Graham, Sorry to be butting in on your debate with Tim,
and I see where you are coming from now, but can I just
add that the SmartASS is g compensated so it gives exactly
the same 'margin over stall' information as an AOA device
(and at a fraction of the price). It might appear that I
am pushing this as if I had some commercial tie up, which
is not the case. I am evangelical about it because we have
now had (subject to confirmation in this latest case) 6
Europas lost to stall/spin accidents, an appalling
statistic for a plane that flies so beautifully and is
slippery enough not to lose speed rapidly. There have of
course been countless crashes of other types also, but in
our relatively small and tight knit Europa community it is
truly sobering and we should all be asking ourselves are
we confident of not becoming number 7.
Regards, David Joyce, G-XSDJ
GRAHAM SINGLETON <grahamsingleton@btinternet.com> wrote:
> Tim
> maybe we are mixing things a bit. ASI will measure
>instantly changes in airspeed.
> When AoA changes aircraft speed will not change
>instantly but will take several seconds.
> The force causing change of airspeed is increase or
>decrease in drag, usually quite a small force.
> During take off acceleration is caused by engine thrust
>and ASI will record speed of course, as soon
> as the aircraft is flying AoA should quickly settle at
>best climb.
> Stall occurs at the same AoA whatever airspeed or total
>weight is. (I'm thinking aloud here)
> In fact best climb, cruise or glide speeds are also at
>fixed AoAs. They are not at fixed airspeeds but
> change as all up weight changes.
> AoA is much the best primary flight control instrument.
>That's why fast jets use it.
> A pity AoA meters aren't mass produced like ASIs are!
> best regards
> Graham
>
>
>
>
> ________________________________
> From: houlihan <houlihan@blueyonder.co.uk>
> To: europa-list@matronics.com
> Sent: Sunday, 11 May 2014, 8:34
> Subject: Europa-List: Re: Europa-List: Re: Europa-List:
>Re: Europa-List: Re: Europa-List: Europa Crash in
>Lbeck/Germany
>
>
>
> Hi Graham.
>
> We may be talking apples against pears here BUT if what
>you say is true then on takeoff I would be at 100'
>thinking about retracting the undercarriage before the
>ASI has moved from zero.
>
> I agree it takes time to accelerate or decelerate a
>600kg mass but the pressure measurement showing movement
>relative to the local air mass will be indicated within a
>small fraction of a second even using our normal
>mechanical manometers that are calibrated in airspeed and
>could be even quicker using electronic pressure sensors
>close to the pitot head.
>
> True an AOA or alpha system would be helpful but I just
>want to be warned if through lack of attention or being
>distracted I allow my speed to decay , these lack of
>attention or distraction events usually build up slowly
>without it being noticed and I would guess rarely happens
>over one or two seconds.
>
> best regards
>
> Tim
>
>
>
> On 10 May 2014 22:28, GRAHAM SINGLETON
><grahamsingleton@btinternet.com> wrote:
>
> Tim
>>don't think so , the ASI won't move (or shouldn't!) until
>>the aircraft has accelerated, or worse slowed down and
>>that takes many seconds.
>>When it says "stall speed!" you.ve already stalled. Not a
>>lot of use.
>>Graham
>>
>>
>>
>>
>>
>>
>>________________________________
>> From: houlihan <houlihan@blueyonder.co.uk>
>>To: europa-list@matronics.com
>>Sent: Saturday, 10 May 2014, 14:31
>>Subject: Europa-List: Re: Europa-List: Re: Europa-List:
>>Europa Crash in Lbeck/Germany
>>
>>
>>
>>Hi Graham.
>>
>>
>>I think you may have put the decimal point in the wrong
>>place. I appreciate what you are suggesting but 20
>>seconds ?
>>I bet the real figure is much less than a second.
>>Mind you how would you measure the lag , my ASI seems to
>>move at the speed of light at times.
>>
>>
>>Tim
>>
>>
>>
>>
>>
>>On 10 May 2014 13:19, GRAHAM SINGLETON
>><grahamsingleton@btinternet.com> wrote:
>>
>>Or an AoA meter as primary attitude/speed instrument. The
>>ASI is always 20 seconds too late.
>>>Very sad, I met Manfred while he was building. A very
>>>nice man and a nice Europa.
>>>Graham
>>>
>>>
>>>
>>>
>>>
>>>
>>>________________________________
>>> From: David Joyce <davidjoyce@doctors.org.uk>
>>>To: europa-list@matronics.com
>>>Sent: Saturday, 10 May 2014, 12:36
>>>Subject: Re: Europa-List: Europa Crash in Lbeck/Germany
>>>
>>>
>>><davidjoyce@doctors.org.uk>
>>>
>>>
>>>I strongly suspect that this another case where a
>>>SmartASS or the equivalent might have saved them both.
>>>David Joyce, G-XSDJ
>>>
>>>
>>>
>>>arget="_blank">http://www.matronics.com/Navigator?Europa-List
>>>tp://forums.matronics.com
>>>_blank">http://www.matronics.com/contribution
>>
>>http://www.matronics.com/con================
>>
>>
>>arget="_blank">http://www.matronics.com/Navigator?Europa-List
> tp://forums.matronics.com
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