WHACK!!!

Please tell what happened and how it might have been avoided. Names should be ommitted. This forum should help others learn from mistakes that caused or nearly caused a mishap.
jcflies
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WHACK!!!

Post by jcflies »

since we have lost two of our brothers to the consequences of unsafe approaches, i wanted to post this. i could have easily been the first death, when i totally, STUPIDLY, blew a landing. somehow, i have been fortunate enough to live through it relatively unscathed, and one of the most important features of my six-month long recovery has been sitting in the l/z with pilots who are willing to share their knowledge and experience with me. when they judge and discuss each other's approaches and landings, it's provided a great opportunity to learn. we never stop learning. there's always the basics, and then fine-tuning, finesse, style, mastery...and we have a great group of pilots who've been there/done that with just about every possible approach and landing there is. since it's one of the most critical parts of the flight and we have a GNARLY l/z, we should discuss our approaches and landings with other pilots--particularly those who have had more experience. we assume levels of competence along with hang ratings, and that's that... there's a lot of ego involved, and that's fine, but i think we should never be above asking our friends for evaluations. THAT's how you improve! and "WHACK!", above all else, is a reminder that landings can kill you. i heard one of our pilots say, "You have to get your glider in a headlock and wrestle it to the ground." another great pilot i know speaks of landings "pulled from the jaws of death." "Mr. Death" at Elsinore, was there to remind pilots to be hyper-aware and vigilant about approaches and landings and, in their fun loving, inimitable style, they all helped each other improve. i'm not saying we should all start giving each other unsolicited advice (CAN YOU IMAGINE HOW UGLY THAT COULD BE?!!), but we are in a sport that is full of dire punishments for mistakes, and there are always pilots we look up to. ask one of them to watch your approaches and landings. i know i will and i want my friends to judge me harshly, so that i can ABSORB, and improve. it might just keep me alive, and flying...
janyce

"You HAVE to make it..."
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Glenn
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Post by Glenn »

I agree Janyce. I also hope our more experienced pilots and instructors will analyze what has happened recently, try to extract some conclusions and make some recommendation for prevention of these "serious" landings going forward. I suggest we use this thread to do that.

I did not witness either fatality and have actually heard little analysis of what happened in either case. Maybe I'm not talking to the right people, and I feel a little uncomfortable asking, but I really want and need to know what happened and why. Anybody....?

ps: I agree that our LZ is a little gnarly. We should explore that and what we can do about technique or even landscaping to mitigate it.
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stebbins
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Post by stebbins »

I haven't been out much lately, so I can't really make too much in the way of observations about the LZ, landings etc. Also, I did not witness, nor have I gotten first hand reports of the two accidents. However, I have noticed two things in general in our LZ.

1) It seems to me that a lot of people are landing a bit slower than what I remember. This is not a good thing. Yes, one can go too fast, but it is better to be 5 mph too fast than 1 mph too slow... If the wind gust-factor is 10 mph, then you need at least 10 mph above stall to be safe from a stall-inducing gust. And the closer to the ground you are, the more that's true.

2) People seem to be a bit complacent about that last turn. I see folks low who want to continue to the "normal" place that they make the turn. Then the last turn has their wing-tip right on the deck. (Or, as in at least one case, in the sand!) If things are going wrong, don't just "continue" as usual. Better too high than too low. Too high you can fix, too low you cannot. If you aren't going to be able to get to your base-leg location high enough, turn early. Landing in the brush, or the part of the LZ you aren't approved for is minor in comparison to catching a wing-tip on the ground. Remember, YOU are in charge of your glider and approach. If it isn't right, do something about it NOW, don't wait for it to get worse.

I am NOT saying that the above had anything to do with the two recent fatalities. I have no information about that one way or the other. I am saying that I've seen the above two problems the last few times I've been out to our LZ, and seen them from quite a few pilots.

Please, fly safely, my friends. And if you see someone else not flying safely, please let them know. Any possible annoyance you or they might feel, or anger you might generate is minor in comparison to what we've all been feeling lately. These are our friends. Let's help keep them alive. (And if someone suggests a change in your safety practices, remember that they are telling you that because they don't want you to be a statistic.)

I'll fold up my soapbox now, with three comments:

Speed is your friend. Be in charge of your landings (and launches too!) Take care of each other.
Fly High; Fly Far; Fly Safe -- George
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Glenn
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Post by Glenn »

Thanks George,

For just this reason I tend to dive pretty fast on final all the way until I need to change hand position. What is too fast on approach? If I avoid PIO, are there any other dangers with a very fast approach?
Flyyyyy
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JD
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Post by JD »

Glenn wrote:.......I did not witness either fatality and have actually heard little analysis of what happened in either case. Maybe I'm not talking to the right people, and I feel a little uncomfortable asking, but I really want and need to know what happened and why. Anybody....?.......
From: http://www.crestlinesoaring.org/forum/20080829/1550
Tom Cornelius wrote:I saw Jeffs crash and it didn't appear he was having any problems other than being to low in heavy sink. There was a comment about earlier heart problems. I didn't see the down wind but in his base turn he was really sinking fast,his final was smooth and he leveled his wings perfectly but was still sinking like a stone.I'm a pg pilot and don't know much about landing hang gliders,but if he could have extended his base another 15 feet he would have come in on level in the normal landing area,off the side of the rocky area of the wash.I'm thinking he did what he had to in adnormally heavy sink to keep from draging a wing tip. I didn,t know Jeff personally,he was well liked and will be missed. my condolances to familey and friends.
Re: Richard's fatal landing: this is from an email I received from Joe Greblo
Joe Greblo wrote:.......

Whereas I don't pretend to have all the answers to Richard's accident, I feel strongly that his angle of attack wasn't low enough to ensure roll control during the latter phase of his approach. This combined with turning flight, (either accidental or purposeful) may have led to the tragedy.

The event further strengthens my commitment to preach to pilots, the need to pursue knowledge of the nature of all forms of turbulence, it's many causes, how to predict it's possible presence, possible magnitude, and it's affect on the wings angle of attack and control.
Armed with that knowledge, and whenever precise command and control is required, hang glider pilots should.......
a) try to minimize turns
b) maintain the most effective hand and body position
c) establish and maintain an angle of attack that is low enough to prevent it from entering the stall range when sudden, inadvertent relative wind changes (turbulence) occur ........
Joe
It's been said before by those wiser than me that it's too easy get to a lot of airtime in just a few flights and so the time spent w/ ground handling, take-offs and landings has left many pilots weak in those skill sets.
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Glenn
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Post by Glenn »

I hope someone with more experience than me can answer my previous question: If you avoid P.I.O. is there really any reason to not dive as fast as possible on approach? I'm not talking about a topless here but on a beginning or intermediate glider.
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Glenn
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Post by Glenn »

Since I have been the one providing and maintaining the triangular streamers in the LZ, Are there any suggestions about improvements to them on my next round of rebuild? Location, more of 'em, etc.? I think they work well and seem to hold up, but they are probably 5 years old and will need redone soon. This is landing related and I hope we continue this discussion here to improve our landings.
Flyyyyy
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Christian
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Post by Christian »

If you avoid P.I.O. is there really any reason to not dive as fast as possible on approach?

The question has many related issues and definitions and so you ought to ask your instructor for a full discussion.

The immediate reasons not to dive as fast as possible on final approach are that

a. You have given up the option of increasing your dive rate.
b. Max dives, esp on a single-surface glider, reduce visibility ahead.
c. They reduce directional control (PIOs aside, it's easier to turn smoothly when the wing is not so highly loaded)
d. They make your arms tired.

The general idea is to obtain the appropriate glide angle, crosswind correction and airspeed for the conditions. We aim to be smooth, with gentle inputs. Maximum inputs are reserved for corrections.
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Glenn
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Post by Glenn »

Thanks Christian, and I will talk to an instructor, but I would like more discussion here to have it up for everyone to see and discuss for current and future readers.

Your suggestions make sense. I guess I really mean a very fast approach but slower than maximum. My concern is avoiding the problems that caused the two recent tragedies. From what I've gathered so far, one was turbulence in the LZ and the other strong sink. While it may turn out to be other causes, these two are certainly possible causes of a serious landing like those. If so, would much faster approaches have prevented such crashes.

Which is better: Fast approach to cut through turbulence, or slower speed to give you a better feel for wind conditions so you can counter them. I feel that if hit by a sudden turning vector that it may be too late to both counter the turn and dive for speed close to the ground. In my thinking I would prefer to already have my speed for more stability and authority through the turbulence. Although I have been flying for about 8 years I have had only a few very turbulent approaches so I haven't yet worked it out through experience. My only broken down tube was a result of flying too slow in turbulence, dropping me from about 30 ft at El Mirage.

The strong sink on approach seems like a tougher situation. I'm lost there.
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Christian
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Post by Christian »

What you say is my understanding of it, too.
Regarding sink, there's a limit to sink as you near ground level--that doesnt worry me. It is getting the final approach set up right so when conditions surprise you, you can recover. That means speed and a good pattern.
We want to shorten the duration of flight near the ground--get down through the crap fast. But that's only possible if you turn final at the right place and the right altitude. The cause of a problem is always one or two steps back in the accident chain.
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stebbins
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Post by stebbins »

What are the problems with too much speed?

1) The obvious, PIO. But we aren't talking that much speed. If you PIO at reasonable landing speeds, you need more practice in a safer environment and/or a different glider.
2) Energy retention. Yea, even on a low-end glider, you will go farther across the ground. But that's not a problem except in a restricted field. And you shouldn't be landing in a restricted field if you have to ask the question that was asked.
3) Higher sink/steeper approach. Usually, this is a good thing. I can imagine circumstances where it isn't, but if you are in them, you set up your approach wrong, (See #2 above.) or you got hit with some truly tremendous sink. If you DID get hit with that much sink, there is probably enough turbulence that you don't want to be going slow. Crashing short, but only from a few feet is (usually) preferable to crashing from higher up. Stalls are very bad unless you are a) high or b) right on the deck with your landing gear down and ready.
4) Fatigue. But don't go fast at 500 feet. That's a waste of your energy. When you get low enough that a stall might not recover by the time you hit the ground, you should be going faster. If you have large trees (or other wind obstructions) around the LZ, then you need to speed up sooner. If you have known turbulence (Santiago Estates) then you need to speed up sooner. If you are flying your downwind, and getting bumped, speed up. If you are getting bumped a lot, speed up more. And of course, adjust your planned approach accordingly.
5) If you are REALLY going fast, I suppose you could misjudge and fly right into the ground. Seems to me that you could do that at any speed though, and it is a far far lower risk than stalling. (Yea, I know, some pilots go 70 mph, prone, within a foot of the ground. We aren't talking about that. Does ANYONE think that is as safe as a more measured landing approach?)
6) I'm having trouble thinking of any others. THere might be some, but the thing is this: It is better to be 10 mph too fast than 1 mph too slow. And you won't know you are too slow until it bites you, or your friends call you an idiot (or maybe a more polite word). Neither of which is pleasant. Oh, one extra issue. If you come in prone, then you might think flying fast is more dangerous than if you come in upright. It can be disconcerting to have the ground go by you at 35 mph when you are prone two feet off the ground (or lower.) But stalling prone at 30 feet is just as bad. And if you are upright with your landing gear down and ready, it is far far less scary (and less dangerous too!)

Note that none of the above (except PIO) are nearly as dangerous as flying too slowly. But you can easily avoid PIO by slowing down. So, it is better to be too fast (within reason) than too slow (even a little.)

And yes, I understand this is mostly about angle of attack, but it is easier to describe in terms of airspeed. And you cannot see angle of attack. You don't KNOW what the vertical component of the wind is. Angle of attack is relative to the air, not the ground, so it is hard to judge. You CAN see your bar position and can get a good idea of your airspeed, so that's easier to work with, even though it is only a proxy for angle of attack.

(In conditions that aren't changing too rapidly, it is a very good proxy. If you raise or lower the angle of attack very rapidly, or the air does it for you, it is a terrible proxy. See "High Speed Stall" in the literature.)

I'm sure that Joe Greblo or Hungary Joe (and others) can give as good or better description than me. So if you don't trust my description, please ask them.

A quick bit of arithmetic to put this all in perspective:

Stall speed of Falcon 18 mph (yours will be different, but you can make the adjustment).

Landing approach of Pilot A at 18.5 mph (All pilot speeds are airspeed)
Landing approach of Pilot B at 20 mph.
Landing approach of Pilot C at 23 mph.
Landing approach of Pilot D at 26 mph.
Landing approach of Pilot E at 29 mph.
Landing approach of Pilot F at 33 mph.

Gusty day. Downwind gust, completely horizontal, of 5 mph hits instantaneously as each pilot approaches LZ on final at 40 feet.

Pilot A: 18.5-5 = 13.5 -- Very bad crash
Pilot B: 20-5 = 15 -- 3 mph below stall, at 40 feet, probable crash
Pilot C: 23-5 = 18 -- Possible crash, but likely "pull it off"
Pilot D: 26-5 = 21 -- Margin of 3 mph.
Pilot E: 29-5 = 24 -- Margin of 6 mph.
Pilot F: 33-5 = 28 -- Margin of 10 mph.

You get the idea. And a 5 mph gust is not all that unlikely. Stand on launch and watch your airspeed indicator held out in front of your head. Gusts of 5 are quite common. Gusts of 10 are not uncommon. And I didn't even include the possibility of vertical gusts. As far as I can tell from the arithmetic, we should almost all be flying faster on approach. Not to the point of PIO, but pretty darned fast.
Fly High; Fly Far; Fly Safe -- George
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Post by abinder »

hmmmm............
"5 mph hits instantaneously as each pilot approaches LZ on final at 40 feet."

Are you assuming that your hang glider 'balloons' when you are hit by that 5mph? If your hang glider doesn't, then your air speed won't decrease; it's your ground speed that decreases.
stebbins wrote:What are the problems with too much speed?


A quick bit of arithmetic to put this all in perspective:

Stall speed of Falcon 18 mph (yours will be different, but you can make the adjustment).

Landing approach of Pilot A at 18.5 mph (All pilot speeds are airspeed)
Landing approach of Pilot B at 20 mph.
Landing approach of Pilot C at 23 mph.
Landing approach of Pilot D at 26 mph.
Landing approach of Pilot E at 29 mph.
Landing approach of Pilot F at 33 mph.

Gusty day. Downwind gust, completely horizontal, of 5 mph hits instantaneously as each pilot approaches LZ on final at 40 feet.

Pilot A: 18.5-5 = 13.5 -- Very bad crash
Pilot B: 20-5 = 15 -- 3 mph below stall, at 40 feet, probable crash
Pilot C: 23-5 = 18 -- Possible crash, but likely "pull it off"
Pilot D: 26-5 = 21 -- Margin of 3 mph.
Pilot E: 29-5 = 24 -- Margin of 6 mph.
Pilot F: 33-5 = 28 -- Margin of 10 mph.

You get the idea. And a 5 mph gust is not all that unlikely. Stand on launch and watch your airspeed indicator held out in front of your head. Gusts of 5 are quite common. Gusts of 10 are not uncommon. And I didn't even include the possibility of vertical gusts. As far as I can tell from the arithmetic, we should almost all be flying faster on approach. Not to the point of PIO, but pretty darned fast.
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stebbins
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Post by stebbins »

I'm sorry you misunderstood. Perhaps I could have been clearer.

The 5 mph gust is from the REAR, as stated. That decreases your airspeed until the glider catches up. That takes significantly longer than the change in the air. During that time, if you are no longer at "flying speed" you are in trouble. Heck, even if you are at flying speed, but below good control speed, you might be in trouble.

A 5 mph gust from the front would increase your airspeed until the glider caught up (likely by ballooning, or by pilot correction, which would keep the airspeed up.)

The key here is that the air changes faster than the glider can react. In some cases significantly faster than the glider can react. If you drop below flying speed at 50 feet, you don't have enough altitude to fix it, and plenty to get in trouble with. If all this happens at 2 feet, and your landing gear are down and ready, it isn't a big deal, of course.

Personal note: I was landing on a dry lakebed years ago. I had a 2 mph (or so) headwind. I was coming in very fast (thank goodness!) Suddenly, the streamer in front of me switched directions. I now had at least a 5 and more likely an 8 mph tail wind. If I'd been flying slowly, I'd have been in a world of hurt. Luckily, I was flying fast, and also luckily, my run-out was enough (barely) to avoid any sort of whack. Not an elegant landing, to be sure, but safe. A couple miles an hour slower, and I'd have been toast. (Or more likely, jam.)
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Post by abinder »

Actually you stated:

"Gusty day. Downwind gust, completely horizontal, of 5 mph hits instantaneously as each pilot approaches LZ on final at 40 feet."
stebbins wrote:I'm sorry you misunderstood. Perhaps I could have been clearer.

The 5 mph gust is from the REAR, as stated.
You stated "downwind gust" and that it hits "instantaneously as each pilot approaches LZ on "final" at 40 feet".

Final is 180 degrees the opposite direction of downwind, thus in that instance the pilot would encount an additional 5mph headwind. However, if you actually meant that the pilot was hit by a 5mph tailwind when on final, then yes, until the glider caught up, the airspeed would be 5mph less.
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Post by Glenn »

So as I read the discussion here it seems agreed that we should be landing faster just for the added margin with little additional risk = net less accidents. I'm sold. Thanks guys. It is unfortunate if this advice is all that was needed to prevent losing two great pilots and men. Damn!
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stebbins
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Post by stebbins »

abinder wrote:Actually you stated:

"Gusty day. Downwind gust, completely horizontal, of 5 mph hits instantaneously as each pilot approaches LZ on final at 40 feet."
stebbins wrote:I'm sorry you misunderstood. Perhaps I could have been clearer.

The 5 mph gust is from the REAR, as stated.
You stated "downwind gust" and that it hits "instantaneously as each pilot approaches LZ on "final" at 40 feet".

Final is 180 degrees the opposite direction of downwind, thus in that instance the pilot would encount an additional 5mph headwind. However, if you actually meant that the pilot was hit by a 5mph tailwind when on final, then yes, until the glider caught up, the airspeed would be 5mph less.
If final is 180 degrees the opposite of downwind, and the pilot is on final, then a downwind gust is 180 degrees opposite the direction the pilot is going. ** That means he has a decrease in headwind, as I stated, or a tailwind gust as you called it. (Your wording is better, no doubt.) But this is all just terminology. The issue is safety, not whether you liked the way I stated it. (If I was confusing, I apologize.)

If the wind gust HITS HIM FROM BEHIND, at 5 mph, he's in a world of hurt. THAT is what I'm talking about. (You can also think of it as the wind dropping in speed by 5 mph. Same exact thing.)

By the way, if he is hit by a 5 mph gust from in front, and keeps the glider from ballooning, then he will now have 5 mph increase in airspeed. If he lets the glider balloon, then he's now primed for trouble when the gust decreases, as it will most likely do. The key is to keep the speed up. That headwind gust usually means there is a tailwind gust nearby... And most times, when a pilots lets the glider balloon because of a gust (as opposed to pilot input), they end up even slower than they started. Not a good situation.

** With the exception of onshore and offshore, all wind directions are named by the direction that the wind is coming from. Hence a downwind gust is one that comes from the direction opposite the direction that the wind is coming from. But again, who cares. The issue is the safety concern of flying too slowly, especially in gusty (thermally) conditions.
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Post by Malury »

I think this conversation illuminates why Greblo uses the phrase "speed as chosen" This is the speed that the pilot finds is appropriate for the risks. For me it is the speed which gives a margin of safety and authority, including the option of pulling on more speed. Yet not so fast as to needlessly amplify the risk of injury from obstacles or whacking.
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Post by abinder »

stebbins wrote:If final is 180 degrees the opposite of downwind, and the pilot is on final, then a downwind gust is 180 degrees opposite the direction the pilot is going. ** That means he has a decrease in headwind, as I stated, or a tailwind gust as you called it. (Your wording is better, no doubt.) But this is all just terminology. The issue is safety, not whether you liked the way I stated it. (If I was confusing, I apologize.)
Read what you just wrote:
(for sake of ease of directions, let's say the pilot is on final flying his glider in the west direction)
"then a downwind gust is 180 degrees opposite the direction the pilot is going."
(you even just stated yourself that the gust is 180 degrees opposite of the direction that the pilot is traveling)

The downwind direction would be towards the east (180 degrees opposite) if the pilot is flying the final to the west which turn would be a head wind, not a tail as you seem to want to say. (and as usual, you say anything you can to convince yourself that you're not wrong)

Maybe I should state it again; If something is traveling 180 degrees different, then it's traveling in the opposite direction, thus it would be a head wind not a tail wind.

Oh by the way, a westerly wind is a wind coming from the west and traveling to the east (look it up if you don't believe me.)
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Post by stebbins »

abinder wrote:
stebbins wrote:If final is 180 degrees the opposite of downwind, and the pilot is on final, then a downwind gust is 180 degrees opposite the direction the pilot is going. ** That means he has a decrease in headwind, as I stated, or a tailwind gust as you called it. (Your wording is better, no doubt.) But this is all just terminology. The issue is safety, not whether you liked the way I stated it. (If I was confusing, I apologize.)
Read what you just wrote:
(for sake of ease of directions, let's say the pilot is on final flying his glider in the west direction)
"then a downwind gust is 180 degrees opposite the direction the pilot is going."
(you even just stated yourself that the gust is 180 degrees opposite of the direction that the pilot is traveling)

The downwind direction would be towards the east (180 degrees opposite) if the pilot is flying the final to the west which turn would be a head wind, not a tail as you seem to want to say. (and as usual, you say anything you can to convince yourself that you're not wrong)

Maybe I should state it again; If something is traveling 180 degrees different, then it's traveling in the opposite direction, thus it would be a head wind not a tail wind.

Oh by the way, a westerly wind is a wind coming from the west and traveling to the east (look it up if you don't believe me.)
I already sated that a West wind is one coming from the West. No need to get snarky. And you are right about one thing. The last post of mine contained a sentence that I didn't check thoroughly, and was thus backwards. I got distracted and posted before I fixed it, thinking I already had done so. My apologies, I should have been more careful. (Note that I admit error, unlike some others.) But the original posts were correct, and the numbers show the key information.

It is more important to get this information out to pilots than to slam me. If you wish to slam me, feel free to email me in person, or start another thread. But THIS one is about protecting our fellow pilots. Safety is more important than your or my ego.


Let's make this very clear by looking at pictures:

"<"----------- Wind is going this way at 3 mph
-----------">" Pilot is going this way 18 mph airspeed
-----------">" Gust is this way at 5 mph (3-5 = -2)
Pilot now has 2 mph tailwind.

Windsock was facing ==() Windsock mouth is the ()
Windsock switches to ()==

We call this a downwind gust. (Everyone else I've ever talked to calls it this, whatever you wish to call it. Perhaps tailwind would be a better term. Note that the downwind gust comes from downwind, as westerlies come from the west, and tailwind comes from the tail.)

Pilot is in deep doo doo, even if the wind is still in his face. He is now below flying speed, and needs altitude to recover. 40 feet is likely not enough. Impact results. And that doesn't even include gradient or vertical gusts!

THAT is the issue. Let's keep our eyes on the ball here. This is about safety, not "pick at each other". I clarified several times, so let's stick to the real issue: Saving lives, arms, and aluminum.

Here is the table above with the "upwind/downwind" clarified for those even more anal than me.
A quick bit of arithmetic to put this all in perspective:

Stall speed of Falcon 18 mph (yours will be different, but you can make the adjustment).

Landing approach of Pilot A at 18.5 mph (All pilot speeds are airspeed)
Landing approach of Pilot B at 20 mph.
Landing approach of Pilot C at 23 mph.
Landing approach of Pilot D at 26 mph.
Landing approach of Pilot E at 29 mph.
Landing approach of Pilot F at 33 mph.

Gusty day. Pilot flying South. TAILWIND gust (From North to South), completely horizontal, of 5 mph hits instantaneously as each pilot approaches LZ on final at 40 feet.

Pilot A: 18.5-5 = 13.5 -- Very bad crash
Pilot B: 20-5 = 15 -- 3 mph below stall, at 40 feet, probable crash
Pilot C: 23-5 = 18 -- Possible crash, but likely "pull it off"
Pilot D: 26-5 = 21 -- Margin of 3 mph.
Pilot E: 29-5 = 24 -- Margin of 6 mph.
Pilot F: 33-5 = 28 -- Margin of 10 mph.

You get the idea. And a 5 mph gust is not all that unlikely. Stand on launch and watch your airspeed indicator held out in front of your head. Gusts of 5 are quite common. Gusts of 10 are not uncommon. And I didn't even include the possibility of vertical gusts. As far as I can tell from the arithmetic, we should almost all be flying faster on approach. Not to the point of PIO, but pretty darned fast.

(And I also didn't include wind gradient! One more reason to speed up.)
Fly High; Fly Far; Fly Safe -- George
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Post by abinder »

Stebbins,

I'm just sick and tired of your "know it all" attitude that always seems to come from you and I have had several other people express the same thing to me.
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