Carenado CJ2 Few problems

[eelb 5]

Hello folks,

 

i have a problem with the performance of my CJ2 any idea what the problem is? The IAS is to low i thing for this performance of ~67% N1

 

 

My guess is you're using the N1 charts incorrectly. Anything above about 15,000 ft, allows 102.4 N1. It's OAT and altitude related. So you have to refer to OAT at the corresponding altitude to set N1. The easiest way is to climb at 3,000 fpm and adjust power to maintain 230 KIAS, until the power is maxed out, then adjust VS to maintain Mach .55. FSX and all the add-on weather programs don't model OAT above 35,000 ft. correctly in my opinion. So the performance charts are useless above that altitude. This is reflected in the OAT and ISA reading on the lower part of the CJ2's MFD, where you'll usually see ISA values around +25C. The + and - ISA values should normally be around 5C above or below ISA, at the higher altitudes. ISA doesn't lapse above 35,000ft. and is -57C.  

[starcaptain82 1]

So new test-flight with the same settings from the original Cessna Citation CJ2

 

The FL450 at 98,5% N1 is unable with this addon.

 

My Flightdeck - check the N1 Power and the IAS

 

Original CJ2 Settings

 

 

Thx

Mike

[eelb 5]

So new test-flight with the same settings from the original Cessna Citation CJ2

 

The FL450 at 98,5% N1 is unable with this addon.

 

My Flightdeck - check the N1 Power and the IAS

 

Original CJ2 Settings

 

 

Thx

Mike

The last pic is of a CJ2+. The CJ2+ has different engines than the CJ2, and the N1 settings are different. The CJ2+ also has FADEC. There are detents on the thrust levers for TO, CLB, and CRU. The pilot simply places the levers in the detent for the appropriate phase of flight. There is no manual adjustment for N1, unless the FADEC fails, or the pilot chooses to do so for situations where CRU would cause the airplane to exceed Vmo/Mmo.

 

If you look at the N1 tape in the pic, you will see a cyan box, with the letters CRU next to it. This is evidence that this is a CJ2+ and not a straight CJ2. The CJ2 does not have FADEC.

 

While the appearance and performance of the 2 and 2+ are not all that different, the engines and their operation are. Especially as it relates to N1.

 

If you want to meet performance figures at the higher flight levels for the Carenado model, you will have to run at full power, and quit using CJ2+ info.

[starcaptain82 1]

i fly only with full power, that's the unreal thing, in every flight altitude above FL150

[eelb 5]

i fly only with full power, that's the unreal thing, in every flight altitude above FL150

At full power at lower altitudes you'll exceed Vmo/Mmo for the aircraft. Which is 275kts indicated or Mach .72. It's usually in the low 30 thousands, where max power no longer exceeds max allowed speed. Anything below that altitude, you will have to reduce power in cruise. This will vary according to weight and OAT. Of course in FSX, you can go as fast as you want to, if you don't mind the overspeed warning.

[ryanbatc 12,836]

i fly only with full power, that's the unreal thing, in every flight altitude above FL150

 

Check your weight....  everyone just takes their new planes out for a spin and never looks at the weight.  Typical default loads are overweight.

[eelb 5]

On 7/31/2016 at 11:10 PM, ryanbatcund said:

 

Check your weight....  everyone just takes their new planes out for a spin and never looks at the weight.  Typical default loads are overweight.

 In his first pic, he's showing 2700 lbs. of fuel and FL450. So with an empty weight of 7600 lbs., that would put him at 10,300 lbs. MGTOW is 12,375 lbs. Assuming an 800 lb. burn he would have to have over 1,200 lbs in payload. Unless Carenado put a half dozen 300 pounders in the seats as a joke, I don't see this as a weight issue. Regardless, this isn't the case, because other than fuel load, I never touch any of the other numbers. The default load is two 190 lb. pilots and 50 lbs. of baggage.

The other issue is he's making it to FL450, which he couldn't do if the airplane was that much overweight.

This is a simple issue of not knowing how to manage a climb. He's climbing at some extreme ROC, and not reducing it with altitude. By the time he reaches FL450, he's down to 123 KIAS. At that point, the angle of attack is such, that he can't gain any speed in cruise.

Passing FL250, maintain Mach .55 by adjusting VS. Leveling off at FL450, the airplane will accelerate to about 390 KTAS. Assuming  MGTOW, with max fuel. The weight at TOC @ FL450, should be around 11,500 lbs., 875 lbs. below MGTOW.   

Edited May 21, 2017 by eelb

[Denis_C 0]

Hi everybody

The plane is nice, I love using it, although still some bugs or pbs ...
- In FMS nav mode, the glide slope indicator NEVER appears during ILS approach (only the glide path appears!), I always have to switch to VOR mode to see it; Am I doing something wrong? Do you have the same problem?

- Is it possible to change the default cruise altitude: for me 28000 ft is always automatically entered!!

Denis