CARBURETOR TROUBLES AND CONTROL SENSITIVITY – part 2 of a series
Last month, I commented on a “first flight” I had made, and some of the errors I made that added to the excitement of that first flight.
In that article, I mentioned there were a couple of items that had to be addressed before any other flights were to be made. Reducing the throttle for landing resulted in no power. To resume power I had to push to nearly full throttle, so the approach to landing was not very smooth. Yet, once the plane was on the ground, the idle was perfect and the response through the range of throttle settings was good.
I asked for help from the few people who had converted VW engines, or had used the Tilletson carburetor. (This carburetor had been used on Harleys and some industrial applications, so I thought it would be OK. That was the whole science behind my selection.)
One opinion offered was that the ram air intake was pressurizing the carburetor and disrupting the diaphragm that controlled the float needle. I constructed a baffle so the air would not directly enter the carburetor, and the problem was solved.
The pitch stability of the plane was a nightmare. The designer elected to use a stabilator, but with no anti-servo capability to offer feedback. The stick acted neutral and did not offer much resistance to my input. Furthermore, it was horribly pitch sensitive, so very little input gave dramatic results.
I checked the designer’s bell-crank and control arm lengths to be sure I had it per the plans, and it was. To reduce the pitch sensitivity I constructed a new control arm on the stabilator that doubled the length of the arm from the pivot point. This effectively required twice as much control stick deflection to move the stabilator. This change made the plane flyable, but it was never “hands-off “ stable.
Remember that all of this happened in the early 70’s when kit planes had hardly developed and some people were selling designs that were truly “bad news”. The next generation of the Jeenie Teenie to come out dispensed with the stabilator, and went to a conventional horizontal stabilizer and elevator.
Lessons learned:
Aircraft designs that have been out for a short time have not had the problems worked out. Only consider a design that has been flying for a number of years, and let someone else do the development.
Get help from people that know the function of particular systems. It may have taken ages to work out the had not someone told me that a diaphragm carburetor was so susceptible to ram air disruption. Lengthening the control arm on the stabilator came from my control line model airplane experience, but still, here is where help from the experienced builder is good to have.
After the changes were made, I flew the plane successfully for six years before selling it to a person from California. He was a brave pilot to fly the plane from California to Oshkosh and back.
WINTER FLYING
By Jim Ylvisaker
It was a long wait through soggy November and most of December, but we finally got a return of those terrific flying days when the air is so smooth you feel suspended up there and the sky so clear you really need the word ‘unlimited’ to describe visibility. I love winter flying, and so does the airplane. Good chewable air, not that anemic stuff of summer. This is meaty air that makes a 172 feel almost like a 182. Of course we don’t get enough flying weather in winter, but that, too, enhances one’s appreciation of the fly days we do get. Each one is precious and to be savored.
My latest flight and the one that prompts these somewhat romantic observations about winter flying was a Christmas Day excursion around Mt. St. Helens with my daughter in law Jessica and grandkids Mat and Michelle. Both kids had been up with me before, but this trip for Mat was special because now he was eight and could qualify as a Young Eagle. He was really looking forward to getting the certificate, like the one his sister got last summer.
After pre-flighting the Skyhawk which included a review of nomenclature and an ‘aha!’ when we found a bubble of water in the gas sample from the left wing tank, we were ready to crank it up. I had to wait a bit longer than usual for oil pressure to indicate but layed that off to the necessary use of single viscosity mineral oil for break in purposes (six new cylinder kits at annual four hours back), but it was still in the ball park - 40 seconds at idle. I made a mental note to have Mike bleed the line when we change the oil after this flight as air in the line could delay a reading.
We departed a bit after 2:30 PM and as we climbed out NE we had Rainier dead ahead and lit up like a Christmas ornament with late afternoon sun bathing its slopes. Mt. St. Helens was not similarly lit but we still had a good view of the crater and Spirit Lake as we approached from the northwest. Mat was flying and with just a little help kept us at 7,500’ and reasonably clear of the mountain as we rounded to a southwest heading. Then came the ‘oohs’ and ‘ahs’ as the late afternoon sun was filtering through several cloud layers and showing a vivid pink to red glow.
I thought about staying up for the sunset but remembered that Iım not current for night flying with passengers and decided not to delay. Mat was fascinated with checking his visual orientation with the artificial horizon and only reluctantly gave up control of the airplane so I could set up for a landing. Our eyes stayed with the light show in the west as we went over the top from the east to circle back for a 45 entry for rwy 30. Its always hard to turn away from a display like that and the disappointment was palpable as I announced and then turned downwind.
Winter flying is often special just because of conditions, but this flight had the added dimension of sharing the specialness with others. The moral of the story? Take a friend up to share the adventure - especially a young friend. The glow lasts.
The meeting was called to order shortly after 7:00pm. Jerry asked for a positive poll as to who received the email newsletter and the majority of those attending raised their hands.
Tony Bequette was recognized for his purchase of the Cherokee sailplane. The sailplane resides in the chapter hangar and now has a much better chance of feeling air under its wings with its new ownership. Although the sailplane appears to have been well cared for over the years, it still needs a bit of TLC before getting back into action. Good Luck Tony!! Tony also opened a box of stuff for bartering. The box included quite a few old Sport Aviation magazines, some old instruments, and other misc. odds and ends. If anyone is interested, please contact Tony. Tony's contact information can be obtained from Jerry Sorrell.
Jerry mentioned he has an electric turn coordinator he recently pulled from his panel. More details in the classifieds section.
Bob Elliot was introduced as a new guest. Bob used to be an active pilot but then lost his medical. There was brief talk about the newly proposed sport pilot aviation classes in the FAA and other ways to continue to legally fly after losing ones medical. Bob graciously donated a kneeboard and a nice compact E6-B to the chapter. The donated materials will be raffled off at the annual EAA 1111 Fly-In at Kelso with the proceeds benefiting the chapter.
A hearty thanks to Bob Taylor who out-did himself by bringing the food to the December meeting. Bob has accepted the position of hospitality chairman for the chapter. Please be conducive to helping him bring goodies when he requests it.
Al Drewry gave the Treasurer's report. We have $74.36 in checking, $2415.77 in savings, and $7000.00 in a CD.
Hopefully by the January meeting, we will have the calendars for the year 2002. Details are in the classifieds section. The calendars promise to have loads of great pictures for everyone. Prices are unknown at this time, but we all know they are priceless, right?
The 2002 Fly-In is rapidly approaching. Fernando is leading the charge on that front and will be organizing a meeting soon. We will do everything we can to avoid having our fly-in on the same weekend as the RV fly-in at Scapoose.
Jay Tabor presented some things to previous officers from the national level which he received in the mail. Terry Creamer and Mike Lewis got certificates and Jay Tabor and Jerry Sorrell got pins in recognition for their service to the chapter in recent years. Congratulations, guys!
Mark Edwards gave an excellent presentation on fabric covering. He proved men can indeed perform wonders with an iron and stitching needle!! Mark is in the process of building a Wag Aero. Mark is more than willing to answer questions and give assistance to others who may have questions about a tube and fabric project. He made it clear, he would love to offer assistance but WILL NOT be performing work for hire!! :-)
Meetings are usually held the first Thursday of the Month, 7:00 p.m. They are held at Kelso Flying Service located on the east side of the Kelso airport. Everyone is welcome! Bring a friend!
The officers generally meet in Mike Lewis’ shop at 6:00 p.m.
After review of the national EAA video, Mark Edwards and Mike Lewis have decided it would be a great idea if the entire chapter watched the EAA video this month. The video includes topics with which we are already familiar and adds an interesting spin/refresher on topics such as incorporated by-laws, insurance, finance, and membership. We will also have a round of project updates from the members to get a feeling of how everybody is doing.
Jay took me in his Glastar last week. We did some time to climb runs to get the best rate of clime speeds. He will probably use 100 mph, as it gives good performance and good view over the nose.
Buy, Sell, and Swap your stuff here!!!
The
calendars are here!! The calendars are here!!
The 2002 EAA calendars are here and they look great! With 13
months of 12" x 24" pictures, you are sure to find a
plane to fit your fancy. The calendar also has dates and web site
details to assist in planning your trip to Oshkosh and many other
EAA Regional Fly-Ins throughout the country. Don't dally, don't
hesitate, get your calendar before it's too late. Price TBA.
Jerry Sorrell has an electric turn coordinator, which was recently swapped, out of his plane for a new one. He says his old one could very well be used as a trade-in core or may even be parted out. Please contact Jerry.
Tony Bequette has a few items for sale and/or trade. Contact Tony at tbquette@pacifier.com or contact Jerry for Tony’s phone number.
Complete "Whing Ding” plans and instructions dated 3/24/71.
A complete Aqua Glider plans and instructions.
Book, "How to build Ultralights" by Herb Beaujon, no date but of early '80s vintage.
Book, "Hang Gliding" by Dan Poynter 1974
A small vacuum venturi.
A "Tactair, Inc" directional gyro w/ t-3 autopilot, requires 4 in vac source. Condition unknown but seals still intact.
Two pair clearance lights
One pair source unknown complete
One pair Grimes, model A 1 missing green lens
One white lens Grimes an 3091-2
Gauges
One Manifold pressure
One vacuum
One tachometer cable 36 inch
An Osprey 2 Project, approximately 60-70% complete, fuselage structure, tail feathers, one wing, some metal fittings (landing gear) plans, instructions, builders log book.
January is the month to make sure you renew your everlasting support to the club!!! Please take care when writing out your checks and lets not have everyone rush Mr. Drewry at once!
Dues are $24.00 per year. If you join midyear, they are pro-rated $2.00 per month. Send dues to treasurer Al Drewry. Include your National EAA number, as the Chapter 1111 bylaws require it for membership.
If anyone has anything they would like to share, (a nice trip, lessons learned from flying or building, project status, or whatever) please don’t be shy. I would love to work with you to get your thoughts and ideas published. Your contributions make the editor’s job much easier and it makes for a better newsletter.
Although we will send the newsletter to you via ‘snail mail’, please seriously consider receiving it electronically via email as it saves the chapter significant amounts of money.
President & Tech Counselor |
Jerry Sorrell | 263-1532 | jsorrell@wa-net.com |
| V. President | Mark Edwards | 225-8821 | cubace32@hotmail.com |
| Treasurer | Al Drewry | 274-6115 | |
| Secretary & Newsletter Editor | Eric Hoppe | 263-6691 | behoppe@tds.net |
| Tech. Counselor | Jay Tabor | 425-6278 | jtabor@scattercreek.com |
| Member at Large | Mike Lewis | 274-8860 | michael@kalama.com |
| Historian | Bev Smith, Lou Ann Tabor | 274-8860 | michael@kalama.com |
| Hospitality chairperson | Bob Taylor | 576-3806 | bobtaylor15@attbi.com |
| Young Eagles Coordinator | Karen Fenton | 546-1550 | figi152@aracnet.com |
| Fly Out Director | Jim Ylvisaker | 636-0242 | jlemieux@teleport.com |