:  Is this aircraft supposed to be modeled with all-metal construction of production models, or Mixed Wooden construction of Prototype?

 

The Max Speed of 720kph limit might indicate all metal construction, but the 2980kg weight seems closer to that of the prototype model with mixed wooden construction.  Any idea which one its supposed to be?

 

Thanks eitherway! interesting to see how Gaijin chose to model it so far, and will be interesting to see how useable (given overheating) Take-off power is as i wasn't expecting that. 

Edited June 26, 2015 by Ottobon

[blakeob 8,078]

It's a shame it's a prem plane. The performance looks 6.0 worthy

[Naughty_17 69]

Quick question:  Is this aircraft supposed to be modeled with all-metal construction of production models, or Mixed Wooden construction of Prototype?

Thanks eitherway! interesting to see how Gaijin chose to model it so far, and will be interesting to see how useable (given possible overheating) Take-off power is as i wasn't expecting that. 

All-metal

[abacs21 15,681]

Will the correct flight model with 715 kph top speed be ready for the live update? Because on the dev server, it was a copypaste of the regular Yak-3

Edited June 26, 2015 by abacs21

[sneedcat 1,462]

Will the correct flight model with 715 kph top speed be ready for the live update? Because on the dev server, it was a copypaste of the regular Yak-3

probably will be fixed like the P-47M-1

[PainGod85 8,050]

Wait, so its maximum dive speed is 720 kph, am I reading this right?

Edited June 30, 2015 by PainGod85

[Naughty_17 69]

Will the correct flight model with 715 kph top speed be ready for the live update? Because on the dev server, it was a copypaste of the regular Yak-3

 

It's better be ;)

 

Wait, so its maximum dive spoeed is 720 kph, am I reading this right?

 

720 IAS + ~40 at your own risk.

[Puse 16]

Why is this premium? It was serial produced and there are other Yak-3s you guys could've put as a premium. But I guess you (Naughty_17) are not a game designer...

[Naughty_17 69]

Why is this premium? It was serial produced and there are other Yak-3s you guys could've put as a premium. But I guess you (Naughty_17) are not a game designer...

Nope, I'm not :(

[Max__Damage 615]

Nice plane, awesome looks as well.

 

Also, 19 sec turn is with a full fuel load. Its around 17-18 for reduced fuel load perhaps.

 

In all honesty tho this looks very similar to the yak9u save for the huge climb rate boost.

 

Well effectively it is yak9u minus 220 kg weight.

 

Best of yak9 and yak 3. What about its BR?

Edited June 30, 2015 by Max__Damage

[C0lander 772]

Just a 2 quick questions...

1) Apparently, 3200 RPM was available only for prototypes, but not serial aircraft (max 3000 RPM), so why put it into the game?

2) If the stall speed with extended flaps is 145 km/h (I'm assuming IAS here), how come the 'landing' speed (I suppose, you're talking about approach speed) is only 120-140 km/h?

[Nabutso 13,131]

Just a 2 quick questions...

1) Apparently, 3200 RPM was available only for prototypes, but not serial aircraft (max 3000 RPM), so why put it into the game?

2) If the stall speed with extended flaps is 145 km/h (I'm assuming IAS here), how come the 'landing' speed (I suppose, you're talking about approach speed) is only 120-140 km/h?

All that your first source says is that it was "impossible" to use the 3200 rpm mode. Why? Heat? Mechanical issues?

 

Heat is already a factor in the game, and if you read more about the VK-107, that's exactly the problem you always find. I can't play WT right now, how quickly does it overheat?

 

I specifically remember one instance of a pilot explaining how, although they liked the newer Yak-9Us with VK-107s, they had to land after about an hour because there was just no way they could keep the engine cool enough any longer.

 

For your 2nd point; consider that the stall speed is always given at full fuel, while the landing speed is typically not at full fuel. This is why there is a little asterisk that denotes that both depend on the aircraft's weight.

 

Landing speed is the lowest speed at which you can maintain a 3 point landing. Due to ground effect, you'd expect a slightly lower landing speed than it's full flap stall speed. 140 km/h vs 145 km/h makes sense, and 120 km/h makes sense at low fuel levels, with ground effect, and a beneficial CG shift.

 

 

Aircraft with huge tail surfaces or other extra lifting surfaces tend to be a bit over 2.1~ CL max with full flaps. A Yak-3 with a CL max just under 2.0 seems sufficiently OK within the realm of reality.

 

For stall without flaps: 

 

 

A value which may be slightly too low, if at all. If you have any data for the Yak-3's CL max, that would help. But no one has that data.

Edited July 1, 2015 by Nabutso

[C0lander 772]

All that your first source says is that it was "impossible" to use the 3200 rpm mode. Why? Heat? Mechanical issues?

Didn't say it's impossible, but asked why since it 'appears' serial planes didn't have/use that.

If you have hard data confirming contrary, all well and fine.

 

A value which may be slightly too low, if at all. If you have any data for the Yak-3's CL max, that would help. But no one has that data.

 

No, I don't have calculated data, but was wondering since approach speed is usually given as a stall speed with addition of 1.15 times safety margin.

Yak-3 uses a Clark foil, so it's a pretty straight road from there...I think, it's something like 1.4x or so CLmax...can't remember exactly.

Edited July 1, 2015 by Colander_

[Nabutso 13,131]

Didn't say it's impossible, but asked why since it 'appears' serial planes didn't have/use that.

If you have hard data confirming contrary, all well and fine.

 

No, I don't have data, but was wondering since approach speed is usually given as a stall speed with addition of 1.15 times safety margin.

Yak-3 uses a Clark foil, so it's a pretty straight road from there...I think, it's something like 1.4, or 1.48 CLmax, or so...can't remember exactly.

On the first point, I think it was more of a personal restriction rather than something built in to prevent something of being used (like ASH-82FN 2nd gear + WEP limiter).

 

Right, it's just that the ones given on these datasheets I would assume are the ones I tested previously as an RP, where the landing speed was the min speed for a 3 point landing.

 

The airfoil is part of it. But so is the lifting capability of the rest of the aircraft. For example, Typhoons and Tempests have a lot of lift just from their body and their tail. They have lower stall speeds that one would expect from their airfoil + weight + wing area. Like I said about the clean stall, it might be too low. But we have to assume that the FM dev who made the FM knows more than we do, unless we can show otherwise.

Edited July 1, 2015 by Nabutso

[C0lander 772]

On the first point, I think it was more of a personal restriction rather than something built in to prevent something of being used (like ASH-82FN 2nd gear + WEP limiter).

In any case you don't appear to be sure, so doesn't this warrant the same diligence in getting to the bottom of the matter as in eg. radial 190, where extensive search showed beyond doubt that D-2 didn't actually use boost in spite of it being technically available up until version A-8, or so?

 

Right, it's just that the ones given on these datasheets I would assume are the ones I tested previously as an RP, where the landing speed was the min speed for a 3 point landing.

It's fine...I didn't know how you measure 'stall' and 'landing' speeds.

 

The airfoil is part of it. But so is the lifting capability of the rest of the aircraft.

Yea, but at large alphas, usually when the wing is already stalled.

 

But anyway, what tools do the devs use to develop FMs?

Do they use CATIA, as in testing 3D models in virutal windtunnel, or something else?

Edited July 1, 2015 by Colander_

[Ottobon 19,137]

Nabutso you give good information and theoretical ideas but the answer to this guys question was way simpler  :lol:

 

2) If the stall speed with extended flaps is 145 km/h (I'm assuming IAS here), how come the 'landing' speed (I suppose, you're talking about approach speed) is only 120-140 km/h?

 

Stall speed is found at a constant altitude, in a descending glide aircraft can land at speeds below their stall speed for the simple reason they are descending

 

A good and very cool example comes from when Eric Brown landed a dehavilland Mosquito on a carrier, he could land at no more then 86mph(137kph) in a aircraft that had a stalling speed of 110mph(176kph)!!!

 

If you have a minute of time you can watch him do it yourself.

 

 

Basically its not completely abnormal that landing speed is lower then stall speed, as stall speed is at a constant altitude with about 1G pull, and landing is in a controlled descent. 

Edited July 8, 2015 by Ottobon

[Ruthless95 1,047]

just test flew it comparing to yak-9ut and ow boy they are almost the same VK107 might go like 10-15 km faster and that's about it

9ut has 23, 37 and 45mm cannon options too if you need to boost your research just talisman the 9UT IMO or if you really want it wait for a 50% discount

Edited October 4, 2015 by Ruthless95

[Max__Damage 615]

Can anyone do the promised 715 kmh at 6 km horizontal, without diving? 

 

I cant seem to acheive it since the patch, only goes ~709 kmh.

Edited March 15, 2016 by Max__Damage

[SubRyan 5,546]

Data sheet updated