I'm going to be putting in a new one piece windshield in my 170 which will eliminate the center strap. I'm trying to decide which kit to go with, LP Aero or Great Lakes Aero. The LP Aero STC uses a new upper retainer strap to hold the windshield in place. The Great Lakes Aero STC uses 4 screws that go through the top of the windshield and into the airframe. Those of you that have been there and done that which windshield do you recommend and why?

robw56 wrote:I'm going to be putting in a new one piece windshield in my 170 which will eliminate the center strap. I'm trying to decide which kit to go with, LP Aero or Great Lakes Aero. The LP Aero STC uses a new upper retainer strap to hold the windshield in place. The Great Lakes Aero STC uses 4 screws that go through the top of the windshield and into the airframe. Those of you that have been there and done that which windshield do you recommend and why?

I went to the LP because too many times I see plexi crack where it has a screw passing through a hole. I realize this is an installation or drilling flaw, but never the less, boo-boos happen, and this type of flaw will go unseen until the cracks start. Replacing a windscreen a year after you install it will suck. Also, don't get so aggressive trimming the bottom. I had one poor installation (by a big reputable shop), that popped the bottom 'corner' up out of the strip while boon docking in Alaska. This turns in to quite a PITA to address in the field. A vee brace or flying wires will lessen the airframe flex and alleviate this, but so will a proper install. On the vee brace note, if you haven't installed one yet, you may consider going with the wires. I believe Gary has set the groundwork in motion for being able to do that on his new 170.

And lastly, you appear to be building a light weight bush beater. Take a good look at the weight differences before you ditch the center strap. I went strapless, but had a hard time making that choice, given the weight difference over the stock windscreen. I'm not interested in the 'latest greatest' or what's in vogue, and the only reason I wanted the strap gone was because I added flying wires and wanted to minimize the stuff in my field of view. YMMV

Take care, Rob

I installed an lp aero w/o the center strap in 2001. Some trimming required. Replaced all the rivets along the bottom with rivnuts and screws so the next one would be easier, though that was kinda unnecessary. No problems since. Happy with optical quality.

The thicker windshield is probably a little more bird resistant. Not sure of actual weight change, but a back of the envelope calculating says that 1 square meter of 1/4 inch plexiglass is about 3 pounds heavier than the 3/16. Windscreen is prob a bit less than 1 m^2. Using density of 1.18 g/cm^3.

Great progress Rob.

I was leaning towards the LP Aero because no holes through the windshield. Hey it's also cheaper! I looked at the installation instructions for both and you gain 3.8 or 3.9lbs... I hate adding weight but I think it's the way to go especially if I have a V-brace. Now I'm trying to decide what to do with the compass. I think sticking it in the panel would look better than on top of the panel or on the windshield. I really don't care how much more magnetic deviation it will have in the panel... I never use it anyways.

Can't offer thoughts on the windshield, but on the compass, I replaced my Airpath last May with a SIRS compass, based on comments on this forum. I'd been having trouble with it leaking a little and having to swing it fairly often. Once swung 7 months ago, the SIRS hasn't needed re-swinging since. I find I use it a lot more, since it's so accurate and doesn't bobble around nearly as much as the Airpath did. It suffers the same problems of any whiskey compass, accelerate/decelerate and northerly turning errors, but straight and level, it's very steady. It makes it very easy to adjust the DG as necessary when it precesses.

Mine is mounted on the panel, in the stock location for 172s. It is affected by turning on the pitot heat or AOA heat, so I have two compass deviation cards mounted. None of the other electronics affect it at all, whether on or off.

Cary

I cant comment on LP as I went with Great Lakes. I did the C170 and now the 180 with all their wiindshields/windows and have been extremely happy. The holes at the top center of the windscreen are no biggie and should not be worrisome. I did have to do a bit of trimming on the bottom to get a perfect fit. Wasn't difficult, just took patience and some time. Make sure you are not too aggressive and remove small amounts at a time. (I used a sander)

FWIW, I went with the darkest tint on the rear windows, then the next lighter tint for the bubbles and windshield. Love em.

I'm a big fan of Great Lakes Aero. We have used their products and used their customer service. Both have been top shelf. Their holes are drilled at the factory and they use elastomer bushings in them which cuts down on movement and noise as all windshield shift around some. I wouldn't worry about cracks either.

My old 172 came with a Great Lakes windshield, complete with cracks around the four screws. I decided to replace it with a LP windshield.

The LP requires you to drill out all the rivets above the windshield (around 50 or so) and rivet in a strip that sandwiches a 1/4" doubler on the windshield itself. With your plane in bare aluminum its not a big deal, but I thought I'd mention it for the sake of anyone else deciding which way to go. If I had to do it again I'd still go with the LP.

One other item of note, The LP was a bit thicker than the existing Great lakes. I too added a sportsman stol kit, and the additional thickness of the fairing that blends the wing cuff to the wing root, coupled with the thicker windshield required me (ok my a&p) to fabricate a new wing root fairing as the old ones no longer fit too well.

Jim

For those that went from the original 1/8" windshield to the 1/4" LP Aero, how noticeable is the reduction in noise inside the cabin? I've heard they are quieter and it makes sense but how big of a difference could it really be? I already have quite a bit of hearing loss from flying on C-130s and I'd like to keep what I have left. The noise reduction aspect of a thicker windshield is appealing but I'm still having a hard time deciding if I want that extra 4lbs.

My P172D is probably the noisiest 172 around. There's just about zip insulation on the firewall, I have no idea how thick the windshield is, and the exhaust note is especially raucous. But when I converted my DC 10-13.4 to ANR with a Headsets Inc. kit a few years ago, suddenly my noisy little airplane is no noisier than my RAV4 is on the highway. That plus Oregon Aero comfort items on the headset makes it, if not the best headset out there, darned close. If you're not already flying with an ANR headset, try it.

Cary

I'm about to install a LP windshield that will require some trimming. What tools are you guys using to trim acrylics?

Can't comment on any installations just yet as my Great Lakes windshield is still in the box. I didn't really do my due diligence when making the decision which one to buy, I just got it because it got rid of the strap, and I wanted it tinted to match my side windows.

When pricing though, don't forget to ask about the shipping cost...my cost for shipping was $150 The box was so big, I was using it as a table for cutting my insulation!! But at least it's still a "one piece" windshield

FWIW, I have a Cee Bailey. I got it because the mechanic that did the install recommended it. I didn't shop around any further but just let him order what he wanted and install it. I have been very happy with it. They have them in a couple of different thicknesses, .125 and .187 and they have clear, green, and gray. I don't know how they compare to the others but I have had no trouble with mine.