Scary Ride For Air Canada E190

[joeyb747]

 

"An Air Canada Embraer ERJ-190, registration C-FHKA performing flight AC-131 from Ottawa,ON to Calgary,AB (Canada) with 84 people on board, was enroute at FL380 about 100nm west of Winnipeg, MB (Canada) about 8nm behind a Westjet Boeing 737-600, registration C-GWCY performing flight WS-103 from Winnipeg to Calgary with 124 people on board, that climbed to FL400. When the Embraer flew through the wake turbulence of the Boeing, the Embraer encountered altitude deviations and roll deviations of up to 20 degrees. Both aircraft continued to Calgary for safe landings."

From:

http://www.avherald.com/h?article=432306f0&opt=0

Below are pics of the aircraft involved, WestJet Boeing 737-6CT C-GWCY / 612 (cn 35113/2022), and Air Canada Embraer ERJ-190-100IGW 190AR C-FHKA / 315 (cn 19000046).

[tyketto]

"An Air Canada Embraer ERJ-190, registration C-FHKA performing flight AC-131 from Ottawa,ON to Calgary,AB (Canada) with 84 people on board, was enroute at FL380 about 100nm west of Winnipeg, MB (Canada) about 8nm behind a Westjet Boeing 737-600, registration C-GWCY performing flight WS-103 from Winnipeg to Calgary with 124 people on board, that climbed to FL400. When the Embraer flew through the wake turbulence of the Boeing, the Embraer encountered altitude deviations and roll deviations of up to 20 degrees. Both aircraft continued to Calgary for safe landings."

From:

http://www.avherald.com/h?article=432306f0&opt=0

Okay.. this doesn't make sense.

8 miles in trail should be okay for aircraft in the same weight class, which both the E190 and the B736 are. But on top of that, assuming a level plane, the E190 would have been UNDER the wake produced by the B736. And while I know that an aircraft's wake spreads wide, similar to boats on a lake, if the B736 stayed level the entire time, does an aircraft's wake at an even altitude stay at that altitude, or does it rise or drop? If it dropped, then I could see this happening. If it rose, something else was going on.

Could it be that the B736 was climbing up to FL400, and caused the E190 to fly into and through its wake, level at FL380?

BL.

[Amante de Aviones]

"An Air Canada Embraer ERJ-190, registration C-FHKA performing flight AC-131 from Ottawa,ON to Calgary,AB (Canada) with 84 people on board, was enroute at FL380 about 100nm west of Winnipeg, MB (Canada) about 8nm behind a Westjet Boeing 737-600, registration C-GWCY performing flight WS-103 from Winnipeg to Calgary with 124 people on board, that climbed to FL400. When the Embraer flew through the wake turbulence of the Boeing, the Embraer encountered altitude deviations and roll deviations of up to 20 degrees. Both aircraft continued to Calgary for safe landings."

From:

http://www.avherald.com/h?article=432306f0&opt=0

Okay.. this doesn't make sense.

8 miles in trail should be okay for aircraft in the same weight class, which both the E190 and the B736 are. But on top of that, assuming a level plane, the E190 would have been UNDER the wake produced by the B736. And while I know that an aircraft's wake spreads wide, similar to boats on a lake, if the B736 stayed level the entire time, does an aircraft's wake at an even altitude stay at that altitude, or does it rise or drop? If it dropped, then I could see this happening. If it rose, something else was going on.

Could it be that the B736 was climbing up to FL400, and caused the E190 to fly into and through its wake, level at FL380?

BL.

Yes because wake turbulence sinks

[joeyb747]

"An Air Canada Embraer ERJ-190, registration C-FHKA performing flight AC-131 from Ottawa,ON to Calgary,AB (Canada) with 84 people on board, was enroute at FL380 about 100nm west of Winnipeg, MB (Canada) about 8nm behind a Westjet Boeing 737-600, registration C-GWCY performing flight WS-103 from Winnipeg to Calgary with 124 people on board, that climbed to FL400. When the Embraer flew through the wake turbulence of the Boeing, the Embraer encountered altitude deviations and roll deviations of up to 20 degrees. Both aircraft continued to Calgary for safe landings."

From:

http://www.avherald.com/h?article=432306f0&opt=0

Okay.. this doesn't make sense.

8 miles in trail should be okay for aircraft in the same weight class, which both the E190 and the B736 are. But on top of that, assuming a level plane, the E190 would have been UNDER the wake produced by the B736. And while I know that an aircraft's wake spreads wide, similar to boats on a lake, if the B736 stayed level the entire time, does an aircraft's wake at an even altitude stay at that altitude, or does it rise or drop? If it dropped, then I could see this happening. If it rose, something else was going on.

Could it be that the B736 was climbing up to FL400, and caused the E190 to fly into and through its wake, level at FL380?

BL.

Yes because wake turbulence sinks

That...and the B736 did climb through the FL the E190 was at, up to FL400. It is stated in the article as "...that climbed to FL400."

[Jason]

And while I know that an aircraft's wake spreads wide, similar to boats on a lake, if the B736 stayed level the entire time, does an aircraft's wake at an even altitude stay at that altitude, or does it rise or drop?

Wake turbulence has a tendency to sink at the rate of approximately 400 - 500 feet per minute (fpm) and levels off about 900 ft. below the flight path of the generating aircraft.

Best,
Jason

[tyketto]

And while I know that an aircraft's wake spreads wide, similar to boats on a lake, if the B736 stayed level the entire time, does an aircraft's wake at an even altitude stay at that altitude, or does it rise or drop?

Wake turbulence has a tendency to sink at the rate of approximately 400 - 500 feet per minute (fpm) and levels off about 900 ft. below the flight path of the generating aircraft.

Best,
Jason

So this brings up another question. If you're following an aircraft in a larger class than you on final for a given runway (say, a small behind a large, or large behind a heavy) and you are given the wake turbulence advisory(granted you are flying into an aircraft's wake just by means of being behind them), wouldn't the wake turbulence be "avoided" (lack of a better word) if given a higher altitude restriction than the preceding aircraft on final?

Say you're on final for 25L at KLAS. The larger class aircraft in front of you is given "Cross PRINO at 8000, cleared visual approach runway 25L." You are given "Cross PRINO at 9000, cleared visual approach runway 25L. Caution wake turbulence, 6 miles behind a Heavy Boeing 767."

Wouldn't you be above the larger aircraft's wake?

BL.

[Jason]

So this brings up another question. If you're following an aircraft in a larger class than you on final for a given runway (say, a small behind a large, or large behind a heavy) and you are given the wake turbulence advisory(granted you are flying into an aircraft's wake just by means of being behind them), wouldn't the wake turbulence be "avoided" (lack of a better word) if given a higher altitude restriction than the preceding aircraft on final?

Say you're on final for 25L at KLAS. The larger class aircraft in front of you is given "Cross PRINO at 8000, cleared visual approach runway 25L." You are given "Cross PRINO at 9000, cleared visual approach runway 25L. Caution wake turbulence, 6 miles behind a Heavy Boeing 767."

Wouldn't you be above the larger aircraft's wake?

BL.

It depends on the generating aircraft's configuration and speed, but generally yes. Wake turbulence is most pronounced when slow and clean (no flaps or gear) although slow and dirty (flaps and gear extended) also creates quite a bit of wake turbulence.  In your example, since it's a visual approach you have a little more discretion over what altitude you maintain on final to avoid wake turbulence.  On an instrument approach it becomes more difficult because of step down fixes and mandatory altitudes.  I know some who prefer to fly the glideslope 1/2 to 1 dot high on an ILS if following a large or heavy aircraft generating wake turbulence.  The MIT restriction exists to allow sufficient spacing between the generating aircraft and your aircraft but it also allows for the wake to subside by the time you reach the previous location of the generating aircraft.

6 miles behind a 767 and 1,000 ft. above should give you enough distance and altitude to avoid wake turbulence, but it is the PIC's responsibility to obtain a revised clearance from ATC if he/she believes wake turbulence avoidance will not be guaranteed.