Lear 25D: Pros and cons please

[NCherches]

...At least if you get a LearJet and you tell some guy at a bar you're a corporate pilot and he says 'So you fly like a LearJet' you can just say 'Yes' instead of trying to explain to the idiot that there are other types of business jets.

 

[avbug]

The Lears had what, 47 different wings? It seemed everyone of them I saw with all sorts of garbage all over it to make it fly right. If it took that many tries, and they still had to glue garbage all over it...

Once the airplanes got to the Century III wing and softflight, then it was fairly standard...pretty much all the 30 series, and much of the later 20 series had wings without all the vortex generators, etc.

The vortex generators are there to address mach effects, incidentally. Lots of myths surround the Learjets, especially stories about how the control yoke slams side to side at higher mach numbers and how the airplane is subject to mach effect...neither of which are true, but both of which the simulator leads one to believe are true (for demonstration purposes). I've met a seemingly unending number of pilots who tell me all about the Lear's mach effects...but who have never actually seen or experienced them in the real airplane...because of what they saw in the sim.

The sabre wing was a great wing. I flew them and worked on them, and was Director of Maintenance for a corporate flight department that flew the Sabre 60. I did the Sabre mx course initially through FSI, and got a lot deeper into the airplane than I'd intended, once I began working on them. The wing was perhaps the best part. The leading edges dont' need anti-ice, and even if the slats don't drop out (which they sometimes don't), it produces no noticible changes in the performance. The speed brake is great, control is wonderful, it's a well designed airplane with better stand-up room than many more modern turbojet airplanes.

The door is an amputation waiting to happen, and the nosewheel steering...don't get me started on that overcomplicated contraption. (The mx manual directs the mechanic to build his own test unit for the nosegear, and supplies the schematics and part numbers...when you test it, you build the equipment with which to test...and it's a lot of relays and--sabreliner had their own method of wiring diagrams--a mess).

I opened up a Sabre for a CAMPS check once, a simple affair involving an outflow valve inspection. I figured 40 minutes and I'd be done, sign the thing off, and go home. Nope. One small spot of corrosion, looked like it was on the surface. I figured a quick treatment with a die grinder to relieve surface corrosion, finish the metal, re-alodine and refinish, and put it back. Give it an hour and twenty total. The problem expanded when I relieved the surface and found it became bigger and bigger, and soon I was facing dimension issues; I couldn't remove more material.

The part was formed, and reinforced with a rib. Part of the rib was corroded. The airframe is made largely from 7075 T-6 aluminum, which is heat-treated, and very hard to work, and very brittle. It work hardens, it age hardens, and it cracks and develops corrosion internally as it ages...particularly with the improper heat treatment that was involved when North American built the aircraft. Replacing or fabricating something as simple as that baffle became very complicated, even to do a simple patch in accordance with the approved structural repair documentation.

After consulting with several sabre experts around the country, the best counsel I got was don't go looking because you WILL find corrosion and you'll get pulled into a web that WILL eventually ground the airplane. (Ask anybody who's had to pull the fuselage tank what they found behind the tank). After sharing the part and find with the owner of the aircraft, his request was to "put it back; we'll be selling it soon, anyway."

Some will call the Sabre outdated. I didn't think so, and still don't. They are older airplanes. Much better technology is available, and they'd be built differently today. They don't look like antiques to me. They still look like a sharp airplane on the ramp, they still fly like a dream. There's no snob appeal in them, but I've spent much of my career flying airplane that are at least as old as, and usually older than I am...the Sabre doesn't bother me.

The Learjets, especially the 24, and the 25, feel like one is riding in the toe of a cowboy boot. It's comfortable for short periods, but relatively cramped. I routinely do 8 and 10 hour or more legs...but in the Lear, I felt like it was a three hour airplane. After three hours, I was more than ready to get out and go get therapy.

I did atmospheric research in the LR35, largely involving thunderstorm penetrations, and have had that airplane loaded heavily with ice, in severe turbulence, and knocked around the sky every which way from Sunday...allowing me some measure of exposure to flight operations somewhat outside the traditional operating envelope of point-to-point flying. I've flown Lears with hardpoints and all kinds of gear stuck on the outside of the airplane, and flown them routinely to the stick shaker and beyond and high and low altitude, high and low speed, in all kinds of conditions. They're great flying airplanes. I really like the Learjets.

As others have noted, the CJ motors are getting somewhat outdated; they're not stage three installations; they burn a lot of fuel; they're loud, parts are getting harder and harder to get, and they're getting very expensive to maintain. Choices of fields are becoming limited due to noise restrictions, and unless the 20 series Lear one buys is RVSM'd, then you're stuck with above or below RVSM with begging permission to transit everywhere you go. I've known operators who worked that way...they weren't about to spend the money to go get the RVSM approval...and the 20 series autopilot is a very poor autopilot for RVSM (or for anything these days...it's more like a light airplane autopilot in it's operation and reliability, even when well maintained).

Then again, a lot of the same can be said about the Sabre. The problem is that a number of these older turbojet airplanes can be had for a song. People think they can buy cheap and have reserve left over to operate them. The acquisition price is a drop in the bucket compared to what it takes to keep them flying...and it's not unusual for someone to go buy a Lear and then shortly thereafter start sucking around for a 135 operator to carry the weight of the airplane, because it's eating the owner alive.

It's great in a Lear 24 to take off and turn downwind at 18,000'...I've done it many times. It's a fun airplane to fly. I've also had to declare minimum fuel twice while taxiing...and return to get more fuel. It's a hog. One can see the fuel gauges move. Older airplanes generally come with much older radios, including nav radios. Many of the 20 and 30 series lears I've flown have had light airplane GPS units in them...Trimbles, KLN-89's, etc. Some have had Universal FMS's in them with glass, but not many. A few had Garmin 530's and so forth, but again, not many. Most are fairly bare bones, steam gauges (powered by real steam), and come equipped with oxygen masks that look like they were made out of rubber from the 1890's, and fashioned out of soda straws.

Investing in an interior refurb may be money thrown away, for the older jets. That leaves one with whatever was in style 20 or 30 years ago...and much of it isn't flattering. I've seen some decent re-works on some Lears (and Sabres, actually) with leather upgrades, refinished wood, etc, for a reasonable sum...but largely tossing too much money after older jets isn't really an investment so much as an act of vanity or temporarily purchased sanity. This is to say nothing of the Spirit conversion...which might be worth it for a private jet, but wouldn't be much of an investment with return.

I like the older airplanes, and I have no qualms flying them if they're properly maintained. They are more labor intensive then newer aircraft. They are more expensive. They're making less sense for many operators, save for small operators or entry-level operations.

 

[Rick1128]

Once the airplanes got to the Century III wing and softflight, then it was fairly standard...pretty much all the 30 series, and much of the later 20 series had wings without all the vortex generators, etc.

The vortex generators are there to address mach effects, incidentally. Lots of myths surround the Learjets, especially stories about how the control yoke slams side to side at higher mach numbers and how the airplane is subject to mach effect...neither of which are true, but both of which the simulator leads one to believe are true (for demonstration purposes). I've met a seemingly unending number of pilots who tell me all about the Lear's mach effects...but who have never actually seen or experienced them in the real airplane...because of what they saw in the sim.

I like the older airplanes, and I have no qualms flying them if they're properly maintained. They are more labor intensive then newer aircraft. They are more expensive. They're making less sense for many operators, save for small operators or entry-level operations.

First of all the Century 3 wing does have devices on the top of the wing. They are called Boundary Layer Energizers (BLE's) The only wing that does have any devices on the top of the wing is the Mark 2 wing. But it does have a stall strip on the leading edge of both wings. And it is probably the best Lear wing out there.

As for the Delta fins, there were never standard on the 35s or 36s, only as an STC.

In regard to 'aileron buzz' I have never experienced it outside of the sim. But when Pete Reynolds and a couple of NASA's Lear pilots tell you it exists, I tend to go with them on this item.

Cockpits in the 35/36's are not any larger than the 20's. And if you are taller than about 5'9", they become uncomfortable quite quickly. And if you are only getting 2.5 hours out of a 31, you need to check your technique. It should be a 3 to 3.5 hour airplane with a decent reserve. There are a lot guys out there that try to cruise the 30's at .79 to .80M. That is high speed cruise. Normal cruise is .75 to.76M. I know of one pilot who regularly turned a 35 into a 3.5 to 4.0 hour airplane with full fuel (instead of 5.0 to 5.5 hour) by always doing high cruise.

While it may look like these older aircraft may be a viable option for small or entry level operators, I believe that it is the worst thing they could do. While at first they think they are making good money as their capital costs are low, it catches up with them and they get hit with large bills that put them out of business. A good portion of these large bills are the learning curves that come with such an aircraft. Older operators that have experience operating and maintaining such aircraft would actually do much better, however they are the ones most likely to have gone on to more advanced aircraft.

I have lost an engine in a Lear 25 on takeoff with the anti-ice on. The aircraft climbed to 180 at over 2000 fpm with no problems. I was right at gross but was not sitting a V2 or V2 + 10 during the climb. I didn't go back to the airport because it closed again right after I took off. Plus at 180 I was cruising at 350 Kts at 94%. If you have the anti-ice on, it is generally cold and the engine has no problems making power. The 35/36 will not good, but they will be reasonably close. Except for the RX airplanes.

Unfortunately, when Lear stopped making the 31, they stopped making REAL Learjets.

 

[OPECJet]

I don't know what this "bulletproof CJ-610" talk is about. Maybe I've only flown trash engines on the 24/25s, but all of them were stall susceptible. Push the power up quickly on the ground and the engine farts. Get below .75 at altitude and hit a bump, descend below 240 to re-light one. Then there's the 4 to 6 week spool up time after you introduce fuel on the start. You've also got the stall / surge bleeds that liked to hang up causing a huge bang in the climb on more than one occasion.

The JT12s on the early Sabreliners are much more "bulletproof" as far as I'm concerned. Much better handing airplane to boot. My only complaint about it is the nosewheel steering. Would have been better off with full time limited steer through the pedals and a tiller like larger aircraft.

The early Lears are the kind of airplane you want to have flown for someone else in your past, but not something you want to be flying now.

 

[Rick1128]

I don't know what this "bulletproof CJ-610" talk is about. Maybe I've only flown trash engines on the 24/25s, but all of them were stall susceptible. Push the power up quickly on the ground and the engine farts. Get below .75 at altitude and hit a bump, descend below 240 to re-light one. Then there's the 4 to 6 week spool up time after you introduce fuel on the start. You've also got the stall / surge bleeds that liked to hang up causing a huge bang in the climb on more than one occasion.

The early Lears are the kind of airplane you want to have flown for someone else in your past, but not something you want to be flying now.

It really depends on who did the engine and how tight it was. I have flown some that were just as bad as what you had. I have had others that would pass the 'burst' test all the way up the 450. It is becoming less and less as new parts become less and less available. The worst ones were the -5's that were upgraded to -6's.

 

[Tristar]

The JT12s on the early Sabreliners are much more "bulletproof" as far as I'm concerned. Much better handing airplane to boot.

We never had any problems with our JT-12s (other than their thirst, but that's any straight pipe engine), nor did I hear of any other operators we knew of having any issues. Do beware that any of these engines have a lot of life-limited components. As they are all getting older, beware of short-build engines which appear to have plenty of time to HSI or overhaul, but may have disks which will time out much sooner - the end result being an engine which will require replacement or a large investment earlier than you think.

Also, the JT-12 does have a compressor corrosion inspection which has a calendar time limit (60 months if I recall correctly). This too requires major disassembly of the engine, and if corrosion is found - again replacement of compressor disks. Again, like any older aircraft - you need to know what you're buying and have people who know what they are looking at insure that there aren't problems.

And from what I can see you've never flown a Lear......

As I've already stated - but thanks for noticing.

I like the older airplanes, and I have no qualms flying them if they're properly maintained. They are more labor intensive then newer aircraft. They are more expensive. They're making less sense for many operators, save for small operators or entry-level operations.

This is exactly correct. The biggest problem with these aircraft for entry level operators (and even some operators who should know better) is that unfortunately too many either don't know enough or are too cheap to do proper due diligence on what they are buying and end up with a piece of junk that breaks the bank, or simply don't understand that the costs associated with these aircraft and are drained little by little (or a lot by a lot) since they haven't properly budgeted for the operation of the aircraft.

I'm also amused by the operators who decide the aircraft costs too much to operate just park it, not realizing that calendar limited inspections are still coming due and/or that the aircraft needs to be preserved to retain any value at all. These are the aircraft you see abandoned with weeds growing up around them.

They can still be good aircraft - but you must, MUST understand all of the costs involved. To reiterate - the acquisition cost is relatively minor compared to the costs of operating and properly maintaining them.

 

[avbug]

First of all the Century 3 wing does have devices on the top of the wing. They are called Boundary Layer Energizers (BLE's) The only wing that does have any devices on the top of the wing is the Mark 2 wing. But it does have a stall strip on the leading edge of both wings. And it is probably the best Lear wing out there.

I'm very well aware of the BLE's, and having flown most of the Lear wings, I think the Century III is the best. Lear thought so so, as it became a best seller, and the standard wing and wing mod. I used to fly a Lear 25B with a Mark II wing on it, and didn't care for it as much as some of the others.

In regard to 'aileron buzz' I have never experienced it outside of the sim. But when Pete Reynolds and a couple of NASA's Lear pilots tell you it exists, I tend to go with them on this item.

Pete Reynolds made it clear that this doesn't exist and isn't found on the Lear. Buzz, yes, but not control yoke slamming side to side. Reynolds noted that this was built into the sim to overdramatize the effect to make a point, and that it didn't duplicate the airplane, and was never intended to. That many pilots still believe the Lear has undesirable mach tuck tendencies and airleron buzz characteristics is a function of what they've seen in the sim. It doesn't happen in the airplane.

Cockpits in the 35/36's are not any larger than the 20's.

The 24 cockpits tend to be more cramped and uncomfortable than the 30 series.

There are a lot guys out there that try to cruise the 30's at .79 to .80M. That is high speed cruise. Normal cruise is .75 to.76M.

Standard for me, by employer requirement, was generally .80 in cruise. With external stores, limited to 200 kts for profile, Vmo set back to 250.

 

[LR25]

I don't know what this "bulletproof CJ-610" talk is about. Maybe I've only flown trash engines on the 24/25s, but all of them were stall susceptible. Push the power up quickly on the ground and the engine farts. Get below .75 at altitude and hit a bump, descend below 240 to re-light one. Then there's the 4 to 6 week spool up time after you introduce fuel on the start. You've also got the stall / surge bleeds that liked to hang up causing a huge bang in the climb on more than one occasion.

The JT12s on the early Sabreliners are much more "bulletproof" as far as I'm concerned. Much better handing airplane to boot. My only complaint about it is the nosewheel steering. Would have been better off with full time limited steer through the pedals and a tiller like larger aircraft.

The early Lears are the kind of airplane you want to have flown for someone else in your past, but not something you want to be flying now.

Never had a CJ610 give much hassle, but most of the 20 series I flew were pretty nice airplanes, except SN#18, and it didnt give me much either.

Kind of miss em, same goes with the BE-18, but wouldnt want to have to make a living in them anymore, unless I had to.

 

[Gulfstream 200]

...At least if you get a LearJet and you tell some guy at a bar you're a corporate pilot and he says 'So you fly like a LearJet' you can just say 'Yes' instead of trying to explain to the idiot that there are other types of business jets.

Try talking to chiks, and try NOT talking about airplanes.

 

[pilotyip]

Why?

Try talking to chiks, and try NOT talking about airplanes.

Why would anyone on this site not want to talk about airplanes and flying?