54 knot CAS MOSAIC requirement, and only that. :)

There's a discussion going on over on the RV sites, regarding the legalities of establishing VS1 for EAB. To wit, there isn't a single one value, and it's clear many phase 1s out there are just not created equal (in practice). There's no standardized methodology for publishing calibrated speed for amateur builders, definitionally.

RV-12s are different in that they were designed and published with the FAA to be offered as S-LSA product, thence E-LSA by extension. As such, they have calibrated Vs1 speeds published (had to, to qualify for LSA in the eyes of the FAA in the first place). So it appears Van's would have to publish Vs1 calibrated values for an S-LSA offering (and go through that legwork) in their more capable kits, in order to allow sport pilots to qualify to fly them. But you can't do that retroactively for EAB anyways.

Simply stating "yeah my RV-7 stalls clean at less than 54 calibrated because I did my test pilot cosplay phase 1 thing with my ipad" doesn't seem to pass the sniff test. I have not heard Van's pushing for S-LSA offerings on their 7/8/9 line either, so that's a pretty open question remains on the EAB space. Doesn't affect me, I can hold basicmed, just thinking out loud for the sake of this mosaic discussion is all.
 
The idea of the NPRM process is somebody asks "why 54 kts" and they have to answer with some sort of reason, not just "because" so let's see what happens.
 
4. Maximum Stalling Speed (VS1)
The light-sport aircraft definition in
§ 1.1 limits the maximum VS1 for lightsport
aircraft to 45 knots CAS at the
aircraft’s maximum certificated takeoff
weight and most critical center of
gravity. The proposal would retain the
45 knots CAS maximum VS1 for gliders
and weight-shift-control aircraft. The
FAA is proposing to increase the
maximum VS1 to 54 knots CAS for
airplanes. Regulatory provisions
addressing VS1 would remain
inapplicable to rotorcraft and lighterthan-
air aircraft (e.g., balloons and
airships), and would be removed for
powered parachutes.
The 45-knot limitation indirectly
prohibits the use of heavier airplanes
due to the correlation between stalling
speed and aircraft weight. Because the
FAA is seeking to accommodate greater
airplane weights to enable more robust
airframe designs and availability of
safety enhancements, the FAA selected
this proposed VS1 speed limit at nine
knots above the current limitation for
light-sport aircraft. The FAA determined
that an airplane with a maximum VS1
limitation of 54 knots would permit
airplane designs up to approximately
3,000 pounds. As proposed in
§§ 22.100(a)(3) and 61.316(a), the new
stalling speed limitation would apply to
airplanes at the maximum certificated
takeoff weight.
In the absence of a specific weight
limitation in the proposed rule, the new
VS1 limit would provide flexibility for
aircraft manufacturers to build more
robust airframes and include desirable
safety enhancements. This proposed
change would expand aircraft that sport
pilots may operate to include any
existing aircraft that meets the sport
pilot performance limitations as
specified in proposed § 61.316. For
airplanes, the proposed VS1 limit is not
more than 54 knots CAS for sport pilots.
The FAA has monitored the accident
history of light-sport category aircraft
since 2004. As of 2021, there have been
984 accidents or incidents involving
light-sport category aircraft, with
approximately half of those accidents or
incidents occurring during the landing
phase. Of the 501 landing accidents,
seven resulted in a fatality. The second
highest number of accidents or
incidents, 164, occurred during an
emergency descent. The FAA chose a
VS1 of 54 knots CAS to strike a balance
between allowing heavier aircraft to
accommodate increased safety features,
while increasing the stalling speed no
more than necessary to retain low
speeds during approach and landing.
While the FAA recognizes that low
stalling speeds will reduce kinetic
energy levels and serve to improve
occupant survivability in the event of an
aircraft accident, enabling the addition
of safety enhancing designs
commensurate with increased weight
could also improve occupant
survivability.
The FAA has determined that
retaining the current VS1 restriction of
45 knots CAS for light-sport category
airplanes would overly restrict the
ability of aircraft manufacturers to
produce heavier airplanes with
additional safety features that this rule
is intending to enable. A maximum VS1
of 54 knots CAS for airplanes would
facilitate the production of heavier,
more robust airplanes without unduly
compromising the ability of these
airplanes to be safely operated.
Although the FAA considered
increasing the proposed maximum
stalling speed of airplanes above 54
knots CAS, the agency’s review of
current aircraft performance data
showed that this proposal would be
sufficient to produce four-seat airplanes.
 
I think the choice of VS1 is thr right choice. Look at the extra training needed for the MU-2 and you'll see they avoided a whole host of weird and wild attempts to hit a rule with crazy flaps or even Wren like systems.
 
I wonder what percentage of fatal accidents occur when the flaps are down?
 
Tusayan said:
I spent $35K on my plane. It’s wonderful and will likely last me forever. These are the good old days, and I think MOSAIC will help - primarily in further aligning FAA medical practice with modern healthcare that has overtaken it and made its impact statistically irrelevant for private pilots in the real world.
Click to expand...
Indeed they are.
In 2015, before I bought, I was very concerned about the risk of buying a plane with a standard airworthiness cert -> getting a 3rd class denial -> being locked out of SP.
BasicMed happened and helped to mitigate those risks.
I renewed my 3rd class in 2016 at 39 and bought my C140 in 2018.
Completely coincidentally, my health is now much better than it was seven years ago.
The fact that my C140 might soon be able to be flown under SP rules would be welcome.
Aviation being the hedonic treadmill that it is, thoughts wander to a $70k plane instead of a $35k plane.
For roughly iso-dollars, I could consider a C170, a 1320lb SLSA, or an EAB.
912iS-powered planes are not yet affordable by me, otherwise that would be a slam dunk decision (see the EFI thread)
Maintenance is becoming the long pole in the tent.
SLSA->ELSA conversion + LSRM sounds mighty attractive. A full blown A&P ticket is also not completely out of the question, if only so I could do highly technical things like work on my brakes.
 
Dana said:
I wonder what percentage of fatal accidents occur when the flaps are down?
Click to expand...
I wonder what effect the choice Vs1 instead of Vs0 in this regulation could have on the use of flaps for landing, regardless of their design, or any hazard associated with use of flaps. It’s not like aircraft designers are suddenly going to start designing planes without flaps, or that pilots will stop using them just because the plane stalls at 54 kts or lower without them.
 
GeorgeC said:
Maintenance is becoming the long pole in the tent.
SLSA->ELSA conversion + LSRM sounds mighty attractive. A full blown A&P ticket is also not completely out of the question, if only so I could do highly technical things like work on my brakes.
Click to expand...

I built my experimental so I have the certificate to do condition inspections on it.

I have owned a couple of ELSA aircraft and went and took the 16 hour weekend course to obtain a certificate to do the condition on any ELSA that I own. It was a good course but in truth I don't feel that the 16 hour course is near enough training for a non-mechanically minded person to be able to do a proper inspection on a plane that they did not build regardless of how simple a plane it is.

So for me I can see no reason to sell the plane I have and buy a certified plane that will cost more to purchase and then I have to have an A&P to do the yearly inspection. Then again I don't have the training/knowledge to inspect a Cessna 172 and determine if it's airworthy or not. A training program to get me up to speed might not take too much time but for others that are not familiar with aircraft construction or not mechanically inclined the training required could be much longer and more costly. Where to draw the line?
 
Tusayan said:
I wonder what effect the choice Vs1 instead of Vs0 in this regulation could have on the use of flaps for landing, regardless of their design, or any hazard associated with use of flaps. It’s not like aircraft designers are suddenly going to start designing planes without flaps, or that pilots will stop using them just because the plane stalls at 54 kts or lower without them.
Click to expand...
probably just as much effect as the Vs1 limit in the current LSA definition has had.
 
Last edited:
Half Fast said:
That’s the point.

The purpose is not to move more legacy planes under the LSA umbrella. The purpose is to sell more new planes. So there’s a reason to exclude legacy planes.
Click to expand...
Nice idea, but I can't afford a NEW airplane. The rule change won't suddenly make me a new aircraft buyer.
 
As long as a bony hand has punched through the crust of this particular Necropost, I'll share the results of a study I did a couple of months ago.
1731964729173.png
There are about 293,000 total aircraft in the US registry. But of that amount, only about 144,000 are the typical GA aircraft that the program is aimed at (e.g., Standard Category, single-reciprocating engines). Based on the January 2024 FAA registry, about 75,700 Standard Category aircraft will qualify under MOSAIC.

However, those aircraft include about 14,000 Standard category aircraft that had previously qualified under Light Sport. So, one could claim that 43% of typical GA aircraft will be newly-capable of being flown by Sport Pilots.

Note that this tally does not include homebuilts! While the FAA issued a list of production-type aircraft that met Light Sport, no such list was every produced for homebuilts…and I figure the same thing will happen with MOSAIC. It'll be up to the owner to decide whether his homebuilt qualifies.

Ron Wanttaja
 
It’s the TC specs, not whatever your airspeed indicator may or may not be marked or whatever mods you think of.
 
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