FSX-MS To Realair Simulations

[tttocs 301]

 

 

at what altitude can you exceed 200KIAS?

 

None.

 

Remember, Indicated Air Speed ≠ True Air Speed ≠ Ground Speed.  You can bump up to around 300 KTAS at altitude.

 

I don't usually respond with "you need to read the manual", but in this case it's appropriate.  The manual does a great, yet simple, job of explaining how to manage the turbine engines (very different from managing a piston engine, despite the superficial similarity in the controls) in different flight segments and gives a good overview of how to fly the Duke.  It's an excellent getting started guide.  Not that long either.

 

Scott

[ryanbatc 12,813]

Vmo (max operating speed) is actually 198 KIAS on this acft,  You should never exceed it.

[mikebxb 20]

thanks all... i was wrong thinking this duke would cruise at 230-250 KIAS

This IS a great plane but considering "real world" similarities, my MILVIZ 310 will cruise right alongside it up to16000' AND burn less fuel.

[PDX Flyer 111]

REALAIR absolutely ROCKS!!!! I own the Dukes, Legacy and Decathelon. They are all my favorites. Am anticipating their C172 some day.

[Dragonmount 5]

I have both the dukes, the fsx spit, and the legacy. I love them all.

[tttocs 301]

my MILVIZ 310 will cruise right alongside it up to16000' AND burn less fuel.

How? The 310R's listed max recommended cruise (75% at 7500') is 195 Kts true. Again, I think you're mixing true and indicated airspeeds - two different things.

 

With a turbine conversion like this, you climb as fast as you can to an optimum altitude for the best combination of speed and fuel burn and with the Duke's power you can climb to the fight levels in a big hurry - just watch torque and temps. What that optimum altitude is depends on conditions, but done right you'll approach 300 kts true. Of course most will sacrifice a bit of speed for a bit better fuel burn IRL, but the numbers are there.

 

You fly a turbine differently. Quite honestly, the biggest real world impact the relatively low Vmo has on you in the Duke is when it comes time to descend. You do need to watch things carefully.

 

Scott

[mikebxb 20]

Scott,

Interesting. You have me double checking my figures. 

I use the shift+Z  for my airspeed comparisons between A?C. (always set at KIAS)  my 310R is turbo'd but you right, I can usually lope along at approx 2200/2200 MAP/RPM just above 170 kias.

So given the Duke its due theres a 20+ kias disparity.

At this time , I'm unfamilier with turbines and it appears to be white knuckled flying for that extra speed.

The Duke realair is a great ac and climbs like a sonofagun and i dont regret purchasing.

However, if what i'm learning so far is true, I see why they had a short run and spent more time in repair than the air. given the price difference in the real world the king air is a better step up..

[ryanbatc 12,813]

Yeah that's 28 kts indicated. Makes a large difference at FL200. (20,000ft). True air speed would be much greater in the T Duke than the 310 (probably about 70 + kts difference at FL200). Pull up your GPS and FL200 in the T Duke and in the 310 and it will show your ground speed. True airspeed + wind component = ground speed.

Not only that, the T Duke will rocket in a climb at around +4000 fpm. 310 won't come close to that.

True the 310 burns less fuel (it is a piston acft, T duke is a turbine engine)

Turbines aren't necessarily much faster than light singles or twins at lower alts, but they are usually meant to carry more people into the lower FL's at moderate speeds (it's all about TRUE AIR SPEED).. also a turboprop's engine is more reliable than a smaller recip piston. Most turbines are slower at low altitudes, where a piston would do very well. Take for example, the Malibu "jet prop." Retrofitted with a turbine engine the thing can do around 160-170 indicated at fL200. Translates to 230-240 ish True. At 4,000 ft the conversion is a lot less, so KTAS (knots true air speed) would only be around 165-178.

The Lancair Legacy piston acft, non turbocharged can do 235-240 KTAS at 8000. Said jet prop above would maybe fly 195 KTAS at 8000. Above 10,000 the Legacy's performance starts to really fall off because of the altitude. Above 10,000 the turbine jetprop starts to fly faster through the air because the air is less dense and the engine manages fuel to air ratio differently than a piston. The piston starts to choke because of the less dense air at altitude. Your turbocharged 310 (not turbine though!) compresses the less dense air therefore allowing the engine to think it's getting the same air at sea level and 10,000 ft (really basic explanation sorry for the pro's out there lol)

oh p.s. - by writing turbine I mean a turboprop engine... different than a turbojet or turbofan.

[tttocs 301]

 

 

The Duke realair is a great ac and climbs like a sonofagun and i dont regret purchasing.

 

It's the "climbs like a sonofagun" that you'll learn to use to your advantage.  Well, that and the fact that it can get into and out of strips as short as 1000'. :-)

 

Don't be hung up on that Vmo number.  Use the power that you have to get high, fast, where the plane can then stretch its legs with high true airspeed numbers up in the flight levels.  From sea level you can climb like a rocket (around 4000'/min) and you can maintain pretty impressive climb rates all the way to the mid 2xx flight levels where you'll typically want to be.  Somewhere back behind and below you, your 310 will still be clawing its way to cruising altitude.  Once you learn to stay ahead of the plane, I think you'll find it fast and a joy to fly.

 

As for the KA, depends on which model and what the role is.  A smaller KA can go faster down low so would be a better choice for short hops, but as an individual owner/pilot, I'd take the Turbine Duke with its short field ability, simplicity and speed at altitude.  As for reliability, keep in mind that the Dukes that spent a lot of time in the shops were the original piston Dukes, in large part due to the geared engines which had a very low TBO to start with and rarely made even that.  The Turbine Duke is a whole 'nother animal and the PT6 engines are among the most reliable engines you can find.

 

Not trying to dis the 310, BTW.  I'm a piston guy at heart (and RW experience) as well.

 

Scott

[mikebxb 20]

I'm getting a good education here. A sincere thanks to all for your input..

While I consider my two home airfields KOWB and KPWG. For giggles I often do the KLAS- KLAX flights. As we all know you have to clear those 10k mountains. The normally aspirated baron took forever to drag itself up & over them.

After turbocharging my beloved 310 its a sweet trip either way..

So, I guess most of my air time is considered low level, 18K and under. I tried the King Air for speed but the bumblebee pitched bzzzz of the engine whine is an aural assault. 

[mikebxb 20]

I'm researching this KIAS vs TAS vs GS stuff & a bit confused.

I changed FSX to default to read TRUE AIR SPEED yet it still reads (across the top in red KIAS)
as you can see the ASI in plane =160(kias) while the gps reads 153 Ground Speed

[mikebxb 20]

To clarify the above post.. I DO realize these numbers arent going to be the same. I'm curious why the shift Z red readout still says KIAS not KAS or TAS. Maybe i'll reboot , reload & it'll self correct.

[ryanbatc 12,813]

It's hard to see your pic... but I think it says you're at 4500 ft. At that altitude TAS and IAS are very similar. You need to go higher, say 10,000 then compare IAS to TAS. Remember ground speed (the one on the GPS) is simply TAS + wind correction. If you're at 160 TAS and you've got a direct 10 kt headwind, your ground speed will be 150.

 

TAS is Calibrated Air Speed (CAS), corrected for non-standard temperature and pressure. (CAS is basically IAS corrected for instrument and position errors - I don't really concern myself with CAS in flight sim).

[mikebxb 20]

Thnx Ryan,

I understand

You are right - b33- FL4500 w/ a headwind KRIC - KEWN

was gonna try same flight in B33, 310, Mooney and TDuke. & mark the differences. But I' need to repeat at 10K for better variances.

Still wondering why FSX still reads KIAS after setting it to TRUE AS..

 

 

 

 

 

-Mike

[tttocs 301]

True airspeed is your indicated airspeed corrected for temperature and pressure (actually, there's calibration as well, but let's leave that aside because we're going to ballpark here). As a rough approximation - and to explain why it's recommended to fly the Duke the way I have - consider that the correction factor is about 2% per 1000'.

 

At or near sea level on a "standard" day, IAS approximates TAS. At 4500' (it's really density altitude that matters, not MSL, but again we're approximating here to illustrate) there still isn't much difference between IAS and TAS, but using this approximation and rounding for simplicity, you can see that the ~200Kt limitation on the Duke translates to ~280 Kts at FL200 (20,000'), and ~300 Kts at FL250 - a 100 Kt difference.

 

The Duke and its turboprop engines can easily maintain that same 200 Kts IAS at FL250, but suddenly it's 100 Kts more "real" speed.

 

Remember, I'm rounding and approximating. You still don't want to exceed Vmo so you have to leave some fudge factor for speed changes and turbulence, and you REALLY have to watch speeds in descent but you get the idea.

 

Scott