Power off 180 w/crosswind

[gprellwitz]

I had some difficulty doing a power off 180 yesterday. The winds were 16G26 direct crosswind, and I was turning base into the wind. The aircraft was a Beech Sierra, which was about a Beech Sundowner, since the maneuver is started with gear down. I turned directly towards the ruwnway (3300'), and still felt I needed to add a bit of power at the last moment in order to stabilize final prior to touchdown. I was turning base to final less than 100' AGL. With the Johnson bar flaps, I had my hand on them as I was turning base, because my head ducks below the glareshield when I reach for them. This meant that there were about 5* flaps in from abeam the touchdown point.

Other than being closer in, what can I do to improve my performance? I think that I *probably* could have made it without adding power, but I don't like that word. (And, for the record, the *demonstrated* crosswind component is about 19Kt.)

 

[brcase]

I havn't done power off 180's in a Sierra, but have in a lot of other planes including a Cherokee six. If you feel like you need to add power you probably need to increase your approach speed a bit so you have the energy required to flare. I would also recommend only adding flaps as required to adjust your approach if required. 1 notch is probably good as a minimum but zero is ok. My opinion, I am sure others will disagree.

Brian
CFIIG/ASEL

 

[RyanShort1]

Some of the glider guys I fly with also say that best glide into the wind may NOT give you the best range / distance...

Ryan

 

[tonycondon]

in low performance gliders like Beech Sierra's and Schweizer 2-33's the general rule of thumb is to add half the wind speed to the published best L/D in order to ~maximize your your glide angle wrt the ground

 

[Dan Thomas]

Other than being closer in, what can I do to improve my performance? I think that I *probably* could have made it without adding power, but I don't like that word. (And, for the record, the *demonstrated* crosswind component is about 19Kt.)

Increase your glide speed. As an extreme example, if you were gliding at 70 kt into a 70 kt wind, you would glide straight down. If you glided at 80 you'd make 10 kt across the ground. You will have less time before reaching the surface but a better chance of reaching the target.

A 19 kt crosswind is measured at or close to the surface. The wind aloft is usually considerably stronger and takes a bigger chunk out of your gliding-into-wind range.

Dan

 

[bbchien]

Grant, if you have control over it, do the opposite pattern for the throttle pull (base tailwind).

OR

Increase your airspeed 1 knot for each 2 knots of headwind (on base) that you headwind exceeds 25% of your IAS. (Melville Byington, ERAU)

OR

Be heavier. The best glide airspeed isn't quite the same, but the progress (sink rate) is higher, and you have less time exposed to the headwind.

OR

Go to full coarse on the prop. This takes cohones in practice, because full power won't be instantly available......

OR

Screw the gear down stuff. Suck 'em up until the turn to final. Takes concentration and cahones, but in a real situation that's exactly what you'd do.

The last two are the preferred methods.

 

[jesse]

Don't complicate things, just fly the downwind closer, you have 1,000 AGL to sort this out and there really isn't a crosswind out there that makes this impossible in the Sierra. You're just too wide.

As far as needing power to flare - you either don't need it and you're doing it for no reason or you're way too slow.

 

[rottydaddy]

Some of the glider guys I fly with also say that best glide into the wind may NOT give you the best range / distance...

Ryan

This is true of any aircraft.... if you have the right speed to get the best glide ratio (most distance gained for every foot of altitude lost), gliding into wind shortens the distance because the whole triangle, so to speak, is drifting backwards. The plane will cover the same horizontal distance in the air, but not over the ground.

Obviously, if you fly faster than vbg, you will lose even more distance. Vbg is the magic number for most distance per vertical foot.... faster or slower than that, and you will gain less distance .So how does flying faster help? The fact is, it doesnt really. Its a common mistake to think that speeding up will get you to your goal before you run out of altitude.... but this is as much a mistake as trying to stretch a glide by slowing below vbg. Faster than vbg means higher descent rate. slower than vbg means less ground covered during the descent. ONLY vbg yields the most distance per foot of altitude.
Flying faster than vbg will only help if you begin the glide closer to begin with.
For example... your example. Rather than fly downwind closer to the runway, start your 180 even closer to where you want to touch down. This way, you can afford to fly a bit faster than vbg while pointed right into the wind, without finding yourself too low and far out as you line up with the runway.
Ask any glider pilot which matters more in the pattern....numbers or angles?

 

[gprellwitz]

Don't complicate things, just fly the downwind closer, you have 1,000 AGL to sort this out and there really isn't a crosswind out there that makes this impossible in the Sierra. You're just too wide.

As far as needing power to flare - you either don't need it and you're doing it for no reason or you're way too slow.

The pattern altitude is published as 800'. I added power to give myself more time to stabilize on final and adjust for the crosswind, not to flare. I didn't mention that the plane ahead of me made a call to me specifically warning of the "wicked crosswinds!". . I think that probably affected my decision making too. In retrospect, I think I also turned too directly to the end of the runway, so I was lower than I felt comfortable with turning base to final. I needed to shorten final, but not as much as I did. Plus, I may have let the speed get a little lower than I should have. Best glide is 91kts, and it calls for 74 on final (with full flaps). Drop both of those a couple of knots because I was a couple hundred pounds under gross.

 

[dmccormack]

In Beech airplanes I keep it in tight and slip aggressively (full rudder deflection and fairly slow) to lose any "extra" altitude.

Actually, I do that in every airplane.

 

[bbchien]

Jesse's right. Keep it simple.

I was going to launch into a discussion of "is your IAS Vy correct for your real weight.....?" but that's not super useful.

 

[Morne]

In Beech airplanes I keep it in tight and slip aggressively (full rudder deflection and fairly slow) to lose any "extra" altitude.

Actually, I do that in every airplane.

That. If you have a real power-off landing to make, your best bet is to err a little on the high side and slip like crazy to shed altitude.

Disclaimer - I have zero time in low wings.

 

[RyanShort1]

That. If you have a real power-off landing to make, your best bet is to err a little on the high side and slip like crazy to shed altitude.

Disclaimer - I have zero time in low wings.

High wing, low wing, same difference.

Ryan