Josh...is that a picture of your gyro ...WHILE IT IS SPINNING AT PROPER SPEED? Or is it while it's sitting on the ground in the hangar at REST? (Makes a difference! Also makes a difference if the airplane is airborne or not.)
Instrument Panel Tilt
Moderators: GAHorn, Karl Towle, Bruce Fenstermacher
Re: Instrument Panel Tilt
Josh...is that a picture of your gyro ...WHILE IT IS SPINNING AT PROPER SPEED? Or is it while it's sitting on the ground in the hangar at REST? (Makes a difference! Also makes a difference if the airplane is airborne or not.)
'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.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
Re: Instrument Panel Tilt
That is in straight and level flight, about 4" indicated on the suction gage.gahorn wrote:
Josh...is that a picture of your gyro ...WHILE IT IS SPINNING AT PROPER SPEED? Or is it while it's sitting on the ground in the hangar at REST? (Makes a difference! Also makes a difference if the airplane is airborne or not.)
--Josh
1950 170A
1950 170A
Re: Instrument Panel Tilt
Follow-up: This morning I finally went to my airplane an measured the angular difference between the upper door sill and the instrument panel. No surprise, the result between the readings indicates an 8º tilt (agreed with the indicator). I took my AI to Aircraft Quality Instruments and explained what I'd seen, what I'd read here, and my own calculations. They put it on their test bench and concurred with my observations. So, my 170 has a tilted panel.
This flies in the face of everything I'd previously thought about single-enine Cessna instrument panels, or at least the 170. I contacted a friend who still works at Cessna engineering and knows just about everything about every single-engine and most multi-engine Cessnas. He referenced a drawing that clearly depicted the stationary panel as NOT being perpendicular to the leveling reference. The particular drawing did not give an exact angle, however here is an excerpt of the email response I received and a portion of the drawing he sent me:
"Yes, you remember correctly in that the Cessna Models 120, 140, 140A, 150, 152 and most of our other models have their Stationary Instrument Panels on a Fuselage Station. i.e. Perpendicular to a Water Line. However: "Same as Except" rules again! i.e. Not all stationary instrument panels are perpendicular to the plane's Water Line. There is a slight "tilt" (forward at the top) on some of our models...I have not investigated deep enough to locate the exact angle (or dimensions to calculate the angel) but my "eyeballing" of the attached drawing would say somewhere around 6 to 8 degrees would be about right.
"Now the reason for the tilt is arguable (other than that is the way the engineer drew it on the drawing). I doubt it had anything to do with being a tail dragger, but probably somebody thought that it would point more of the instruments upward to where most pilots eyes were located. First of all, the airplane, in flight, does not necessarily fly with its Water Line level. i.e. Depending on aircraft weight, cg position, engine power setting and model, the inclination of the Water Lines, most likely, is not level and may vary as much as 10 to 15 degrees from stall to high speed, low weight, cruse attitude..."
While my friend's comments about variables affecting pitch while in level flight are certainly valid, I think the condition we've discussed here does not pertain to that as much as it does the structural composition of the aircraft. Once your eyes adjust to the attached .pdf (portion of the drawing referenced), you'll note that the upper engine mount longeron is depicted, along with the forward door post and the instrument panel clearly extending forward relative to the engine mount longeron. Keep in mind this is for an A model; I imagine the B is a little different (or at least those that had the later style stationary panel).
This flies in the face of everything I'd previously thought about single-enine Cessna instrument panels, or at least the 170. I contacted a friend who still works at Cessna engineering and knows just about everything about every single-engine and most multi-engine Cessnas. He referenced a drawing that clearly depicted the stationary panel as NOT being perpendicular to the leveling reference. The particular drawing did not give an exact angle, however here is an excerpt of the email response I received and a portion of the drawing he sent me:
"Yes, you remember correctly in that the Cessna Models 120, 140, 140A, 150, 152 and most of our other models have their Stationary Instrument Panels on a Fuselage Station. i.e. Perpendicular to a Water Line. However: "Same as Except" rules again! i.e. Not all stationary instrument panels are perpendicular to the plane's Water Line. There is a slight "tilt" (forward at the top) on some of our models...I have not investigated deep enough to locate the exact angle (or dimensions to calculate the angel) but my "eyeballing" of the attached drawing would say somewhere around 6 to 8 degrees would be about right.
"Now the reason for the tilt is arguable (other than that is the way the engineer drew it on the drawing). I doubt it had anything to do with being a tail dragger, but probably somebody thought that it would point more of the instruments upward to where most pilots eyes were located. First of all, the airplane, in flight, does not necessarily fly with its Water Line level. i.e. Depending on aircraft weight, cg position, engine power setting and model, the inclination of the Water Lines, most likely, is not level and may vary as much as 10 to 15 degrees from stall to high speed, low weight, cruse attitude..."
While my friend's comments about variables affecting pitch while in level flight are certainly valid, I think the condition we've discussed here does not pertain to that as much as it does the structural composition of the aircraft. Once your eyes adjust to the attached .pdf (portion of the drawing referenced), you'll note that the upper engine mount longeron is depicted, along with the forward door post and the instrument panel clearly extending forward relative to the engine mount longeron. Keep in mind this is for an A model; I imagine the B is a little different (or at least those that had the later style stationary panel).
- Attachments
-
- Structure1.pdf
- (108.76 KiB) Downloaded 313 times
--Josh
1950 170A
1950 170A
