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Cox Engine of The Month
How will gal fly?
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How will gal fly?
It's been a long time since I scratch built anything. Even longer since I flew a ukie. Here are the stats:
Wing area: 80 square inches
Airfoil: Flat bottomed
CG: About 15% MAC (Mean aerodynamic chord), I'm thinking a bit nose heavy but manageable
Rudder area: About 3 square inches with +/- five degrees offset
Engine offset: +/- five degrees
Weight: 6.3 oz. dry weight
Engine: Stock EZ start
Lines: 35 feet
She is just something I threw together (please don't look too closely at the finish... been a long time since I used dope and it didn't agree with some of my adhesives). Should I keep her as a "hanger queen" or fly her?
Last edited by nitroairplane on Mon Mar 25, 2013 9:34 am; edited 2 times in total (Reason for editing : Fixed images.)
flyjsh- Gold Member
- Posts : 129
Join date : 2013-03-12
Location : Houston, Texas
Re: How will gal fly?
Sounds like a winner. Looks good too.
Phil
Phil
Last edited by pkrankow on Mon Mar 25, 2013 8:34 am; edited 1 time in total
pkrankow- Top Poster
- Posts : 3025
Join date : 2012-10-02
Location : Ohio
Re: How will gal fly?
Looked at your scratch build. I see no reason not to fly it. Wait for low or no wind day and go get dizzy
First flight use just enough fuel to make a few laps to see if trimming is required (less offset, more or less tip weight, change CG etc...)
Cool looking aircraft...have fun
First flight use just enough fuel to make a few laps to see if trimming is required (less offset, more or less tip weight, change CG etc...)
Cool looking aircraft...have fun
fredvon4- Top Poster
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Posts : 4012
Join date : 2011-08-26
Age : 69
Location : Lampasas Texas
Re: How will gal fly?
Hello I fixed the image in your original post, unfortunately it's too large to display in full so I added a link to the full image as well.
The plane does look like it'll fly if you get the CG right.
The plane does look like it'll fly if you get the CG right.
Mudhen- Gold Member
- Posts : 489
Join date : 2011-09-19
Re: How will gal fly?
I once built a plane using a used cedar single and IT flew.
I called it "SOS" (_ _ it on a Single)
SD
I called it "SOS" (_ _ it on a Single)
SD
SuperDave- Rest In Peace
- Posts : 3552
Join date : 2011-08-13
Location : Washington (state)
Re: How will gal fly?
I like it. It'll fly fine. 15% is a good safe place to start with the CG. 35' is right. Where's the fuel tank, I didn't see it in the pic? Be sure and file a report when you fly it.
_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
RknRusty- Rest In Peace
- Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA
Re: How will gal fly?
Thanks for the replies and compliments.
The tank is one of these http://coxengines.ca/3-8oz-fuel-tank-for-cox-engine.html. Mounted on the right cheek with the feed line at the same level of the crankshaft.
As for waiting for a no wind day, here in Texas anything under 15 knots is calm, so I may just need to find a big field and be ready to back peddle
The tank is one of these http://coxengines.ca/3-8oz-fuel-tank-for-cox-engine.html. Mounted on the right cheek with the feed line at the same level of the crankshaft.
As for waiting for a no wind day, here in Texas anything under 15 knots is calm, so I may just need to find a big field and be ready to back peddle
flyjsh- Gold Member
- Posts : 129
Join date : 2013-03-12
Location : Houston, Texas
First flight report
Well, got her up today. About half a dozen flights in all. New engine, so I ran it rich. The first three fights my only goal was staying level. The last few included some downwind climbs and upwind dives. (hey, it's been 30+ years since I last flew cl. I didn't want to over do it)
The good news:
The stooge I threw together at the last minuted worked
She took off nicely from short grass
VERY stable in pitch
Only had to back peddle once
Glides reasonably well
Managed 2 wheel landings and 1 almost three pointer
The bad:
TOO stable in pitch/not enough elevator throw (noticed the push rod was flexing and have added a guide to reduce flex)
The "tip tanks" didn't last through two nose overs oh well, they were just for show and I can redo them latter if I choose
Landing gear may need to be beefed up
All in all, I'm am very pleased. I'm just glad the cops weren't around after the first flight: between my smile, giggles, and the staggers, I would have been taken away for Public Intoxication!
The good news:
The stooge I threw together at the last minuted worked
She took off nicely from short grass
VERY stable in pitch
Only had to back peddle once
Glides reasonably well
Managed 2 wheel landings and 1 almost three pointer
The bad:
TOO stable in pitch/not enough elevator throw (noticed the push rod was flexing and have added a guide to reduce flex)
The "tip tanks" didn't last through two nose overs oh well, they were just for show and I can redo them latter if I choose
Landing gear may need to be beefed up
All in all, I'm am very pleased. I'm just glad the cops weren't around after the first flight: between my smile, giggles, and the staggers, I would have been taken away for Public Intoxication!
flyjsh- Gold Member
- Posts : 129
Join date : 2013-03-12
Location : Houston, Texas
Re: How will gal fly?
Good work. Thanks for filing an official flight report. You'll gradually get the bugs worked out. Then you can get bold and ease the CG back and maybe it'll do a loop.
_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
RknRusty- Rest In Peace
- Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA
Re: How will gal fly?
Hey! Good for you. I am glad it went well. Epoxy those tanks on. They won't come off again. Glad it flew for you, it must be a good feeling to build something out of your imagination and actually watch it take flight.
Ron
Ron
Cribbs74- Moderator
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Join date : 2011-10-24
Age : 50
Location : Tuttle, OK
Re: How will gal fly?
SuperDave wrote:I once built a plane using a used cedar single and IT flew.
I called it "SOS" (_ _ it on a Single)
SD
Now that's funny
Cribbs74- Moderator
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Posts : 11907
Join date : 2011-10-24
Age : 50
Location : Tuttle, OK
Re: How will gal fly?
cribbs74 wrote:Hey! Good for you. I am glad it went well. Epoxy those tanks on. They won't come off again. Glad it flew for you, it must be a good feeling to build something out of your imagination and actually watch it take flight.
Ron
Thanks! The glue joint held, but the sheet (1/8") was way to thin and snapped at the joint. After I beat her up some more I may go back and use 3/8". But there is a part of me that likes having a ding or two to prove it isn't just a hanger queen.
Yeah, I was actually quite surprised how mild mannered she was. Either that or 7000 hours of flying full scale birds has made me less ham-handed than that 12 year old kid I used to be.
flyjsh- Gold Member
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Join date : 2013-03-12
Location : Houston, Texas
Ooops!
Went out today to see if the push rod guide improved things. It did, now she has a lot more elevator authority. Also I started to lean the engine out. Extra speed probably also helped with the pitch response.
Unfortunately....
On the second flight, she went suddenly nose first into the grass (at least it WAS grass not pavement). A full investigation by the NTSB was conducted. This is the report:
NTSB Identification: CEN13LA001
14 CFR Part 91: General Aviation
Accident occurred Tuesday, 26 March 2013 in Houston, TX
Probable Cause Approval Date: 03/26/203
Aircraft: JSH T-5 (experimental) registration: N100TF
Injuries: 1 Uninjured.
NTSB investigators used data provided by various entities, including, but not limited to, the Federal Aviation Administration and/or the operator and did not travel in support of this investigation to prepare this aircraft accident report.
While on a testing flight following modifications made to the elevator control system, the pilot experienced a sudden, uncommanded full down elevator condition. The pilot was unable to recover from the resulting dive, and the plane impacted the ground approximately 32 feet south of the pilot in an open field. Examination of the aircraft showed the engine, fuel cell, and landing gear all separated from the airframe. Further examination of the elevator control system identified a failed "up" lead out line.
The National Transportation Safety Board determines the probable cause(s) of this accident to be:
erosion of the dacron lead out line caused by the line guide.
Following the release of the Board's findings, the FAA made the following statement:
“As a result of a JSH T-5 accident today, the FAA will issue an emergency airworthiness directive (AD) to address a potential elevator lead our line failure risk in the T-5 and require operators to temporarily cease operations. Before further flight, operators of U.S.-registered, JSH T-5 aircraft must demonstrate to the Federal Aviation Administration (FAA) that the lead out lines and entire elevator control system is safe."
The management of JSH Aviation Inc. released the following statement:
We are cooperating fully with the FAA on this matter. We have already developed a steal wire replacement for the dacron lines. Additionally, we have repaired the prototype and expect to resume testing tomorrow.
Yep, she's back together... WITH new, more robust tip tanks and landing gear. Tomorrow, we fly again!
Unfortunately....
On the second flight, she went suddenly nose first into the grass (at least it WAS grass not pavement). A full investigation by the NTSB was conducted. This is the report:
NTSB Identification: CEN13LA001
14 CFR Part 91: General Aviation
Accident occurred Tuesday, 26 March 2013 in Houston, TX
Probable Cause Approval Date: 03/26/203
Aircraft: JSH T-5 (experimental) registration: N100TF
Injuries: 1 Uninjured.
NTSB investigators used data provided by various entities, including, but not limited to, the Federal Aviation Administration and/or the operator and did not travel in support of this investigation to prepare this aircraft accident report.
While on a testing flight following modifications made to the elevator control system, the pilot experienced a sudden, uncommanded full down elevator condition. The pilot was unable to recover from the resulting dive, and the plane impacted the ground approximately 32 feet south of the pilot in an open field. Examination of the aircraft showed the engine, fuel cell, and landing gear all separated from the airframe. Further examination of the elevator control system identified a failed "up" lead out line.
The National Transportation Safety Board determines the probable cause(s) of this accident to be:
erosion of the dacron lead out line caused by the line guide.
Following the release of the Board's findings, the FAA made the following statement:
“As a result of a JSH T-5 accident today, the FAA will issue an emergency airworthiness directive (AD) to address a potential elevator lead our line failure risk in the T-5 and require operators to temporarily cease operations. Before further flight, operators of U.S.-registered, JSH T-5 aircraft must demonstrate to the Federal Aviation Administration (FAA) that the lead out lines and entire elevator control system is safe."
The management of JSH Aviation Inc. released the following statement:
We are cooperating fully with the FAA on this matter. We have already developed a steal wire replacement for the dacron lines. Additionally, we have repaired the prototype and expect to resume testing tomorrow.
Yep, she's back together... WITH new, more robust tip tanks and landing gear. Tomorrow, we fly again!
flyjsh- Gold Member
- Posts : 129
Join date : 2013-03-12
Location : Houston, Texas
Re: How will gal fly?
Thorough report, JSH. Glad you're cooperating. Standing by for further testing.
Sincerely,
RknFly Aviation and Gopher Divers, LLC
_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
RknRusty- Rest In Peace
- Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA
Re: How will gal fly?
Funny stuff!
Been there, it sucks when a line departs from the plane. Try Spyder wire. It's pretty forgiving.
Been there, it sucks when a line departs from the plane. Try Spyder wire. It's pretty forgiving.
Cribbs74- Moderator
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Posts : 11907
Join date : 2011-10-24
Age : 50
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Re: How will gal fly?
cribbs74 wrote: Funny stuff!
Been there, it sucks when a line departs from the plane. Try Spyder wire. It's pretty forgiving.
I have Spyder wire as the flight lines. I had the dacron left over and thought I would use it as the lead outs. The thing I hate about Spyder Wire is it is darn near invisible when lying on the grass.
Funny thing about building these planes at my age: when I was a kid, I would have been upset about a crash, but now I realize it is just a couple hours to fix and I fly tomorrow. I'm just mad I broke a perfectly good prop... at least I ordered a few spares.
John
flyjsh- Gold Member
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Join date : 2013-03-12
Location : Houston, Texas
Re: How will gal fly?
If I can build and fly a plane based on a used cedar single (I did as joke) most anything can fly given enough power. The "SOS" would even do a passible loop with a healthy BW up front.
A begining CL pilot should start with a simple, profile slab wing design and consider it expendable advancing to "prettier" planes as flying proficiency advances. It's called a "learning curve" and everyone goes through it crashes included. Consider them as inevitable but learn from them and you'l do fine.
SD
A begining CL pilot should start with a simple, profile slab wing design and consider it expendable advancing to "prettier" planes as flying proficiency advances. It's called a "learning curve" and everyone goes through it crashes included. Consider them as inevitable but learn from them and you'l do fine.
SD
SuperDave- Rest In Peace
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Join date : 2011-08-13
Location : Washington (state)
Re: How will gal fly?
I've flown a shingle before too. Set up proper they can fly pretty good. The coroplast wing in the plans section is effectively a plastic plank.
Do a doubled knot, form a bight in the line (fold it over double) and pass the bight through the terminal, then tie the knot in the doubled line. This should improve the wear resistance. Also double check for a burr on the bell crank, especially if it is a metal crank.
Lastly, you can reinforce the eye of the loop with a bent tube.
http://www.stunthanger.com/Bellcrank.htm
http://www.stunthanger.com/tips.htm
Phil
Do a doubled knot, form a bight in the line (fold it over double) and pass the bight through the terminal, then tie the knot in the doubled line. This should improve the wear resistance. Also double check for a burr on the bell crank, especially if it is a metal crank.
Lastly, you can reinforce the eye of the loop with a bent tube.
http://www.stunthanger.com/Bellcrank.htm
http://www.stunthanger.com/tips.htm
Phil
pkrankow- Top Poster
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Join date : 2012-10-02
Location : Ohio
Re: How will gal fly?
Funny..in the PNW (Pacific North West) I used to poach cedar from the Olympic National Forest for profit (cash)..Super Dave may know of what I speak
Once I crafted a crude airplane from a cedar "shingle" for a sickly Enya .35.... on 50' lines the sucker flew pretty well
Later I added a "Underdog" profile...
Back to the NTSB report.....as a U.S. Army crash investigator, I am interested in the notes to aviator, management, and any remedial considerations that are not normally publicly disclosed.
Safety being paramount---- was a proper pull test conducted? Was the construction such that a failure of a control component had a fail safe configuration to prevent loss of life or property?
This all in jest for the OP.... But the stories I can recount from real life aircraft accidents are NOT.
Once I crafted a crude airplane from a cedar "shingle" for a sickly Enya .35.... on 50' lines the sucker flew pretty well
Later I added a "Underdog" profile...
Back to the NTSB report.....as a U.S. Army crash investigator, I am interested in the notes to aviator, management, and any remedial considerations that are not normally publicly disclosed.
Safety being paramount---- was a proper pull test conducted? Was the construction such that a failure of a control component had a fail safe configuration to prevent loss of life or property?
This all in jest for the OP.... But the stories I can recount from real life aircraft accidents are NOT.
fredvon4- Top Poster
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Location : Lampasas Texas
Re: How will gal fly?
Fred: Actually if you visit shake mills on the Olypmpic Peninsula they have plenty of scraps to give away free. Just don't swipe an entire shake "block" from which singles are cut.
SD
SD
SuperDave- Rest In Peace
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Join date : 2011-08-13
Location : Washington (state)
Re: How will gal fly?
I suppose that would be the other line. At least it protects other people's property.fredvon4 wrote:...Was the construction such that a failure of a control component had a fail safe configuration to prevent loss of life or property?...
_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
RknRusty- Rest In Peace
- Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA
Re: How will gal fly?
fredvon4 wrote:
Back to the NTSB report.....as a U.S. Army crash investigator, I am interested in the notes to aviator, management, and any remedial considerations that are not normally publicly disclosed.
Safety being paramount---- was a proper pull test conducted? Was the construction such that a failure of a control component had a fail safe configuration to prevent loss of life or property?
This all in jest for the OP.... But the stories I can recount from real life aircraft accidents are NOT.
Initially, the FAA wanted to violate the pilot, mechanic, and builder. The pilot for not doing a proper preflight (I'm not sure what a "proper" pull test is, but I yank 'em a lot harder than the plane does). The mechanic for not servicing the line guide until it was pointed out that the grommet requires no mx. The builder for poor design of the guides until we reminded the investigators that the inspectors at the Houston FSDO had signed off on the plans and construction.
Yeah, real investigations are not fun. I've had the "honor" of participating in a few... on both sides of the table. I've got the 44709 ride to prove it.
On to today's progress. Five flights. 123 laps total (I want to practice for the upcoming contest ).
First flight: Shortly after takeoff, unbeknownst to me, the little binding post on the handle used to trim the lines broke off. Anytime there was a significant difference in tension between the lines, the line slipped through the holes on the control handle and the trim was reset. I managed to land safely. I made a battle field modification to the lines, and testing continued. 28ish laps (I was a bit preoccupied the first few and may have miscounted).
Second flight: Nosed over on take off: I let the tail come up too quickly. No damage. Zero laps.
Third flight: Flew well. Nice wheel landing with fairly long roll out. 33 laps.
Forth flight: Flew well. Began working on climbs, descents, level flight at different altitudes (boy, I just got a flashback of instructing in a 152 ). Nice 3 point landing. 34 Laps.
Fifth flight: Continued to work at various altitudes. Engine quit turning from the upwind (moving to a tailwind condition) and at about 7 feet AGL. Pilot failed to set Vbg (best glide speed) resulting in an excessive sink rate. The plane landed hard on the wheels in a slightly nose down attitude. Landing gear sheared off taking the engine with it. 8 laps.
The gear continues to be a weak link. I need to redesign it... maybe figure out a rubber band mounting. Hmm.
flyjsh- Gold Member
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Location : Houston, Texas
Re: How will gal fly?
I love this thread flyjsh
Did you fly for the military in a previous life?
remember if you bend the wire struts forward so tires are below prop (probably the best fix) you will change the CG forward
Did you fly for the military in a previous life?
remember if you bend the wire struts forward so tires are below prop (probably the best fix) you will change the CG forward
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