1/4 glass, any difference?

[Lionudakis]

Well were prepping our bird for paint, our glass isn't bad, they just werent installed to my liking. Is 1/4" glass worth the effort and expense? I've read its quieter, and so on.. anyone have a side by side comparison vs. the factory thickness? 

[takair]

I went thicker on the windshield (two piece) and stayed thin on the sides.  Can't say that I can tell much difference.  Psychologically it makes me think I can take a slightly larger bird strike.  The thicker window is also slighly more work fitting it in the existing lower sheetmetal.  Takes a little extra work.  That said, I think I woudl do it all the same except would get grey tint.

[jetdriven]

Rumor is the thicker glass is quieter. Mooneys are prety loud airplanes as the tubular structure transfers a lot of the vibration to the non-structural skin.

[aviatoreb]

Quote: takair

I went thicker on the windshield (two piece) and stayed thin on the sides.  Can't say that I can tell much difference.  Psychologically it makes me think I can take a slightly larger bird strike.  The thicker window is also slighly more work fitting it in the existing lower sheetmetal.  Takes a little extra work.  That said, I think I woudl do it all the same except would get grey tint.

[Lionudakis]

I checked yesterday and the front is already 1/4", I agree on the resistance to airborne debris !! Ive repaired a few wings that took a bird strikes, amazing what a stupid bird of any size will do at 100+mph. I measured the side glass and they're .185. not sure if it's worth the $6-700 plus my time to replace them for minimal gain. 

[aviatoreb]

Quote: Lionudakis

I checked yesterday and the front is already 1/4", I agree on the resistance to airborne debris !! Ive repaired a few wings that took a bird strikes, amazing what a stupid bird of any size will do at 100+mph. I measured the side glass and they're .185. not sure if it's worth the $6-700 plus my time to replace them for minimal gain. 

[jetdriven]

Jets use 1-2" heated multilayer windshields with an inner and outer glass layer, many have a polycarbonate or plexiglas  middle layer as well.  You can even dispatch some of the for one leg if one layer is shattered.  They are also something like 50-100K a side, so don't look for an STC anytime soon for a Mooney.  A bird strike in a Mooney can end really badly. I had a friend took one in an Arrow going 150 knots and it blew out both panes of the windshield, then continued through the aft cabin wall.

[Lionudakis]

1/4" won't, but the slope might help deflect slightly. I work on Embraer145's, they have roughly 3/4" thick, laminated acrylic type material. That stuff only shatters but the lamination maintains some itegrity. I have pics of birds and larger beings that have destroyed large amounts of  sheetmetal at very slight angles on approach, at speeds similar to what we cruise at. I wouldn't even want to imagine that coming through a windshield on our birds !!

 

[jetdriven]

I gave an IPC to a gentleman one night in a turbonormalized AC-500 Shrike.  Things went well, and on short final to KSGR on the ILS, we heard several loud thumps and the airplane shook a little. Birds.  We got the hell out of there and went back to West Houston and landed uneventfully.  Next morning we surveyed the damage. We must have hit a whole flock of birds at around 140 knots because we cracked the left windshield, the left cowl lip, a landing light, OAT probe, and the right prop took one enough to take the deice pad off it, which hit the fuselage hard enough to put a hole in it.

from:  www.int-birdstrike.org/Athens_Papers/IBSC27%20WPI-3.pdf

For instance, during the FAA sponsored high- speed climb test at Houston, Texas in 1998, a Delta Air Lines B727 collided with a flock of snow geese (5-7 pounds) at 280 KIAS. The #1engine was destroyed by bird ingestion, the #2 engine was damaged by ingestion of radome parts (radome and radar unit were knocked off the aircraft by collision with birds) and the #3 engine, while suffering no direct ingestion damage, was put at risk as two birds penetrated the pylon which holds the engine onto the airframe and contains both fuel lines and control cables. Obviously this was a serious event, but it was not recorded as a multiple bird ingestion event as the #2 engine was not damaged by birds, rather by airplane parts knocked off the airplane by birds. The #3 engine had no ingestion, so the pylon penetration was considered by the engine certification group as a structures matter.    As the aircraft did not crash there was no reason to amend the standards.

this too:  http://www.birdstrike.org/commlink/signif.htm

[Ned Gravel]

Here is one datapoint on the subject of birdstrikes in a Mooney.

About two years ago, I was on final to 09 at Rockcliffe and just about to touch down doing close to 75mph.  One stupid sheithawk (seagull) jumped straight up off the runway as I am about to flare and hit the top of the prop.  It had entered the meatgrinder.  Biggest mess was on my right main gear.  Other than the cleanup, it was really a non-event. 

That one incident made me feel a whole lot better about a birdstrike on my windshield and convinced me that, unless the big cooling fan up front is not turning, there is very little likelyhood that a bird will make it as far as the windshield in any pieces big enough to cause real damage.

YMMV.

[N601RX]

There is also a 3/8" front windshield available.

[aviatoreb]

Quote: jetdriven

Jets use 1-2" heated multilayer windshields with an inner and outer glass layer, many have a polycarbonate or plexiglas  middle layer as well.  You can even dispatch some of the for one leg if one layer is shattered.  They are also something like 50-100K a side, so don't look for an STC anytime soon for a Mooney.  A bird strike in a Mooney can end really badly. I had a friend took one in an Arrow going 150 knots and it blew out both panes of the windshield, then continued through the aft cabin wall.

[scottfromiowa]

DP

[scottfromiowa]

Weight.

[DaV8or]

Quote: aviatoreb

I have always wondered why we do not already have safety glass available like we do in our cars?  Or some plastic version of that.

[jetdriven]

A twin cessna heated windshield is 25k.  per side

[rbridges]

Quote: edgargravel

Here is one datapoint on the subject of birdstrikes in a Mooney.

About two years ago, I was on final to 09 at Rockcliffe and just about to touch down doing close to 75mph.  One stupid sheithawk (seagull) jumped straight up off the runway as I am about to flare and hit the top of the prop.  It had entered the meatgrinder.  Biggest mess was on my right main gear.  Other than the cleanup, it was really a non-event. 

That one incident made me feel a whole lot better about a birdstrike on my windshield and convinced me that, unless the big cooling fan up front is not turning, there is very little likelyhood that a bird will make it as far as the windshield in any pieces big enough to cause real damage.

YMMV.

[rainman]

While redoing my interior I decided to get new side glass, the windshield had been replaced last year.  Ultimately, the side glass is not a safety issue and the sound reduction is reported to be minimal. The window makers can't provide good data on additional sound reduction.  The one thing that I did do is replace all the insulation with a much better type which is a true benefit on noise reduction as well as better thermal insulation.  Aero-Comfort did the interior and Rob Fisher did the window replacement. All very well done.

[Ned Gravel]

Quote: rbridges

 does hitting a bird with your prop constitute a prop strike?  Did you have to have anything inspected?

[aviatoreb]

Quote: edgargravel

This happened just as I was getting ready to fly to my MSC to diagnose a little oil leak which turned out to be a 6" crack in the crankcase down from number 2 - leading to my 2009 overhaul.  So the bad stuff had already occured.  There was no change in the amount of oil appearing on the engine as a result of the bird strike, but if I had not been going in for this diagnosis anyway, I would have had it examined.   I was just lucky this all happened at the same time.

As for whether the birdstrike constitutes a prop strike, I am not certain, but why risk it?

[aviatoreb]

Quote: DaV8or

Expense. Our winshields would cost a whole lot more and the number of fatalities caused by birdstrike to the windshield is very, very low. Fortunately, here in the US, they don't mandate new safety features until it becomes a statistical problem or there is a really high profile lawsuit.

Basically, laminated polycarbinate plastic doesn't exist to my knowledge. Because I suspect only piston GA would be the only customers fro this material, it would be very, very, very expensive. So first they would have to invent the material and then they would have to invent the way to form it while maintaining acceptable optical purity. My brother owns a plastic forming company and I can tell you that this would probably not be an easy one. I could see our windshields costing well north of $10,000.

[aviatoreb]

Quote: jetdriven

A twin cessna heated windshield is 25k.  per side

[fantom]

Quote: aviatoreb

[John Pleisse]

Quote: N601RX

There is also a 3/8" front windshield available.

[N601RX]

Here is what a flock of quail did to an RV.

http://www.vansairforce.com/community/showthread.php?t=77750