request for input about skylights and sea plane doors for QB kits

M

Mark Goldberg

Bearhawk Aircraft
Yesterday, a kit builder made two suggestions about two "options" he would have liked to have seen when ordering a kit. I would like input from kit builders or just guys interested in the kits. We are talking 4 place BH here.

First, a decent percentage of builders install a skylight and usually have to modify some things to get it to work as Bob designed the upper cabin for fabric covering. My question is this: How many have used skylights or alternately wish their kit had been set up by the factory for a skylight? I understand the serious mountain flyers view the skylight as very beneficial. But not everyone flies in those mountain valleys.

The easiest way to do this would make all kits set up for a flat skylight piece that goes all the way across. And source some really dark plexi for builders who are in HOT areas like Texas where I am.

Seaplane doors - it would seem possible to design a one piece swing up door that would basically fit in with what we have always done. Either put a mouse door on the bottom so it clears the strut or alternately have a cut out on the lower door and a piece attached to the door sill that would seal the cut out when the door is closed. I expect not as many builders would want this as the upper window that opens on the ground and in flight is used often. The idea is to keep our normal doors/windows but make some seaplane doors that work with everything else and be optional.

Please let me know what you guys think. We appreciate the input and will help us decide what the best way is to go forward with these potential changes. Mark
 
+1 for skylight. As Mark explained to me once the "Bearhawk hump" is there for fabric purposes as being flat would cause it to drum in flught, for those who didn't know and were curious. Personally I like the aesthetic of no hump. Maybe if folks really didn't want one they could just cover that area with some AL skin, if there were provisions for that?

Flying low and slow with the window open is a significant portion of my daydreaming about my Bearhawk, so I'm good with the doors as is.
 
My fuselage is plans built, but I considered a skylight a must have. When I recovered my Maule I put a skylight in with a 337 and I really liked it. If I had purchased the fuselage would have definitely modified. It. The seaplane doors would have been a must have if I had stayed in Alaska, would have had the plane on floats. Otherwise I really like the separately opening windows.
 
Mark why couldn't there be a window in the top half of a one piece swing up door ,for any model 4pl,or the 2 seaters--
george --lsa plans builder
 
I'm neither flying a BH nor a kit buyer, but I have many hours in airplanes with/without both. I would have absolutely modified it for a skylight and seaplane doors, but the latter only because I see floats in its future. I would also raise the door sill to eliminate the mouse door, as I did on my fuselage.

For those flying with seaplane doors, have you opened them in flight? If you could comfortably fly with them open, that may make a difference in what people want. I never closed the doors on my Kitfox, but I was only flying at 50 knots.
 
Hi Mark, I think those two options would be frequent selections for your builders. I would absolutely have gone with the skylight for three reasons: it is a huge awareness helper in turns for mountains, it helps to spot traffic in busy uncontrolled areas, and in places where sunlight can be hard to come by at times (all north country) it really keeps the cabin from feeling like a cave.

I would have considered the seaplane doors but I’m not sure what I would have selected. certainly a great option!

cheers
 
nichzimmerman said:
I'm neither flying a BH nor a kit buyer, but I have many hours in airplanes with/without both. I would have absolutely modified it for a skylight and seaplane doors, but the latter only because I see floats in its future. I would also raise the door sill to eliminate the mouse door, as I did on my fuselage.

For those flying with seaplane doors, have you opened them in flight? If you could comfortably fly with them open, that may make a difference in what people want. I never closed the doors on my Kitfox, but I was only flying at 50 knots.
Click to expand...

I added a parallel tube 2" above where the lowest part of the door is to shim up the horizontal part then welded tabs to it and built door sills out of aluminum. I then welded up seaplane doors out of 3/4 square tubing (expensive stuff) and added an extra hinge in the middle.

The door itself is lighter than the factory doors without the handles/pins so I figure it will be just barely heavier (couple of oz) when I get the hinges worked out and it pins the front and rear of the door.

As for opening in flight, I'm not sure if this will work or not. My plan is to get some rope and a friction lock of sorts and while flying inch the door open slowly to see how much the wind catches it.

The door with the raised sill isn't tremendously bigger than the factory window which people open in flight, so it might work fine. If it doesn't, then later on I'll fabricate a window that opens and closes.

As for the function of the doors, they make it way easier to get in and out of, and given that I have 31" tires, it's already a beast.
 
Mark, you might want to ask non-skylight builders if they would have built a skylight in if it was an option, or standard equipment.
 
My intention is to make a skylight "standard" but have a way for builders who do NOT want one also easy. Like I think I said - instead of normal plexi, it could be done with a super dark acrylic that would not let the sun cook you like happens in our summers here or in Arizona. MG
 
I fly in the mountains, but I hate skylights. Even in Alaska, where it's not so much the heat of the sun that is the problem, it's just the sunlight itself. Direct sunlight always obstructs your vision.
In order to get any real use out of them you have to be in a fairly steep bank, 45 degrees or better before you're using them to look through. That just doesn't happen that much in a non-acro plane. Compared to the always sun on my face a skylight causes, I don't find the few times it adds utility worth the 100% of the time it adds discomfort and reduced visibility.

Seaplane doors on the other hand are a must. Especially on a seaplane. I plan on modifying mine.
 
For those flying with seaplane doors, have you opened them in flight?
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I do have seaplane doors, but haven’t tried to open them up in flight, and i’m really hesitant of doing it.

The doors are not perfectly “planar”,they actually have a curved shape, like an airfoil. I suspect that they might open quite drastically....

If i try it, I think the best approach would be to have the door open while on the ground, and do some high speed taxi test (with a helper in the right seat), to assess how the opened door behave, and try to close it and feel the resistance to the air load. If all good, I will then proceed with a flight with the door open, and repeat the same test. Something for me to try in couple months, when we start seeing decent temperature up here...
Mike
 
Mark,

I would option for the seaplane doors / up swinging door.
My skylight ts 3 separate panels sandwiched between
two aluminum skins. This assembly can easily accommodate the “hump” and can be outfitted with
with two clear side panels and a solid center or three
clear panels.
Oh, yes on skylight.
 
My thoughts:

Skylight
Seems very popular, for a whole range of reasons. Personal view, in the mountains its a must-have.
The option of an easy install would be a good addition. Definitely an advantage, maybe a selling point though not very likely the deciding factor?

Seaplane doors
The "funny doors" are definitely putting some buyers off. I know of at least two New Zealanders who didn't buy because of the split door or mouse door.
I think a seaplane doors are the best solution for the Bearhawk geometry. You can still taxi with doors open, like with the windows. This is the main use for the window in my experience, seeing where I am taxiing or keeping cool. I don't think many people are regularly flying with windows open, you have to go too slowly... not practical, just for fun.
I think a seaplane door option would sell more planes.

P.S You can still fit a hinged window into a seaplane door, for only a modest weight increase, if flying with windows open is important to the builder.
 
Mark; I typed two sentences, but erased the second. I was going to say what you just did. Make it standard, but easy to delete. it is easier to bolt on some extensions to the upper stringer stand-offs, than to cut them off and make them shorter. Or have inserts for the stringer stand off tubes, shorter for skylight, longer for hump.
 
Mark, we discussed these options via email in December last year, so I’m very pleased to see that you are considering the possibly of making them a standard kitset feature. For several years I’d noticed that many builders were including both of these options, and it’s probably a natural evolution of the Bearhawk.

Seaplane Doors
A well designed seaplane door should simplify the design in that area, and make egress slightly easier. Whether they can be opened inflight is not important to me, but as others have mentioned having an opening window on the door should be relatively simple to include for interior ground cooling, or as Battson mentions - taxi with the doors open.

Skylight
Regarding the skylight, I will also take that option. I prefer the aesthetics without the “hump” though I realise it does serve a purpose. Aesthetics will win over in this area (and a few other areas) when I build my kit.

Will this be known as the Bearhawk “Charlie” ?
 
These changes are not that significant enough to call it a new model. Perhaps you are joking. And they will be options of a sort. Mark
 
Battson said:
My thoughts:

Skylight
Seems very popular, for a whole range of reasons. Personal view, in the mountains its a must-have.
The option of an easy install would be a good addition. Definitely an advantage, maybe a selling point though not very likely the deciding factor?

Seaplane doors
The "funny doors" are definitely putting some buyers off. I know of at least two New Zealanders who didn't buy because of the split door or mouse door.
I think a seaplane doors are the best solution for the Bearhawk geometry. You can still taxi with doors open, like with the windows. This is the main use for the window in my experience, seeing where I am taxiing or keeping cool. I don't think many people are regularly flying with windows open, you have to go too slowly... not practical, just for fun.
I think a seaplane door option would sell more planes.

P.S You can still fit a hinged window into a seaplane door, for only a modest weight increase, if flying with windows open is important to the builder.
Click to expand...

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Thank you all for your input. I just spoke with Bob discussing with him the possibilities. It is his call exactly what we do with his design, but I bet he will develop something worth the trouble to make the changes. Anyone else that wants to give suggestions - they would be welcome. Mark
 
I'm working as fast as I can to scratch build my wings! When I am ready to order the fuselage kit, I would definitely order it with the the skylight and seaplane door options!
 
Mark Goldberg said:
Thank you all for your input. I just spoke with Bob discussing with him the possibilities. It is his call exactly what we do with his design, but I bet he will develop something worth the trouble to make the changes. Anyone else that wants to give suggestions - they would be welcome. Mark
Click to expand...

If the seaplane doors were backwards compatible with the A model and current B model planes, that would be an advantage for some of us :) Nice to have, but not required!

I could easily raise the door sill and make a seaplane door from scratch, but I am time poor and a bolt-on solution would be great.
 
I'm leaning heavily towards a QB for the fuselage once I get my wings done, or at least close. I'm indifferent about the seaplane door, but would love to have a skylight option with the kit.
 
Mark, as you are aware my build will not start until Dec of this year, I will be including both the skylight and sea plane doors, if they are engineered and backwards compatible to my kit I would like to order the factory options asap

i plan on putting the plane on floats in yr 2 and the seaplane doors are a must, plus they look better as well
Dan Dagasso
 
I will definitely want seaplane doors which can either be opened in flight or have a window that can open (within speed restrictions).
 
Working with Bob, we are zero'ing in on a skylight design for the 4 place kits that will allow skylight panels on the two sides back to the rear spar carry through. But not the middle. The Lexan panels will just slide in and be secured in channel on 3 sides. But the center will remain fabric. And all could be fabric with no skylight if the builder wants.

Design not done yet but that is the direction we are heading. Mark
 
We keep our skylight covered most of the year, but the other day I was flying with it uncovered and found that in turns away from my seat, I could see the horizon at about 30 degrees of bank. It definitely makes the plane feel more open, but I'm not one to enjoy sitting in the sun, especially from April to November or so.
 
Mark Goldberg said:
Working with Bob, we are zero'ing in on a skylight design for the 4 place kits that will allow skylight panels on the two sides back to the rear spar carry through. But not the middle. The Lexan panels will just slide in and be secured in channel on 3 sides. But the center will remain fabric. And all could be fabric with no skylight if the builder wants.

Design not done yet but that is the direction we are heading. Mark
Click to expand...

Sounds like a nice solution but I'm wondering how much visibility will be lost due to the lack of middle panel. Seems like the middle is the area the pilot would want to look though especially in a right hand turn. Maybe someone with a flying BH and a skylight could tell us whether this is the case or not.
 
I would suggest the skylight be just the front 8 to 10" but all the way across on the 4-place and fabric the rest. I love the skylight in my Patrol as I can see all directions easily. My 4 place has just the 2 small skylights on each side and they aren't very useful for looking out of. The real benefit is some natural light in the cabin.
 
I am not sure I would like the 2 piece skylight with a fabric section in the middle. I think I would prefer the whole thing be glass.
 
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As expected. there is not a one size fits all solution. We will probably do something that I hope most will like, but expect others to still be modifying what we do to get their preference for their plane. Pretty wide area of what you guys say you want. And remember that many want no skylight. Like me here in Texas. Mark
 
My most significant experience with skylights is with our Citabria which we converted to a skylight with a clear plexi. The improvement is awesome for us, but it is important to note that most days in the vicinity of Anchorage/Mat-Su Valley are cloudy. Clear skies (ironically like right this moment) are historically the minority. In fact when I was a kid working as a tour guide we used to proclaim that Denali was only visible 25% of the year due to cloud cover. In environments like ours I would without hesitation opt for a clear or very nearly clear skylight. From reading above comments I can understand that I may not be the standard but the option to not have it “very dark” would suit me best. We find it useful not only in steep banks as commented above but also in congested uncontrolled areas where planes are coming and going all over in semi-informal manners. This was reinforced very recently on a trip to a popular backcountry site not far from Wasilla. We have indeed spotted planes through it and I look through it often despite rarely banking as much as 45 degrees. Options are always good for the opinionated builders like myself :)
 
Just a quick update on something almost done at the kit factory - a new ceiling design for the Model B. The purpose was to allow skylights to be installed with no welding while still allowing fabric to cover the ceiling if a skylight is not wanted (Texas summer).

On the front will be a double channel of aluminum (like the Patrol). Double channel meaning two channels butt welded with the forward one capturing the windshield and the aft one the skylights. In place of the steel tubing now used on the "hump", two channels of aluminum (facing outboard) will extend aft following the same shape/height of what has been. Using the shrinker/stretcher to get the shape. Aft channel of aluminum as well. The upper fuselage formers of 3/8" steel tubing (above the upper longerons) will stay exactly the same.

This structure of aluminum will be welded together and provisionally installed in place on the fuselage from the factory. To install the lexan panels - they will just slide in from the outside. Captured in place on three sides (front, inboard side, and aft) with the lexan being screwed or pop riveted to the 3/8" square tubing on the sides with a 1/8" aluminum strip on top better securing the lexan.

So there will be the ability to install two skylights pieces quite easily that will extend aft to the rear spar carry through. Doing another piece in the center will be possible as well but some challenge sealing it up properly. It is really intended to just have the skylight pieces on the sides and not in the center. While there is no doubt some builders will want to do something different, this seems a good solution for most. We would have got it finished already but I didn't understand well what Bob wanted on the aft side of this where the stringers come up to. How it all connects. But with a couple phone calls to Bob from the factory we got it more or less figured out.

It is a lot more fun to undertake something like this when Bob is there at the factory with me and 3 or 4 workers scrambling around like ants following Bob's instructions. Make this/bend this/tack weld this etc. Bob has seen preliminary pics, and with a few suggestions/corrections he is happy with how it is turning out. Hope to post pictures soon. Mark
 
I'm late in finding this thread. I fly a 4 place and have a long list of tweaks I'd love to make. Rather than making lots of little (and moderate) changes to a perfectly good flying airplane, I have aspirations to have one built that fits me closer.

I find that the leading edge of the wing and top of the windshield is a bit further forward than most high wing aircraft and limits visibility in all phases of flight. It is quite workable, but an area that I see might be improved. A skylight might help, but haven't flown in one with a skylight.

I also fly an RV-4 with a bubble canopy. There is no doubt is can get hot in the sun, but at least when not in Texas, the visibility is very much appreciated. A hat and open vents keeps things manageable.

I'd love seaplane doors. Though I grew up in a J-3 with the doors open when weather was warm enough, I never fly my Bearhawk that way. ...except when I take off and then remember to close it during climb out. The wind and noise level from a Lyc O-540 is not the same experience as a Continental A-65. Having the door open during ground operations is sufficient. A small sliding window to open in flight would be nice. Having the lower door completely out of the way while getting in and out would be outstanding, even if the door sill were a little higher to do it.
 
Mark, can you send me a retro fit kit for the LSA, just send the pieces and I'll make it fit.
I'll email you too.
 
Mark, I haven’t started my build yet, but I’m planning on doing so soon. We met and spoke at the Great Alaska Aviation Gathering in ANC this spring.

I would prefer a skylight and the gullwing/seaplane doors as an option when I order and start my build.

Just my $0.02
 
The skylight option is a done deal. Al the new kits coming will have that. The sea plane doors depend on Bob getting motivated to help with it getting designed. Mark
 
Maybe it's a misperception on my part, but I get the impression that Bob isn't a fan of the sea plane doors. Does he think they are a bad idea for some reason?
 
Bob has been receptive to doing seaplane doors. My guess - he thinks they will be heavier than what he designed. But we had talked about potential ways/designs of doing this before the accident. I should have pictures next week of the ceiling mod of the 4 place. Bob came up with. Mark
 
For what its worth, and for those that say a skylight provides no value cause you have to be to steep to use them. Well... not true at all. The only reason I'm even still alive is because there was a skylight in the citabria I was flying. Long story short - I was at an uncontrolled airport and had someone in a low wing plane above me descend down on top of us (I was actually with my instructor at the time), this person never made a radio call and tried to drop in out of nowhere, was coming down right on top of us - we would never have seem the plane above us without the skylight - and he didn't see us below him cause of the low wing. Instructor jammed the stick forward and banked. The other plane ended up being to high to make the runway and just flew straight off - I don't think he ever saw us or even knew we were there, or how close we came to a mid-air collision.

So yes I'm a big +1 for the skylight.
 
jaredyates said:
We keep our skylight covered most of the year, but the other day I was flying with it uncovered and found that in turns away from my seat, I could see the horizon at about 30 degrees of bank. It definitely makes the plane feel more open, but I'm not one to enjoy sitting in the sun, especially from April to November or so.
Click to expand...
Jared,

What do you cover it with (pictures)? Also is there a seaplane door kit with part numbers for the gas struts?

John
B5 #76 Build assist, Caldwell ID
 
I don't know about the seaplane doors but for the skylight I used a foil bubble wrap that is popular for insulating pole barns, with magnets held to that by tape.
 
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