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Hughes 269A VNE


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Hi

 

Sorry if this has been covered before.....

 

So the VNE for a 1968 Hughes 269A is 75kts....

 

Am I right or wrong in thinking that the only reason for this is the fitment of thinner bubble 'glass' on the 'A' model...that can and has 'popped' in towards pilots who have exceeded the VNE ??

 

Comments/facts appreciated

 

Kev

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Hi

 

Sorry if this has been covered before.....

 

So the VNE for a 1968 Hughes 269A is 75kts....

 

Am I right or wrong in thinking that the only reason for this is the fitment of thinner bubble 'glass' on the 'A' model...that can and has 'popped' in towards pilots who have exceeded the VNE ??

 

Comments/facts appreciated

 

Kev

 

the bubble plexi on a 269 is the same thickness for all series, ie 269A,B,C,CB,CBi.

 

i owned a TH55 (269A) and at 75 knots it would begin vibrating.

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Guest pokey
the bubble plexi on a 269 is the same thickness for all series, ie 269A,B,C,CB,CBi.

 

i owned a TH55 (269A) and at 75 knots it would begin vibrating.

 

 

For the record, the glass on the A, B, & TH-55's was 0.080" vs the C @ 0.100" . Altho i do have a 269A here that someone has replaced the glass w/ "tech-tool" 's replacement glass & its 0.100' ( but this was NOT the original thickness)

 

 

There was a discussion about this same topic on the "schweizer manufacturer forum",, but it has since moved & i cant find it. I had discussed that a friend of mine in his TH-55 exceded the VNE & the windshield caved in, he just "popped" it back out & surprisingly, there was no sign of any damage. Talking with some ex military ft rucker pilots, they said the same thing & that they would fly over VNE w/ their feet on the glass to avoid it popping in on them, at least one in the thread that i cant find also verified this.

 

As far as vibrating above VNE? news to me, but i suspect something else wasnt "quite right"

 

 

ANd YES that horiz stab on the TH-55's with the military modification was much better for entering an auto ! The nose will stay much more level upon entry ( which IMO is safer), as opposed to the non-modified stab which upon enty "flies the tail into the air" & nose points down aggressivly & immediately. The reason for this was the military "chopped" 2 inches off the span, & installed a leading edge stall strip. Too bad no one ever took the time to "re-certify" this stab as it is much safer to enter autos with. ( plus there are tons around in the scrap heaps)

 

BTW If anyone needs replacement glass? I have replaced many ships w/ "cee bailey's", they are in long beach ca., & the quality is excellent ( make sure you specify the thickness tho !) they call the .080 for a 269, & the .100 for a 300, but we ALL know the 269B was the 1st 300, (which had the .080) their number is: 800 788-0618 to request a quote OR catalog. (theirs doesnt come w/ the geons, so you will need to reuse your old ones)

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For the record, the glass on the A, B, & TH-55's was 0.080" vs the C @ 0.100" . Altho i do have a 269A here that someone has replaced the glass w/ "tech-tool" 's replacement glass & its 0.100' ( but this was NOT the original thickness)

There was a discussion about this same topic on the "schweizer manufacturer forum",, but it has since moved & i cant find it. I had discussed that a friend of mine in his TH-55 exceded the VNE & the windshield caved in, he just "popped" it back out & surprisingly, there was no sign of any damage. Talking with some ex military ft rucker pilots, they said the same thing & that they would fly over VNE w/ their feet on the glass to avoid it popping in on them, at least one in the thread that i cant find also verified this.

 

As far as vibrating above VNE? news to me, but i suspect something else wasnt "quite right"

 

My mistake. We only use the Tool Tech plexiglass, which calls for the same part number for all models. I honestly didn't think anyone was still using the old geon method anymore. geon has a tendacy to become brittle with age, and the general fit and finish is somewhat lacking. Tool Tech uses a better material for their geon, and it's bonded to the plexiglass.

 

Nice war story on the TH55, however I seriously doubt the truth of that. >>>Talking with some ex military ft rucker pilots, they said the same thing & that they would fly over VNE w/ their feet on the glass to avoid it popping in on them

 

As far as the VNE vibration on my ship, yes it happened right at 75 knots.

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Guest pokey

I had , (years ago) contemplated having a die made & extruding new geons, i talked w/ a few plastic extruders & it was "do-able"---even from a PMA stand point.... however i never persued that avenue. I found a guy a few years back tho that did, i cant off-hand remember his name, but i think he was from michigan or thereabouts. The reason i say this is because tech-tool has excellent glass too, but it is ALOT more expensive than cee bailey.

 

If anyone is interested, PM me & i will try to dig up the source.

 

 

And the "war-story" is verified on this forum "somewhere" by a military TH-55 pilot,, i just cant find it !! :angry:

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I had , (years ago) contemplated having a die made & extruding new geons, i talked w/ a few plastic extruders & it was "do-able"---even from a PMA stand point.... however i never persued that avenue. I found a guy a few years back tho that did, i cant off-hand remember his name, but i think he was from michigan or thereabouts. The reason i say this is because tech-tool has excellent glass too, but it is ALOT more expensive than cee bailey.

 

If anyone is interested, PM me & i will try to dig up the source.

And the "war-story" is verified on this forum "somewhere" by a military TH-55 pilot,, i just cant find it !! :angry:

 

 

I bought some "geon" from that guy in Michigan once. It was total crap. Very hard plastic, and very difficult to work with. Eventually threw it away and put on Tool Tech.

 

Tool Tech is very expensive, but in my book it's worth it.

 

oh, btw I called an old friend of mine that instructed at Rucker and told him the "feet on windows above VNE" story, and he busted out laughing. Told me "damn, that myth is still floating around out there!?" at least he got a kick out of it.

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Hi Guys

 

Thanks for the input

 

My question hasn't really been answered fully yet

 

Can anyone else pitch in ??

 

Many thanks

 

Kev

 

If Bob Stage is still working at Schwiezer as a Tech Rep, call him and ask. He's been one of the best sources for factual information on the 269 series.

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Guest pokey
So does anyone actually know the reason for the 269a's low vne ??

 

Many thanks

 

Kev

 

 

Apparently not ! :blink: Looking thru my old training manual tho, they do talk of all kinds of improved blades in the early years of the A, A-1, & B; and then go on to say "269C improvements provide for a 41% payload increase, utilizing a 190 HP engine and larger rotor diameter ( 26 feet 10 inches). The combined engine and rotor system improvements increase the indicated airspeed at sea level to 109 MPH"

 

 

This leads one to believe that that A's didnt have the needed HP to go faster AND the blades were too short !? I am sure that IF one would speak to anyone at Schweizer, they would tell you the same as in the training manual that i quoted. I have been working on and flying all the different models for close to 20 years & have seen alot of mistakes in the manuals, confusing and contradicting information, and have even been mis-led at times by the factory themselves.

 

I also have been told by the instructor that taught me to fly, that in his TH-55 he exceeded Vne & the windshield popped in. ( i didnt see this OR know him at that time) but i do believe him. ( i've heard other stories similar too)

 

As far as the different blades go? I have a very old (Jan 1, 1971) $$ list from hughes, and they list a 269A1125, 269A1131, and 269A1160. But NOT the 269A1145, (which is the basic A&B model blade from that era) I have never seen an 1125 OR 1131 blade, however the 1160 is the same as the current 1185 C model blades but w/ out the leading edge abrasion strip. The current A&B model blade is the 1190, (which is identical to the C 1185-except is about a foot shorter) You all confused yet? BUT WAIT ! it gets werse ! All of these blades ( w/ exception of the 1125 & 1131, which are so old that i doubt you will even find one still alive in a museaum) have about an 8 degree twist to them AND are a NACA 0015 airfoil. NOT sure i "buy" the part about the "rotor system improvements". OH BTW? A,B&C ALL use the same identical rotor head !

 

SO? unless we could talk w/ one of the design engineers from wayyyyy back in the late 50's-early 60's, i think this debate could go on tilll the cows come home. OR ,, unless we can find a pilot that is willing to take an A model (1 w/ the thinner, & 1 w/ the thicker windshields) AND a C model, & go do some "test piloting" & see at which airspeed, either the windshields pop in OR they experience retreating blade stall. ANY takers? (not me no thank-you) :o

 

 

OH OH OH !!! BTW? the price of the blades back in 1971? just a tad over ONE thousand apiece !

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  • 11 years later...

I'm in the process of installing Tech-Tool glass in my 269A (TH-55). I'm finding a 1/4' difference in the size of the green house canopy sections at the longitudinal center line. Tech-Tools tech rep says that's the way it's supposed to be? If I install these sections the left to right horizontal molding will not line up and look terrible.

Has anyone else run into this?

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