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updraft and downdraft landing in summer (Cessna-152)

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updraft and downdraft landing in summer (Cessna-152)

Old 10th May 2019, 11:00
  #1 (permalink)  
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Join Date: May 2019
Location: las vegas
Posts: 2
Red face updraft and downdraft landing in summer (Cessna-152)

I recently moved to Las Vegas.

It's pretty hot during the day already. So, even tho the wind is calm, i am experiencing updraft and downdraft especially when I land the airplane (C152).

I think I can manage updraft pretty okay. Just keep pitching down for the airspeed and reduce the power and maintain the altitude.

Still, my problem is about the downdraft. ( i am not even sure it's downdrafts.) yesterday when i was practicing landing, my airplane sink so fast with 1700rpm. So I had to add up more than 2200rpm to maintain the glide path. And I don't know why but even tho I added up so much power still, my airspeed was stuck at 60kt (which is my approach speed). so I think my approach was pretty nice. But the problem started at roundout and flare.

My airplane constantly ballooned or floated long when i reduced the power and initiated pitch level attitude at the roundout point. (i had no floating or ballooning issues during the weather was chill in here). I think it was because my power setting was too high. But i couldn't even hold my glide path without such a high power setting. That means, i have to maintain my high power setting until the roundout point.

Also, my airplane drops too fast when i idle the power ( still the airspeed remained relatively high even tho i maintained my approach airspeed 60kt)

My IP said i was pitching level and reduce all that power too aggressive when I am leveling my aircraft. But i think that was not the only problem that caused ballooning and floating.

Do you have any tips for improvement?
Juno Kim is offline  
Old 10th May 2019, 12:46
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Welcome Juno Kim,

It is possible to have air simply too violent for a "nice" landing in a light Cessna. You'll find that Cessnas have more control available that you expect, but you have work at it! One thing to remember is that air does not move through the ground. When you get close to the ground, the downdraft will stop, though spitting you out the bottom is still a risk. Fly a flatter approach, and allow yourself a longer [runway distance] flare to settle down before landing - and, you can go around, if you don't like it.

Horizontal air movement at the ground can become a problem, as the downdraft changes direction. If the air is too rough, which can happen with daytime heating in the desert, fly in the morning or evening instead. Otherwise, if you must fly, fly the plane to manage approach speed closely, but don't overwhem yourself trying to keep it right on, it may vary up and down a bit. Approach with less flap out. Change the power less if possible, don't chase speed with power changes.
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Old 10th May 2019, 14:29
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Join Date: Dec 2001
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My take, and I hear what Pilot DAR is saying so I just give my opinion FWIW, would be to fly a standard descent (or even ever so slightly high) rather than a flatter approach (and I understand why you suggest that Pilot DAR re flaring I guess - but read on...) as, if closer to the ground, you have less time to react to a downdraught or other issue. No screaming dives - on or slightly above the G/P, that's all. And, as Pilot DAR says, if it gets "interesting", go around [early?] and sort it out.

I digress - back on Topic! My qual for all this advice/suggestion? 1st flight as a PPL with my 1st wife (now ex-wife ... but not due to this incident!!!) landing into unexpected but, with hindsight, entirely predictable rotor off sea cliffs upwind of the runway. Unlike you, I ended up with full power, aircraft sinking still - hence my comment about keep on G/P (or a tad higher) and wondering "What the Hell????!!!". I, to this day, have no idea exactly how I got it down (I had no go-around capability by then as was at full power and still sinking rapidly!). Once I'd pulled off the runway and asked ATC if I could hold where I was for 30 seconds or so (basically, so I could stop shaking!), I clocked the issue, realised that, by sticking with a rapidly worsening situation, and not going around as soon as I'd started encountering (having encountered it it was too damn late!) a real "Oh, oh!!!!!" moment, I'd rapidly got myself into a one-way ride over which, fortunately, the plane itself seemed to have some control over. The flight back was uneventful, especially as I'd found a local and had a quick chat about the conditions. "Don't worry lad, you found all the sink at the threshold - you'll be fine until you reach the cliffs - when you'll climb like a rocket!". He was spot on - but I was waiting for it - and that bit was quite fun!!!!!

Enjoy your flying JK! You've done the right thing seeking suggestions. Locals especially, are always glad to help. Sadly, stuck in Blighty - long way from Vegas!

Cheers, H 'n' H

Last edited by Hot 'n' High; 12th May 2019 at 17:47. Reason: to remove some dross!
Hot 'n' High is offline  
Old 10th May 2019, 19:08
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Join Date: Oct 2007
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Is it the hotter black runway that's affecting you? More rising air over the runway than the approach? Maybe watch others landing. An inelegant but gentle touchdown? If local professional tour pilots don't look to be doing much better, relax, smile.
Maoraigh1 is offline  
Old 10th May 2019, 19:41
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Join Date: Dec 2001
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Here’s my recommendation:
Practice your landings first thing in the morning, I’m talking preflight at dawn.
You have to eliminate all “external” factors or at least most of them for your errors to reveal themselves.
Then fix your errors before you tackle crosswinds or strong thermals.
You can’t learn to land from reading about it, you can only learn how to land by practicing it.
Talk to your instructor and move your lessons to early and I mean EARLY morning.
B2N2 is offline  
Old 10th May 2019, 20:06
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Join Date: Jan 2008
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Originally Posted by B2N2 View Post

Talk to your instructor

That's the best advice to date. I've been to Las Vegas several times so understand what hot is! A local instructor is your best bet.
GiveMeABreak is offline  
Old 11th May 2019, 06:40
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Join Date: May 2019
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I think you are right: "When you get close to the ground, the downdraft will stop, though spitting you out the bottom is still a risk."

I think due to dissipating of downdraft near the ground created all the problems: sinking, ballooning and floating. I should've reduce some power little early before my aiming point. I think it would help a lot! Now I can't wait to test for it! ( still, I prefer to fly in a smooth and calm weather! )
Juno Kim is offline  
Old 12th May 2019, 17:45
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Join Date: Dec 2001
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Originally Posted by B2N2 View Post
Talk to your instructor ......
Again, agree with B2N2 and GiveMeABreak - I'd really talk this through with an instructor before you try anything. After all, you say you have recently moved to Las Vegas .... the instructors will have been landing in these conditions for years! "Now I can't wait to test it!" is a nice way to bend a plane to be honest (and frighten an Instructor!) if they are not expecting it! I've subsequently mainly encountered rotor at various locations and am always keeping an eye out for such conditions. Personally, I always fly high for anticipated rotor conditions on approach - but your condition is different.

I've removed some of the dross from my last post (I can witter on!!! ) but the point worth hanging onto is such things can get out of hand real quick. In my case, my height above the undershoot that day saved a crash! But that was in my scenario. If you are not sure, talk to local Instructors even if you are qualified. That's (a) what they are paid to explain/demo and (b) I always saw a student asking questions as being a someone who was ahead of game so less likely to kill me.

Cheers, H 'n' H
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Old 13th May 2019, 17:16
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Join Date: Jan 2005
Location: Kent
Age: 56
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Sounds like lovely (from a glider pilots point of view) thermals going through.

I the air you will feel them as up / down draught.
On the ground you will feel them as gusts - lasting from a few seconds to many minutes.

You could try visiting your local gliding club and explaining your problem - any decent gliding instructor will be able to explain precisely what is going on.

While this may not explain with how to handle them in a C152, understanding the air you are flying through will certainly help.

OC619

P.S. Be prepared, if you visit a gliding site, to be sucked into "pure" flying - it happened to me
OpenCirrus619 is offline  

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