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

[Mark Goldberg]

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

[Archer39J]

+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.

[rodsmith]

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.

[gdsikes]

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

[nichzimmerman]

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.

[AKKen07]

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

[schu]

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.

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.

[svyolo]

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.

[Mark Goldberg]

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

[svyolo]

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.

[zkelley2]

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.

[Aero_tango]

For those flying with seaplane doors, have you opened them in flight?

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

[AZBearhawk272]

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.

[Battson]

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.

[Nev]

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” ?

[Mark Goldberg]

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

[whee]

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 Goldberg]

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

[AKKen07]

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