Author Topic: c/n 1215, HC-ATD  (Read 6658 times)

Doug Johnson

c/n 1215, HC-ATD
« on: April 07, 2015, 08:01:23 AM »
1 picture check your albums. Please do an internet search maybe you'll come up with one I couldn't find, I need all the help I can get.

Previous posts about HC-ATD or anything click on  http://flyhelio.com/smf/index.php?action=search  Enter ?

c/n 1215, built 08/66 as model H-295 original registry N275VM Helio factory reserves special registry for customer, AFLC inc (John Hughes) leases to Vulcan Materials co AL sold '69, (SIL) CA (Jaars 19th Helio of 46) NC, dereg export HC-ATD Quito Ecuador, Instituto Linguistico de Verano, Quito (Jaars) accident no details @ unknown area Ecuador '76, dbr, salvage returned to US wings and fuselage used by Clarence Brent in 3800lb upgross STC destroyed in testing dereg ?

    (It was this mishap that led to JAARS developing the crash worthy energy absorbing S-frame seats)

Maybe one of the Jaars people will dig through the files and come up with a description of the accident when it was dereg and a picture.

« Last Edit: October 28, 2019, 07:43:42 AM by Doug Johnson »
Doug

Doug Johnson

Re: c/n 1215, HC-ATD
« Reply #1 on: February 07, 2016, 03:31:55 PM »
found some interesting info upgraded history paragraph

salvage returned to US wings and fuselage used by Clarence Brent in 3800lb upgross destroyed in testing
Doug

Louis

Re: c/n 1215, HC-ATD
« Reply #2 on: February 07, 2016, 08:24:41 PM »
Does the 3800 upgrade, besides it's speed limit, was approved with lowering the amount of G from the original 3.8 for a lower limit ?

Doug Johnson

Re: c/n 1215, HC-ATD
« Reply #3 on: February 07, 2016, 11:04:20 PM »
Louis, I have no idea.

I sent a copy of the upgross file to you.

Maybe you can figure it out and tell us.
Doug

Louis

Re: c/n 1215, HC-ATD
« Reply #4 on: February 09, 2016, 05:58:57 AM »
Very interesting to read.  It give the dimension of the work you have to do to approve a bigger gross weight.  Landing gear, stabilisator, main wing.  I do not yet understand everything, but i continue reading and trying to figure it out.  A lot of the work is done by trying to calculate the safety margins.  And extrapolate for turbulent air.  These calculations are probably why we end up with different speed limits with a 3800 gross weight increase.  So we already can understand that some of the approval for the higher gross weight comes from changing in the POH some speeds limit.  Not just by reenforcing the structure.  It is like approving a new airplane, but using calculation from another.  But i still don't figure out if those change in the speed limit are to approve with a lower G factor than the original 3.8.

I started asking that question when i saw your post about the Car 8 operation at 4500 pounds and over.  Those approval where only based on lowering the G factor limit.  If i remember well, the old Car 3 had a limit down to 3.4  .   But i am not sure at all of that assumption

Louis

Doug Johnson

Re: c/n 1215, HC-ATD
« Reply #5 on: February 09, 2016, 07:17:00 PM »
IN the last month I recall seeing a paragraph in some of the stuff I posted, about the Helio factory giving some consideration to certificating the Helio  under a different part of C.A.R 3.xx than normal,  utility I believe ? If I remember correctly it was a slightly lower G-factor 3.5?

Does anyone following these postings lately remember seeing that ?

I can't seem to find it, and it might help understand this g factor thing I seem to find that the safety factor for normal category is 1.5 of something.

If you've ever tried to read the C.A.R now F.A.R (Federal Aviation Rules Part 3.00) its got a million parts. and then there's the restricted category part F.A.R. 8.00 another million.

I have another study of the the H-395 U-10B that increases the gross to 3600 lb but lowers the VNE by 10 mph it is an interesting study it appears to be a study to increase cg range for marker rockets on the U-10bs that were built as FAC (forward air command) aircraft c/n 547-560, only installed on 552 and 557, 10 others.

Another interesting thing one of the reasons 527 failed the L-28A evaluation was range and endurance because of 60 gal fuel tanks the next four 528-529-530-531 were placed in placed in experimental category for testing of 120 gal fuel tanks and by 10/61 LR fuel became an option for H-395s.

Also interesting is the fact that current owner says 527 has military 120 gal fuel, but it was built with 60 gal tanks possible it was converted while with CIA or DEA.

and all of the air national gaurd Helios 595-625 are equipped for quick disconnect 25 gal fuel bladder that hangs just inboard of passenger door right side.[/color] 

In the CG study it clearly shows the that 532-537 are U-10As the rest are U-10Bs and Ds except the army contract 605-638 designated U-10As but the contract shows they were built under u-10B specs with a 300 lb increase in gross weight. All U-10As appear to have 60 gals of fuel.

AF maintenance records appear to show that that contract 547 to 560 were built as U-10As up until near the middle of the contract some of the last built may have been U-10Bs the earlier aircraft in 08/63 are converted to U-10Bs. 556 seems to be the point where civilian upgross to 3800lb is possible while 3300lb upgrossis possible with 502

The model difference list appear to show that all U-10As have 60 gal fuel and the rest have 120 gals of fuel. edit And we find that doesn't hold strictly true. with first 6 U-10As.

I guess what I'm trying to say is the difference between U-10As and Bs seems to be fuel capacity.



« Last Edit: February 12, 2016, 05:04:36 PM by Doug Johnson »
Doug

Louis

Re: c/n 1215, HC-ATD
« Reply #6 on: February 09, 2016, 08:55:24 PM »
I know that wing attachement are longer inside the wing for a 250  60g wing compare to a 295   120 gallons

But that is no 391 or 395 60 vs 395 120

Louis

jmetzler

Re: c/n 1215, HC-ATD
« Reply #7 on: February 10, 2016, 03:57:10 PM »
Attached is a page out of the Military Manual that shows the configuration/tanking between the various serial numbered Helios.

Regarding wing rear spars, the material thickness of the rear spar is .040 through the H395's. I don't see where the thickness was different for the H391's. When they built the H250/H295 they went to .050 thick material for the inboard spar. The military 120 gallon H395 wings do NOT have the heavy spar as is commonly thought. (It has to be changed or reinforced for the 3800 lb. gross weight) The 60 gallon rear spars are longer (.050, 78") but stop at the end of the spar. The 120 gallon wing rear spars are .050, 68" but then have two more sections, the intermediate spar .040, 57" long and the outboard spar .025, 70" long. I rounded off the numbers a bit.  Jim

Doug Johnson

Re: c/n 1215, HC-ATD
« Reply #8 on: February 12, 2016, 05:00:57 PM »
I added an older U-10 aircraft difference table

It seems to show an upgrade in aircraft.

Apparently the speakers have been removed from all U-10s.

The seating has changed no aircraft have just two seats. some of the U-10Bs have 6 seats.

Tacan has been installed on some of the U-10Ds.

It still appears to me that the difference between an aircraft designated A or B is tankage.

See open aircraft difference tables above I opened Jims table as well the one with light blue background.
« Last Edit: February 12, 2016, 05:03:33 PM by Doug Johnson »
Doug

Doug Johnson

Re: c/n 1215, HC-ATD
« Reply #9 on: October 28, 2019, 08:03:20 AM »
Added the photo above that I found at a Jaars site the caption of the photo is "Griffin (R) and Bub Borman (2nd from L) with colorful Cofan and friends in eastern Ecuador"

There were only 2 Helios that fit the time frame in Ecuador c/n 1215 and c/n 067 had a completely different factory color scheme.

This aircraft is probably c/n 1215 as N275VM.

Can anyone prove or disprove my theory.
Doug