Crosswind component

[benpilot]

 

Crosswinds are fun! I had two days in a row training in 15-20knot cross winds, in a C172, wee! Still as a student pilot good experience.

[bd32322]

 

Crosswinds are fun! I had two days in a row training in 15-20knot cross winds, in a C172, wee! Still as a student pilot good experience.

Thats a pretty hefty crosswind .. Was it the actual crosswind component 90 degrees off the runway heading?

Personally I preferred th 152 over the 172. I thought the 152 was much more nimble.

[FlyingAggie]

This afternoon I did my first IPC and it was a little windy at BJC:

 

KBJC 160245Z 24017G23KT 30SM FEW080 BKN150 BKN200 18/M10 A2992
KBJC 160148Z 24019G26KT 30SM FEW080 BKN150 BKN200 18/M11 A2992
KBJC 160045Z 23009G14KT 50SM FEW080 BKN150 BKN200 19/M11 A2991
KBJC 152345Z 27015G21KT 50SM SCT080 BKN150 BKN200 20/M11 A2991
KBJC 152247Z 26020G26KT 60SM SCT080 BKN140 OVC220 22/M12 A2991
KBJC 152158Z 26020G30KT 50SM SCT080 SCT120 BKN200 23/M13 A2991
KBJC 152048Z 25020G26KT 50SM SCT080 SCT120 BKN200 25/M14 A2992
KBJC 151945Z 00000KT 50SM FEW080 SCT120 BKN200 22/M13 A2994
 

 

In fact a Navion had an incident on landing on Rwy 29R and the airport was shut down for awhile.  Fortunately all four occupants walked away.  

 

 http://www.thedenverchannel.com/news/local-news/4-walk-away-from-small-plane-crash-at-rocky-mountain-airport

 

My instructor and I had been playing "20 questions"  and were unaware of the accident until we taxied out.   The tower opened up Rwy 29L just in time for our departure.  This was my first IPC and was probably the roughest conditions in which I have attempted to fly instruments.  We discussed rescheduling, but decided to go ahead to see how I would perform in challenging conditions.  There were 500 FPM updrafts/downdrafts, which made holding altitude challenging and we were knocked around quiet a bit by mod turb.   I had done a few approaches in the simulator last week with my instructor and needed to finish the IPC in the airplane with recovery from unusual attitudes, a circle to land and some partial panel work.  My instructor had no problems setting up the unusual attitudes---all she had to do was let mother nature take control of the plane and tell me to look up!   We flew up to KFNL and flew an approach there with a CTL.   On our return to BJC, I flew the 29R ILS approach with a partial panel, but 29R was still shut down so the Tower had us sidestep to 29L.  The tower reported the winds as 24020G30 at the time we were landing.  At about the same time we "broke out" and I lifted the foggles, we hit major downdraft (BJC is located on top of a plateau so sink off the end of the runway is to be expected with any wind.)   I over applied power to counter the sink and wound up being too high and fast, so elected to go around. I flew a conventional traffic pattern and chose to land with flaps up and added 1/2 the gust speed to my approach speed.  I was ready for the sink the second time and powered through it coming out of it on glideslope and at 80 knots. I love the way the Mooney handles crosswinds and received kudo's from my instructor for my landing.

 

By the time, we debriefed the IPC and put the plane away, they had moved the Navion to a hangar near mine.  I drove by and took the attached picture.  It appears both wings were severely bent and the prop, but so glad no one was hurt.  High crosswinds are not something to be taken lightly.

 

Alan Higgins,

N262MB, M20K w/Trophy 262 Conversion

KBJC

[DaV8or]

This afternoon I did my first IPC and it was a little windy at BJC:

 

KBJC 160245Z 24017G23KT 30SM FEW080 BKN150 BKN200 18/M10 A2992

KBJC 160148Z 24019G26KT 30SM FEW080 BKN150 BKN200 18/M11 A2992

KBJC 160045Z 23009G14KT 50SM FEW080 BKN150 BKN200 19/M11 A2991

KBJC 152345Z 27015G21KT 50SM SCT080 BKN150 BKN200 20/M11 A2991

KBJC 152247Z 26020G26KT 60SM SCT080 BKN140 OVC220 22/M12 A2991

KBJC 152158Z 26020G30KT 50SM SCT080 SCT120 BKN200 23/M13 A2991

KBJC 152048Z 25020G26KT 50SM SCT080 SCT120 BKN200 25/M14 A2992

KBJC 151945Z 00000KT 50SM FEW080 SCT120 BKN200 22/M13 A2994

 

 

In fact a Navion had an incident on landing on Rwy 29R and the airport was shut down for awhile.  Fortunately all four occupants walked away.  

 

 http://www.thedenverchannel.com/news/local-news/4-walk-away-from-small-plane-crash-at-rocky-mountain-airport

 

My instructor and I had been playing "20 questions"  and were unaware of the accident until we taxied out.   The tower opened up Rwy 29L just in time for our departure.  This was my first IPC and was probably the roughest conditions in which I have attempted to fly instruments.  We discussed rescheduling, but decided to go ahead to see how I would perform in challenging conditions.  There were 500 FPM updrafts/downdrafts, which made holding altitude challenging and we were knocked around quiet a bit by mod turb.   I had done a few approaches in the simulator last week with my instructor and needed to finish the IPC in the airplane with recovery from unusual attitudes, a circle to land and some partial panel work.  My instructor had no problems setting up the unusual attitudes---all she had to do was let mother nature take control of the plane and tell me to look up!   We flew up to KFNL and flew an approach there with a CTL.   On our return to BJC, I flew the 29R ILS approach with a partial panel, but 29R was still shut down so the Tower had us sidestep to 29L.  The tower reported the winds as 24020G30 at the time we were landing.  At about the same time we "broke out" and I lifted the foggles, we hit major downdraft (BJC is located on top of a plateau so sink off the end of the runway is to be expected with any wind.)   I over applied power to counter the sink and wound up being too high and fast, so elected to go around. I flew a conventional traffic pattern and chose to land with flaps up and added 1/2 the gust speed to my approach speed.  I was ready for the sink the second time and powered through it coming out of it on glideslope and at 80 knots. I love the way the Mooney handles crosswinds and received kudo's from my instructor for my landing.

 

By the time, we debriefed the IPC and put the plane away, they had moved the Navion to a hangar near mine.  I drove by and took the attached picture.  It appears both wings were severely bent and the prop, but so glad no one was hurt.  High crosswinds are not something to be taken lightly.

 

Alan Higgins,

N262MB, M20K w/Trophy 262 Conversion

KBJC

 

That bent Navion reminds me of why I don't challenge strong crosswinds myself and why I love my home field's crosswind runway. My airport only has two runways, but the army way back in the day really had it right when they used to build airports with three runways in a triangle.

[Hondo]

N6719N

 

"Rules and recommendations are usually there for a pretty good reason.  If you land in a crosswind situation where the crosswind component is high enough (or that side gust comes at the wrong time), you will run out of rudder, and there will be no way to keep the airplane straight down the runway and prevent side loads and potentially damaging stresses to your aircraft, regardless of how much skill you possess."

 

My instructor always wanted full flap landings.  Then I tried to land on a very gusty day and realized I might not have enough rudder.  I decided to go around, but the density altitude was over 7000 and I was down to less than 65 knots and low.  For a go around, my POH says full power till 65 knots, then after climb established, retract flaps, raise gear and open cowl flaps.  The drag was very high and for awhile I doubted I could arrest the descent and get back to 65.  After that experience, I wondered if there might be a better way.  I checked the drag in different configurations starting at 110 KIAS in level flight.  I found that gear down reduced speed by 22 knots, half flaps by 5 knots, 3/4 flaps by 15 knots and full flaps by 35 knots.  With approach speed at 1.3Vso + half gust speed,  I use 3/4 flaps up to about 20 knots, any higher than that - no flaps.  Still use full flaps for short fields and low crosswinds.

 

What do you recommend? 

[bd32322]

N6719N

 

"Rules and recommendations are usually there for a pretty good reason.  If you land in a crosswind situation where the crosswind component is high enough (or that side gust comes at the wrong time), you will run out of rudder, and there will be no way to keep the airplane straight down the runway and prevent side loads and potentially damaging stresses to your aircraft, regardless of how much skill you possess."

 

My instructor always wanted full flap landings.  Then I tried to land on a very gusty day and realized I might not have enough rudder.  I decided to go around, but the density altitude was over 7000 and I was down to less than 65 knots and low.  For a go around, my POH says full power till 65 knots, then after climb established, retract flaps, raise gear and open cowl flaps.  The drag was very high and for awhile I doubted I could arrest the descent and get back to 65.  After that experience, I wondered if there might be a better way.  I checked the drag in different configurations starting at 110 KIAS in level flight.  I found that gear down reduced speed by 22 knots, half flaps by 5 knots, 3/4 flaps by 15 knots and full flaps by 35 knots.  With approach speed at 1.3Vso + half gust speed,  I use 3/4 flaps up to about 20 knots, any higher than that - no flaps.  Still use full flaps for short fields and low crosswinds.

 

What do you recommend? 

Why did you use 110 knots to do your experiment?

You should repeat your drag experiments at a lower approach speed, say 80 knots.

When you are low and slow, drag is coming from induced drag (from lift) and not parasitic drag (from airflow obstructions). So partial flaps or no flaps wont help much in terms of getting energy back into the plane and doing a go around.

People use partial flaps on windy days for other reasons. I used to do that in the cessna 152s but havent had to in the mooney

[midlifeflyer]

I remember some advice that Don Kaye once gave another Mooney bulletin board group (or it was perhaps on the MAPA site) and I have put it into my approach checklist.

 

______________________________________MPH_____KTS

Over Threshold (1.3 x VSO)                                   75            65

            Add 5 mph for each 10kt X-wind

            Subtract 5 mph for each 300 lb under MTOW

 

I normally approach full flaps with no crosswind. I normally use T/O flaps (2 pumps = 10 degrees) up to 10 knots crosswind component and I do not use flaps on any approach with more than 10 knots crosswind component.

Definitely for gusts, but all adding airspeed does for a steady state crosswind is increase your touchdown speed. And, so far anyway, I haven't heard of a crosswind landing accident where the loss of control took place in the air; they all seem to take place after touchdown. Why would you want to be going faster at the point where the accident happens?

 

I used to follow the no-flaps and higher airspeed mantra. Then during my CFI training, my instructor made me do a full flap short field landing in  172 in a 20-kt direct crosswind. No excess speed allowed. It was a non-event. 

[Hondo]

Why did you use 110 knots to do your experiment?

You should repeat your drag experiments at a lower approach speed, say 80 knots.

When you are low and slow, drag is coming from induced drag (from lift) and not parasitic drag (from airflow obstructions). So partial flaps or no flaps wont help much in terms of getting energy back into the plane and doing a go around.

People use partial flaps on windy days for other reasons. I used to do that in the cessna 152s but havent had to in the mooney

 

I used 110 to get a feel for the relative drag of configuration changes without making power changes.

Full flaps dropped 35 knots, while 3/4 only dropped 15 with about a 1 knot increase in stall speed.

No flaps increases the stall speed by 8 knots and increases rudder effectiveness.

 

Since induced drag predominates at approach speeds, I'll try a similar test at 80, but will have to add power to stay above stall speed.

At 2700 each 1% power increase requires about .3" MP.  Also, max available power drops from 100 at SL to 70% at 10,000, so excess drag can be a problem at high density altitudes.

 

Just want to know what to expect without breaking something trying to find the limits.

[Hondo]

http://flighttraining.aopa.org/magazine/2006/April/200604_Features_Crosswind_tutorial.html

 

A minor addition, if it is gusty and you use flaps, raising the flaps on rollout when all the wheels are on the ground,

would make it safer to use the brakes if you had to.