Your resident asker of questions irrelevant has a new earworm/headscratcher that he would like to share with the membership.
Is is possible to drill out a strapless windshield to add a center strap? My dad replaced the windscreen in 56D several years ago with a strapless screen...but that seems a bit sacrilegious and I think that the airplane looks better with a center strap. This would seem to be a relatively easy thing to retrofit, unless the STC for the strapless windscreen would prevent this modification. Also, it should be noted that I don't feel it's worth replacing the windscreen at this time as it's in great shape, so if it cannot be done without possibly damaging (causing the plastic to crack) it or compromising anything, then I'll wait to install a windscreen with a center strap at a later date.
I realize that this is probably the first time this questions has even been thought of and is backwards thinking given that most people seek to eliminate the center strap, but it's been nagging at the back of my mind.
Would it help you to know that all windshields for 170's are "one piece"...??? (just that originally, they all have the center, strengthening-strap?)
Just be careful to use the proper type of bit when drilling plastics. (A standard 135-degree bit will crack it out.)
(And I congratulate you on realizing the center strap is a good design.)
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention. An originality nut (mostly) for the right reasons.
As George stated you could drill out the windshield if done with proper bits. The other hurdle would be if using a stock strap, the top strap attaching points interfere with the newer windscreen interlocking method. Or the new interlocking method might prevent installation of screws or rivets in some fashion.
I don't agree the Cessna method of windscreen with or without the strap is a good design. I always thought relying on a windscreen to slide at the top, and not be positively sealed all around from rushing air and water as the Cessna design is not, is hooky
I think the development of that strap went something like this. Clyde designed a high wing fuselage but upon it's first flights that new fangled windscreen cracked from fuselage flexing. Clyde brilliantly decides to leave the screws out of the top of the second windscreen so it can flex but then finds the windscreen is now sucked out of the top frame due to pressure differences. Wondering what to do Clyde decides what they've been doing to hold cowlings closed for years will work but keeping with the metal skin theme he has this belt made out of aluminum rather than leather.
The center straps are often found broken or broken and repaired at the top as mine was when removed. Of course even still, broken and all I couldn't throw it out.
CAUTION - My forum posts may be worth what you paid for them!
Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
When I changed to a strapless windshield 4 years ago, I was amazed at the improved visibility. Doing the math, a 1-inch strap 3 feet from the eye will block a 36-foot wingspan only a quarter mile away. No way I'd ever go back.
Miles
“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
c170b53 wrote:Mine is a LP Aero but I would think they are the same, so I guess I'm wrong about the profile of the widow but they look different to me.
I don't think your wrong Jim. I Replaced mine in 1985 and it did have a different contour.The old one was almost flat where the strap was. I like the looks of the strapless and as Miles pointed out the increased visibility was amazing. With the new windshield profile and red paint, the airplane was extremely fast.
I think the contours are different but not necessarily because one is strapless and one is not. More likely the difference in the molding between manufacturers or the difference in the different manufacturers to hold to the original shape rather than use a later 172 profile and call it good.
There are at least two methods to hold the windscreen in at the top rather than the strap. C Baileys if I remember right uses on method. Miles I recall documented that and how it is held in place. The other is to update the catch flange in the fuselage to engage a flange now molded into the top of the screen like the more modern 172 uses.
Pretty sure no matter the contour of the window, a strap could be wrapped around it. Might need a longer than original strap. You might also not be able to secure the strap at the top of the fuselage with the same method as original because of the new screen mounting method.
You could pretty easy glue a fake strap to the legal one piece. Wondering what the legalities would be.
CAUTION - My forum posts may be worth what you paid for them!
Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
I installed an LP Aero windshield in my 170A and the inside 1/4 inch strap fit fine but I had to make a new outside strap as it would not reach the top of the window frame. The LP Aero windshields use a Cessna style hooked strap at the top of the windshield when going Strapless. I wanted the strap.
Jim+
A&P, IA, New owner C170A N1208D, Have rebuilt some 50 aircraft. So many airplanes, So little time!
bigrenna wrote:You guys make absolutely no sense to me... why the heck you would want something blocking your vision is perplexing. One of the first things I did in the Skywagon was toss the strapped windscreen and never looked back. And as far as where to hang the compass goes... thats what double stick tape is for.
^^^ This. When I went strapless, I bought the LP Aeroplastics with the compass mount already bonded to the windscreen. After years of having my view obstructed by that strap and compass, not to mention the rattling (by the decades-old sealant being brittle) and buffeting (of the thinner material), the quietness and beauty of the unobstructed view was well worth the effort.
bigrenna wrote:You guys make absolutely no sense to me... why the heck you would want something blocking your vision is perplexing. One of the first things I did in the Skywagon was toss the strapped windscreen and never looked back. And as far as where to hang the compass goes... thats what double stick tape is for.
bigrenna wrote:You guys make absolutely no sense to me... why the heck you would want something blocking your vision is perplexing. One of the first things I did in the Skywagon was toss the strapped windscreen and never looked back. And as far as where to hang the compass goes... thats what double stick tape is for.
One could say the same thing about your V-brace, Greg. Or using bush wheels on pavement. Or your flight suit. Or helmet. Jeez, it's just a preference, and I like the aesthetic...a term you've used frequently in your projects. Different strokes for different folks. I've been very supportive and eager to watch your 170 and 180's progression, but honestly, you're pretty derisive against anybody that enjoys these airplanes as a classic hamburger cruiser and causal traveler instead of a backcountry ute. If I wanted visibility, I'd get a helicopter. Even with the center strap blocking my view, I've still got better forward view out of a 170 than just about any other airplane ever made, including your 180.
Sorry to be blunt.
Last edited by Ryan Smith on Sat Dec 06, 2014 4:53 am, edited 2 times in total.
