Bert - PC12 Feedback on v57 and St Barts

[scottb613 1,188]

Hi Bert,

One thing I noticed on v57 - not a biggie - the red warning light/switch has a sound associated it - the yellow warning light/switch seems to be missing the sound - these are the ones above the attitude indicator...

Started nailing St. Bart’s after some more practice - thanks for the help with that as well...

 

 

Regards,

Scott

[ppo 68]

Nice shot Scott. I'll have to try that meself.

Cheers

[scottb613 1,188]

Hi Pierre,

Thanks - using ChasePlane’s new replay facility to position everything just right for a good snap... Landing takes some practice but I think I have it down now...

Regards,

Scott

[Bert Pieke 7,591]

Looking good!

[mikebxb 20]

Yup. Looks great

[mgr 29]

 

Hi Scott,

Now you managed the rwy 10 approach, try now the 3 runway 28 approaches... believe me they are more difficult then the rwy 10.

Some videos:

Last one, is from 2:22.

Regards,

Marcel

 

[scottb613 1,188]

Hi Marcel,

Hah - keep upping the ante - LOL - honestly - all the years I've owned that airport - I've never used the other runway... I'll give it a shot - no go around - I could see that adding pressure in real life...

I came across an article of a Twotter crash here in 2001 - interesting read - seems the pilot tried to use beta range to slow down while still in the air - a definite no no and I'm sure prohibited in the POH... If you can avoid the stupid mistakes - flying is relatively safe...

I'm going to start using that plate of yours you were kind enough to post...

Kai Tak has nothing on St. Barts... That curved approach over the hill looks wicked...

 

Quote

The Twin Otter plane was on a 10-minute inter island flight between St. Maarten, Dutch/French Antilles, and Saint-Barthélémy, French Antilles, and approached Saint-Barthélémy from the West for a visual approach and landing on runway 10. While on finals over the 'Col de la Tourmente', the aircraft was seen making a sharp turn to the left. The Twin Otter struck a house on the 'Col de la Tourmente' and caught fire. The 17 passengers and 2 crewmembers were killed. A man on the ground was also killed and his wife was injured. A house was destroyed.

The most probable hypothesis is that the pilot would have selected the reverse beta range for the propellers with the intention of losing energy to correct the airspeed, regain the descent path or shorten the landing as much as possible. In fact, the propeller then acts as a powerful brake.

It is possible that an asymmetry developed at that moment, though it would have been of relatively low amplitude, given the low thrust setting on approach, and could have been detected and likely quickly countered. However, following entry into reverse beta range, the aircraft may have developed undesirable behavior (stall warning, buffeting, etc.) or have reached the target airspeed, which would have been the desired result. In either case, it is necessary at that moment to de-select reverse beta range. Then the pilot would have pushed the levers energetically back to their normal use range by increasing the thrust, which would explain the change in the engine noise. Asymmetry in the power levers movement, or in the operation of the propeller mechanism, or even in the position of the propeller levers, would then have led to asymmetry between the engines, to an extent that would have led to a violent yaw movement, inducing a sharp roll to the left, possibly associated with a stall of the left wing, then a dive. The pilot would not have been able to regain control of the aircraft, which would have been both too slow and too near the ground at that moment.

Difficulty of the approach to runway 10

The turbulence upstream of the La Tourmente pass can affect flying; it therefore requires vigilance and permanent attention during approaches to runway 10. Pilots are conscious of this phenomenon but cannot completely avoid it. Thus, some adopt a track with which they are more at ease, given their habits, feelings, skills and their knowledge of the aircraft; some offset to the right or to the left, while others prefer to start high relative to the normal approach path.

There is an additional difficulty. As soon as they have gone over the pass, pilots must adopt a nose down attitude, which is not natural so near to the ground, in order to guarantee as short a landing as possible, taking into account the infrastructure. The unease exhibited by some pilots may also occasionally lead to a runway overrun.

Conclusion

The investigations have established that the accident appears to result from the Captain's use of the propellers in the reverse beta range, to improve control of his track on short final. A strong thrust asymmetry at the moment when coming out of the reverse beta range would have caused the loss of yaw control, then roll control of the aircraft.

The investigation could not exclude three other hypotheses which can nevertheless be classified as quite unlikely:

A loss of control during a go-around.

A loss of control due to a stall.

A loss of control due to sudden incapacitation of one of the pilots.

The Captain's lack of recent experience on this airplane type, the undeniable difficulty of conducting an approach to runway 10 at Saint-Barthélemy and the pressure of time during this flight were contributory factors.

The low height at which the loss of control occurred was an aggravating factor.

 

Regards,
Scott

[Raller 86]

On 28.1.2018 at 6:13 PM, scottb613 said:

Hi Bert,

One thing I noticed on v57 - not a biggie - the red warning light/switch has a sound associated it - the yellow warning light/switch seems to be missing the sound - these are the ones above the attitude indicator...

Hi,
in the file "Gauge_Anum_MASTER_CAUTION.xml" a entry is missing:

161 (L:PUSH_AM_ANUM_PC12_CAUTION) 0 >
162 if{
163     0 (>L:PUSH_AM_ANUM_PC12_CAUTION)
164     1 (>L:ClickSoundCar8,   number)
165     (L:TEST1_MASTER_CAUTION,number) 1 == if{ 2 (>..........

Maybe Bert can implement it in the Mod.

Regards
Raller

[Bert Pieke 7,591]

That is not a gauge that I have touched thus far... but I will put it on the list..

[Raller 86]

That's right, Carenado missed the line...

[scottb613 1,188]

10 hours ago, Bert Pieke said:

That is not a gauge that I have touched thus far... but I will put it on the list..

 

7 hours ago, Raller said:

That's right, Carenado missed the line...

Hi Folks,

Thanks so much - gentlemen... I know it's trivial - but - every little bit helps with immersion - been flying this plane a whole bunch lately after it stagnated on my drive for years - thanks to Bert's fine mod/enthusiasm and third party gauges... ChasePlane adding some dynamic camera movement truly helps as well...

Raller - That's one fine black PC12 you painted there - sir !

Bert - You've really made 57 mods to this panel ? Wow...

Regards,
Scott

[Bert Pieke 7,591]

It is actually V5.7.