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Re: REFLECTOR: airspeed indicator markings

Sounds like I pretty much had the right idea, huh?

Duane Swing wrote:

> We at the factory have established the following airspeed limits on all our
> airplanes.  White arc (actually speed brake speed) of 65 to 110 knots.
>  Green arc of from 65 to 170 knots. ( the 170 knots would be the maximum
> structural cruise speed) and the yellow arc from 170 knots to 200 knots.(
> 200 knots being the Vmc)  All speeds are indicated assuming proper
> calibration has been done.  Although no markings are normally used for
> maneuvering speed, this is 140 knots. (this is the speed where instant and
> full deflection of the controls can be made safely) Many of our airspeed
> indicators have the green arc stopping at 140 knots, however, this should
> actually be 170)   It is important in an experimental airplane that the Vmc
> and all flutter testing be done by the builder.  Many kit manufacturers
> refuse to publish any airspeed limitations due to liability.  We, as kit
> manufacturers, can never be sure YOUR airplane was built properly.   We
> generally test our airplanes up to about 220 knots indicated as a 10%
> buffer.
> Sincerely,  Duane Swing
> -----Original Message-----
> From:   Bob Ginsberg [SMTP:bgins@intrstar.net]
> Sent:   Sunday, July 11, 1999 6:49 PM
> To:     Velocity Reflector
> Subject:        REFLECTOR: airspeed indicator markings
> The question of the markings on the airspeed indicator is a good one.
> Other than the speed brake limit of 110 knots on my fixed gear 173, I
> know of no factory designated maximum speed, normal operating speed,
> minimum speed, or maneuvering speed.  Now, some of these should probably
> be determined by the builder during flight trials.  But as far as I
> know, maneuvering speed (which isn't typically marked, and varies with
> weight anyway), can only be calculated.
> I put the white arc at 60 to 110 knots, representing the minimum speed
> at which I ever stalled the canard, to the speed brake limit.  I put the
> green arc up to 163  knots, simply because that was what Dan Maher said
> was his best speed on the 173 fixed,  I put red at 200 knots because,
> ... I don't really know because.  I figured the FAA would want some type
> of markings on the plane's airspeed indicator.
> I would love to hear what other people have done here.
> --
> Bob Ginsberg, M.A., CSCS, CPT
> Big Ape Gyms - Velocity 173

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