Tecnam twin crashes northwest of Calgary. Two fatalities

[India Four Two]

Aviation school fleet grounded as Mount Royal University mourns loss of 2 instructors in crash near Calgary - Calgary - CBC News (http://www.cbc.ca/beta/news/canada/calgary/plane-crash-waiparous-east-calgary-instructors-killed-1.3981615)

[India Four Two]

Photos from the crash site seem to show a near-vertical descent with a very small pitch angle.

https://shawglobalnews.files.wordpress.com/2017/02/crash22.jpg?quality=70&strip=all&w=672&h=448&crop=1

https://shawglobalnews.files.wordpress.com/2017/02/crash3.jpg?quality=70&strip=all&w=672&h=448&crop=1

Flight instructors killed in plane crash near Calgary were experienced pilots: Mount Royal University president | Globalnews.ca (http://globalnews.ca/news/3247194/crews-search-for-missing-plane-west-of-calgary/)

[B2N2]

Simulated single engine exercise gone wrong?
Inadvertent spin?

[India Four Two]

B2N2,

There is no official information yet. However, two things to note:

1. This was a flight with two very experienced instructors, presumably doing some continuation training exercises.

2. The crash site photos imply an almost vertical impact with little or no pitch angle. I remember seeing confirmation of this somewhere else. The second photo I posted shows an impact scar which might indicate rotation, but it might also have been caused by the wreckage sliding downslope.

I've not been able to find any information on stall-spin Tecnam twin accidents.

[Vilters]

@TangoAlphad

That would be problematic as there were only 2 persons on board in this accident, and with 4 adults and bagage the cg would move further aft.

[B2N2]

It's been a while since I looked this up but twin engine aircraft have no certification requirements as far as spins...as you're not supposed to spin them.
I don't know of any GA twin which is authorized to spin.
But an accident with two experienced instructor pilots is usually training related which would lead you to believe a SE demo gone wrong.

[B737C525]

I don't know of any GA twin which is authorized to spin.

Perhaps I can enlighten you...

http://https://en.m.wikipedia.org/wiki/Speedtwin_E2E_Comet_1

http://http://www.pprune.org/flight-testing/552626-intentional-spinning-speedtwin-e2e-comet-1-a.html

[India Four Two]

I've been trying to find a POH for the P2006T. Does anyone know if spinning is approved or not?

[B737C525]

From the AFM Section 2:

14. APPROVED MANEUVERS
The aircraft is certified in normal category in accordance with EASA CS-23 regulation.
Non aerobatic operations include:
 Any manoeuvre pertaining to “normal” flight
 Stalls (except whip stalls)
 Lazy eights
 Turns in which the angle of bank is not more than 60°
 Chandelle

And then, with a big red warning triangle next to it:

Acrobatic manoeuvres, including spins and turns with angle of bank of more than 60°, are not approved for such a category. In addition, stall with one engine inoperative is forbidden.

...and from Section 3, with another red triangle:

The spin recovery has not been demonstrated during certification process being not required for this aircraft category. Should an unintentional spin occur, the classic recovery ma- noeuvre is deemed as being the best action to undertake.

[India Four Two]

B737C525,

Thank you for that information, which was as I suspected.

During some searching, I stumbled on this interesting video of spin-testing a Beech Duchess:

3cJkjk0hOU8

As pointed out in the video, even after successful spin-testing during certification test-flying, the Duchess was certified in the Normal Category and placarded "Normal Category Aircraft: No acrobatic maneuvers, including spins, approved."

Previously discussed on PPRuNe here:

http://www.pprune.org/flight-testing/552626-intentional-spinning-speedtwin-e2e-comet-1-a.html#post8778999

[Pilot DAR]

Note the certification differences:

Normal category singles may be spin approved, but are not required to be. They will, however, for certification, have demonstrated recovery from a one turn spin in no more than one additional turn. Nothing says that this recovery has to be easy, just possible.

Utility category aircraft, if to be spin approved, are required to demonstrate recovery from more demanding spin conditions.

The forgoing shows the difference on the spinning categories approved for the 172 - normal vs utility.

Multi engined aircraft are not required to demonstrate spin compliance at all for certification, unless they are requesting spinning approval as a utility aircraft. I'm not aware of any examples of this. They are required to demonstrate single engined stalls, but if you're spinning a multi engined aircraft you are probably a test pilot for that flight.

[megan]

you are probably a test pilot for that flightAnd perhaps an unwilling one. The RAAF had a C-130 make a six turn spin, and the USN had a P-3 make five turns.

[janrein]

I've not been able to find any information on stall-spin Tecnam twin accidents.

20160817 TC-TUO
https://aviation-safety.net/wikibase/wiki.php?id=189329

20121113 YL-SVN
http://www.taiib.gov.lv/uploads/Final%20Report%20%20Bukultix%200.pdf

[9 lives]

That accident report is pretty interesting reading. I have not flown the Tecnam, but other types I have flown, including the Partenavia Observer, demonstrated good tolerance to wing drop and spin entry, when flown within their certified parameters. The flying I did on these types included single engined and 30 degree banked stalls. Though I was guarding myself for an upset, I was always rewarded with a benign aircraft.

[India Four Two]

Aviation Investigation Report A17W0024 - Transportation Safety Board of Canada (http://www.tsb.gc.ca/eng/rapports-reports/aviation/2017/a17w0024/a17w0024.asp)

Findings as to causes and contributing factors

These are findings related to the unsafe acts, unsafe conditions, or safety deficiencies that are associated with the safety significant events that played a role in causing and/or contributing to the occurrence.

1. For unknown reasons, the aircraft entered a spin from a stall exercise.

2. The instructor and trainee recovered the aircraft from the spin, but insufficient altitude remained to recover from the ensuing dive.


Findings as to risk

These findings are not causal or contributory to the occurrence. They identify a risk that was found during the investigation that has the potential to degrade safety. They may describe a condition that is systemic in nature that applies to an audience beyond those involved in the immediate occurrence.

1. If flight training units do not emphasize that the most important reaction to a stall or approach to stall is a reduction in the angle of attack, a loss of aircraft control may occur.

2. If organizational safety processes do not identify and mitigate non-standard practices, manoeuvres that are outside of the aircraft limitations defined in the aircraft flight manual may be conducted, increasing the risk of aircraft accidents.

3. If full-stall demonstrations are required as part of a multi-engine rating test, there is an increased risk that, due to unknown spin characteristics, pilots may not be able to regain aircraft control if the stall progresses into a spin.

Other findings

These findings are not causal or contributory to the occurrence and are not systemic in nature. They identify an element or contain a message that has the potential to enhance safety. They can resolve an issue of controversy or provide a data point for future safety studies or analyses.

1. It could not be determined whether the instructor or the trainee involved in the occurrence had been exposed to the non-standard practice in use for stall-recovery training or whether the instructor had used it on the accident flight or on previous flights.

2. Given that the aircraft was almost entirely destroyed by the crash and subsequent post-impact fire, it could not be determined whether any pre-impact system failure or malfunction contributed to the accident; however, the components that were examined showed no signs of malfunction.

3. The information contained in Advisory Circular 700-031, Prevention and Recovery from Aeroplane Stalls, was not incorporated into TP 11575, Instructor Guide—Multi-Engine Class Rating.

[RatherBeFlying]

Interestingly some pilots had been experimenting with adding yaw to stalls and sharing results by word of mouth.

Flight data was extracted from SD cards that had been shared among the 3 Tecnams. Unfortunately the SD card in the accident aircraft was consumed by fire.

The most exciting outcome was a 1500' altitude loss with inversion and a maximum descent rate of 12,500 fpm:eek:

It seems this excursion was not shared. Certainly it was not formally reported. Perhaps if it had been formally reported, other pilots and operators would have become informed of the hazard.


Tecnam is not the only twin with unidentified stall excursions when yaw is present. Quite some time ago the USAF tested single engine stalls in a Baron. They needed 10,000' to recover.

[janrein]

Why these manoeuvres?

The most exciting outcome was a 1500' altitude loss with inversion and a maximum descent rate of 12,500 fpm

It seems this excursion was not shared.

From the flight-path graphs on the last page of the report it appears there have been ca 10 flights that departed well beyond an aggravated wingdrop plus immediate recovery, resulting in half or full turn spins and picking up high speeds in the recovery with massive altitude loss (average 960 feet).

Although it was not officially reported, I would think it unlikely it was not shared (among flight instructors at least).

While demonstration of "incipient spin", in the sense of a provoked wing drop and immediate recovery, is not uncommon in single engine airplane stall/spin avoidance training, most if not all Airplane Flight Manuals of twins caution against or outright prohibit any asymmetry in combination with stalling.

It's puzzling why in so many stall training flights in the Tecnam Twin the "incipient spin" was exercised. Was it to make a point of perceived critical behaviour (*) of the Tecnam Twin and wanting to secure being current in recovering from it? ... with failiures to do so in ca 10 cases and one fatal? Or were the half and full turn spins deliberately sought? The latter would seem unlikely, if only because no significantly higher initial altitude was used.

(*) Refer to similar accidents with same model

[India Four Two]

One thing that has aways surprised me about this accident, is the flightpath. It is over "foothills" terrain and outside the designated practice area which is a few miles to the east.

If they had been in the practice area (the cultivated areas in the satellite image in the report), they would have had at least another 1000' of terrain clearance.

After the accident, Mount Royal College replaced the Tecnams with Senecas. It's not clear if this was for technical reasons or was purely a PR exercise.

[janrein]

Another two Tecnam P2006T fatal crashes apprently due to loss of control

From the more distant past, and without full accident reports:

20100902 OE-FAX, loss of control after low pass / go-around
https://aviation-safety.net/wikibase/wiki.php?id=76652

20110311 UR-ITD, loss of control during approach to landing
https://aviation-safety.net/wikibase/wiki.php?id=121066
Êðûëüÿ - Âñå îá óêðàèíñêîé àâèàöèè - Â Êèåâñêîé îáëàñòè ðàçáèëñÿ TECNAM (http://www.wing.com.ua/content/view/8679/40/) (in russian)

Google-translated from the latter link
... during the approach to landing with the course 314 in the area of ​​the third taxiway tilted, fell and completely burned down.

(latter link looking funny after pasting, can also be accessed directly from first link on UR-ITD)