Bringing G-BMSL up to snuff!
G-BMSL was snuggled up nicely to Guy’s Isaacs Fury project on arrival in Devon in 2016.
Guy Smith has been working diligently in his spare time to get Clutton FRED G-BMSL flightworthy since purchasing the plane from me last summer. One of the key items on his punch list was finding a better alternative to the tailwheel spring that broke when the plane was delivered to me by the previous owner. Guy also points to this “Tailwheel Shimmy” article by a Bearhawk builder as a useful reference for getting the tailwheel geometry right. Here are some notes and pictures of his recent progress.
Here is the offending broken tailwheel spring, originally a Slingsby glider skid as per the plans.
April 11, 2017
Hi Matthew, Just a note to say hi, and I have begun working on Fred to make him flyable this season. I have sourced an Aeronca tail spring, designed to fit a tail wheel, that fits a treat (throw away one leaf) and shortly it will be back on the ground, in fact a few nuts and bolts came this morning. I have some issues with the fuel gauge leaking, so intend to blank it off in the shorter term. The inspector is ready to go, so watch this space. I hope to have it permitted in the near future. Hope all well with you and your flying. All the best, Guy
Here’s the old Slingsby skid, which was never designed for a tailwheel, and the new Aeronca tailwheel spring as delivered (left) and with the tailwheel attached but minus one leaf for the lighter load of a single-seat FRED (right).
April 12, 2017
Hi Matthew Here are a few details. I bought it from LAS in the UK. [EDIT: It is actually sourced by them from Univair.] It is from an Aeronca 7AC or 11AC, according to the web site: Aeronca part number U3-428-1 130302 and U3-428-2 130303. It is LAS part number 06-14400 and comes with 3 leaf springs. I have binned the short one. I enclose a picture, which shows the difference in angle compared with the Slingsby Glider skid spring, which is specified in the FRED drawings. The problem with the glider skid, is that it was never designed for a tail wheel, and mounts the tailwheel king pin at too shallow an angle, and it is prone to shimmy. I have the same problem on my T31M and will change that one soon as well. This new spring is a greater angle, and as you can see, mounts the king pin more vertically. I will follow up with a picture when it is fitted. Kind regards, Guy
Here is G-BMSL’s new tailwheel spring installed.
April 14, 2017
OK it is on, and I have a tail wheel for the first time since I bought it. It looks really good, as you can see the king pin angle is much better. It remains to be seen if it shimmys. I have also made a longer plate to fit right under the whole thing on the bottom of the fuselage. The idea being to spread the load of the spring bouncing against the wood. I did the same on my T31m, because it was never designed for the loads of a wheel, just a skid. Pictures enclosed. Guy
And here is another shot of the final installation.
May 18, 2016
Hi Matthew, Just a quick Fred update. I have been working on it this spring, and have had a few small jobs to do prior to permit. I have fitted a nice Aeronca tail spring, and it now has a tailwheel again. I have replaced the fuel gauge with a new one from Aircraft Spruce, and that looks super. The latest thing to hold it up now is a very small hairline crack in the prop tip, so the prop is off and about to go back to Chris Lodge tomorrow.So not yet flown it, but it gets gradually nearer. It runs and starts very well indeed, so will be a good flyer, I have also rigged it several times by myself, so all very promising. All the best, Guy
Keep up the great work, Guy, I can’t wait to see your (formerly, briefly “my”) FRED flying!
BONUS: Here are a few comments from Eric Clutton himself on the tailwheel in the original prototype FRED:
FRED never had an aircraft tailwheel. They were too big and too heavy, not to mention too expensive! It was intended for only a 4" wheel (off a shopping trolley ) with a urethane solid tyre. I only used two in fifty years because FRED's ground speeds are not sufficient to warrant something off an Aeronca and similar but the steering is excellent and I figure if I fastened a pencil to the tailwheel I could write my name on the runway with a bit of practice! The shopping trolley wheel is easy to modify with a ball bearing centre if desired. It was so much lighter than the wheelbarrow device in your photos that the fastening etc was perfectly adequate. ERIC.
All photos courtesy of Guy Smith