A DA42 went down around 18 Z east of Västerås in Sweden. The airplane was operated by a FTO.
3 people are severely wounded.
An interview with the passenger (in Norwegian). The passenger was also a student at the flight school. According to him, the instructor demonstrated a “deep stall” at 5000 feet. The aircraft went out of control and entered a spin. At the time the conditions were darkness, VMC on top of an overcast layer between about 300 and 1000 feet.
From the description in the article it appears that the “deep stall” was an accelerated or full power stall.
The maneuver they did before the crash is called a deep stall.
- This is not something we had done before in the United States. It is an aggressive maneuver, where you almost have to fly a bit aerobatic, it’s a very high nose-up attitude of the aircraft. I had the impression that the instructor had done this several times previously, he said
The stall exercises for multi are all to first indication of the stall, the definition of which includes being 5 – 10 knots above IAS stall. In most training twins first indication is around Vsse (safe single engine speed, the speed you use for Vmc demonstrations), so a nice safe envelop. With stall strips you are getting buffet before this.
A HASELL check may have given pause about stalling at night and over an undercast. Thankfully there appear to be survivors.
“Deep stall” in a DA42? Hmmmmm.
Pointless exercise which potentially brings problems. It would be interesting to see if the stall occurred in a specific configuration and whether the variable elevator backstop had a part to play.
Multiengine planes don’t have to be spin tested. Does anyone know if the DA42 is?
I think in these cases you should remember that you have two engines and make use of asymmetric power quickly to try to get out of such situations.
It will be interesting to see the report in due course. The T-tail should allow rudder authority, and the DA42 is not swept wing so arguably not prone to a ‘deep stall’. That is the centre of pressure will move aft in the stall causing a pitch down, swept wings work opposite and deepen the stall.
The engines will create a wing loaded spin behaviour, which referring to, for example Alan Cassidy’s Better Aerobatics ‘an aircraft..with a relatively heavy wing and light fuselage will spin flatter’. A high rotational flat spin might not be recoverable even with asymmetric power.
Twins (some) may be tested to incipient spin, but none that am aware of are approved for spins!
This is just flat out bizarre – spin training in darkness, with backseat passengers in the cabin, above a cloud cover & presumably at freezing temperatures?!
RobertL18C wrote:
Thankfully there appear to be survivors.
That’s just amazing, given the condition of the airframe and should indicate superb crash caracteristics of the DA40/42.
Sadly, what isn’t known is the “condition” of the survivors… their lives might never be the same again.
The plane looks totally wrecked
It seems there is some suggestion that this was a deliberate spin or incipient spin manoeuvre….where did that come from?….For reference the FAA Practical Test Standards for CPL Multi-engine Land or Sea require demonstration of Power-On stalls….normally this is limited to 65% of max power however there is a note in the PTS which states that for some high performance airplanes a lesser power setting may be required in order to avoid an excessively high nose attitude…. Recovery should be initiated at the “onset”….and obviously not be allowed to develop into a spin….It sounds like this is the kind of manoeuvre that was being demonstrated….Not a totally bizarre manoeuvre in itself…but with a passenger, at night etc…probably not clever.
