Hatz Biplane Association

I crawled in the pilot seat of the CB -1 project I bought to find I was gonna be cramped....legs too long. I noticed Mark Lightsey said his was comfy so I called him to see why. Mark said the seat and accompanying structure was moved back to give more leg room. I'd like to go 4" back. Does anyone know what the mod called for? 3" or 4"? Thanks for any feedback. Gaylon

I tilted the top of the seat back 4" but didn't move the seat itself.

Jeff Moore

I would consider moving/tilting the seat back as well but you might also consider moving the rudder pedals. Attach them to the lower longerons rather than the X tubing. This is done on the classic and gives more room. You might also consider running the rudder cable outside the fuselage tubing, again as is done on the classic. All these things added up are what gives the Classic cockpit the larger "feel".

Bill

Bill is right about reclining the seat and moving the pedals. IF you are an EAA member go online and look at the October 1997 issue of Sport Aviation. In it is a write up on Billy Dawson's Classic (the first Classic) and lists some of the changes he made vs. the CB-1.

Regarding the seats & rudder pedals, these changes include:
Front Seat: More reclined and moved back 2 inches
Front Rudder Pedals: Moved forward 2 inches
Rear Seat: More reclined and moved back 4 inches
Rear Rudder Pedals: Moved forward 3 inches

Also, as Bill points out: the attachement points for the rudder pedals was moved outboard to the longerons and the cables were routed down the outside of the fuselage tubing.

If you go the the Builders Pages section of our website and look at Hans & Sam Gautschi's website (click on the "Vintage Hatz link and then Gallery) you will be able to find some shots that show the rudder pedal installation.

Hi guys...thanks for the input

Tilting the seatbacks sounds like a great idea for comfort but I will need more room than that generates so guess I'll think about moving the rudder pedals. Hate to ....they are already cabled together and to the rear as they are now....will be some serious redoing. But if I can't do it any other way ....as needs be.

I really think the seat will have to go back some ... any CG problems there? The battery, and cables are behind the seat now .....M.Lightsey suggested moving them forward to offset the weight movement in CG and that sounds like a plan .....but will it be enough if the seat moves my weight back 3 or 4"? I'm 215 lbs. so that might be a consideration... I dunno. Thing is the top of both seats are attached to a crossmember welded to the top longerons.....if I move them back or even tilt them back I'll have to move the fuselage crossmember to do it....back seat not as much problem as the front....in front you're talking about the space between the rear seats control panel and the front seat back which is already filled with gages and wiring....a dilema. I think the only way to stretch the front is move the bottom of the seat and the rudder pedals forward ( see above complaint ). Goodness complaining already.....believe me when I say I will have a big grin on my face regardless....really can't wait to feel her in the air.

I had thought to move the rudder cable outside the fuselage before you guys mentioned it, glad to hear you all say that..... I'm definitely going to add the extra stringers as Billy Dawson did to round the fuselage......like that look.

Doug I'll check out that issue of Sports Aviation ....I've been an EAA dreamer for years. Billy Dawson's Classic is an awesome looking plane. I'll also check out Hans and Sam's website you mentioned for the tech pics too.

I'm going to an EAA class in covering in March so I should know more then but I'm wondering .....will I completely trash the skin on the fuselage now taking it off to do what I need to ( its on, pinked and stretched ) or is there any way to save some of it or is that even something to worry about? Don't see how I'll get around taking it off....and I'd like to work on the fixes I need to before March comes around. I had hopes of flying this summer.

Enough for now. Back at you all later.

Gaylon

Since you are dealing with a fuselage that is already complete (or mostly complete), moving the seats may not be an option. I believe the Classic has had the crossmembers moved as well (as you noted) to accomodate the changes for the seats. I don't have a set of CB-1 plans to compare to the Classic, but I'm fairly certain that this is the case.

Someday I'll get a set of CB-1 plans and make a thorough analysis of the differences between the Classic & CB-1.

As for the fabric, I agree that you won't be able to make these changes without removing it. You'd be welding way too close to avoid damaging it. Besides, if you want to add stringers, then you'll have to take it off anyway.

Routing the rudder cables down the outside of the fuselage will involve adding some short pieces of tubing to hold fairleads to guide the cables.