Lear 20's Power settings

[LearjetGA]

Hi everybody.

Who is using reduced take off and climb power settings on the Lears 20 and 30.

I try to compare with you the fuel efficiency of these parameters (if you allow me to use that expression on a Lear 25)

I usually take off at 94% on runways with more than 8000 ft pavement. Climb out is 600 degrees until FL 200 or higher.

This the difference recorded in an hour flight :
(zero wind, 85 degrees temperature, average taken on 8 flights)

without 2350 lbs
with 2050 lbs

Anybody out there who has good tips how to keep the fuel longer in the tanks ? Lear 30's and 50's comments more than welcome !

LearjetGA

 

[corp_da20_guy]

I used to fly 20/30 series lears. The only thing, my opinion, about RPTO is...I don't believe there is any performance data from Learjet to use for performance computations. With this in mind you are being a test pilot using anything less than takeoff power. I personally would not uses this procedure for any airplane unless there were manufacturer data to support this. (just my $0.02)

Now as far as the climb power settings...it has been a little while but I think in the 20 series we used 650 degrees EGT. This usually worked for both the -6 and the -8A engines. Now as far as the 30 series, I do not remember the numbers.

Happy flying!

 

[LRDRVR]

Our company policy is to power back to 90% as soon as practical,just for noise abatement.We always use takeoff power.Then at 3000 agl it's 98% or 680.Fly red line up to 410 usally takes 18 to 22 minutes and under 1200lbs.First hour fuel burns with taxi is 2000 to 2200lbs.Thats an avregage on 8 different 25's.the most i've seen was 2300lbs first hour.Of course these are with only a short stop at and intermittant altitude.My thinking is the faster you can get to thin air the better.If your already close to cruise speed at altitude you don't have to leave the power in to get up to cruise speed once you level off.But if I can't land with 1500 lbs we'll bounce for fuel.Specially in the North East.

 

[Timebuilder]

No RPTO for us. Figure the numbers with eight degrees flaps, get going and climb to an efficient altitude.

I have been told that the RPTO just isn't worth it in the grand scheme of things.

 

[LRDRVR]

Your right it probably doesn't matter...too many other variables outside of our control like atc. I just plan on being min fuel at engine start.I tanker fuel big time every time.Never know when someone going to gear up on the runway and close it down after a long leg and then divert.We plan the leg with sever clear at destination.I've notice fuel planning can get real tricky in a hurry in these 20's.

 

[justApilot]

Partial Power N1 settings (reduced power) are published in the Learjet/FSI QRH. The real savings with reduced power takeoffs is seen during the hot section inspections/overhauls.

 

[LearjetGA]

Many thanks

 

[501261]

Old Lears will scare you in a hurry. Ever notice how much fuel you burn on a full approach? I can remember crossing the FAF at HOU one day with 1800#'s remaining. Low visibilty so we were full flaps and on speed. Went missed got an immediate vector to IAH (18nm away). Shot the approach landed with only 600#'s fuel remaining, total time about 15 minutes! They burn a ton down low!

With old Lears the subject of packing fuel always comes up. Here are some of the more interesting ways I have hears of. To get the most fuel in the trunk, fill it while descending or on a downhill ramp. To get the most fuel in the wings, transfer from the side being fueled into the side thats already full. For best climb CG try to keep about 700lb's in the trunk (supposedly to make you climb faster). I take no responsiblity for any of these old wife's tales, just sharing some of the things I have heard.

 

[LJDRVR]

RPTO

I don't recall any RPTO procedures. I seem to remember the Simuflite folks saying they were a no-no. I'll do some research and post back. On the CJ 610's LRDRVR is right on. (680 or 98% whichever comes first. For the 35's, Garrett recommends 800 @ 10,000, 810 @ 20, 820 @ 30 and 830 @40. If your engines are rigged well and not worn out, following this rec will keep you from having to continually pull the thrust back during climb. It has the added benifit of keeping you under MAX continuous N1.

Best fuel saving strategies I use for the really long legs are: Follow the book climb profile, and try not to level off. annoy the heck out of ATC if you have to. Climb as high as possible and pull em' back. .72 or so seems to work pretty well. Unless over water, burn the tips dry and wings down to 1000 a side before you transfer up. (nice aft CG) Wrong direction 410 over the course of a few hours is a little bit extra. And like all the other fine advice here, always have a plan B. You will always underestimate the burn on a 20 series. 2:1 descent at redline. Thrust pushed up to keep it there. Sound counterintuitive, but it works.

94% in the clinb sounds like test pilot territory. Your first hour burns may be lower, but I can guarantee you you're not as far down the road. Groundspeed is everthing.

Cheers!

 

[501261]

How could I forget this old "Clay Lacy" trick. In an old 20 series if it has an alternate flap control. You can put down 2-3 degrees of flaps. This will supposedly "keep your ass from dragging" at heavy weights at altitude. Just like moving the trim on a boat helps it plane. Of course this is pure test pilot stuff.