HarryH wrote:
After noticing that Diamond Aircraft makes its airplane flight manuals available for download, I downloaded the DA 42 AFM and reviewed it on the subject of engine failure and engine-out operations.
Thanks for the analysis. I just want to point out that you can download POH both for DA42-VI (or NG, equipped with AE300 engines) and DA42 TDI (equipped with CD-135 engines, Revision 8). In addition, supplement covering performance differences for CD-155 engines is also available. This supplement contains some errors to which I pointed DAI immediately after releasing (some 5 years or so ago) but nothing has been corrected since.
I always had understood Vsse was introduced in the 1970’s by the FAA after a consistent loss of life during Vmca demonstrations.
It is defined in POH/AFM as Minimum Safe Single Engine Speed and it does what it says on the tin, do not go below this during training. With wings level Vsse is approaching max rudder (applying up to 5 degree bank towards the live engine restores some rudder authority), while having a comfortable margin above 1 g un accelerated stall speed.
The FAA, unlike EASA, is very risk averse on Vmca demo in MEP/MET. Most of these light twins have Vmca and the clean stall speed reasonably co located, a bit of acceleration in approaching Vmca and you have a classic yaw aggravated stall, aka spin.
While have carried out some ME instruction in the beloved Twinkie, fortunately 99% of my instructing has been in the Seneca which (not wanting to jinx it) has never suffered a Vmca training incident.
The Twinkie has a wonderful smoking causes cancer warning on the concept of Vsse, and the POH clearly states treat Vsse as a minimum.
HarryH wrote:
After noticing that Diamond Aircraft makes its airplane flight manuals available for download, I downloaded the DA 42 AFM and reviewed it on the subject of engine failure and engine-out operations. I am a bit disappointed that the manufacturer of such a good looking airplane provides flight manuals that are not so good on the subjects mentioned. Airplane control after engine failure is not explained in accordance with the EASA Flight Test Guides that are used during flight-testing and certification. Knowledge faded away here too. Therefore I wrote a review that I will also send to DA. The review is loaded with explanations to learn from and to help improve the manual; it is not written to apportion blame or liability. Many remarks apply to flight manuals of other multi-engine airplane types as well. It can be downloaded here: https://www.avioconsult.com/downloads.htm#DA42.
Very interesting document. Actually my flight school have 3 of these same CD135 version of the DA42 is providing SOP that are mostly complying with your recommendation about VR and bank angle during OEI, although they also show that is gets tricky to operate the plane at 68kias with full rudder deflection, as well as Vyse. I remember asking them about the voluntary imprecision of the AFM about these, but your nails it perfectly.
Their SOP state a VR of 72kias, then take a 1st segment climb speed of 82kn (VR+10) until gear is retracted where you have to keep 86kn until acceleration for en-route climb. The also trains a lot on feeling the ball and bank on the live engine when manoeuvring.
Another usage is the so called transparent mode of then engine, actually the power setting of 20% where the engine doesn`t give any power but the prop move to coarse (20%) to full fine (0%). When simulating engine failure, instructor set simulated dead engine lever to 0%, and when students shows the good engine master, instructor changes is to 20%.
I think many IRME ATO uses these kind of « SOP ».
I’ll send them your report.
Another one you have probably already seen.
After noticing that Diamond Aircraft makes its airplane flight manuals available for download, I downloaded the DA 42 AFM and reviewed it on the subject of engine failure and engine-out operations. I am a bit disappointed that the manufacturer of such a good looking airplane provides flight manuals that are not so good on the subjects mentioned. Airplane control after engine failure is not explained in accordance with the EASA Flight Test Guides that are used during flight-testing and certification. Knowledge faded away here too. Therefore I wrote a review that I will also send to DA. The review is loaded with explanations to learn from and to help improve the manual; it is not written to apportion blame or liability. Many remarks apply to flight manuals of other multi-engine airplane types as well. It can be downloaded here: https://www.avioconsult.com/downloads.htm#DA42.
HarryH wrote:
Together we can make aviation safer.
Thanks for this great materials.
Very good detailed video. Just one though which came to my mind is I remember this applies to normal places with normal controls only? The Mitsubishi MU2 does not have ailerons but spoilers and I somehow remember reading pilots got themselves into big trouble by banking the plane on one engine as this did increase the drag and did kill some lift. Apparently this was one of the reasons special training had to be introduced for the MU2. Maybe we have some MU2 experts here?
Great video – thanks for pulling this together – I’m sure you have saved some lives, Harry!
Thanks Robert, I really appreciate your feedback.
