ptwffz

Yes Cliffy. A big deal indeed.

Gotcha.

Understood. When you say "modified" are you referring to the aircraft being modified with retractable gear/ constant speed prop or my airspeed indicator. I'll reach out to Mooney.

I must have missed the setion stating "manufacturer tested."

I wish AI would reveal its source. My Owners manual does list VS1 as 67 MPH IAS. Does anyone on the board have a Master manual that shows CAS conversions at that low of an airspeed? AI Overview The Mooney M20D Master's calibrated stall speed in a clean configuration is approximately 58 knots (67 MPH). This figure is derived from the indicated airspeed (IAS) and the airspeed calibration information provided in the aircraft's Pilot's Operating Handbook (POH) and related documentation. Details on the Mooney M20D Stall Speed Indicated Airspeed (IAS): The POH for the M20D Master typically lists the clean stall speed as 67 MPH IAS, which converts to approximately 58 KIAS (Knots Indicated Airspeed).

I guess I'll have to visit FOSDO and see exactly how to document an airborn calibration test and hope for the best. I see it described in the advisory circular but thery're going to believe my test results? Not that I'd lie but I could see a pilot having a very subjective result.

Makes sense. I was of the mindset that the bottom of the green arc is the clean stall speed. I guess that's why stall speed clean shows 67 MPH IAS on a different page. I just need to find out what my calibrated VS1 is and convert it to knots. For that I have no chart. Might need the airborn check. Any thoughts on that other M20D airspeed indicator with such low green and white arc speeds? I've never seen one so low.

I just noticed the top of my white arc is taped over as well.

This is my airspeed indicator. It looks like someone placed black tape over the bottom of the green arc. Like I said, maybe the other airspeed indicator shoud be in my bird. Is my Owners Manual incorrect? I have a 1964 M20D Master and my manual says 1965. I doubt it changed by one year. Nothing is making sence here. Or I'm retarted.

The above airspeed indicator was copied from a different post. The owner states it's from his M20 D/C model which is exatly mine. Granted I don't know his year but there's a big difference in his VSo and VS1. Both way lower than mine. What the !!!!!!!!!

Hello Ron, Bare with me on this message. I'm needing some help. I recently started a post regarding the new MOSAIC rules and was curious if our M20's clean stall speed was slow enough to qualify (at or less than 59 KCAS). I own a 1964 D/C as well (serial #217.) I noticed that the photo of your airspeed indicator in a prior post shows a lower VSo and VS1 stall speed than my airspeed indicator. Your speeds at least on the airspeed indicator would show a clean stall speed (VS1) around 62 MPH. That converts to 54 kts. Correcting for calibrated must still put you at or under 59 KCAS. My airspeed indicator shows the bottom of the green arc at 70 MPH but my owners manual says the clean stall speed is 67 mph IAS. Clearly both of your stall speeds are showing lower than mine and we have the same aircraft basically. I'm curious what your manual lists as your clean stall speed and if it says indicated or calibrated. Maybe I have the wrong manual and/or someone replaced my original airspeed indicator. It looks like tape might have been added to the bottom of my green arc to make my clean stall speed higher which matches my manual that says VS1 is 70 mph calibrated. I'll try to attach a pic of my airspeed indicator. If your manual lists the lower speeds maybe you coud snap a pic of the front cover and I could try to find one. This has been very frustrating. Hope you're doing well. Joe

All I'm gonna say is I wish that chart was in my Owners Manual. I'd be golden.

Makes sense if IAS = CAS at low speeds.

I won't continue to harp on this subject. One last thing. My Owners Manual says bottom of green arc is 70 mph calibrated and my stall speed is 67 mph IAS. If true, then there must be a 3 mph increase from IAS to CAS. Hank shows a chart showing a 70 mph IAS corrected to 67 mph CAS with his 1970 C. How is it that possible? One increasing by 3 mph and the other decreasing by 3 mph. Can the installation error be that far off?