Reading SGS 2-32 Polar Curve

On Wednesday, March 16, 2016 at 12:48:49 PM UTC-4, kirk.stant wrote:
The whole flight manual is so quaint!

I had forgotten that Vne is higher with the dive brakes open (158) than closed (150), and is called "Max Glide Speed". Are you still technically gliding when going straight down standing on the rudder pedals? (BTDT)

Aerobatics get two short sentences, basically, "no restrictions, but be careful". Meanwhile, flying in cold weather gets a couple of pages, including a paragraph on Wheel Freeing that ends with "The consequence for landing with a locked wheel is not severe at most, a blown tire."

Anyone who has been around a 2-32 with a flat or blown tire knows how un-fun that can be!

Still my all time favorite Schweizer!

Kirk
66

In the 1980's (?) I believe Schweizer came out with an "update" to all their flight manuals stating "Aerobatics are not approved", mostly to cover themselves "in case someone pulled the wings off, etc.".
Having an old manual does NOT mean you can "do what you want" since the FAA would look at the current MFR manual.
;-)

On Tuesday, March 15, 2016 at 1:25:54 PM UTC-7, runner4065 wrote:
I'm struggling how to read the polar curve for an SGS 2-32

Others have taken care of the important points, so I will address the semantics: The L/D curves you are looking at are not polars. They are plots that show the same data as a glide polar, but in a different way.

However, I think that the sink rate curves shown lower on the graph are indeed polars in the traditional sense. They are shown upside-down, and the origin is beyond the scope of the data shown, but if you extrapolated the horizontal speed out to 0 and converted the vertical speed to something less crazy (feet per second? Really?) you can use it just like any other polar.

I could be wrong, but I think that at the time that the 2-32 manual was published, what we now think of as a standard glide polar was not standard here in the US. Or it might be that the FAA folks who reviewed the manual were not familiar with the polar format. So maybe Schweizer formatted the data in a way that they thought their US-centric regulators and customer base would be more comfortable with.

Thanks, Bob K.

In the 1980's (?) I believe Schweizer came out with an "update" to all their flight manuals stating "Aerobatics are not approved", mostly to cover themselves "in case someone pulled the wings off, etc.".
Having an old manual does NOT mean you can "do what you want" since the FAA would look at the current MFR manual.
;-)

Aerobatics not authorized per a SB in 1987, covering most (if not all) of their sailplanes.