Small holes on the leading edge of horizontal

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motoadve
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Small holes on the leading edge of horizontal

Post by motoadve »

Cessna 170B 1953.
I see small holes in the leading edge of the horizontal stab, I think there is 4 of them.
What are those small holes made for?
If installing an abrasion boot , they will all be covered.
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n2582d
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Re: Small holes on the leading edge of horizontal

Post by n2582d »

I don't know for certain but my best guess is that they are holes used for alignment pins in the factory's jigs when the parts are formed.
Gary
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GAHorn
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Re: Small holes on the leading edge of horizontal

Post by GAHorn »

n2582d wrote:I don't know for certain but my best guess is that they are holes used for alignment pins in the factory's jigs when the parts are formed.
Yep, that’s what I’ve always been told. Former Historian (and aircraft engineering consultant) also said this was their purpose.
'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. ;)
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cessna170bdriver
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Re: Small holes on the leading edge of horizontal

Post by cessna170bdriver »

Hmmm… I have always ASSuMEd they were vent holes to reduce condensation inside the surface, but the tooling hole idea makes a LOT more sense. :oops:
Miles

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n3833v
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Re: Small holes on the leading edge of horizontal

Post by n3833v »

I thought some were used to mount longwire antennas.

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ghostflyer
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Re: Small holes on the leading edge of horizontal

Post by ghostflyer »

I agree with Miles, I was told to keep them clear of dirt and bugs.
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GAHorn
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Re: Small holes on the leading edge of horizontal

Post by GAHorn »

n3833v wrote:I thought some were used to mount longwire antennas.

John
No, ... long wire antennas connected to a ceramic-tower on top of the boot-cowl in front of the windshield, travelled up to the linen/resin post above the windshield, then went aft and passed-through a fitting on top of the rudder and trailed-behind.

HOwever, an ADF “sense” antenna was attached to a “key-slot” cut in the leading edge of the vertical stabilizer.

The small holes were not drain holes or anything other than spigots for assembly-line alignment jigs. (Again, per Cleo and I believe I’ve heard Del Lehman say the same.)
'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. ;)
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