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| The story of the LearFan is a complex one. Designed by Bill Lear as a
cheaper alternative to business jets, with nearly the same performance
but a pusher propeller, the LearFan became the first business aircraft with a
composite (carbon fibre) structure, as opposed to conventional metal
construction. Unfortunately in the late 1970s this was all a bit radical for the
Federal Aviation Administration, who repeatedly refused certification of the
LearFan. Bill Lear died in 1978 and his widow carried on the programme,
seeing the first of three prototypes fly in 1981. Problems with the gearbox,
which managed the two PT-6 turboprops on a common shaft, and structural
problems with the new composite materials caused costs to escalate, and
despite orders and options at one time for over 130 aircraft, the company
went bankrupt in 1984 with debts approaching 500 million dollars. FACTS AND FIGURES © The LearFan was made almost
entirely of graphite/epoxy and
Kevlar composite materials, and
it was one of the first aircraft to
make such extensive use of
them. © Some critics have said the LearFan
was designed too much like a
conventional aircraft made of
composites to make the best use of
the strengths of these new materials. © Putting the propeller at the rear
reduced drag and helped the
LearFan approach jet speeds. © Some unfinished LearFans were
used by NASA to test composite
structures, being dropped from
towers in controlled crashes. © To meet a deadline of the end
of 1980, the LearFan's first
flight was officially recorded as
'December 32nd'.
| CREW | 2 |
| PASSENGERS | 8 |
| ENGINE | 2 x 650hp Pratt & Whitney PT6B 35F tutboshafts |
| WEIGHTS |
| Take-off weight | 3334 kg | 7350 lb |
| DIMENSIONS |
| Wingspan | 11.99 m | 39 ft 4 in |
| Length | 12.50 m | 41 ft 0 in |
| Height | 3.70 m | 12 ft 2 in |
| PERFORMANCE |
| Max. speed | 684 km/h | 425 mph |
| John J Morton, e-mail, 05.11.2013 15:43 Worked on Learfan in Newtownabbey plant , Northern Ireland for 4 years,good job,great working environment, the very best of mates to be with...would any of the U /S contractors, notably BOB STEWART still be about...a great pity the plug was pulled on it,a very sad day. reply |
| Mark Watson, e-mail, 29.05.2013 22:44 I have the only photographs ever taken of all 3 flying prototypes side-by-side on the flight ramp in front of the hanger. It was the only time all three had been together outdoors, and I happened to have my camera with me because the Reno Air Races were to start. It was late 1984 or early 1985. I stayed on the program until Moya gave us her farewell speach, just before the sheriff padlocked the doors. reply |
| roman, e-mail, 13.02.2013 05:55 I followed this plane's progress in the aviation magazines on a monthly basis. The projected fuel consumption would have beaten the other exec-jet companies to a pulp. Perhaps this is the forerunner of that plane with the twin pusher props and the winglets ahead of the main wings - you all know that one... reply | | Stuart, e-mail, 01.02.2013 08:01 Error in S /N should be E003 not E006. E003 is hanging in the Frontiers of Flight Museum in Dallas. If I remember E006 was one of the structural test articles. reply | |
| | Stuart, e-mail, 01.02.2013 04:54 Kurt, I worked on Proto 1 and E006. Where are you located and sense you are working on E009 what are you doing? reply | | Mike, e-mail, 19.11.2012 22:22 Did anyone ever consider using counter-rotating propellers with each engine turning seperate shafts? reply |
| tom geberth, e-mail, 23.10.2012 20:47 I never saw one of these before,then I got the word to disassemble one to get painted and put on static display at the FAA in Oklahoma city.It had been stored in a lot at the FAA for years. Sn 009 N-98LF reply | | Kurt, e-mail, 19.10.2012 21:58 Im working on SN-009 at this moment. reply | | richard, e-mail, 02.06.2012 06:18 the 2100 was befor its design time , the gear box and gear box cooling due to manfactue engineering skill level failed lear beon question . and remember the flying wing it dident make it eather. the big boys in aircraft manfacturing made sure the goverment would not approve lear design . todays engineering proves beon question lear was correct . yes you would see the 2100 flying today or one equial to it . no question about it . reply | | Scott Boyd, e-mail, 09.04.2012 07:05 Everything else aside the airframe is still a Lear and is still decades ahead of anything that is in production now.
Having flown the 24 and 25 they are still as advanced as most commercial aircraft built today.
I had an 8-track in my Volkswagen Bus, in the early 70's, when I was in College, the bus was 6 volt so I had a wooden box for the 8-track and a 12volt battery. Charged the battery every couple of months, but the 8-track was a Lear, I had been given, worked great and lasted a long time.
The jet pump is probably the most important advancement, but there is a lot more that was there in the 23, which was not that much harder to fly and got much improved with the 24.
I could see the LearAvia at 51,000 and .80. Much faster would be pretty easy though, with a new wing. reply | | Chiuck Colby, e-mail, 09.04.2012 00:40 I knew Bill Lear Jr. And also Steve Wozniac and I introduced them in my living room in 1980
Woz ordered a Lear Fan from Bill but since there were so many delays in the Lear Fan project Woz cancelled his order and bought another airplane.
He had only taken a few flying lessons when he decided to take his new
airplane up without his instructor
He crashed the plane and almost died in the crash
I have videos of the first flights of the learFan that Bill gave to me.
I need to digitize them and put them on YouTube reply | | Michael Mears, e-mail, 28.01.2012 00:49 I was employed at Lear Fan as a Buyer. reply | | Scott Boyd, e-mail, 04.05.2011 06:34 The airframe design would be just as revolutionary today and with the latest composite technology could be even lighter and easier to build. The problem that remains unsolved is the gearbox and single propeller, while it works well on helicopters, the rotor can autorotate, with a propeller autorotation of the prop creates huge amounts of drag and takes you to your crash site even faster then if it is feathered. Add to it losing the gearbox with two good engines and I still scratch my head wondering while Bill Lear continued with it as long as he did.
Instead of weight and complication it would be much easier to stick a couple of current generation Williams engines to it and doing away with the prop and gearbox. Lighter and more fuel efficient it would put the Mustang and the other lite jets to shame. reply | | Mark, e-mail, 03.05.2011 23:49 Hi,
I think the 2100 would be very competitive today. Jet speeds with turbo efficiency. For efficient manufacturing, the fuselage would need to be filament-wound, as opposed to the mold lay-up process we used back then. A big part of its fuel efficiency came from the pusher-prop configuration, which drives a unique aft fuselage design. That airframe slipped through the air very smoothly. I don't know about the weights, but I would bet my house that the 2100 propulsion system overall was much lighter than the Skymaster. Here's more trivia: On one of the last two days in operation (in 1985), we in engineering were looking through some of Bill's old notebooks. We came across one that showed, in pencil sketches, the evolution of the engine inlets. It started with one inlet on top of the fuselage. As the weight and target speeds grew, so did the thrust requirement, so so did the inlet, which cycled around several times. Each sketch showed that inlet a little bit larger in diameter. Eventually, it was about half the diameter of the fuselage! The next sketch in the book was of the 2100 with an inlet on each side. take care. reply | |
| | Markus, e-mail, 29.04.2011 22:29 Hi,
Apart from the engine, would the airframe (layout) be competitive nowadays (Y-tail configuration, ...). How did actual weight come in compared to orig. planned?
Unfortunately there is little information available, at least what I have come across so far.
What would have been the weight (& performance?) penalty by using an engine layout like the Cessna Skymaster (push-pull configuration)? reply | | mark, e-mail, 09.03.2011 17:26 Here's some trivia; In the photo above is the 2nd flying prototype. The tail number, N626BL, reflects June 26 Bill Lear. June 26 is his birthday. The 3rd flying prototype, N327ML, is, you guessed it, March 27 Moya Lear. March 27 is her birthday.
We referred to the planes as Engineering models, and they were commonly called E1, E2, and E3.
The wax-in-the-gearbox idea in 1979 was tossed out because it just didn't work. They found that by the time the wax melted and spread, the gb was already overtemped. In 1984 we were still trying to meet FAA requirements for no oil, and finally got the spin-jet thing to do the job.
The reason for the Dec 32nd first flight date is that on Dec 31, on taxi out for first flight the plane seized a brake. It took all night to fix it.
The write-up says LF went bankrupt in 1984. It was actually May (I think) of 1985. I was out of work for 5 months, starting at Mcdonnell Douglas in Oct, 1985. Article also says "two PT-6 turboprops on a common shaft". Each engine actually had its own low-speed output shaft (about 75 rpm) driving into the helicopter gearbox. reply | | Mark, e-mail, 09.03.2011 17:01 The FAA did not deal the death blow to the lear Fan. That was delivered by Bob Birch, who wrote the checks with Saudi money, then they just became bored with the project and pulled the plug. I was the electrical systems design engineer on the plane up until the day they shut the doors.
The difference between the single gearbox, single fan on this plane and the same design on a helicopter is that a helicopter has auto-rotation. The dry gearbox issue had been solved by the use of a small oil tank feeding a "spin jet" in the gearbox, spraying oil on the main gears every X number of seconds (i don't recall how many). The FAA requirement was that we had to fly for 45 minutes with no oil in the gb. At Western Gear in L.A. we ran the fan on their test fixture, with the spin-jet system, for over 3 hours. I was designing the control and monitoring system for the oil spray, and had already completed the Preliminary Design Review, when they came down and said to roll up all blue prints, write a note about where we were at with the work, and exit the building. The last thing we did was gather in the hanger for Moya's farewell speach. Very sad day. Again: The Lear Fan program was shut down because the Saudi prince (who flew on our Space Shuttle a few months later) didn't want to play any more. reply | | airboss, e-mail, 28.09.2010 19:07 One of the Learfans (N21LF) is located at the Museum of Flight, Dallas Love Field. I believe another is located at the museum close to Boeing in Seattle, WA reply | | John Burford, e-mail, 18.09.2010 00:49 Does anyone know where one of the three prototypes are today? reply | | Dave, e-mail, 10.08.2010 02:53 It wouldn't suprise me to learn that the government had something to do with the demise of this fantastic aircraft, and used the FAA to deal the death blow.
The single gearbox issue with two engines turning a single prop is hard to understand since thousands of helicopters use the same design!
Some forward thinking aviation individuals should take up where Lear left off and push this design. reply |
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Do you have any comments?
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All the World's Rotorcraft |
Mark Watson
still interested to work in a project like that?
what role would you like?
reply