Wheel Pants Alignment

[bagarre]

This came up in another thread.
So far, I'm on record stating two different things.

Should the bottom edge of the wheel pants be level on the ground or level in flight.
I've seen them mounted both ways.
Mine are a compromise of the two and angled somewhere in between. This MIGHT be a result of of changing gear legs as mine didn't come originally with the Lady Legs she has now. Plus the pants are fiberglass - not stock.

If you look at photos or even early literature from Cessna, you can find evidence of both setups.

Does anyone know of a reliable source that states the alignment of the wheel pants relative to the aircraft?
An official Cessna drawing would be great.

[4583C]

Sorry, the board attachment quota has been reached.
So you will have to go to the pics here: http://www.cessna170.org/forums/viewtop ... f=5&t=8864
I don't think there is a finer more original example in existence than 2935D and her panties look parallel to ground to me. This is the bird that puts all of us in the "rat plane" category!

[bagarre]

Wouldn't that mean wheel pants on a 172 should be canted forward while sitting on the ground?

[bagarre]

What other taildragger is set up with the pants level on the ground?
Or is this a 170 specific thing cuz I can't find any other plane set up that way.

I think it is up to what makes you happy cuz I really don't like the look of the pants flat level on the pavement.

[pojawis]

Or is this a 170 specific thing

Not absolutely sure of the answer, but my informal data collection supports the hypothesis that this is unique to the 170.

There's at least one reason to align the fairings with the flat bottoms parallel with the ground. If aligned with the longitudinal axis of the aircraft, the aft of the hole is significantly closer to the runway/ground. When and if tire pressure is lower than normal, the fairings can contact the runway during landing operations. This does not seem to occur if oriented level with the runway.

In level flight, the fairings are tilted forward a bit. Air strikes the front top portion first and quarters (for lack of a better term) down the structure and past the openings. This seems more streamlined than when the fairings are aligned with the fusleage. In this position, it seems that the openings are available to the relative wind thereby increasing drag, in my opinion.

In short, I believe the wheelpants were designed to be installed "level" with the ground. This is for ground operations and flight operations.

Many other fairings do not have a flat lower edge like the 170 style...?

[hilltop170]

Example of factory wheel pants on a 1955 B model.

Factory wheel pants installation on a 1955 B model

[johneeb]

Example of factory wheel pants on a 1955 B model.

image.jpg

Looks like this 1955 B model needs some air in the tail-wheel!!!!

[Ryan Smith]

Not to brown nose or anything...but I like the angle of the 195's wheel pants better.

[GAHorn]

My wheel fairings are genuine Cessna-factory as are their mounting plates. They were pre-drilled/fitted so as to present the lower edge of the fairing parallel to the ground.
The 172 used a completely different fairing and mounting plate design, and were also mounted to be level with the ground.
Therefore, I believe the alignment with ground is the "correct" manner. I'd love to find the mounting instructions for adding them.

[GAHorn]

The picture is not what I meant. I wanted the actual instructions to see if they referred to any means of levelling.

[Bruce Fenstermacher]

I forget all the stuff we have in the library.

Doesn't answer the question but the mounting plate clocks pants. You can't adjust them. Of course you could be using a mounting plate that is not clocked as the original was.

[GAHorn]

Well, I admit I'd forgotten that also,...you got me!... but it still isn't what I was desiring. That is the install dir's for the Goodyear brake version.
When Cessna reproduced them for my predecessor they were not cut for brake calipers and I was hoping for instructions which described that fitment in the hopes it might also refer to orientation. I'll follow up with my restorer.

[bagarre]

When switching to Cleveland brakes, does the STC provide a new backing plate or instructions on how to modify the existing ones?

If I remember right, mine look like they've been cut to fit the new calipers - implying they are original.
But, being fiberglass pants - who really knows

[bagarre]

David, what are the backing plates on your fiberglass pants made of? Are they aluminum?

Yep. Aluminum and they look amateur cut to fit the calipers which is why I suspect them to be originals.

[GAHorn]

The install instructions clear up the previous question (different thread) regarding fasteners. It appears the original fasteners were PK screws.
The later-production fairings used nut-plates and #10 MS screws.