Author Topic: Helio's early days Part 1 of The Factory Prototypes  (Read 6751 times)

Doug Johnson

Helio's early days Part 1 of The Factory Prototypes
« on: March 09, 2016, 12:43:41 AM »
This was put together with the FAA files OF N9390H, N74151, and N92859, and some stockholders reports.  If the aircraft was never assigned a registry number it has no FAA file.
 
I have only been able to find 1 Helioplane-four file apparently 2 and 3 were never assigned registry numbers. In the first registry for N74151 it is an H-3 s/n 1, after conversion it is an H-390 s/n 100 last registry when asking for permission for flight to Canada it is listed as a H-391 s/n 1.

I have included the stockholders reports and reviews that Bob Mikkelson sent to me.
Bob purchased these files from Clarence Brent's Widow, the pencil parks are were probably added by Clarence Brent.

For the pictures and magazine articles.

See previous posts of prototypes part 2     http://flyhelio.com/smf/index.php?topic=641.0

After looking at this post check out the 3rd part    http://flyhelio.com/smf/index.php?topic=1297.msg5127#msg5127


Helio's early days,
was a series of Prototypes from late '49 to 11/54.

First was a model HC-1, Second model H-3 then 1 of 3 converted to model H-390 renamed H-391, Third model an H-391A converted mostly with paint scheme to Army YL-24A

The Helio aircraft begins with N9390H a 2 place model HC-1 (a highly modified Piper Vagabond) as proof of concept prototype Helioplane and after some testing of control modifications, change from full span flaperons alone added spoilers then (removed) them, replaced with similar interceptors, wide chord Frieze ailerons and 3/4 span Fowler flaps that were to be used on next model H-3. N9390H was removed from service and placed in storage at Smithsonian.
 
Next a proof of concept prototype N74151 (1 of 3) a 4 place Helioplane-Four (Executive) model H-3, with 145 hp Continental Engine (C-145-4) with V belt reduction drive and 108'' Aeromatic prop was built and placed in experimental category (a plan for Aeronca to certify and build 100 H-3s was dropped shortly after the Korean war began in 06/50 because of material shortages) the H-3 model was placed on hold.
 
N74151 was modified changing from spoilers to interceptors and increasing tail size and cowling modification for conversion to larger 240hp geared Lycoming eng and Hartzell 101'' prop to develop a military version.

Renamed  model H-390 s/n 100 "Helio Courier" because with larger engine and shorter prop it was no longer considered a Helioplane.

Renamed model H-391 s/n 1 "Helio Courier" when 260hp lycoming eng was installed

Shortly before a planned demonstration trip to Fleet mfg in Canada there was an accident, a crash 1 fatality while returning from Benington VT to Norwood MA the pilot encountered severe snow squall with marginal VFR and turbulent winds up to 70 mph crashed about 200 yds from Assabet river @ West Concorde MA 01/54, dereg as destroyed 02/54.

The other two H-3 Helioplanes built, I believe one was probably converted to the H-391A N92859 used to continue developing an A/C suitable for the military and the last incomplete H-3 was stored, probably for the proposed lower powered less expensive HelioPlane for personal and pleasure use, it was still stored at Canton MA during flood 04/55 its fate unknown, but as in future practice, probably recycled into one of the later H-391B Helios.

Replaced with the 3rd prototype N92859 was built using incomplete H-3, and was named ''Helio Courier'' Model H-391A because it was no longer considered a Helioplane, with the increase to 260 hp geared Lycoming eng with pressure carburetor and shorter Hartzell 101'' prop. N92859 was then converted (painted) as a US Army YL-24A prototype reg canceled 08/53 when sold to Army as s/n 52-2540. A plan to build 2 more H-391A/YL-24s was dropped probably due to canceled L-24 contract AF-33(600-9974). the aircraft is listed by US Army as being preserved at Ft Rucker AL Army Aviation Museum, but not there in 06/97, fate unknown  ?


stockholders report 1950, may 15




Note that 3 H-3s are under construction only N92859 seems to have been completed as no other Helioplanes were assigned registry numbers by the CAA.


 note the reverse tricycle gear


note fabric covered tail cone. I suspect the penciled in reference to a metal covered tail cone is for the H-391A/L-24A






stockholders report 1950, sept 11




stockholders report 1951, jan



stockholders report 1951, aug


stockholders report 1951, sept

note the ref to H-391A











stockholders report 1952 sept



stockholders report 1952 nov
this is ref to H-391B

« Last Edit: April 28, 2021, 07:09:19 PM by Doug Johnson »
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« Reply #1 on: March 09, 2016, 12:46:42 AM »
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« Reply #7 on: March 09, 2016, 01:15:16 AM »
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Doug

Doug Johnson

Re: Helio's early days
« Reply #8 on: March 10, 2016, 01:24:38 AM »
While checking to see if anyone was actually interested in This I noticed that while cutting and pasting the above together, I had left out the links

to the two previous posts on prototypes. If you do compare the three and notice any conflicts would you point them out to me.

For the pictures and magazine articles.

See previous posts of prototypes part 1     http://flyhelio.com/smf/index.php?topic=641.0

After looking at this post check out the 2nd part    http://flyhelio.com/smf/index.php?topic=1297.msg5127#msg5127
Doug

Doug Johnson

Re: Helio's early days Part 1 of The Factory Prototypes
« Reply #9 on: April 28, 2021, 07:11:54 PM »
changed title
Doug