Lear Fan(s)

[Bill Marsh]

Re: Lear Fan(s)

Hey RGRSTNDGBY (memories of a B36)

Gee... am i a ol'timer too?

I posted this same message a long time ago....

_________________

whatching a b36 doing t & gs at SFO (had the huge main wheels too)

god... what a sound... i went nutz ( i was 10) in 1955)... its burned into my brain

the SAC movie with allison and stewart nailed the sound


any idea why since a distictive exhaust note? maybe plumbed to add thrust?

never heard that on a ride with a UAL Super Strato liner with 4 corn cobs in the normal - in front placement.


any ideas "good timer"

BM

[Skyracer]

Re: Lear Fan(s)

By "chopped up" it would be all of the above and more. When you think about it, there is a "noise" at some frequency from the exhaust, whether it be turbine or recip. That "noise" is then rythmically blocked and unblocked, and reflected and not reflected, at varying angles by the passing prop blades. Thus, the sound is effectively modulated by the frequency of the passing blades and what you hear is that modulated noise. "Reflected" refers to the "noise" bounced off the passing blade, and "chopped" refers to the "noise" that passes between blades. Depending on the listeners position with respect to the aircraft, the sound heard may be reflected or chopped and will change as the aircraft passes. Mix in noise reflected off the fuselage and wings, some prop tip noise, and you have that wonderful sound we call "airplane noise". (Hmmm, somewhere I have a "I (heart shape) Airplane Noise" t-shirt.)

That's my theory and I'm sticking to it.

[Skyracer]

Re: Lear Fan(s)

I also share in the B36 sound experience, first growing up near Lincoln AFB NE. Many years later, I heard that sound once again and ran outside my Dad's shop in Colorado, looked up, and there she was high overhead on a SW course. I read shortly after that, that the last B36 had flown to the boneyard at Davis-Monthan, and, yes, a tear formed in the corner of my eye.

[Leo]

Re: Lear Fan(s)

That's my theory and I'm sticking to it.

Sounds good to me! A person of conviction.
I have the "I (heart) airplane noise" bumper sticker on my toolbox...

["Bear" Driver]

Re: Lear Fan(s)

For those interested, I will try to add some clarification to the "E" number/"N" number history of the LearFan program.

E-001/N626BL:
First flight was on 12/"32"/1980. Contract commitment to the British government for continued funding was to fly on or before 12/31/1980. It was an "act" by parlaiment to declare that day as 12/32/1980 as they obviously felt that we had fulfilled the spirit and intent of the contract.

The first takeoff was made by Hank Beaird in the left seat with test pilot Dennis Newton in the right seat. The first landing was made by Dennis Newton in the left seat with Hank in the right seat. Don't even ask..........

My first flight in E-001 was on 7/21/1982 with Hank as my instructor. E-001's last flight was 7/20/1983. Mark Gamache was with me and we were accomplishing hydraulic system heating tests at FL250. We experienced an explosive decompression, declared an emergency, descended very carefully and landed straight-in on RW26. Two days prior, a combined pressurization/bending/torsion ultimate load static test ended in an explosive decompression due to collapse of the lower aft pressure bulkhead of the static test article. That failure was on our minds during the emergency return to Stead. Maintenance could find nothing wrong with E-001 over a three day examination, but the plane was grouded, parked in LearFan's back lot and was relagated to becoming a garbage can for discarded carbon-fiber parts. E-001 still hangs in the Museum of Flight at Boeing Field.

E-002 was, as I remember, was the static proof test airframe.

E-003/N327ML/N21LF:
This was our first data bird and had a lengthened fuselage compared to E-001. First flight was June or July 1982. My logbook detail doesn't show if I chased E-003 first flight in our T-33 or E-001. N327ML was re-registered N21LF sometime between 6/7/84 and 6/23/84. Rumor had it that there was no love loss between our CEO at that time and Moya Lear and that the N number was changed to spite Mrs. Lear. The blue stripes were also repainted green to reflect the national color of Saudi Arabia (Prince Sultan Bin Salman Al Saud, nephew of the King and a major investor, was a friend and business associate of the CEO). My first flight in N327ML was on 11/11/1982 and last flight in N21LF was 5/10/85 with Dave Anderson. The photo of E-003 at the Frontiers of Flight Museum shows that the data boom has been removed from the nose.

E-004 thru E-008:
My recollection is that these numbers were reserved for static and subcomponent test articles.

E-009/N98LF:
Bob Jacobs was my flight test engineer for the first flight of E-009 on 12/15/1984. My last flights in N98LF were from 4/22/1985 thru 4/24/1985 when Dave Anderson and I flew to Houston Hobby to give an orientation flight to Prince Sultan. He was in training with NASA and later flew on the Space Shuttle. As pointed out in a previous, N98LF is suffering gross neglect by the FAA in the back lot of their OKC facility.

Prop noise? Simply stated...dirty air entering the prop disc.

John Penney

[LearFanKid]

Re: Lear Fan(s)

Whoa..... it certainly interests me. Thank you Mr. Penney!

This is some amazing information. I was just a young kid hired for a summer to sweep the hangers and did not know all of this had happened.

Long time ago, but I seem to recall an event on one first flight attempts. It occured on the runway toward Red Rock. All I remember or knew was a bunch of smoke coming from the wheel(s) of the plane. I think it might have been on the actual 31st and might have prompted the scrub for the successful "retry" on Dec 32. Am I correct and do you know what happened in that scenario?

Thank you again
Bill

[Skyracer]

Re: Lear Fan(s)

Thank you Mr Penney for clarifying the "N" v.s. "E" number business. I had no idea anything beyond the flying airframes would have been serialized as such. Makes perfect sense when you think about it however. Also clears up my "speculation" in trying to corelate numbers to numbers to airplanes.

Excellent explanation of the prop noise thing also...

[First time Juke]

Re: Lear Fan(s)

Many thanks mr. John Penney !

How were the flying qualities of the Learfan ? Why was the second model lenghtened for instance.

regards,

Juke

[First time Juke]

Re: Lear Fan(s)..once more !

Here is another link to Learfan 2100:

http://www.lionheartcreations.com/Learfan_2100_page.html

One question if you took 50-100 mph away of the cruise speed of a LF 2100. How much cheaper woud it have been to operate ?

[Peashooter]

Re: Lear Fan(s)

Here's a sampling of that great B-36 sound!

http://www.youtube.com/watch?v=eNnAUS__jIQ

[First time Juke]

Re: Lear Fan(s)

Here yet another interesting link to LF 2100:

http://www.flyingmag.com/columnists/653/flashback-to-1981.html

I have been trying to figure out the consumption of the plane.

P & W PT6-35 is said to use 54 gallon/hr...that is exactly not very economical is it..two of those makes 108 gallons.

In another site same engine was tuned to yield 500 hp ( istead of flatrated 850 hp of the original )..LF was tuned for 650 hp..and that 500 hp one was said to consume 30 gallon/hr with max TAS.

Does anyone know for sure what was the fuel consumption of LF 2100.

I also found this: http://www.turbokart.com/about_pt6.htm

I appreciate a lot if the info is available. I have been drawing a twin pusher passenger plane.

The Dh Havilland Dragon Rapide engine Gipsy Six uses 10 gallons / hr...okay the plane flies 250 km/h top speed, but is slightly more economical than LF 2100 I assume.

Any suggestion for an engine of 225-250 hp engines for a pusher ?

[First time Juke]

Re: Lear Fan(s)

I rescanned the LF 2100 story on FLIGHT 1981 issue.

Holler me if you want it 4 pages of text ( not the cutaway ).

[LearFanKid]

Re: Lear Fan(s)

Thanks Juke! I PM'd you. Kind regards

[First time Juke]

Re: Lear Fan(s)

I also scanned the cutaway...I'll sent that too.

[First time Juke]

Re: Lear Fan(s)

Here is another good story about it; http://books.google.com/books?id=pQt...202100&f=false