achimha wrote:
The “same smart financial deal” was offered for virtually all new aircraft unless the vendor doesn’t need customer loans. More often than not, they turn out to be not that smart at all.
They should just call it “crowd funding”, and it would be much cooler.
As a PA18 driver I have no dog in this hunt!
The SF50 seems considerably cheaper than the competition, and has an SFC which might be 20-25% less efficient? I have used the Williams engine SFC and made assumptions on what thrust is required for the 300 KTAS cruise (80%?). Not sure if the aircraft overhead intake allows operating off unpaved runways, but presumably its runway requirements are shorter than the balanced field requirement of a multi jet, which may improve utility to compensate for the less efficient SFC.
They boast 550 firm orders so arguably they will have established a reasonable market presence.
I personally like the new Meridian M600 at a similar price point and with very good SFC numbers, but financially the early birds I think will be money good on the SF50.
The humble PA18-90 comes in at over 2.5nm/lb of Avgas. On a passenger seat basis I fear the SF50 is actually on a par.
RobertL18C wrote:
presumably its runway requirements are shorter than the balanced field requirement of a multi jet
Under EASA even with one jet engine it falls into the complex bucket. And, unless I’m mistaken, it will have to comply with the same requirements as multi-engine jets and turboprops.
SETs are quite a different proposition. And have you seen prices of few year old Mustangs?
And, unless I’m mistaken, it will have to comply with the same requirements as multi-engine jets and turboprops.
Martin how would this work for a single engine? Most lighter twin turbo props are Class B so would not plan for a V1 accelerate stop. Apologies for stating the obvious, but V1 is an impossible concept for single engine.
The five year old and older Mustangs seem to be coming in on the SF50 price point.
RobertL18C wrote:
V1 is an impossible concept for single engine
Why? The concept covers more than just engine failures. Consider smoke in the cockpit, as one example.
As I wrote, even single jet engine makes it complex which means this applies (for non-commercial operations):
NCC.POL.125 Take-off — aeroplanes
(a) When determining the maximum take-off mass, the pilot-in-command shall take the following into account:
(1) the calculated take-off distance shall not exceed the take-off distance available with a clearway distance not exceeding half of the take-off run available;
(2) the calculated take-off run shall not exceed the take-off run available;
(3) a single value of V1 shall be used for the rejected and continued take-off, where a V1 is specified in the AFM; and
(4) on a wet or contaminated runway, the take-off mass shall not exceed that permitted for a take-off on a dry runway under the same conditions.
(b) Except for an aeroplane equipped with turboprop engines and a maximum take-off mass at or below 5 700 kg, in the event of an engine failure during take-off, the pilot-in-command shall ensure that the aeroplane is able:
(1) to discontinue the take-off and stop within the accelerate-stop distance available or the runway available; or
(2) to continue the take-off and clear all obstacles along the flight path by an adequate margin until the aeroplane is in a position to comply with NCC.POL.130.
Unless I’m missing something.
[ formatting – is there a way to create multi-level lists and quote them? ]
…where a V1 is specified in the AFM…
I have yet to see the AFM of a single (or light twin) that gives v1 figures. And any other (arbitrary) speed above which a takeoff must be continued is technically not v1.
@what_next There is still the NCC.POL.125(b)(1). PS: The (b)(2) is not an option for single-engined aeroplane, obviously, which the Cirrus is.
There is still the NCC.POL.125(b)(1).
Yes. But again, in all AFMs for singles and light twins that I have seen so far, the accelerate-stop-distance is given for a takeoff abort at rotation speed (Vr). I have never seen V1 figures, which would be lower than Vr, in that context. And they would not make much sense to most pilots of these aircraft anyway as these speeds and their meaning is not taught at PPL level.
what_next wrote:
n all AFMs for singles and light twins that I have seen so far, the accelerate-stop-distance is given for a takeoff abort at rotation speed (Vr)
For the DA42 you need to determine the TORR and LRR from tables and add them together to obtain the ASDR.
AFAIU there are no V1 figures for class B performance airplanes because takeoff should be aborted if engine failure occurs before rotation since the performance does not allow for a safe intial climb OEI.
Apologies for continuing the thread drift. Under EASA aren’t balanced field calculations applicable to Class A only? Other classes you would apply the public transport safety factors to TODR and LDR, but not required to calculate ASDR. For example, I don’t recall accelerate stop tables in the typical CAA AFM for multi Pistons. The FAA does want accelerate stop but only for multi engine?
