Hi Folks,

Re: 4.2a

Hah - OK - who done it - who took my engine and threw it overboard  - Mr. Roberts ? I opened the throttle for my first takeoff run and - wow - what a difference a day makes - she must have added some weight and became lethargic - she’s no longer the absolute rocket ship heading for the moon at 6000 FPM - it’s like she had an invisible third engine removed... That’s some seriously different performance - in the old model - you needed to be careful or you would blow through 250 KIAS in the blink of an eye - now - not so much now... Normal cruise in the old model was down around 82% - this one needs around 92%...

This is in no way a complaint - just an observation - I’m assuming we’ve just made it more realistic given Joe’s RW experience... It’s much more manageable now...

Anyone test the fuel consumption - ball park of the real deal ?

Nice job people...

Regards,

Scott

 

Edited August 17, 20196 yr by scottb613

2 hours ago, scottb613 said:

Normal cruise in the old model was down around 82% - this one needs around 92%...

Hi Scott,

that sounds pretty accurate! Here is a quote from Peter D. Condon's book  "Flying the Classic Learjet" (p.183):

CRUISE

During the cruise phase of flight, be conservative with the thrust settings. Again set an ITT limit of say 780° which gives a 15° margin and will result in savings on long term maintenance costs. At high altitude (above F310), cruising at about 93% N1 will give an approximate cruise Mach of ·73, TAS of 420 kts and ITT of 760°C. Fuel Flow will be about 1200 lbs/hour. However, these figures will vary quite a bit, depending on the atmospheric conditions at the time.

 

2 hours ago, scottb613 said:

Hi Folks,

Re: 4.2a

Hah - OK - who done it - who took my engine and threw it overboard  - Mr. Roberts ? I opened the throttle for my first takeoff run and - wow - what a difference a day makes - she must have added some weight and became lethargic - she’s no longer the absolute rocket ship heading for the moon at 6000 FPM - it’s like she had an invisible third engine removed... That’s some seriously different performance - in the old model - you needed to be careful or you would blow through 250 KIAS in the blink of an eye - now - not so much now... Normal cruise in the old model was down around 82% - this one needs around 92%...

This is in no way a complaint - just an observation - I’m assuming we’ve just made it more realistic given Joe’s RW experience... It’s much more manageable now...

Anyone test the fuel consumption - ball park of the real deal ?

Nice job people...

Regards,

Scott

 

Agree completely Scott !  Fuel consumption seems right on !  A few weeks ago Joe wrote that RW climbs were started at 800 degress ITT and adjusted from there.  While flying the old version (4.1) I tried the 800 degree ITT climb and blew thru the barber pole within seconds.  Now I set the 800 degree ITT and the climb is very realistic .  Once you reach cruise altitude, let her get up to M 0.78 and set fuel flow to 600 lbs/hr per engine and she settles in to a real sweet cruise.  I really like the new FDE.  My fuel burns are very close to estimates from fltplan.com for a LJ35A 

Hi Tim,

Hah - you know you're hardcore when you buy the book - LOL - I have it on my iPad as well...

Hi Carlo,

Thanks - yeah - I use Flyplan.com as well - they have performance profiles for just about every GA and BizJet ever made - what a great resource...

Regards,
Scott

Wait, are you all saying the previous version was totally inaccurate? Seems to me there were countless thread/posts expounding on the virtues of the flight model.

Just now, odourboy said:

Wait, are you all saying the previous version was totally inaccurate? Seems to me there were countless thread/posts expounding on the virtues of the flight model.

Hi,

LOL - there's always room for improvement - it was fun to fly and challenging - but very few of us have actually ever flown one... It certainly felt plausible from my perspective but my RW experience hasn't had me fly anything over Cirrus airspeeds... I can't fault a developer - for improving his product...

Regards,

Scott

4 minutes ago, odourboy said:

Wait, are you all saying the previous version was totally inaccurate? Seems to me there were countless thread/posts expounding on the virtues of the flight model.

I think what we're saying is the current version 4.2 having been modified by a RW Lear 35 pilot is very close to RW expectations by a Lear 35 pilot 🙂

You're a real 'glass half full' kind of person Scott,  I'll give you that! Always upbeat. 😊

Bummer.... I liked the old rocketship.  I think I could do about mach .86 hehe.  What is MMO on this thing anyway?  Seems around .80

I remember when Realair fixed their Turbine Duke.  Originally VNE was 250 KIAS...but that was pretty far off.  The real Rocket engineering mod can do it but the airframe couldn't....the correct speed was 198 KIAS. Anyway a lot of people were actually upset LOL....So I guess the point is, that if this plane is now more realistic....I'm okay with that....but it was sure nice to scream up to the sky!

Sounds like from the above the cruise performance is pretty accurate, but on a standard 3 deg ILS with F40 and gear down I need about 78%N1 which seems high to me. Can anyone confirm that -- I'd like to determine if it is just my system that requires that high of N1 on approach.

Thx,

Al

Glad to read the take off performance for this latest version had been adjusted to be more "real world" like. I thought maybe I was missing something since I was no longer experiencing "jet fighter" like fpm climb rate. Really am enjoying this latest version of the Lear 35A. Thanks again!

1 hour ago, ark said:

Sounds like from the above the cruise performance is pretty accurate, but on a standard 3 deg ILS with F40 and gear down I need about 78%N1 which seems high to me. Can anyone confirm that -- I'd like to determine if it is just my system that requires that high of N1 on approach.

Thx,

Al

Hi Al,

I concur - from a layman's perspective it seems to need quite a bit of power to ride the glideslope - it's a shame - I really like how it handles in the other aspects of flight... Yep - and I see it as well... Hopefully it's something relatively simple - like too much flap drag - just watch out for Murphy... 

Regards,
Scott

Edited August 17, 20196 yr by scottb613

Hey everyone. I spent a good deal of time really evaluating the FDE and making tweaks and changes to get it as close to the real thing as I could. With some help from Mark, I was able to get the engine parameters to match up pretty nicely.

I'll try and tune up the approach power setting without messing up everything else. In real life, fully configured on a 3 degree glidepath, 65% N1 yields about 130 knots.

The climb and cruise performance is far more accurate now, and for those of you who really like to go the extra mile, I adjusted the rudder effectiveness so that a V1 cut can be flown properly. Having done at least a dozen V1 cuts in the real airplane for training purposes, I can now tell you that the V1 cut behavior of the FSW Lear is shockingly similar to the real airplane. If you'd like to give it a try, here's how you can simulate it the same way we do in the real airplane:

 

-Assign a key that you can press quickly to shut down either the left or right engine.

-Set the aircraft weight to 15,000lbs with an OAT of less than 80 degrees F.

-Your speeds at this weight and temperature will be: V1: 115 Vr: 130 V2: 133

-Make a normal takeoff using Flaps 8.

-At V1, fail one engine. Upon failing the engine, you will need almost, if not all of the rudder available, to you to keep the airplane going straight.

-Rotate at Vr, and pitch for V2.

-V2+30, flaps up.

 

And now you've flown your first V1 cut in a Learjet! The type rating requirements to pass the checkride for this event require you to maintain the runway heading after rotation plus or minus 2 degrees. The most common failures result from an inadequate amount of rudder application resulting in a loss of directional control at worst, or a heading drift greater than two degrees at best, and rotating prior to Vr (super common mistake) When flown properly, a V1 cut really looks no different than a normal takeoff. Don't get discouraged if it takes some practice to be able to fly it well. When you do your initial type in the simulator at school, you'll spend a lot of time doing "batting practice" where you'll fly a V1 cut, and then the sim instructor will reposition the simulator back to the end of the runway so you can do it again. Over and over. Having done them in both the real airplane and the Level-C simulator at school, I can tell you that the simulator V1 cut is challenging and aggressive, and the airplane V1 cut is more benign and manageable. The FSW Lear behaves more like the real airplane than it does the Level-C sim. 

The airplane we modeled, along with all three of the Lears I fly in RW, has the -2C engines. The original airplanes, including the one referenced in the "Flying the Classic Learjet" book, have the B engines. The -2C mod gives a bit more performance at altitude, and increases maximum ITT to 865 with no limit. The B engines had a maximum continuous recommendation of 795, with a limit of 832.

Unfortunately, the 35 is not the whopping rocket ship that the 25 was. When you get the 35 loaded heavily, say above 17,800lbs, it really starts to show that it's carrying the weight. Thankfully, its exceptionally rare to actually fly the airplane that heavy. I've been in the airplane for two years and 750hrs, and have yet to fly it loaded to its MTOW of 18,300lbs. Closest I've been is 17,900lbs.

Most days, the airplane starts to get tired around 37,000 feet, with climb rates deteriorating down to 800fpm or less. It's almost always possible to nurse it up to FL400, but the last few thousand feet can take a while. If it's unusually warm at altitude, it won't get there without stopping around FL370 to accelerate, and then continuing your climb with a bit more energy. FL430 is attainable as long as it isn't warm and you've burned a couple thousand pounds of fuel, but it really doesn't like being there. The slightest bump, and you can feel the airplane rocking about on its tiny wing in the super thin air. I'd compare sitting at FL430 in a LR35 to sitting on a fully inflated beachball while trying to keep one foot off the ground. Doable, but uncomfortable. FL450 is basically unobtainable. The airplane needs to be incredibly light, or it needs to be incredibly cold. But based on my experiences with the airplane at FL430, I doubt I'll ever want to take it to FL450.

Maybe once at some point, just to say I did it.

 

Edited August 17, 20196 yr by capceo

Ok, you’ve convinced me. I’m installing this today. It’s great to see a developer that has so much passion for his product and likes to discuss it’s operation.

Ted

17 minutes ago, Ted Striker said:

Ok, you’ve convinced me. I’m installing this today. It’s great to see a developer that has so much passion for his product and likes to discuss it’s operation.

Ted

Great to see ya here Ted.  I got tired of waiting on Eaglesoft (Citations, etc etc).  I'm now a Lear (FSW) supporter and they have excellent support !  With a new texture man and RW Lear 35 pilot, it is AWESOME !! 💪👍