respect those winds and DA - My Oh F&^k moment

WannFly

WannFly

Final Approach
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Priyo
yesterday, I was on a IFR XC and landed in KSTP for for food, the plan was after taking off from there do a low approach in KFCM (Flying Cloud) on IFR plan, go missed, fly VFR and land at KMIC (Crystal) for a fuel stop. Here is how the next of the stuff unfolded:

  • Went to Thunderbird and topped off both tanks (Mistake #1)
  • it was super hot, like 92 degrees hot and humid, the density alt was 3300 at the field
  • upon take off we were given 14R (about 3300 ft), winds were 13G23 from 180 and garmin Pilot showed XW component of 8G14. this is more than i want to handle. if i was alone, i would have waited for the winds to die down, but i had a CFI with me and i wanted try it anyway
  • i did a mental math of our weight, and the take off roll i need to get above those damn trees at the end of the runway and my calculations were right, i broke ground right at 2000 ft, flew in ground effect until VY and took off
here is when things got ugly, i was holding center line, the tree line was getting bigger in the windscreen, i fought the instinct of pulling the yoke and was getting tossed around pretty bad. then the stall horn came on, i lowered the nose - this continued for 3 times, every time the stall horn would go off and i would lower the nose and the trees would get bigger and bigger. at one point i asked the CFI with my cool as a cucumber voice ... are we going to make it? his response was you are doing great, the trees are closer than i like it it to be though.

tell you what, it sure as hell didnt look like i was doing great, i am we were about 100 feet above the trees, but approaching the trees with stall horn coming up as i was holding VY was fairly nerve wrecking and it took every bit of composure to ensure i am not pulling hard on the yoke.

my #2 mistake was not asking for 14L and use the whole displacement threshold and the biggest mistake was failing to realize how the winds would behave when coming over the tree tops. it created pretty bad sink that i was trying to fight with my mighty 180 HP engine, on a hot day with 2 big guys in it and full fuel.

in retrospect, i should have done a lot more not to put myself in that position, but a great lesson learned about high DA take off and add more margin to what those book numbers says... cant imagine doing this from 5k or 7k DA ... it surely was a big eye opener for a flat lander who regularly takes off from 9000 ft runway
 
Good job. It definitely makes a difference...

I took off from Santa Fe this morning, leaving from the fly-in, and I had 2 on board with less than full fuel, and 235 HP --- and I still used a healthy amount of runway, then stayed in ground effect a little more before getting a real climb going. DA there was over 8k, but at least no obstructions departing.
 
At least in a certified aircraft you have density altitude and takeoff distance charts. They don't come standard with experimentals.
 
It's all what you're used to. Don't know what to do with all the extra pavement when I go somewhere with a tower. But I got my PPL and was based for seven years at an obstructed 3000' field. Two people, full tanks were no flap takeoffs even when DA was ~3000. Leaving with the wife for a week, luggage, full fuel called for Takeoff Flaps even in the winter. Nice tall trees at the end . . . . with several hundred feet of displaced threshold landing the other way.
 
Were you at gross? With full fuel and 2 big dudes, you still had some wiggle room, right?

What was the CFIs advice during the debrief? Anything helpful?
 
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WannFly said:
yesterday, I was on a IFR XC and landed in KSTP for for food, the plan was after taking off from there do a low approach in KFCM (Flying Cloud) on IFR plan, go missed, fly VFR and land at KMIC (Crystal) for a fuel stop. Here is how the next of the stuff unfolded:

  • Went to Thunderbird and topped off both tanks (Mistake #1)
  • it was super hot, like 92 degrees hot and humid, the density alt was 3300 at the field
  • upon take off we were given 14R (about 3300 ft), winds were 13G23 from 180 and garmin Pilot showed XW component of 8G14. this is more than i want to handle. if i was alone, i would have waited for the winds to die down, but i had a CFI with me and i wanted try it anyway
  • i did a mental math of our weight, and the take off roll i need to get above those damn trees at the end of the runway and my calculations were right, i broke ground right at 2000 ft, flew in ground effect until VY and took off
here is when things got ugly, i was holding center line, the tree line was getting bigger in the windscreen, i fought the instinct of pulling the yoke and was getting tossed around pretty bad. then the stall horn came on, i lowered the nose - this continued for 3 times, every time the stall horn would go off and i would lower the nose and the trees would get bigger and bigger. at one point i asked the CFI with my cool as a cucumber voice ... are we going to make it? his response was you are doing great, the trees are closer than i like it it to be though.

tell you what, it sure as hell didnt look like i was doing great, i am we were about 100 feet above the trees, but approaching the trees with stall horn coming up as i was holding VY was fairly nerve wrecking and it took every bit of composure to ensure i am not pulling hard on the yoke.

my #2 mistake was not asking for 14L and use the whole displacement threshold and the biggest mistake was failing to realize how the winds would behave when coming over the tree tops. it created pretty bad sink that i was trying to fight with my mighty 180 HP engine, on a hot day with 2 big guys in it and full fuel.

in retrospect, i should have done a lot more not to put myself in that position, but a great lesson learned about high DA take off and add more margin to what those book numbers says... cant imagine doing this from 5k or 7k DA ... it surely was a big eye opener for a flat lander who regularly takes off from 9000 ft runway
Click to expand...

Maintaining what you believe was Vy and hearing a stall horn?
 
Terry M - 3CK (Chicago) said:
Were you at gross? With full fuel and 2 big dudes, you still had some wiggle room, right?

What was the CFIs advice during the debrief? Anytime my helpful?
Click to expand...
i was at least 15% less than MTOW. during the debrief he said i should have lifted off way sooner and build up speed in ground effect, he was ready to take over, but since i did everything right, he didnt have to. still fairly nerve wrecking to hear the stall horn over trees, close to ground
 
Clip4 said:
Maintaining what you believe was Vy and hearing a stall horn?
Click to expand...
i was climbing at 76 kts, thats my VY, the wind shear/ sink./ turbulence whatever it was caused the stall horn to come on is what i believe happened. i wish i had a gopro to record it, which i ordered after i came home last night
 
Leaning is very important. I am based at 4500' so it's not too often that I take off at low elevations. However, at anything above 3000', I am leaning for best power. Out here, many airports have DA signs like this one:

Density_Altitude.jpg
 
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Only thing I would have done different if it were me would have been to stay down in ground effect past VY to build as much energy as possible for as long as possible before I started the climb.
 
DesertNomad said:
Leaning is very important. I am based at 4500' so it's not too often that I take off at low elevations. However, at anything above 3000', I am leaning for best power. Out here, many airports have DA signs like this one:

Density_Altitude.jpg
Click to expand...
Yikes!!!
 
FORANE said:
At least in a certified aircraft you have density altitude and takeoff distance charts. They don't come standard with experimentals.
Click to expand...

Not necessarily. Density altitude doesn't appear anywhere in the Navion books (either the required one or the informational one). It does have a takeoff distance chart which mentions "altitude." A savvy pilot would construe that to mean density altitude, but the book doesn't.
In fact, my plane easily outperforms what's in that chart. The additional 115 HP over what the plane came with gets you off the ground a lot faster. So does the modification that allows you to set takeoff flaps.
 
Warning: Dumb questions to follow....

Should this have been a short field takeoff? Some flaps, use all runway, full power with brakes first and then release, etc.???

Obviously you would do this for a truly short field and those trees...but how does higher DA effect the choice of using flaps for takeoff?

Also, it sounds like you felt like the higher winds coming over the trees (and at you to some degree) were then also pushing you down? Is it possible that the higher winds were actually getting almost killed off right near the trees as there is usually much less airflow right near a surface due to friction. Or put another way, did you maybe actually lose your headwind?

Just curious. lots to learn from this one!!!

I bet you'll be coming back to Crystal now again and again and again :)
 
It might have been helpful,if you and the cfi had discussed the plan of action,before you did the takeoff. I’m sure the pucker factor was off the comfort scale.
 
Easy to criticize after the fact from a lounge chair, but one thing always on my mind in the summer is DA. Comes from training in the Adirondack region... At some of those airports I’d have to spiral up to an altitude to clear the ridges, before turning on course, and in a C-152 that can make for a long day... For those asking why he wasn’t at VX; if the stall horn was screaming at VY, why would he pull the nose up to VX?
 
At least you are learning from it. I had one of those oh crap moments on the way out to Oshkosh a few years back. I landed at an airport in Pennsylvania to get gas only to find out that their self serve tank was dry. I hopped over to an airport I didn't really research ahead of time but on the sectional it looked good (had gas, uncontrolled field, and 4000' runway in the general direction of the wind). The problem came when on landing it seemed to take forever to get it on the ground. After taxiing off I realized that the airport was sitting in a bowl and one side of the runway had a significant upward slope to it. I filled up on gas and was getting ready to take off when a look at the windsock showed the wind shifted direction. It was still in alignment with the runway but was now blowing 10 knots in the opposite direction. I had two choices and neither were great. One was to take off into the wind but go up the slope of the runway. The other was to take off with a tail wind and go down the slope. Both ends of the runway had tall trees. I chose to takeoff up the slope and into the wind figuring that the headwind would help compensate for the slope. I got off the runway quickly but it seemed like the runway was rising almost as fast as my plane was climbing. It was very hard not to just keep pulling back on the stick as the trees got bigger and closer each second. I was able to step over to the right to clear the very top of the biggest set of trees and then finally gained enough speed to out climb the rest a little further away. I really thought at one point that we were going to clip the tops of the trees and that would be the end of it. To this day I'm still not sure if taking off in the other direction would have been better or worse. In a no wind situation it would have been no problem but with a 10 knot tail wind I just don't know. What I should have done is unloaded the plane and had my dad uber over to another local airport with more favorable conditions or not take off at all until the wind had calmed down or changed directions. Seeing those trees coming at me is not something I ever want to repeat.

Keith
 
Sinistar said:
Warning: Dumb questions to follow....

Should this have been a short field takeoff? Some flaps, use all runway, full power with brakes first and then release, etc.???

Obviously you would do this for a truly short field and those trees...but how does higher DA effect the choice of using flaps for takeoff?

Also, it sounds like you felt like the higher winds coming over the trees (and at you to some degree) were then also pushing you down? Is it possible that the higher winds were actually getting almost killed off right near the trees as there is usually much less airflow right near a surface due to friction. Or put another way, did you maybe actually lose your headwind?

Just curious. lots to learn from this one!!!

I bet you'll be coming back to Crystal now again and again and again :)
Click to expand...

I did the calculation after coming home and with the winds and temp and flaps, it would have taken more to clear those trees. i am little confused about that myself. it is possible i lost headwind at some point, i reviewed the G5 track log and the GPS GS last night, it was all over the place for few seconds, the lowest was 45 kts GS.

next time i am going to Crystal is when its -20 on the ground :D
 
kmacht said:
At least you are learning from it. I had one of those oh crap moments on the way out to Oshkosh a few years back. I landed at an airport in Pennsylvania to get gas only to find out that their self serve tank was dry. I hopped over to an airport I didn't really research ahead of time but on the sectional it looked good (had gas, uncontrolled field, and 4000' runway in the general direction of the wind). The problem came when on landing it seemed to take forever to get it on the ground. After taxiing off I realized that the airport was sitting in a bowl and one side of the runway had a significant upward slope to it. I filled up on gas and was getting ready to take off when a look at the windsock showed the wind shifted direction. It was still in alignment with the runway but was now blowing 10 knots in the opposite direction. I had two choices and neither were great. One was to take off into the wind but go up the slope of the runway. The other was to take off with a tail wind and go down the slope. Both ends of the runway had tall trees. I chose to takeoff up the slope and into the wind figuring that the headwind would help compensate for the slope. I got off the runway quickly but it seemed like the runway was rising almost as fast as my plane was climbing. It was very hard not to just keep pulling back on the stick as the trees got bigger and closer each second. I was able to step over to the right to clear the very top of the biggest set of trees and then finally gained enough speed to out climb the rest a little further away. I really thought at one point that we were going to clip the tops of the trees and that would be the end of it. To this day I'm still not sure if taking off in the other direction would have been better or worse. In a no wind situation it would have been no problem but with a 10 knot tail wind I just don't know. What I should have done is unloaded the plane and had my dad uber over to another local airport with more favorable conditions or not take off at all until the wind had calmed down or changed directions. Seeing those trees coming at me is not something I ever want to repeat.

Keith
Click to expand...

i can relate!! it is NOT comforting to see the trees get bigger and bigger and fill up the wind screen and not pull on the yoke.

experience is a very tough teacher
 
kmacht said:
At least you are learning from it. I had one of those oh crap moments on the way out to Oshkosh a few years back. I landed at an airport in Pennsylvania to get gas only to find out that their self serve tank was dry. I hopped over to an airport I didn't really research ahead of time but on the sectional it looked good (had gas, uncontrolled field, and 4000' runway in the general direction of the wind). The problem came when on landing it seemed to take forever to get it on the ground. After taxiing off I realized that the airport was sitting in a bowl and one side of the runway had a significant upward slope to it. I filled up on gas and was getting ready to take off when a look at the windsock showed the wind shifted direction. It was still in alignment with the runway but was now blowing 10 knots in the opposite direction. I had two choices and neither were great. One was to take off into the wind but go up the slope of the runway. The other was to take off with a tail wind and go down the slope. Both ends of the runway had tall trees. I chose to takeoff up the slope and into the wind figuring that the headwind would help compensate for the slope. I got off the runway quickly but it seemed like the runway was rising almost as fast as my plane was climbing. It was very hard not to just keep pulling back on the stick as the trees got bigger and closer each second. I was able to step over to the right to clear the very top of the biggest set of trees and then finally gained enough speed to out climb the rest a little further away. I really thought at one point that we were going to clip the tops of the trees and that would be the end of it. To this day I'm still not sure if taking off in the other direction would have been better or worse. In a no wind situation it would have been no problem but with a 10 knot tail wind I just don't know. What I should have done is unloaded the plane and had my dad uber over to another local airport with more favorable conditions or not take off at all until the wind had calmed down or changed directions. Seeing those trees coming at me is not something I ever want to repeat.

Keith
Click to expand...
I only recently faced the same decision regarding slope of a runway. I elected to do the downwind down hill said the uphill Was only about 5kts but that downhill take off with 10deg flaps in the 182 felt like i was on a sling shot!!! It helped that I was slungshot into a farmer field as opposed to trees though.
 
WannFly said:
i was climbing at 76 kts, thats my VY, the wind shear/ sink./ turbulence whatever it was caused the stall horn to come on is what i believe happened. i wish i had a gopro to record it, which i ordered after i came home last night
Click to expand...

Your Vy? What is the aircrafts Vy at that DA?
 
Clip4 said:
Your Vy? What is the aircrafts Vy at that DA?
Click to expand...

As altitude increases (actual or just density), Vy for my plane decreases. So if I forget to compensate for high DA, I'm flying at (Vy + 1mph per 1000'); if the stall horn chirps there, it would definitely sound at the correct, lower Vy.
 
Oh, ALWAYS use all of the runway available! Then if you're not climbing right, you have a chance to pull throttle and set her back down. Even if you run off the end and into trees, better doing so at 30-40 knots than at 80-90 knots, eh?
 
VX and VY always meet at the absolute ceiling, it is sometimes appropriate to add to Vx and subtract from Vy, if you haven't done the math ahead of time :) or in a tight spot, split the difference.
 
FORANE said:
At least in a certified aircraft you have density altitude and takeoff distance charts. They don't come standard with experimentals.
Click to expand...

The RVs climb like a scalded cat, so no issue(s) there ...

Clip4 said:
Maintaining what you believe was Vy and hearing a stall horn?
Click to expand...
Salty said:
Yeah, I don’t get it.
Click to expand...

In gusty winds with a shift, occasionally the stall horn will chirp even when you are not near the stall. My field gets unusual winds, and my Tiger stall horn would occasionally chirp on downwind while doing near 100 mph
 
Winds at 13G23 from 40* come out to a 4kt average crosswind component on my calculator. 8kts if you enter 23kts as the constant. What's up with that?
 
WannFly said:
i broke ground right at 2000 ft, flew in ground effect until VY and took off
Click to expand...
I agree with the guys, Vx should have been used if you needed to clear nearby obstacles. Live'n'learn. Though I am surprised the instructor did not advise right there on the spot.

Also, if you broke ground at 2000ft in a 180hp machine with 2 guys and full fuel, this does not sound really right. You should see closer to a 1000ft ground roll. (consult your POH)
I'd have someone look at the airplane. 3000ft DA won't double your ground roll. When we fly in 100+F here, we still don't need that much rwy. (now Denver in the summer is different :) )
 
Stewartb said:
Winds at 13G23 from 40* come out to a 4kt average crosswind component on my calculator. 8kts if you enter 23kts as the constant. What's up with that?
Click to expand...
? Your calculator needs calibrating? I think OP had it right.
 
There's no displaced threshold on 14L at Crystal. There is 500ft of paved surface extending off the end of the runway but it's marked with yellow chevrons and is only useful as an emergency stopping area in the event of a runway overrun, so you shouldn't feel bad about not insisting on 14L.
 
Hank S said:
As altitude increases (actual or just density), Vy for my plane decreases. So if I forget to compensate for high DA, I'm flying at (Vy + 1mph per 1000'); if the stall horn chirps there, it would definitely sound at the correct, lower Vy.
Click to expand...

Even at Vx you should not have a stall warning. Vx minus 5-10 knots is where you should get a stall warning.
 
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