This video raises a question about wake turbulence...

Discussion in 'Aviation Mishaps' started by mr_happyland, Jan 27, 2021.

  1. Bill

    Bill Touchdown! Greaser! PoA Supporter

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  2. Kenny Phillips

    Kenny Phillips En-Route

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    I was given a 360 to let N1PG (previous one, a G5, I think) get past me at KLUK, and I came right around into its wake. I never would have thought that a Gulfstream would generate the wake that it did, but it seriously took over my plane for a moment. Anything larger and that would be that. Some day we'll be able to "see" wake turbulence and other air movements (it can be done to some degree now, but not for cheap or light) so we can avoid them.
     
  3. 3393RP

    3393RP En-Route

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    The pilot had an ATP rating. Obviously he was aware of the effects of wake turbulence.

    The Arrow pilot had a visual on the MD-80. The separation was 1.7 miles when it encountered the turbulence.

    He was northbound out of Racine, the jet was inbound to KMKE Runway 25. He was instructed to fly a 090 heading parallel and opposite the jet's flight direction of flight, and resume the NB course at his discretion. ATC said "…just pass behind that traffic and then you can proceed northbound as requested."

    Based on time and distance figures given in the report, the Arrow pilot had flown east a very short time before he turned north and crossing the MD-80's flight path.

    It appears the Arrow broke up immediately, because multiple primary radar returns appeared on the controller's radar scope seconds after the transponder return vanished.
     
  4. Racerx

    Racerx Cleared for Takeoff

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    If memory serves correct the pic was a flight instructor and passenger was a pilot who just bought a plane. They were heading to Oshkosh for air venture. I think the passenger worked for NASA. Passenger had the pilot do a pre-buy on a plane, then signed the papers. They were going to OshKosh, then passenger was going to fly his new plane home. Worst part about it was the seller wouldn't nice the sale and the wife had to get the plane. Who does that?
     
  5. Zeldman

    Zeldman Touchdown! Greaser!

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  6. WannFly

    WannFly Final Approach PoA Supporter

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    Bw can a rotor wash turn a plane upside down otherwise cause nasty things when the said plane is on the ground? A Blackhawk or big navy helos might, but I am talking about your average medevac helos. The reason I ask is, few weeks ago I landed and was taxing to my hangar, a local med helo was taking off from the ramp, tower specifically told them “do not overtly the poor little archer on Charlie” . I got a chuckle out of it, so did the helo driver, but makes me wonder
     
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  7. Daleandee

    Daleandee Pattern Altitude

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    Gotta love them ATC guys that are always in front of a possible concern and address it before it can become a problem. I got permission to take a trip into a tower (and the radar room) recently and I was just amazed at how friendly and professional these guys/gals were. You also realize that they are human too and are not there to be the bad guy but are a very important part of the airspace system.

    So if you and the helo driver got a laugh out of it that makes three as I found that to be a very amusing way to make a point ...
     
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  8. tspear

    tspear En-Route

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    Yes, a helo can flip a plane on the ground.
    Depends only on the amount of downwash and the size of the plane.

    Tim

    Sent from my HD1907 using Tapatalk
     
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  9. Kelvin

    Kelvin En-Route

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    I got me teeth rattled near McGuire by a C5 or a C17 that I never saw and never got closer to 5 miles of my plane. To describe it as violent sell the experience short. My shoulder blades were pinned to the ceiling.

    To the topic of the OP, I have always thought that going by JFK over the water below 500 feet was a fools mission for just this reason. Not a lot of altitude to recover.
     
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  10. MikeNY

    MikeNY Pre-Flight PoA Supporter

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    Agreed 100% and the reason I stopped flying south shore, east-west, south of JFK, at/blw 500’.
    If Kennedy is:
    Landing 4L/4R or 31L/31R or departing 13L/R or 22L/R, flying at 500’ under those flight paths appears (to me) as elevated risk.
    Yet it’s flown by light aircraft all the time, safely, with no wake turbulence disaster.
    How it that possible?
    Is it luck, or some unperceived way to avoid wake flying under the known paths of heavy turbine aircraft landing/departing Kennedy.

    [UPDATE]:
    On January 25th, a Piper Archer flying south of JFK, westbound blw 500', reported a wake turbulence upset from an Air France heavy landing 4R. It appears the battery position in the Piper was disrupted and with ensuing smoke in the aircraft, the PIC made an emergency landing rwy 13R at Kennedy to extinguish fire. Subsequent maintenance involved replacing the battery, battery box, and trim/stabilator cables.

    Remarkable teenage pilot obtained his private certificate just two months previously, and without missing a beat, Kennedy Tower assisted the aircraft-in-distress for a safe outcome.

     
    Last edited: Jul 27, 2021
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  11. jpskies

    jpskies Pre-Flight PoA Supporter

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    I often fly between from KEMT to the aerobatic box near Point Fermin by way of KCPM in the past 12 years in my Nanchang CJ6. I had encountered quite a bit of large jets including 777 within 1000 feet vertical separation. I usually level at 1500 msl. Especially when they turning base (south) for LAX RWY24 ~ 2500 ft while I am flying NE and dead ahead, they're looked amazingly huge. I usually divert further east to get out of their way but I had several times they crossed above me when they were on a long final. I had not encountered any wake turbulence but the scene is amazing as I have a unobtrusive canopy. The point I like to make is that it seems as long as there's 1000 ft vertical separation and you don't climb through (or near) their altitude, the wake turbulence won't get to you on a low altitude near ground as there is no strong down draft momentum to push the wake turbulence down to over 1000 feet lower. Of course, in high altitude such as in flight level, the strong wind could push the wake turbulence over 1000 feet as we've seen the report of private jet encountered with A380 in flight level.

    On another topic about the PA28, while I was still in a flying club long long time ago, I encountered a violent engine malfunction during take off at 500 agl in a used Piper Arrow that my flying club just purchased at a time. One of the push rod in a cylinder were bended after that incident. The engine shook violently while it was in full t/o power. The sudden shake was so hard I thought the engine gonna break-off from the mount. The violent shaking caused a large poof of white smoke came out the instrument panel. Till today, I still not sure whether the smoke was just the age-old dust shook off from the panel or the electrical shortage due to the poor grounding between the metals. Well, in that incident, within 4 seconds, I lowered the throttle and leveled off at 700 msl and declared emergency (and reported smoke in the cockpit). Fortunately, the remaining power could still hold off the altitude so I turned back and landed safely.

    upload_2021-1-31_7-29-50.png
     
    Last edited: Jan 31, 2021
  12. pmanton

    pmanton Pattern Altitude PoA Supporter

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    20 years ago or so, I was flying an Ercoupe in WA State just to the east of McChord AFB. I spotted a C-17 that was crossing in front of me from right to left.
    He was way out in front of me, descending for landing, and his flight path would put him lower than me when our paths intersected.
    Thinking his wake would be below, me I continued on.
    WRONG!! The wake hit the plane like a hammer. My head punched a hole through the canopy, I lost hat, glasses and headset.
    Just for an instant of time it seemed that I was looking down into the plane. If my seat belt had broken I would have departed the plane.
    My headset was banging on the fuselage held by the cord. I pulled it in and found one ear phone gone.
    ( sent it in to David Clark for repair explaining what happened. The repaired it free)

    Thermal activity carried the wake up into my flight path.

    I now run, with my tail between my legs, away from anything that would cross my path. :(
     
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  13. woodchucker

    woodchucker Pattern Altitude

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    Feel almost like I dodged a bullet today departing Idaho Falls in a C150. About five miles out a Sky West aircraft came out of nowhere on approach to land. Passed directly overhead with maybe 1200 feet of clearance. Nowhere to go. Nothing I could do. Can’t outfly it. Just held on to the yoke and hoped for the best.

    During primary training a pair of F16s overflew us on a training flight. Got a pretty good rock out of that.
     
  14. MauleSkinner

    MauleSkinner Touchdown! Greaser!

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    Vortices sink at a rate of “several hundred ft/min”. From 1200 feet above you, making a turn 90 degrees to the track of the overhead traffic should put you a mile or two away from them by the time they get to your altitude...even in the mighty Cessna 150 Heavy.
     
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  15. Velocity173

    Velocity173 Touchdown! Greaser! PoA Supporter

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    Tower really doesn’t understand the effects of rotor wash. If the aircraft flew over you at a low altitude but above effective translational lift (16-24 kts), you get hardly a whiff of wind.

    Now hovering is a different story and it’s all about helo weight, disk area and air density. Height also plays a factor. A typical MEDEVAC helo is producing maybe worse case 30-35 kts of downwash. Enough to flip you? Doubtful but might cause some damage. Typically in helos we like to hover at least 3 disks away from other aircraft.
     
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  16. woodchucker

    woodchucker Pattern Altitude

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    I don’t know. Four minutes doesn’t buy much space at 70 kts. Lol
     
  17. MauleSkinner

    MauleSkinner Touchdown! Greaser!

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    You don’t need to outrun the bear if you can outrun your friend. ;)
     
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