I suggest there are several golden rules here:
1. Never, ever, exceed the Never Exceed Speed of 165 kts. (Question
for better aerodynamicists than me: should this be taken as 165 RAS
since that is the direct indication of the aerodynamic load?? In
practice, the big red line on the IAS scale is what we abide by in
practice.)
2. Be super gentle pulling out of a Vne speed dive (eg as we have to
do for Permit renewal in the UK - not sure whether there's an
equivalent routine flight test elsewhere). That means plenty of
height so that a modest positive g force will recover to straight and
level flight with plenty to spare.
3. Abide by Va (97kts for Europa) and Vno 131 kts for Europa) and Vfe
(83 kts for Europa) limitations (definitions below):
VA
design maneuvering speed (stalling speed at the maximum legal G-
force, and hence the maximum speed at which abrupt, full deflection,
control inputs will not cause the aircraft to exceed its G-force
limit). Maneuvering speed is limited by aircraft structural
characteristics.
VNO
maximum structural cruising speed (the maximum speed to be used in
turbulent conditions) or can refer to the velocity of normal
operation. VNO is specified as the upper limit of the green arc on
many airspeed indicators. This speed is specific to the aircraft
model. The range above VNO is marked on the airspeed indicator as a
yellow arc from VNO to the VNE
VFE
Max speed for flap extension
4. Be wary of Brochure performance claims.
Willie Harrison G-BZNY
On 12 Dec 2006, at 23:25, Graham Singleton wrote:
> <grahamsingleton@btinternet.com>
>
> Jim
> RAS is I assume Rectified Air Speed. Corrected for instrument and
> position errors. (The position of the static and pitot sensors. )
> TAS ( true air speed ) is IAS corrected for altitude and
> temperature and it will usually be higher, so you could still be
> below Vne.
> Graham
>
> h&jeuropa wrote:
>
>> <europa@triton.net>
>>
>> I have recently become aware that Vne is normally expressed in
>> True Airspeed (TAS). According to Derek Piggott=92s Gliding text,
>> =93it is important to limit indicated airspeed so the true airspeed
>> is kept below the Vne placard speed. Otherwise there may be risk
>> of flutter and structural failure=94.
>>
>> My XS Owner=92s Manual states that Vne is 165 kts (page 2-1, issue
>> 1). The same manual states that for a 914 typical performance is
>> Cruise speed (100% @ 10,000 ft) 170 kts TAS (page 12-2, issue 1).
>> But that is 5 kts greater than Vne!! That page also states Top
>> Speed (sea level) 144 kts RAS. What is RAS? Is it a typing
>> error (R is adjacent to T on a keyboard)? RAS is also referred to
>> on the 912 performance page.
>>
>> What are the performance numbers for the MG? Brochure says 151
>> kts TAS max cruise speed for 914 at 10000 ft. So is 151 KTAS Vne?
>>
>> It is very easy to exceed 165 KTAS when descending from altitude.
>> Should this be avoided?
>> Jim Butcher XS N241BW
>>
>>
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=81100#81100
>>
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