Foxbat oops at Casino this morning 26/3/21

[Mike Gearon]

Back on topic although I enjoy a meander away as much as the next and Yeah, I don’t get beer or at least not fosters and Carlton and the stuff we grew up with and no better in USA with Budweiser (butwiper) 

 

Discovered craft beers and totally different experience.

 

Was just reviewing the Foxbat website this morning. Reason was annoying floats in the A22 last weekend where I was really trying to keep the speed under 50 knots. 55 knots seems to pretty much guarantees a nice long float...I would like to put it down to the covid vaccine 24 hours prior but not a very good excuse.

 

Here’s a few bits lifted from site. Bold relevant and underline really relevant depending of course on what actually went wrong.

 

Let’s go ballooning
So, what’s wrong with more speed? There are two main reasons but first, remember light sport and recreational aircraft are very low weight (read: low inertia) aircraft. So, like a small car, these types of aircraft will change direction much more quickly than a limo, a ute or a truck. Not that I’m suggesting your average Cessna/Piper etc are trucks…. As a result, when landing, the controls are much more effective than bigger GA aircraft and to much lower airspeeds. At only slightly faster speeds the controls are even more powerful, so if you are too fast when you pull back to flare, the aircraft will not just flare, it will start to climb again, even with the engine at idle. This is called ‘ballooning’. When you go ballooning, the impulse is to push the nose down to reduce the sudden climb. Unless you are very quick (and/or experienced) you’re likely in for a bent nose leg and/or busted propeller. Another alternative, just holding back the controls during the balloon, can result in a stall from an ‘unsuitable’ height above the runway, leading to a (very) heavy landing, which could damage the landing gear or worse.

 

Calculating the correct threshold speed
Which is where we get back to speed. There’s a GA rule of thumb about landing speed over the threshold. This says you should aim for about 1.3 times stall speed in landing configuration. As an example, with a stall speed of 45 knots the aim is (technically) 58.5 knots over the threshold – which is usually rounded to 60 knots. With low-inertia light sport aircraft, which have lower landing speeds, it’s probably safer to go for about 1.75 times stall speed, as wind gusts can be a much higher proportion of approach speed. So, for a stall speed of 27 knots (A32 Vixxen) the threshold speed should be about 47 knots – which is exactly what the pilot manual gives. Note – this is 20 knots ABOVE the stall speed!! If you come in at 55-60 knots over the threshold, you are flying about twice as fast as the stall speed – no wonder the aircraft is difficult to land!
What a drag
There are big differences in drag between aircraft. And drag affects how quickly the aircraft slows down when you throttle back for landing. The more the drag, the quicker the aircraft will slow down and vice-versa. To some extent, high-drag aircraft are easier to land than their more slippery siblings. As you cut power and round out to land, they will slow down more quickly, so if you are a few knots over the correct speed, they will help you out by slowing quickly. However, the more slippery the aircraft, the more accurate you need to be with the threshold speed; this is because if you are faster than you should be, the speed will not wash off quickly and ballooning and floating become much more likely.
As a comparison, our A22LS Foxbat is much much draggier than the A32 Vixxen. This is clearly evidenced in the fuel economy and the extra 20knots at cruise speeds. While the book figures for landing threshold speeds are much the same at 49 knots, coming in at 55 knots in the Foxbat will still allow you a reasonably easy landing. Try it in the Vixxen and because of its low-drag airframe, you’ll probably do a lot more floating. Add yet another 5 knots ‘for safety’ and even the Foxbat will take a while to land and the Vixxen will take you all the way down the runway into the fence at the end.
Landing weight
There’s an important additional piece of information needed here – the landing weight of the aircraft. All manufacturers quote stall speeds at maximum gross weight – for light sport aircraft, this is 600 kgs. If the stall speed is 28 knots at 600 kgs, it will be noticeably slower at (eg) 450 kgs actual weight, which in an A22LS Foxbat equates to the aircraft with one pilot and 50 kgs (70 litres) of fuel. In fact, it could be as much as 3-4 knots slower. Re-calculating the approach speed for this weight: (eg) 25 kts x 1.75 = 44 kts.
Hopefully, instructors  teach their students properly about the difference weight can make to stall – and thus landing – speeds. This is particularly important for light sport aircraft, where the pilot, passengers, fuel and baggage make up a much bigger proportion of the weight and therefore have a much more significant effect on speeds than heavier GA aircraft.

 

 

[Old Koreelah]

2 hours ago, Mike Gearon said:

Bottles, yes, just not drinking enough to justify...

Mike if you don’t want to drink a whole bottle of good wine in one session, just squirt a little CO2 into it from a Soda Stream and cap it tell the next night.

[facthunter]

Then you have  "spritzig" Shiraz. All your friends will be impressed. You can get Carbonated reds. Quickest way  (other than Champagne on a hot  day)to get stoned without noticing till it's too late. Nev

[APenNameAndThatA]

44 minutes ago, Old Koreelah said:

Mike if you don’t want to drink a whole bottle of good wine in one session, just squirt a little CO2 into it from a Soda Stream and cap it tell the next night.

Stops things oxidising because on oxygen? 

[Old Koreelah]

2 hours ago, facthunter said:

Then you have  "spritzig" Shiraz...

That would be nice, but I should have been more specific, Nev.

I squirt the CO2 into the bottle above the wine; as you’d know from your winery days, it should keep overnight.

[facthunter]

Screw top. The best thing for wine since the paper cup near the barby. Keep it on and if it tips over you don't spill any. Keep it in the fridge till a few hours before you want it. The most used preservative is sulphite. Generally bottles and corks were washed in it. Let it breath for a short while.. 

  Spritzig can often happen if the fermentation continues in the bottle. Not oxidation which is becoming vinegar. It's often regarded well with some varietals. Cheers. Less of Better is best. I went to Tahbilk over the Easter weekend  Very old Winery. All info on the  web. Worth a peep

  Life is too short to drink crap wine  drive Landrovers and eat English food. That's an olde one and may have changed. Closes lid on foxhole...Nev

[Blueadventures]

4 hours ago, Mike Gearon said:

Back on topic although I enjoy a meander away as much as the next and Yeah, I don’t get beer or at least not fosters and Carlton and the stuff we grew up with and no better in USA with Budweiser (butwiper) 

 

Discovered craft beers and totally different experience.

 

Was just reviewing the Foxbat website this morning. Reason was annoying floats in the A22 last weekend where I was really trying to keep the speed under 50 knots. 55 knots seems to pretty much guarantees a nice long float...I would like to put it down to the covid vaccine 24 hours prior but not a very good excuse.

 

Here’s a few bits lifted from site. Bold relevant and underline really relevant depending of course on what actually went wrong.

 

Let’s go ballooning
So, what’s wrong with more speed? There are two main reasons but first, remember light sport and recreational aircraft are very low weight (read: low inertia) aircraft. So, like a small car, these types of aircraft will change direction much more quickly than a limo, a ute or a truck. Not that I’m suggesting your average Cessna/Piper etc are trucks…. As a result, when landing, the controls are much more effective than bigger GA aircraft and to much lower airspeeds. At only slightly faster speeds the controls are even more powerful, so if you are too fast when you pull back to flare, the aircraft will not just flare, it will start to climb again, even with the engine at idle. This is called ‘ballooning’. When you go ballooning, the impulse is to push the nose down to reduce the sudden climb. Unless you are very quick (and/or experienced) you’re likely in for a bent nose leg and/or busted propeller. Another alternative, just holding back the controls during the balloon, can result in a stall from an ‘unsuitable’ height above the runway, leading to a (very) heavy landing, which could damage the landing gear or worse.

 

Calculating the correct threshold speed
Which is where we get back to speed. There’s a GA rule of thumb about landing speed over the threshold. This says you should aim for about 1.3 times stall speed in landing configuration. As an example, with a stall speed of 45 knots the aim is (technically) 58.5 knots over the threshold – which is usually rounded to 60 knots. With low-inertia light sport aircraft, which have lower landing speeds, it’s probably safer to go for about 1.75 times stall speed, as wind gusts can be a much higher proportion of approach speed. So, for a stall speed of 27 knots (A32 Vixxen) the threshold speed should be about 47 knots – which is exactly what the pilot manual gives. Note – this is 20 knots ABOVE the stall speed!! If you come in at 55-60 knots over the threshold, you are flying about twice as fast as the stall speed – no wonder the aircraft is difficult to land!
What a drag
There are big differences in drag between aircraft. And drag affects how quickly the aircraft slows down when you throttle back for landing. The more the drag, the quicker the aircraft will slow down and vice-versa. To some extent, high-drag aircraft are easier to land than their more slippery siblings. As you cut power and round out to land, they will slow down more quickly, so if you are a few knots over the correct speed, they will help you out by slowing quickly. However, the more slippery the aircraft, the more accurate you need to be with the threshold speed; this is because if you are faster than you should be, the speed will not wash off quickly and ballooning and floating become much more likely.
As a comparison, our A22LS Foxbat is much much draggier than the A32 Vixxen. This is clearly evidenced in the fuel economy and the extra 20knots at cruise speeds. While the book figures for landing threshold speeds are much the same at 49 knots, coming in at 55 knots in the Foxbat will still allow you a reasonably easy landing. Try it in the Vixxen and because of its low-drag airframe, you’ll probably do a lot more floating. Add yet another 5 knots ‘for safety’ and even the Foxbat will take a while to land and the Vixxen will take you all the way down the runway into the fence at the end.
Landing weight
There’s an important additional piece of information needed here – the landing weight of the aircraft. All manufacturers quote stall speeds at maximum gross weight – for light sport aircraft, this is 600 kgs. If the stall speed is 28 knots at 600 kgs, it will be noticeably slower at (eg) 450 kgs actual weight, which in an A22LS Foxbat equates to the aircraft with one pilot and 50 kgs (70 litres) of fuel. In fact, it could be as much as 3-4 knots slower. Re-calculating the approach speed for this weight: (eg) 25 kts x 1.75 = 44 kts.
Hopefully, instructors  teach their students properly about the difference weight can make to stall – and thus landing – speeds. This is particularly important for light sport aircraft, where the pilot, passengers, fuel and baggage make up a much bigger proportion of the weight and therefore have a much more significant effect on speeds than heavier GA aircraft.

 

 

I was taught if stall occurs, in one of the above examples, at 27 kts then 1.3 times is 35.1 kts. Also taught to apply 1.4 which would be 37.8 kts.  Also anything above extra 10% (35.1  being 38.61 kts) will increase the effect of float ) any slight bump on surface or bounce will see you remaining airbourne. I am not an instructor so that my comments as sharing conversations I have had with some of my direct instructors. Cheers  and P.S. you will enjoy the Nynja you have. I have flown the 22’s and now fly the NY.

[Mike Gearon]

11 hours ago, Blueadventures said:

I was taught if stall occurs, in one of the above examples, at 27 kts then 1.3 times is 35.1 kts. Also taught to apply 1.4 which would be 37.8 kts.  Also anything above extra 10% (35.1  being 38.61 kts) will increase the effect of float ) any slight bump on surface or bounce will see you remaining airbourne. I am not an instructor so that my comments as sharing conversations I have had with some of my direct instructors. Cheers  and P.S. you will enjoy the Nynja you have. I have flown the 22’s and now fly the NY.

Yes, I was just thinking the last few days about the Nynja obviously being more slippery in air than the A22. Not quite as good as the streamlined A32 in the crash. 
 

Speed. Yes, 1.3 or so in the heavier aircraft like Cessna. They are so forgiving. Any wonder they can stay in flight school service for decades without incident. I think my second lesson in Foxbat coming back from USA and 172 I was with one of the invariably nice instructors at Tyabb. Over the numbers with about 20% throttle and say 15 knot headwind and I completely cut the throttle. It surprised me, the instructor and the Foxbat. We all dropped most of the way to the runway and instructor eased some throttle on. Lesson learned! These lightweight aircraft stop penetrating the air in front of them quickly where the Cessna just lumbers on without much fuss.

 

I then learned the same thing in ultralight flying in Philippines. Tried reducing the power at pattern altitude and again on final. Grizzly old local instructor told me that we are all the same. Want to cut the power. These aircraft just won’t fly without it. 4:1 drag so double hit. Drag and light weight.

 

At this stage of my flying I’m mostly expecting the A22 to behave if I’m sneaking under 50 knots with a windscreen held landing spot on runway. The 1.3 or so would be say 35 knots or even lower with just pilot and low fuel. Add safety factor of that 15 knit headwind suddenly dropping away and you’d be at 20 knots quite fast. Not a realistic example of course. Still, a drop from 15 to 10 would be pushing the safety factor. So, the light weight recommendation of 1.7 or in this case approx 47 knots. 
 

That’s my book theory and practical to date. I still float a bit and wave my wings around a bit and occasionally over compensate right rudder when the wheels leave the ground... work in progress 🙂 

 

You have the actual experience. May I ask what airspeed you’re at prior to round out typically in Nynja? 
 

I’m guessing you’re turning final around 50 knots and looking for around the 40. Last year I remember being down to 43 knots on final with a young mainly GA instructor in Foxbat and told to push the nose down. Understood and did so. I do think 45 to 47 knots would result in safer landings in the Foxbats. Only problem of course is the variable of the wind.

 

This is my take home from LSA flying after GA

 

Yes, these light weight aircraft have more fun factor with their lively climb and response! Tick that box!

No, you don’t have to fiddle the controls a lot and try to remove the yaw and roll as they start. I think this was my biggest hurdle. Instructors helped and I started to let the aircraft settle again. Bit like reacting to each wave in a boat. Yes, react but not always and not so much. Maybe starting LSA I’d have had an easier time of it.

Yes, these aircraft both slow quickly and conversely won’t land. 
No, don’t take the throttle out too quickly in windy conditions.

No, the aircraft doesn’t want to land and you’ll just have to be patient. 
No, the aircraft didn’t want to descend on final and you better sort that for next go around. Particularly with a strong crosswind or thermals.

 

Cessna does all this of course. Just so much more gently.

[RossK]

2 hours ago, Mike Gearon said:

....... Add safety factor of that 15 knit headwind suddenly dropping away and you’d be at 20 knots quite fast. Not a realistic example of course. Still, a drop from 15 to 10 would be pushing the safety factor. So, the light weight recommendation of 1.7 or in this case approx 47 knots. 

I've had this exact scenario Mike, so quite a realistic example.

Did a trip out to Horsham, forecast wind on arrival was 15kt Easterly, which on paper looks fine as they have a east/west sealed strip, 1300m long 30m wide.

Actual wind was 10-30kts easterly, confirmed on the BOM observations.

So if you're 50knots in the gust, you're 30 in the lulls

First approach got the plane on the ground nicely and got hit with a gust and was airborne again - 1st go around

2nd attempt - plane got squirrely just above the ground, yawing with the gusts, 2nd go around

3 attempt got it down, not on centreline, not my best landing, but down.

[facthunter]

That type of aeroplane is always going to be affected by winds.  When your stall speed is way down the gust is a big % variation. A common allowance is 1/2 wind and all of the gust so a wind 15 gusting to 25 has a 17 knot allowance approx.. Headwinds diminish near the ground. ALL winds do unless the ground is sealed and has  a very smooth  surface.' You have ground effect also if you don't get too high..This can aid the slow speed situation I found the plane much as described here. Extra speed is going to delay the touchdown and  even when you are "there" a gust can put you in the air again.  I couldn't help wishing for a good set of spoilers like a glider has. Nev

[Mike Gearon]

I was watching YouTube of Ido Segev short land the Foxbat by pulling out flaps. Not something you’d do without a load of experience and definitely not while under instruction. Would have enjoyed meeting Ido.
 

 

Edited April 21, 2021 by Mike Gearon

[facthunter]

It's an option to get more weight on the wheels for braking. Nev

[Blueadventures]

6 hours ago, Mike Gearon said:

Yes, I was just thinking the last few days about the Nynja obviously being more slippery in air than the A22. Not quite as good as the streamlined A32 in the crash. 
 

Speed. Yes, 1.3 or so in the heavier aircraft like Cessna. They are so forgiving. Any wonder they can stay in flight school service for decades without incident. I think my second lesson in Foxbat coming back from USA and 172 I was with one of the invariably nice instructors at Tyabb. Over the numbers with about 20% throttle and say 15 knot headwind and I completely cut the throttle. It surprised me, the instructor and the Foxbat. We all dropped most of the way to the runway and instructor eased some throttle on. Lesson learned! These lightweight aircraft stop penetrating the air in front of them quickly where the Cessna just lumbers on without much fuss.

 

I then learned the same thing in ultralight flying in Philippines. Tried reducing the power at pattern altitude and again on final. Grizzly old local instructor told me that we are all the same. Want to cut the power. These aircraft just won’t fly without it. 4:1 drag so double hit. Drag and light weight.

 

At this stage of my flying I’m mostly expecting the A22 to behave if I’m sneaking under 50 knots with a windscreen held landing spot on runway. The 1.3 or so would be say 35 knots or even lower with just pilot and low fuel. Add safety factor of that 15 knit headwind suddenly dropping away and you’d be at 20 knots quite fast. Not a realistic example of course. Still, a drop from 15 to 10 would be pushing the safety factor. So, the light weight recommendation of 1.7 or in this case approx 47 knots. 
 

That’s my book theory and practical to date. I still float a bit and wave my wings around a bit and occasionally over compensate right rudder when the wheels leave the ground... work in progress 🙂 

 

You have the actual experience. May I ask what airspeed you’re at prior to round out typically in Nynja? 
 

I’m guessing you’re turning final around 50 knots and looking for around the 40. Last year I remember being down to 43 knots on final with a young mainly GA instructor in Foxbat and told to push the nose down. Understood and did so. I do think 45 to 47 knots would result in safer landings in the Foxbats. Only problem of course is the variable of the wind.

 

This is my take home from LSA flying after GA

 

Yes, these light weight aircraft have more fun factor with their lively climb and response! Tick that box!

No, you don’t have to fiddle the controls a lot and try to remove the yaw and roll as they start. I think this was my biggest hurdle. Instructors helped and I started to let the aircraft settle again. Bit like reacting to each wave in a boat. Yes, react but not always and not so much. Maybe starting LSA I’d have had an easier time of it.

Yes, these aircraft both slow quickly and conversely won’t land. 
No, don’t take the throttle out too quickly in windy conditions.

No, the aircraft doesn’t want to land and you’ll just have to be patient. 
No, the aircraft didn’t want to descend on final and you better sort that for next go around. Particularly with a strong crosswind or thermals.

 

Cessna does all this of course. Just so much more gently.

Why was he wanting the nose pushed down, maintain aiming point /or increase speed??  If to maintain aiming point I would have increased rpm to maintain the picture.

 

[Blueadventures]

12 hours ago, Mike Gearon said:

Yes, I was just thinking the last few days about the Nynja obviously being more slippery in air than the A22. Not quite as good as the streamlined A32 in the crash. 
 

Speed. Yes, 1.3 or so in the heavier aircraft like Cessna. They are so forgiving. Any wonder they can stay in flight school service for decades without incident. I think my second lesson in Foxbat coming back from USA and 172 I was with one of the invariably nice instructors at Tyabb. Over the numbers with about 20% throttle and say 15 knot headwind and I completely cut the throttle. It surprised me, the instructor and the Foxbat. We all dropped most of the way to the runway and instructor eased some throttle on. Lesson learned! These lightweight aircraft stop penetrating the air in front of them quickly where the Cessna just lumbers on without much fuss.

 

I then learned the same thing in ultralight flying in Philippines. Tried reducing the power at pattern altitude and again on final. Grizzly old local instructor told me that we are all the same. Want to cut the power. These aircraft just won’t fly without it. 4:1 drag so double hit. Drag and light weight.

 

At this stage of my flying I’m mostly expecting the A22 to behave if I’m sneaking under 50 knots with a windscreen held landing spot on runway. The 1.3 or so would be say 35 knots or even lower with just pilot and low fuel. Add safety factor of that 15 knit headwind suddenly dropping away and you’d be at 20 knots quite fast. Not a realistic example of course. Still, a drop from 15 to 10 would be pushing the safety factor. So, the light weight recommendation of 1.7 or in this case approx 47 knots. 
 

That’s my book theory and practical to date. I still float a bit and wave my wings around a bit and occasionally over compensate right rudder when the wheels leave the ground... work in progress 🙂 

 

You have the actual experience. May I ask what airspeed you’re at prior to round out typically in Nynja? 
 

I’m guessing you’re turning final around 50 knots and looking for around the 40. Last year I remember being down to 43 knots on final with a young mainly GA instructor in Foxbat and told to push the nose down. Understood and did so. I do think 45 to 47 knots would result in safer landings in the Foxbats. Only problem of course is the variable of the wind.

 

This is my take home from LSA flying after GA

 

Yes, these light weight aircraft have more fun factor with their lively climb and response! Tick that box!

No, you don’t have to fiddle the controls a lot and try to remove the yaw and roll as they start. I think this was my biggest hurdle. Instructors helped and I started to let the aircraft settle again. Bit like reacting to each wave in a boat. Yes, react but not always and not so much. Maybe starting LSA I’d have had an easier time of it.

Yes, these aircraft both slow quickly and conversely won’t land. 
No, don’t take the throttle out too quickly in windy conditions.

No, the aircraft doesn’t want to land and you’ll just have to be patient. 
No, the aircraft didn’t want to descend on final and you better sort that for next go around. Particularly with a strong crosswind or thermals.

 

Cessna does all this of course. Just so much more gently.

Mike, a bit of a landing I did recently to check on a few things  is now posted in the Skyranger section 'New Nynja to the area'.  Cheers.