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.

 

[LearjetGA]

Thanks again for sharing your experience.

 

[Lindy]

I thought Garrett recommended 795 for the 30 series. Yes, it is below max continuous, but that is the number I've seen floated at lear operators.

 

[flyboy62]

TFE731 -2-2

FurloughedGal,
You are correct! That is exactly what Garret recommends. They only want 860C for 5 minutes. 795C is good for the rest.

Ron

 

[LR25]

How to save fuel in a 20 series.

NXXXX hold as published efc of XXXX.

Unable to comply, we are a lear 25, thanks anyway.

Anyway, Go as high as you can get and as fast as you can get it, I have found that .74-.76 up high does real good on the burn, around 1450 on -8 engines.

As far as reduced T/O power, no way. Stick those EPR's right up there, more noise the better.

The 20 series will scare you with the fuel.

I am a surviver, I was an SIC one time and we landed with 400 lbs total one time in a 25 due to the PIC's retardedness, I was not a happy camper.

My plan was to start beating his head in right when the first engine would quit.

Any of you 20 drivers out there ever get into the position when you flip that quantity switch back and forth between the mains and the needle barely moves, it sucks.

 

[LJDRVR]

Yeah LR 25, I can picture that needle movement, no fun.

I'm reminded of that warbird dealer up in New Hampshire ten or fifteen years ago with the MIG 21. (a 45 minute airplane with no external tanks) This guy's strapped in, hooked up to the huffer and GPU, ready to start. He's talking to clearance delivery, and they're giving him some roundabout clearance that wouldn't allow him enough fuel to do whatever it was he was doing. After asking for a better routing and being the declined, the guy declares minimum fuel, ready to copy. Didn't exactly endear him to ATC, but I think it got everyone angry enough to where all parties were able to work something out.

FurloughedGal, to answer your question completely, the Garrett's are 860 MAX T.O., (5 minutes) 832 MAX CONT, 795 recommended after 30 minutes. Some corporate Lear operators actually pull them back to 775. The recommedation is simply that, not a limitation. As JustAPilot aptly points out, it is designed to save big bucks during the hot section. Not everyone does it. For instance the Air Force runs their C-21's right up at max continuous the whole flight. Most of us pull back to 795 after 30.

LearjetGA, I re-read your post. I 'm just a dumb charter pilot, but in my humble opinion you really should not be doing RPTO's. There are no published 20-series numbers that i've been able to find in the 5-600 pounds of Simuflite and Flight Safety stuff I've got around the house. I do not currently have access to our 25 AFM, I will certainly check the next time I am in, but I don't think there are RPTO numbers for the 20 series. I only have about 600 hours of 25B & D time, but I don't remember seeing anything in there.

If you go out there and do a 94% takeoff and lose a motor at V1, Are you even going to be able to accelerate to VR? Are you going to have sufficient pitch authority to keep the nose of the AC on the ground and therefore maintain directional control? Balanced field length? If we fly the book profiles we are guaranteed certain performance. If we start making things up, we could very easily do ourselves harm. I suppose it could be said one could just push it up if you lose one, but is that realistic? I fear you are trying to do your employer a favor, (not having to stop for fuel) at the expense of endangering yourself, crew, passengers and employer. I don't wan't to sound harsh or judgemental dude, I'm just trying to help answer your question. More than anything though, I don't want any of us to get hurt.

If anyone can show me I'm full of it, please post. I'm not proud, let's all learn something.

Best of Luck Dude,

DAN

 

[LearjetGA]

The RPTO idea came after i talked to a guy working for a 135 company in one of the carolinas. He told me that they had RPTO settings approved by the FAA. I was pretty curious about it because i never heard about it, that's why the question came up. At simuflight, nobody knows about it.

Another question, anybody out there who goes higher than FL450 in a 25D with the 510 cabin ?

 

[corp_da20_guy]

I believe, in a 25D with the 51,000 ft cabin, the aircraft approved to go above FL450 are the ones equipped with the engine stall provisions. I am not sure of all of the details as to what this includes as it has been a while (auto-ignition is one of the things). I had heard at one point though that the FAA came back and made operators change the restrication in the AFM to limit operations at FL450 on all Lear 20 series, but I don't know the accuracy to this. Any current Lear driver out there with any further info?

Happy flying!!

 

[Gulfstream 200]

never heard of a 25 certified to go higher than 450, but they will definitly go up there........
Any 25 pilot tight on fuel (hello!!!) will attest it is very tempting to pop up to FL490 and clear wx instead of zig zaging around it..
but i heard lots of stories of flame-outs.....bummer...

Whats with the reduced power T/Os????
I thought the only thing good about flying that old junk was waking EVERYONE up at that god-forsaken hour which that rat-$%^# charther operator has you flying!!!
COME ON HAVE SOME FUN.