Since the excuuuse me thread seems to be winding down, I thought I'd write down my story from the other perspective.

I was flying a few weeks ago here in Mexico at a controlled airport that gets commercial traffic. Most airports here want contact at 25 miles, so I had made that contact, let him know it was just a fuel stop - because we have user fees here and buying fuel avoids them most places - and been listening to the radio for a while and knew there was an American flight coming in from the states at the same time flying, as they always do, an approach.

I knew he was going to be higher priority traffic and correctly predicted that tower would extend my downwind to allow the jet to land. No big deal. On this day I really doubt that I could have gotten down and clear in time for the jet to avoid going around, and it was a beautiful day so I spending a couple more minutes in the sky was definitely no hardship.

I do, however, know how to fly my plane better than the guy in the tower, so requested a turn to base immediately as the jet got past me instead of flying 4 miles as he had requested. That turn was granted and I slowed the plane to about 40kts.

This airport is at 6,000ft, which isn't super high, but is high enough to notice. As you all know, at higher altitudes your ground speed increases a little. In this case about 10%. So even if the jet was flown perfectly he needed a little more room to stop.

He touched down as I turned final and hit the brakes to get the thing stopped.

Tower: "American 602, can you expedite to the ramp for landing traffic?"

America: "Negative, brakes are too hot"

In addition to 10% more speed there is about 20% less air to cool the brakes after landing.

At this point I'm on a near the threshold at about 300 feet and I'm certain that tower is going to tell me to go around, so I jump on the radio.

Me: "Take your time, I'm only going 40kts and can land, stop and exit at midfield as necessary"

Tower accepts this implicit request to not go around and lets me continue.

The American jet exits the runway when I'm at the landing threshold at about 200ft and I get a clearance from the tower. I fly the remaining distance to the near taxiway, land, turn off and beat the jet to the ramp.

Tower: "Well done Maule, I've called the fuelers for you."

Gotta love it when a plan comes together...

No trouble with the wake turbulence?

CFOT wrote:No trouble with the wake turbulence?

Sounds like this could have easily been a 'Tribute to rw2' thread.

This was a helicopter wake, but the wake from almost any airliner would be similar or worse.

CFOT wrote:No trouble with the wake turbulence?

Good question. Not a single burble. But more importantly, here was my thought process. Throw darts at it...

1) I turned final *well* above where the jet had been. He was flying a normal approach. Even though this was a huge airport with a runway over 11,000 feet long I like to stay high and fly steep approaches for additional safety margin in case of an engine out and so that when I'm at a shorter strip it isn't the first time I've flown a STOL approach in a while. So I intercepted his line of flight somewhere between 1000-1500 feet above where he flew. I would estimate that I didn't get down to pattern altitude until I was half a mile from the threshold. At that point he would be, what, about 400-500ft AGL?

2) Because of the difference in speeds, I intercepted his flight path 30 seconds to a minute behind him. Increasing further the altitude difference between his wake turbulence and my flight path.

3) I landed in the neighborhood of 2000 feet past his touchdown point about three minutes behind him as he had to stop, turn around and taxi back a mile or so to get to the taxiway.

Make sense? Said another way, the reason it was an interesting flight wasn't because I was flying close formation with a 737, but because the logistics of the airport meant that we ended up nose to nose for an extended period when I was on final and he was taxiing back to exit the runway.

I really don't think there was a hazard present, but let me know if you disagree and why.

Cannon wrote:This was a helicopter wake, but the wake from almost any airliner would be similar or worse.

In addition to my other note, a key difference between these specific scenarios is that the fixed wing in the video flew right through the wake turbulence from the helicopter. If he was required to touch down at that position due to the landing zone of the runway then he needed to wait 2-3 minutes instead of 30 seconds to do so. Hope they were ok!

Not a problem. You stayed above his wake turbulence, you touched down past his touchdown point, you had lots of room, and you had lots of potential gravity thrust available until just before touchdown. I always tried to approach upwind of the center line extended and touch down upwind of the center line when behind big airplanes. Jets land on really wide runways.

contactflying wrote:Jets land on really wide runways.

Yup. 11155 x 148 feet in this case. For the curious, MMMM was the airport in question.

rw2 wrote:

CFOT wrote:No trouble with the wake turbulence?

Good question. Not a single burble. But more importantly, here was my thought process. Throw darts at it...

1) I turned final *well* above where the jet had been. He was flying a normal approach. Even though this was a huge airport with a runway over 11,000 feet long I like to stay high and fly steep approaches for additional safety margin in case of an engine out and so that when I'm at a shorter strip it isn't the first time I've flown a STOL approach in a while. So I intercepted his line of flight somewhere between 1000-1500 feet above where he flew. I would estimate that I didn't get down to pattern altitude until I was half a mile from the threshold. At that point he would be, what, about 400-500ft AGL?

2) Because of the difference in speeds, I intercepted his flight path 30 seconds to a minute behind him. Increasing further the altitude difference between his wake turbulence and my flight path.

3) I landed in the neighborhood of 2000 feet past his touchdown point about three minutes behind him as he had to stop, turn around and taxi back a mile or so to get to the taxiway.

Make sense? Said another way, the reason it was an interesting flight wasn't because I was flying close formation with a 737, but because the logistics of the airport meant that we ended up nose to nose for an extended period when I was on final and he was taxiing back to exit the runway.

I really don't think there was a hazard present, but let me know if you disagree and why.

You handled it perfectly. (I missed the part where you mentioned still being a few hundred feet high over the threshold and was envisioning you dropping right in on the numbers to keep the landing short.) I got tossed around following a King Air in in the little plane the other day. It was a good reminder.

I have a lot of respect for wake turbulence due to some early experience while a student; therefore, tend to be a bit cautious.

That being said. I was flying some kids for Young Eagles at Paine Field (KPAE) which is where the big Boeing plant is located. We were sharing 34L with 777's and DreamLifters that day. On one of the landings I hear and see a 777 on final and when cleared for landing planned my touchdown past the 777 touchdown. Tower comes on when on short final and tells me to go around....OK can do. Then he evidently realizes I am really slow and there is a lot of the 9000 ft runway available....tells me to land if I wish. Went ahead and landed and took a bit of a longer taxi back to base.

Ok, I have gone from landing config, to go around. to landing config all on same approach. No issues and the kids thought it was really cool.

I will have to say the ATC folks that day at KPAE did an outstanding job of keeping a swarm of GA aircraft safely separated from one another and the heavy iron on a gloomy day. Hats off to them. I am sure they were wasted by the end of their shift.

TD

One of the first times I ever flew into Boeing Field in Seattle by myself, I was on a long straight-in for 13L with a light breeze out of the west when the tower advised me of a Boeing doing the same for 13R. I said something about being concerned about wake turbulence, the tower then asked me "what are your intentions?" I stuttered something about hoping they'd tell me what to do (a low low time pilot and brand new ticket). It turned out to be a non-event- the Boeing went by below me on my right, and landed close to the threshold of 13R. The threshold for 13L is quite a ways farther down, well past their touchdown point so no problem with wake even if the breeze had been strong enough to blow it across toward me.

I've also taken off pretty close behind another GA airplane-- maybe closer than some folks are confortable with, but only when I'm sure I will be lifting off well short of where they did, and either staying above their wake or dog-legging to the windward side of it.

Because of this event, I'm extraordinarily wary of wake turbulence from anything much bigger than my airplane:

A friend and I were flying my partnered TR182 from Laramie to old Denver Stapleton in about 1980, on a windy, bumpy day--typical Springtime in the Rockies. Approach told me of a 737 that would be passing us on our right (between us and the mountains) about 1000' lower than our altitude. I mentioned it to my friend, pointed at the 737 as he passed us about a mile west of us, and suddenly the airplane was yanked into a roll to the right that went well beyond vertical but not completely inverted--I'm guessing about 120-130 degrees. Because I'd just finished a basic aerobatics course, I used full left aileron, full left rudder, and pushed, and we righted and continued to Denver.

A year ago, I ran into my friend after not seeing him for many years. In the course of our conversation, he asked if I was still flying. Then he said, "Do you remember that time we were flying to Denver and almost turned upside down?" Then he mentioned some other details of the flight. So it was pretty dramatic, for him to remember in such detail almost 35 years later.

So you won't see me landing or taking off after any airliner for a at least a couple of minutes, and maybe longer if they're heavy. You see, the diagrams in the FAA's handbooks aren't completely accurate. Note that my scenario described a situation in which we were hit by wake turbulence from an airplane flying lower than we were. Why? Because the mountain wave effect of the wind coming over the mountains lifted the wake of the airliner from below its altitude up to our altitude--and you're not likely to find any mention of such an event in any of the handbooks.

Just because an airplane has touched down doesn't mean its wake turbulence has ceased. It's not until they've slowed enough that their wing isn't producing lift, and that's well after touchdown. Similarly, their wings produce a lot of lift long before they break ground. So landing after their touchdown point or taking off before their lift off point isn't safe enough.

Your situation worked, but honestly, I wouldn't take that kind of chance.

Cary

TomD wrote:I have a lot of respect for wake turbulence due to some early experience while a student; therefore, tend to be a bit cautious.

That being said. I was flying some kids for Young Eagles at Paine Field (KPAE) which is where the big Boeing plant is located. We were sharing 34L with 777's and DreamLifters that day. On one of the landings I hear and see a 777 on final and when cleared for landing planned my touchdown past the 777 touchdown. Tower comes on when on short final and tells me to go around....OK can do. Then he evidently realizes I am really slow and there is a lot of the 9000 ft runway available....tells me to land if I wish. Went ahead and landed and took a bit of a longer taxi back to base.

Ok, I have gone from landing config, to go around. to landing config all on same approach. No issues and the kids thought it was really cool.

I will have to say the ATC folks that day at KPAE did an outstanding job of keeping a swarm of GA aircraft safely separated from one another and the heavy iron on a gloomy day. Hats off to them. I am sure they were wasted by the end of their shift.

TD

There is a mandatory wake turbulence delay behind "Heavy" aircraft. Was that 777 a heavy that day? He'd be using the "Heavy" term as part of his call sign....."Tower, Boeing 777 Heavy is short final for 34". If he was a heavy, there'd be a delay, and that delay is not waive-able by the pilot. Not sure if a 777 is ever NOT "Heavy" category.

MTV

mtv wrote:There is a mandatory wake turbulence delay behind "Heavy" aircraft. Was that 777 a heavy that day? He'd be using the "Heavy" term as part of his call sign....."Tower, Boeing 777 Heavy is short final for 34". If he was a heavy, there'd be a delay, and that delay is not waive-able by the pilot. Not sure if a 777 is ever NOT "Heavy" category.

I was curious, so looked it up.

Heavy starts at 300,000 pounds.

There is a single model of 777 that has an empty weight below that. 297,000. So once you put fuel enough to take off into any 777, even if otherwise empty, you'll be "heavy". All but one would be heavy even if towed into flight to be used as gliders.

You guys are scaring me, but it's too late now. I flew under 747s every week at Memphis. My line was right across the southern boundary under 36L and 36R (no 36C then) and then inside the western boundary (near where the new 36L is) to just across 09 and then east to the tank farm just west of 18R. I avoided the time frame when Fed X was all inbound and when they were all outbound. I was around 100' and they didn't touch down until well north of the southern boundary. There is no way to judge altitude of big airplanes unless you are a big airplane guy. They seemed fairly high and their touchdown zones were about 1/4 mile from the boundaries. Tower put me between them (both runways) but no way was there more than a couple minutes at most. The one coming (both runways) was getting really big by the time the one landing touched down.

So is that why they identify with the prefix "heavy?" To tell tower that spacing should be a little greater for wake turbulence?

Zzz wrote:So is that why they identify with the prefix "heavy?" To tell tower that spacing should be a little greater for wake turbulence

Yup. "Separation standards" is the official phrase used.

Also, my comment earlier about the lightest of the 777 being 297,000 pounds and therefore not 'heavy' was wrong. The FAA says that any aircraft capable of a takeoff weight above 300,000 pounds is classified as heavy.