Sign in to follow this  
ryanbatcund

Power setting for climb?

Recommended Posts

What should I use?  I usually do about 250 kias in the climb but this is with the power lever all the way forward.  Is this ok?

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

I would think 250 KIAS is too fast.

 

I think 160 to 180 is a good climb speed.

 

Problem though is that I think Carenado's climb fix works better at higher speeds and Mach numbers so it makes you want to keep speed too high.

Share this post


Link to post
Share on other sites

I think 160 to 180 is a good climb speed.

 

 

160 to 180 is entirely too slow.

 

I've never actually flown the 850 in real life, but with things like this it's pretty standard across the board.

 

In the Lear we climb at 250. The idea in a jet is to get up high as fast as you can, where you burn less fuel. But at the same time, do it while covering enough ground that the climb is still efficient. 250 is generally a good number because you conform to the speed restriction below 10,000 feet, and still maintain good climb rates above 10,000. Meaning you don't have to reconfigure the autopilot when you cross 10,000.

 

When you have to step climb, you climb even faster. A step climb from, say, FL320 to FL410 will be done at only 20 or 30 knots below Vmo. You'll only be getting 500-1000fpm, but it keeps the climb efficient.

Share this post


Link to post
Share on other sites

160 to 180 is entirely too slow.

 

I've never actually flown the 850 in real life, but with things like this it's pretty standard across the board.

 

In the Lear we climb at 250. The idea in a jet is to get up high as fast as you can, where you burn less fuel. But at the same time, do it while covering enough ground that the climb is still efficient. 250 is generally a good number because you conform to the speed restriction below 10,000 feet, and still maintain good climb rates above 10,000. Meaning you don't have to reconfigure the autopilot when you cross 10,000.

 

When you have to step climb, you climb even faster. A step climb from, say, FL320 to FL410 will be done at only 20 or 30 knots below Vmo. You'll only be getting 500-1000fpm, but it keeps the climb efficient.

Ah sorry i must have gotten my cruise climb and initial climb numbers mixed up.

 

Reading on the web I see suggestions of 250 knots up to Mach 0.7 for cruise climb speed.

Share this post


Link to post
Share on other sites

But at what power setting? Is there an N1 I'm supposed to be at?

Share this post


Link to post
Share on other sites

Ryan, the recommended climb chart calls for 250 Kts/0.70 Mach. Unfortunately, Carenado did not include any charts for 2-engine climb power.

 

I use full power/thrust for my climbs. If we do find the power/thrust climb table, I suspect it will be almost full power all the way up. Just keep an eye on your Temps and reduce power if needed, but do not reduce airspeed. The jet engines needs plenty of ram air and that comes from the higher speeds.

 

Regards,

.......... More ........

Ryan,

 

I looked at the 800XP MANUAL that I have and the Table LIM-5. Thrust Conditions has Max Continuous Engine RPM as 100% for unlimited continuous use. Max ITT is 968.

 

The time limit is 'Unrestricted'. This may be why we don't have a Power Table.

 

Regards,

 

Ray

Share this post


Link to post
Share on other sites

The TFE-731 engines on the Hawker are equipped with engine computers known as DEECs. They are activated by a pair of switches in the overhead panel, which are normally kept in the "Auto" position.

 

While not having all the functionality of a full-fledged FADEC, the DEECs do continuously calculate the maximum-allowable N1 for the current atmospheric conditions, and will prevent the engines from being overboosted or overtempted at the normal maximum throttle position. Though the engine computer switches are present on the overhead panel in the Carenado 850, and can be toggled, I doubt that they actually do anything.

 

The real DEECS also continuously store records of engine operational performance parameters in non-volatile memory, which is typically downloaded at regular intervals and sent to Honeywell for maintenance tracking. Impending problems with various internal parts will often show up in these records well before any performance degradation becomes evident to the flight crews.

Share this post


Link to post
Share on other sites

The TFE-731 engines on the Hawker are equipped with engine computers known as DEECs. They are activated by a pair of switches in the overhead panel, which are normally kept in the "Auto" position.

While not having all the functionality of a full-fledged FADEC, the DEECs do continuously calculate the maximum-allowable N1 for the current atmospheric conditions, and will prevent the engines from being overboosted or overtempted at the normal maximum throttle position. Though the engine computer switches are present on the overhead panel in the Carenado 850, and can be toggled, I doubt that they actually do anything.

The real DEECS also continuously store records of engine operational performance parameters in non-volatile memory, which is typically downloaded at regular intervals and sent to Honeywell for maintenance tracking. Impending problems with various internal parts will often show up in these records well before any performance degradation becomes evident to the flight crews.

Jim,

 

Is this part of the Automatic Performance Reserve (APR) system? I doubt anything like this is coded in the Carenado version.

 

Regards,

 

Ray

Share this post


Link to post
Share on other sites

The real question is whether it's correct to have to use full throttle for climbs or not.  Not whether it exceeds engine limits.

Share this post


Link to post
Share on other sites

The real question is whether it's correct to have to use full throttle for climbs or not. Not whether it exceeds engine limits.

I have a lot more questions than where is the 2-engine climb thrust and a fuel flow tables. The whole Climb Profile would be nice to know.

 

There must be someone out there with access to the real world AFM or some documentation from CAE or FSI training programs.

 

Maybe someone's neighbor or friend of a friend was a Hawker Salesman or demo pilot before they went belly-up and ended up at Textron. That might be a possible source of speeds, flows, specific profiles and basic configurations.

 

Regards,

 

Ray

Share this post


Link to post
Share on other sites

Jim,

 

Is this part of the Automatic Performance Reserve (APR) system? I doubt anything like this is coded in the Carenado version.

 

Regards,

 

Ray

Correct. The APR kicks in automatically during takeoff if one engine fails. In this case, the computer allows the good engine's thrust to increase about 250 pounds above the normal calculated maximum. Not a lot extra, but in an engine-out scenario, every little bit helps.

 

Emulating this in the sim would probably require a custom-written engine module, and I'm sure Carenado has simply used a stock FSX jet engine.

I have a lot more questions than where is the 2-engine climb thrust and a fuel flow tables. The whole Climb Profile would be nice to know.

 

There must be someone out there with access to the real world AFM or some documentation from CAE or FSI training programs.

 

Maybe someone's neighbor or friend of a friend was a Hawker Salesman or demo pilot before they went belly-up and ended up at Textron. That might be a possible source of speeds, flows, specific profiles and basic configurations.

 

Regards,

 

Ray

Our company operates an 850XP. It is away on a series of trips at the moment, but I can look at the POH when it returns. I would not feel comfortable directly posting any performance tables from the manual due to copyright restrictions, but perhaps I can paraphrase the main points.

 

I have also just emailed one of the pilots who is a friend of mine, and aware of my interest in flight simulation. I have asked what mode would typically be used in climb to cruise (FLC, VNAV or VS) and whether full throttle in the climb is normal or not. I'll let y'all know what he says.

Share this post


Link to post
Share on other sites
Excerpt from another RW forum...
 
10th Jan 2009, 02:22
An excerpt from a Real World forum......
-
 
---------------------------------------------------------------------------------------
Hi all,

Does anyone have any recommended techniques for saving fuel on Hawker 800XP.

We are very happy with ours but would like to cut down on our fuel bill.

We normally climb at about 280kts, cruise about M.76 and descend at vmo

 

 

supermoix
10th Jan 2009, 04:14
IMHO not much, I tried for several years and basically no other climb, descent profile will save fuel in the Hawkers.

The only things we could do to save some fuel was to:

- Step climb to optimum all the time (with ATC help)
- Slow down to mach . 72-74 in cruise.
- Reduce your fuel load for a lower TOW will help a lot to get you higher soon.

But those above are obvious of course. but no tricks that i could find.
Denim and leather
10th Jan 2009, 10:49
Hello,

Try 250kt as climb speed,and M0,70 if you are not to much hurry.
Safe flights:ok:

If you need help you can pm.
Flintstone
10th Jan 2009, 14:13
What does the manual say?
Denim and leather
10th Jan 2009, 14:43
That's the manual say.

Safe flights:ok:
Habari
11th Jan 2009, 05:46
Climb at 250kts to Mach 0.63. Maintain 0.63 to cruise altitude and then use manual for long range cruise settings.
No other secrets, manual knows best.
B200Drvr
11th Jan 2009, 06:33
Or 250 kts to .70 which is the "normal climb" in the book. .63 is the best rate of climb and then use the book for long range cruise settings. As was said above, "the book knows best".
----------------------------------------------------------------------------------------------
 
 

..........perhaps some ideas here,,,,

 

aero

Share this post


Link to post
Share on other sites

At ISA conditions I'm expecting a 19 minute climb to FL370.

 

First test, ISA conditions, full throttle:

 

250 knot/M0.70 climb to FL370, 14:30 minutes, 77 Nmi, 800 lbs fuel used. Started with 50% fuel in the wing tanks only and 4 passengers @200 lbs with 100 lbs cargo. Full throttle used.

 

Second test, ISA conditions, same load, 95% throttle:

 

250 knot/M0.70 climb to FL370, xx:xx minutes. Started with 50% fuel in the wing tanks only and 4 passengers @200 lbs with 100 lbs cargo. Same as first test. 95% of throttle used. Couldn't climb up to FL370. After 30 minutes, pretty much leveled off at 245 knots and 27,800 ft.

 

Third test, ISA conditions, full fuel, full throttle:

 

250 knot/M0.70 climb to FL370, 20:00 minutes, 116 Nmi, 1125 lbs fuel used. Started with 100% fuel in all tanks and 4 passengers @200 lbs with 100 lbs cargo. Full throttle used.

 

 

So basically the way the FDE works, you need to be at full throttle.

 

This is not surprising given the thrust vs CN1 vs Mach table of 1507 from the .air file. At 99% of CN1 thrust is 1.264 at Mach 0.3 and 1.62 at Mach 0.55

 

At 96% CN1, thrust is 1.05 at Mach 0.3 and 1.207 at Mach 0.55. So you're basically you lose 20-34% of thrust for 5% of throttle and 3% of CN1.

Share this post


Link to post
Share on other sites

I just spoke to our pilot. He said that above 10,000 feet, the normal procedure would be to climb at 250 knots indicated in FLC mode, until reaching the Mach changeover point at about FL 280, then maintain Mach 0.70 until reaching their cruise altitude.They do indeed carry full power in the climb - advancing throttles to the DEEC-calculated max N1 bug, which at typical weights would give a rate of climb of about 2000-2500 FPM.

 

He said that in the 850, FLC mode starts to get a little "touchy" at altitudes at and above FL 300, with a tendency to porpoise in pitch trying to hold the selected speed, so they will often switch to VS mode for the last few thousand feet of climb, dialing the VS rate down to about 1000 FPM while monitoring speed.

 

In cruise, if economy is the main goal, they would typically cruise at Mach .74. If "get there fast" is the main goal, they would take it up to Mach 0.77 0r 0.78

 

They rarely use VNAV mode in climb, but do use it in descent. The FMS will calculate the Top-Of-Descent point, and upon reaching it, will initiate descent with a typical calculated descent rate of 2000 FPM - with the pilot's main concern to manually control power to hold the FMS-calculated descent airspeed.

 

Unfortunately, VNAV in the Carenado aircraft is of little use, as the FMS does not even have the necessary PERF page to enter things like cruise altitude or speed - the best we can do is to enter altitudes on a per-waypoint basis on the LEGS page. Although the FMS will import altitude restrictions as part of a database SID or STAR, it makes no attempt to calculate a vertical profile - giving an absurd scenario like expecting the aircraft to descend from FL 280 to 5000 feet in 15 track miles. I don't expect any improvements in this regard from Carenado , they would have to completely re-write the FMS emulation to add the missing PERF modes, and I doubt that that will happen. 

Share this post


Link to post
Share on other sites

Thanks Jim for taking the time and making the effort to dig out this valuable info. Nothing much new to me other than the 0.63 Mach mentioned a little earlier as the best ROC at +FL280. But, it is great to have my guesses confirmed by current professional pilots.

 

I appreciate you sharing your detailed knowledge of the avionics and systems. The APR might actually be coded into the FDE. Maybe someone will step up and discuss it with Carenado.

 

If you talk to your pilot friend again, would you ask about Takeoff flaps (15 deg or Zero) and the initial climb speed (up to 10,000')?

 

Regards,

 

Ray

Share this post


Link to post
Share on other sites

Thanks Jim for taking the time and making the effort to dig out this valuable info. Nothing much new to me other than the 0.63 Mach mentioned a little earlier as the best ROC at +FL280. But, it is great to have my guesses confirmed by current professional pilots.

 

I appreciate you sharing your detailed knowledge of the avionics and systems. The APR might actually be coded into the FDE. Maybe someone will step up and discuss it with Carenado.

 

If you talk to your pilot friend again, would you ask about Takeoff flaps (15 deg or Zero) and the initial climb speed (up to 10,000')?

 

Regards,

 

Ray

They normally takeoff at flaps zero, unless fully loaded. Once established in climb, they use 245 knots up to 10,000 feet unless procedural or ATC restrictions call for less. No reason why 250 knots can't be used, but our particular SOP calls for 245 to provide a buffer below the 250 knot limit.

Share this post


Link to post
Share on other sites

They normally takeoff at flaps zero, unless fully loaded. Once established in climb, they use 245 knots up to 10,000 feet unless procedural or ATC restrictions call for less. No reason why 250 knots can't be used, but our particular SOP calls for 245 to provide a buffer below the 250 knot limit.

Thanks Jim.

 

Regards,

 

Ray

Share this post


Link to post
Share on other sites

Thank you Jim for those reports! Very helpful!

 

Basically confirms again I've been doing it correct.

Share this post


Link to post
Share on other sites

The engine computers take care of setting power, so it's levers full forward for takeoff.  Should an engine fail, the computers automatically increase the output from the remaining engine (APR), and the rudder bias system driven by bleed air from the operating engine steps on the proper rudder to help you hold the airplane straight. 

 

Once up and away (on two good engines) power is reduced slightly until  the word "climb" appears near the N1 fan speed indication on the Pro Line 21 display.  At least that's the way the RW Aircraft operates.  I have logged a few hours in the Carenado Version and I don't recall seeing thrust settings, i.e., "climb", cruise, on the MFD or anywhere else.  It's pretty much guess work if you are a Carenado Hawker Pilot.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this