Wake turbulence and ATC

My instructor and I had ATC say "caution wake turbulance" for take off. My CFII requested we wait a few minutes to let it dissipate and it was approved. ATC requested call when we were ready.
 
noobJohn said:
How should the Baron pilot have responded to ATC's warning, "Caution wake turbulence?"
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Slow down the approach. If the RJ was in sight, fly a slightly higher approach path and touch down beyond the touchdown point of the RJ. If not in sight, fly a higher than normal approach and land long.
 
saracelica said:
My instructor and I had ATC say "caution wake turbulance" for take off. My CFII requested we wait a few minutes to let it dissipate and it was approved. ATC requested call when we were ready.
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This was a landing incident, not takeoff.
 
"Can I have 36L instead?"
 
Bill Jennings said:
A good potential solution as long as you cross the jet wake at a higher than jet altitude.
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Based on the winds (out of the west), approaching from the SW and landing 36L ought to have put him out of the wake completely.
 
Simple, stay high on final especially when you have 9,000 ft of runway to play with. Landed in C-150 once in Myrtle Bch just after a DC-9. Stayed high, landed a 1/3 of the way down the runway with no issues.
 
noobJohn said:
I stumbled upon this article :

http://www.genebenson.com/wake_turbulence/wake_turbulence1.htm

How should the Baron pilot have responded to ATC's warning, "Caution wake turbulence?"

I have some ideas, but would love to hear the thoughts of more experienced pilots.
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Just a newbie, but I think the proper response would be to get your eyes on the large aircraft, perhaps with tower's help, and then MAKE SURE that your flight path is above their flight path and beyond their touchdown point, accounting for wind drift too. If you can't find the large plane much less determine its touchdown point, maybe request a 360 to delay?

Our local controllers ALWAYS seems to confirm that we have a large aircraft that is inbound for the parallel runway in sight and, only when confirmed, say "clear to land, .... caution wake turbulence". I believe that's to make sure we can stay above and land beyond, or choose to go around.
 
Years ago my CFI and I were on a 9-mile final to San Jose airport in a C-172 when a tower controller inexplicably allowed a 757 on short right base to cut in front of us to land. We encountered his wake turbulence and were nearly rolled inverted. Fortunately, we recovered.

The 757 was higher than we were and in retrospect, the only way we could have avoided the encounter would have been to immediately break off our approach with a sharp left turn to get the hell out of harm's way.

Since that time I've never hesitated to reject an ATC instruction or request if I think wake turbulence will be an issue. Most of my flying is in a Mooney at Denver Centennial (KAPA) and John Wayne (KSNA), with lots of commercial jets and bizjets, so it's something I pay a LOT of attention to. Just last month I rejected a takeoff clearance when KAPA tower wanted me to depart "no delay" right behind a departing Gulfstream G650 due to landing jet traffic on a 5-mile final. Instead, I waited for the incoming jet to land and was able to make an unhurried departure 5 minutes later with much more peace of mind... and no wake turbulence.
 
colojo said:
Since that time I've never hesitated to reject an ATC instruction or request if I think wake turbulence will be an issue. Most of my flying is in a Mooney at Denver Centennial (KAPA) and John Wayne (KSNA), with lots of commercial jets and bizjets, so it's something I pay a LOT of attention to. Just last month I rejected a takeoff clearance when KAPA tower wanted me to depart "no delay" right behind a departing Gulfstream G650 due to landing jet traffic on a 5-mile final. Instead, I waited for the incoming jet to land and was able to make an unhurried departure 5 minutes later with much more peace of mind... and no wake turbulence.
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Is there a concern about wake turbulence on takeoff when you know that the departing traffic won't be airborne for several thousand feet beyond your takeoff point?
 
F01LA said:
Is there a concern about wake turbulence on takeoff when you know that the departing traffic won't be airborne for several thousand feet beyond your takeoff point?
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If you're both on the same departure path, I'd assume at some point you'd be under the jet which means you'd fly through his wake?
 
Thanks for all the replies. I was thinking similar things. If you can see the other plane then I understand what to do, but then I started wondering what to do if you didn't spot them.

Would it be improper to announce that you intend to land 1/2 way down the runway? I realize that, absent of LAHSO instructions, you can use the entire runway. I reckon I answered my own question. :) No need for an announcement, just land where you need to taking potential wake turbulence into account.
 
noobJohn said:
Thanks for all the replies. I was thinking similar things. If you can see the other plane then I understand what to do, but then I started wondering what to do if you didn't spot them.

Would it be improper to announce that you intend to land 1/2 way down the runway? I realize that, absent of LAHSO instructions, you can use the entire runway. I reckon I answered my own question. :) No need for an announcement, just land where you need to taking potential wake turbulence into account.
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I always said "Request long landing" on BFI's 10,000 foot long runway just to help the local controller with spacing.

Bob Gardner
 
bobmrg said:
I always said "Request long landing" on BFI's 10,000 foot long runway just to help the local controller with spacing.

Bob Gardner
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This is doubly useful because then you can keep a ridiculously high airspeed and cut the power high over the numbers and let it settle into the middle half of the runway length. Helps avoid messing up the controllers spacing too much and helps cut through any turbulence should you encounter it.
 
F01LA said:
Is there a concern about wake turbulence on takeoff when you know that the departing traffic won't be airborne for several thousand feet beyond your takeoff point?
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No, if you can turn before flying through the wake... No real reason to reject a takeoff clearance behind a jet like that unless you're forced to fly runway heading. I've only had a situation like that twice but both times ATC allowed me to make the turn way before I would have flown through the wake.
 
ATC has a minimum amount of space they must provide between aircraft where wake turbulence might be an issue....but that minimum doesn't really factor in the wind or the vertical flight path of the trailing aircraft. I think most ATCers would accommodate a request for more than the minimum spacing for wake turbulence without it being an issue.
 
fiveoboy01 said:
No, if you can turn before flying through the wake... No real reason to reject a takeoff clearance behind a jet like that unless you're forced to fly runway heading. I've only had a situation like that twice but both times ATC allowed me to make the turn way before I would have flown through the wake.
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When I'm sharing a runway with jets (like at SJC), on takeoff, I'll ask Tower for an early crosswind and turn at 500 AGL. That's WAY before the DER, and often before the jet's rotation point.
 
MAKG1 said:
When I'm sharing a runway with jets (like at SJC), on takeoff, I'll ask Tower for an early crosswind and turn at 500 AGL. That's WAY before the DER, and often before the jet's rotation point.
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Do you think it's really necessary to do an early crosswind or you just do it to be extra cautious? (and nothing wrong with that in my opinion).

My understanding is that a piston single will over climb a jet in angle of climb (of course not in rate, I meant it will have a steeper angle), so as long as you are climbing at Vx (probably Vy as well), there's no need to turn as there is no risk of crossing the wake.
 
Johann said:
My understanding is that a piston single will over climb a jet in angle of climb (of course not in rate, I meant it will have a steeper angle), so as long as you are climbing at Vx (probably Vy as well), there's no need to turn as there is no risk of crossing the wake.
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A 737 at sea level will climb at more than 3000 FPM. Even if you factor in that they are twice the speed or more, that's still a higher angle, by quite a lot.
 
Johann said:
My understanding is that a piston single will over climb a jet in angle of climb (of course not in rate, I meant it will have a steeper angle), so as long as you are climbing at Vx (probably Vy as well), there's no need to turn as there is no risk of crossing the wake.
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Also, at KSNA, commercial jets are required to zoom-climb to 1,000' AGL or so for noise abatement, so their climb angle is super steep at that airport.
 
MAKG1 said:
A 737 at sea level will climb at more than 3000 FPM. Even if you factor in that they are twice the speed or more, that's still a higher angle, by quite a lot.
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Depends on the plane. I was getting >1500fpm yesterday up through 4000' at about 100kts IAS. Angles would be pretty close, I may have even been steeper. I don't know what a '37 climbs at indicated. And when you figure I'm off in 1000' and the jet is 3/4 of a mile down the runway past my take off point...
 
EdFred said:
Depends on the plane. I was getting >1500fpm yesterday up through 4000' at about 100kts IAS. Angles would be pretty close, I may have even been steeper. I don't know what a '37 climbs at indicated. And when you figure I'm off in 1000' and the jet is 3/4 of a mile down the runway past my take off point...
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I'd like to see a good comparison. I can figure out a 172, but now nada about the takeoff performance of a 737:)
 
EdFred said:
I don't know what a '37 climbs at indicated. And when you figure I'm off in 1000' and the jet is 3/4 of a mile down the runway past my take off point...
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Depends upon weight and departure profile. If the 737 is doing a NADP (noise abatement departure procedure) he may be climbing as low as 135/145 knots through 3000' before level off, clean up to 250KIAS. If he's on normal departure, level off at 1000' and accelerate then after 1000' he will accelerate and clean up to 250KIAS.
 
fiveoboy01 said:
No, if you can turn before flying through the wake... No real reason to reject a takeoff clearance behind a jet like that unless you're forced to fly runway heading. I've only had a situation like that twice but both times ATC allowed me to make the turn way before I would have flown through the wake.
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And I've had the opposite, turn denied after taking off, so I bounced thru the wake turb. Luckily I didn't get rolled. Now I ask for the turn before accepting the takeoff clearance. No turn? No thanks, I'll wait it out.
 
I've had countless encounters with wake turbulence flying out of a high traffic class c airport. I've never encountered any noticeable effects of it though. One thing to consider is wake turbulence dissipates after about 2 minutes. If you are landing and more than 2 minutes behind the jet in front of you and above his glide path then you have nothing to worry about. Because jets approach the airport at a much faster speed then the mighty 152's and 172's I fly they will often be on the ground and at the gate before I touch down even if I'm as close as 5 miles behind. While I buy the whole stay above his approach path I don't know why you are encouraged to touch down beyond where he did other than that, theoretically means no wake turbulence is generated. My thoughts are though that when the jet is close to the ground, within 600 feet or so, their wake turbulence will hit the ground and be a non issue for any plane unless the plane is literally right on the jets tail.
 
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fiveoboy01 said:
No, if you can turn before flying through the wake... No real reason to reject a takeoff clearance behind a jet like that unless you're forced to fly runway heading. I've only had a situation like that twice but both times ATC allowed me to make the turn way before I would have flown through the wake.
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Cleared for "immediate take off, caution wake turbulance" from San Antonio behind a B737, I was in a Cessna 150. I asked for an "immediate left turn, or I would wait"...."approved as requested" was the reply.

I knew I would be off the ground before the heavy metal's rotation point, but I could'nt out climb him. Full throttle and a quick left turn out...way before any potential wake, no problem.
 
Just wanted to throw in one more thanks for all the responses. I have learned a lot hanging out around here. I mean that in a good way. :D
 
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