Falcon 50 Performance (TFE 731-3)

[HowAreYourRides 4]

Finally found some performance data for the Falcon 50 with TFE 731-3's.  It's hidden at the end of the checklist document at freechecklists.net (linked below and also in the sticky "reference information" post). Looks like the takeoff N1 we're aiming for is 101.5%.  It also has climb thrust settings, cruise thrust/fuel flow/TAS charts, etc.  Very interesting and useful stuff.  I think my times-to-climb are going to get even longer with compliance with these tables, especially the 300kt/M.80 profile. (It's realistic though - I've been studying FA50s on FlightAware and they're definitely in no hurry to reach cruise.  30 minutes or more is very common when heavy.  Here's an example.)

http://freechecklists.net/Resources/Dassault/DA50+Falcon+50/

Best,

Tony

Edited June 6, 2020 by HowAreYourRides

[pilatuz 141]

I've been using those tables for a week now, and really think the FSW bird needs more N1 from the mid 30's to cruise. I edited the cfg to make the jet thrust scalar 1.05 and that helped a lot in being able to nail the numbers, but once I get to about FL350 I'm firewalled and run out of N1, ie the tables usually say I can get to around 98% but Im pegged at 96-97%. This is the same in cruise, I dial back the thrust to get the desired fuel flow interpolating from the charts, and usually 2-3% N1 below the published values. I think the actual power is accurate at 1.05, I'm nailing my fuel burn predictions (PFPX) and times, but the N1 values should be higher. All in all pretty dang close but maybe can be closer!

[HowAreYourRides 4]

When you check your fuel burns against your PFPX-generated flight plan, are you comparing "Fuel Used" numbers or "Fuel Remaining" numbers?  I've found that if you compare fuel remaining, the aircraft actually manufactures fuel.  So I have one PFPX profile (originally built off the -40 numbers I think) that I'm trying to get biased to match fuel remaining (for an unrealistically, yet still fun, long range) and another for fuel used.  I'm way over on time-to-climb vs flightplan, though.  I should probably hunt around for a PFPX profile built off these tables we're talking about.  Or see if I can fumble through and make my own.

[pilatuz 141]

1 hour ago, HowAreYourRides said:

When you check your fuel burns against your PFPX-generated flight plan, are you comparing "Fuel Used" numbers or "Fuel Remaining" numbers?  I've found that if you compare fuel remaining, the aircraft actually manufactures fuel.  So I have one PFPX profile (originally built off the -40 numbers I think) that I'm trying to get biased to match fuel remaining (for an unrealistically, yet still fun, long range) and another for fuel used.  I'm way over on time-to-climb vs flightplan, though.  I should probably hunt around for a PFPX profile built off these tables we're talking about.  Or see if I can fumble through and make my own.

I use the one that's referenced from this forum, and have set a bias (forget what it is, can tell you it later) that is pretty dang accurate. And on the flight plan the fuel used vs fuel remaining are actuate too, I'm usually within a few hundred lbs. I would offer it to you but it's also modified pretty heavily to suit the FSEconomy operations I like to use it for.

[znatusch 3]

On 6/6/2020 at 2:16 PM, HowAreYourRides said:

Finally found some performance data for the Falcon 50 with TFE 731-3's.

Thanks for posting this up - I feel that performance tables and thrust charts should have been included in the manual, but hooray for helpful community members.

On 6/6/2020 at 5:24 PM, pilatuz said:

.I edited the cfg to make the jet thrust scalar 1.05 and that helped a lot in being able to nail the numbers....

I adjusted the scalar, and got around to my first flight in Falcon this evening. Felt like a T-38. Post-flight I checked the scalar. I set it to 1.5, instead of 1.05.

Beautiful plane.

[HowAreYourRides 4]

I adjusted mine to 1.05 too after pilatuz mentioned it above.  I'm liking it!  Also getting used to checking the climb thrust table every 5000' to make sure I'm where I need to be.  At 1.05 it still climbs slow when it's hot outside or when I'm heavy - especially on the 300/.80 profile.  I just got done flying from India to Texas today, and there were some seriously hot climbouts - I was operating on multiple occasions in blocks on the chart warmer than it had numbers for.  ISA +15 or more was common over India and Canada.  The climbout over Canada took forever at those temps - although I shoulda stopped at FL380 instead of going all the way up to FL400 on the 300/.80 climb profile.  Tech stopped in Helsinki and Goose: VIAR-EFHK-CYYR-KSGR. 

Videos being uploaded on my youtube channel for posterity/reference/science.  Includes the entire climb to cruise.

https://www.youtube.com/channel/UCRl_fqsGwIFuEBnQDJYsjwA

http://www.gcmap.com/mapui?P=viar-ksgr viar-efhk-cyyr-ksgr&MS=wls&DU=nm

-Tony

Edited June 12, 2020 by HowAreYourRides

[pilatuz 141]

I feel like I have better results from the 260 KIAS / .72 climb, keeps to the tables well until about FL300 then I start to run out of N1 eg the thrust levers are pegged and I cannot raise N1.

[HowAreYourRides 4]

So I've been comparing my performance with aircraft I can confirm as Falcon 50 Classics on FlightAware (times to climb, etc) and I've backed my thrust scalar back to 1.02, and I might even bring it back to 1.00 again.  1.05 is behaving too much like a -40 or EX.  Making the change also wrecks the biases on Santiago's Falcon 50 PFPX Profile that I've been working on for weeks.  Hah. 

What we really really need is a Falcon 50 Classic (TFE731-3) Flight Manual with a complete Section 5 - Performance.  If we had that, with climb performance charts, etc, we could make an accurate PFPX aircraft profile and everything.  Then the trial-and-error task of biasing would be minimal because our data more closely matches Flysimware's model.  I've been back and forth across the internet and, while coming close with the -4 performance doc (significantly outperforms the -3), the AFM on avialogs (completely missing sections 5 and 6), and the checklist/performance doc from the sticky resources post (only has cruise tables - which are still useful), we're still missing important pages like climb performance.  I wish I knew someone with access to a Falcon 50 Classic.

[phil747fan 14]

any luck on the task to find that section 5?

[HowAreYourRides 4]

On 12/14/2020 at 8:43 PM, phil747fan said:

any luck on the task to find that section 5?

Nope, unfortunately.  Just flying around using the performance at the back of the .doc file I found at the top of this thread.