Flight Envelope Data Tested

[FLIGHTO 8]

I did a short fight to check the climb and cruise performance compared to the book charts and found some issues. The book that comes with this A/C is lacking. We need a real POH.......

 

MY FLIGHT:

FL350 / -47C = ISA +8

99% Thrust / 101.9 N1 (Full power)

Fuel Flow: 823 Lbs/Hr.

KTAS: 392

M: 067

-------------------------------------------

BOOK DATA:

FL350 @ ISA

(Unknown % Thrust) / Assuming 102.5ish N1 (Full power)

Fuel Flow: 1083 Lbs/Hr.

KTAS: 407

 

1) The problems are, The max thrust is 99% which is around 101.5 N1. I cannot achieve above this despite the book stating maximum thrust under certain conditions should be around 102.5 N1. This needs to be fixed.

 

2) Although the KTAS of 392 I saw is most likely spot on being I was at ISA+8 the fuel flow is too low.

 

3) There is a major drop off in power if I reduce power even a small amount at cruise. Going from (max thrust) 99% to 98% which is 100.6 N1 the aircraft slows to 331KTAS / M.56 with a fuel flow of 554 Lbs/Hr. This seems like a huge drop for less than 1% thrust reduction. Something seems wrong here. This is a 61 knot difference??????? #####?

 

-------------------------------------------

Is this aircraft supposed to be flowed at max throttle all the time????  How do we fix the throttle to get 100% thrust?

 

Can anyone here verify what I am seeing - I would like to confirm this b4 I submit a ticket to Carenado. Perhaps some of you RW CJ drivers can chime in?

 

[scottb613 1,186]

Check your throttle calibration - I see 102.4% N1as WOT - which had me around 403 Knots TAS at FL360 somewhere in the neighborhood of 1000 Lbs/Hr...

 

Concur - even a slight reduction of throttle is like throwing out a boat anchor - reported same to Carenado via ticket...

 

Regards,

Scott

[vonmar 121]

I did a short fight to check the climb and cruise performance compared to the book charts and found some issues. The book that comes with this A/C is lacking. We need a real POH.......

 

MY FLIGHT:

FL350 / -47C = ISA +8

99% Thrust / 101.9 N1 (Full power)

Fuel Flow: 823 Lbs/Hr.

KTAS: 392

M: 067

-------------------------------------------

BOOK DATA:

FL350 @ ISA

(Unknown % Thrust) / Assuming 102.5ish N1 (Full power)

Fuel Flow: 1083 Lbs/Hr.

KTAS: 407

 

1) The problems are, The max thrust is 99% which is around 101.5 N1. I cannot achieve above this despite the book stating maximum thrust under certain conditions should be around 102.5 N1. This needs to be fixed.

 

2) Although the KTAS of 392 I saw is most likely spot on being I was at ISA+8 the fuel flow is too low.

 

3) There is a major drop off in power if I reduce power even a small amount at cruise. Going from (max thrust) 99% to 98% which is 100.6 N1 the aircraft slows to 331KTAS / M.56 with a fuel flow of 554 Lbs/Hr. This seems like a huge drop for less than 1% thrust reduction. Something seems wrong here. This is a 61 knot difference??????? #####?

 

-------------------------------------------

Is this aircraft supposed to be flowed at max throttle all the time????  How do we fix the throttle to get 100% thrust?

 

Can anyone here verify what I am seeing - I would like to confirm this b4 I submit a ticket to Carenado. Perhaps some of you RW CJ drivers can chime in?

 

Are your posted results for climb and cruise or just one of them?

 

Which Carenado performance charts (chart titles) were you using?

[FLIGHTO 8]

Are your posted results for climb and cruise or just one of them?

 

Which Carenado performance charts (chart titles) were you using?

 

The results are for cruise @ FL350.

 

Using the High Speed Cruise Chart. My time to climb to FL350 was around 21 minutes as where the book states should be 15 at max thrust. This maybe a because I cannot get more than 101.5 N1/99% thrust?

 

How do I check the throttle cal? I am using a Microsoft joystick...

[Gregg_Seipp 565]

I spent hours reviewing Mustang youtube vids for power/airspeed values when I was working on a thrust mod for it.  Might be worthwhile for someone to look to see if there are similar vids for the CJ1. 

[vonmar 121]

"MY FLIGHT:

FL350 / -47C = ISA +8

99% Thrust / 101.9 N1 (Full power)

Fuel Flow: 823 Lbs/Hr.

KTAS: 392

M: 067"

"Using the High Speed Cruise Chart."

 

 

A quick look at that chart : That is almost exactly what the chart is for 41,000 feet...?
 

[scottb613 1,186]

Hi...

 

In P3D - I think it's recommended to use the built in "Joystick Calibration" functions...

 

In FSX - I think you can use the built in "Joystick Calibration" or FSUIPC if you have the paid version...

 

Should be under the settings for your controls - I believe...

 

Note: I'm no expert on high altitude jet flights - I'm sure I was seeing 102.4% N1 with a wide open throttle though - does this performance change with weather ???

 

Regards,
Scott

[raymar 969]

I did a short fight to check the climb and cruise performance compared to the book charts and found some issues. The book that comes with this A/C is lacking. We need a real POH.......

 

MY FLIGHT:

FL350 / -47C = ISA +8

99% Thrust / 101.9 N1 (Full power)

Fuel Flow: 823 Lbs/Hr.

KTAS: 392

M: 067

-------------------------------------------

BOOK DATA:

FL350 @ ISA

(Unknown % Thrust) / Assuming 102.5ish N1 (Full power)

Fuel Flow: 1083 Lbs/Hr.

KTAS: 407

 

1) The problems are, The max thrust is 99% which is around 101.5 N1. I cannot achieve above this despite the book stating maximum thrust under certain conditions should be around 102.5 N1. This needs to be fixed.

 

2) Although the KTAS of 392 I saw is most likely spot on being I was at ISA+8 the fuel flow is too low.

 

3) There is a major drop off in power if I reduce power even a small amount at cruise. Going from (max thrust) 99% to 98% which is 100.6 N1 the aircraft slows to 331KTAS / M.56 with a fuel flow of 554 Lbs/Hr. This seems like a huge drop for less than 1% thrust reduction. Something seems wrong here. This is a 61 knot difference??????? #####?

 

-------------------------------------------

Is this aircraft supposed to be flowed at max throttle all the time????  How do we fix the throttle to get 100% thrust?

 

Can anyone here verify what I am seeing - I would like to confirm this b4 I submit a ticket to Carenado. Perhaps some of you RW CJ drivers can chime in?

\

Regards,

 

Ray

 

CJ2 book

[FLIGHTO 8]

I just submitted a ticket to Carenado..... Their a/c are usually closer to book performance than this....

 

In the RW CJ - it full power climb and cruise used most of the time? If this is the case, once T/O power is set we would not have to touch the throttle until decent. Could this be correct?

[raymar 969]

I just submitted a ticket to Carenado..... Their a/c are usually closer to book performance than this....

 

In the RW CJ - it full power climb and cruise used most of the time? If this is the case, once T/O power is set we would not have to touch the throttle until decent. Could this be correct?

High speed cruise at altitude takes full power. Full Continuous Thrust is not limited for these engines. I posted this somewhere in this forum.

 

Ray

[xtended 1]

So what about great loss of power from very slight throttles decrease at higher (102% to 98% N1) rates? Is this similar to real CJ2?

[raymar 969]

So what about great loss of power from very slight throttles decrease at higher (102% to 98% N1) rates? Is this similar to real CJ2?

No, not at all. Linear thrust in the real one. Well, not linear as in a straight line.  How about this.

 

Regards,

 

Ray

[scottb613 1,186]

Hi Folks,

 

Is the throttle performance any better with 1.1 ??? I forgot to check...

 

Regards,
Scott

[raymar 969]

Yes they are, much better. Make a test flight and see what you think?  Looks like a big improvement.

 

At present, I don't think any of the performance numbers are real close to book.  Not that everything will be fixed, but, my tests of the new air file pretty much confirms that the air anchor speed drop has been cured and the TAS and FF are very close.

 

The FLT INFO box that Janek gave us is perfect for checking the performance against the charts.

 

I chose to work with the FL370 numbers and do some detailed checks at ISA (-56 C).  The Fuel Flow (902 lb/hr) is a bit lower (10%)  than expected but the TAS (411 kts) is almost right on the money.  This is at mid weight (GW 10.5).  n1 99.7  n2 98.0

 

We may have to end up making our own charts for flight simming.

 

Regards,

 

Ray