Slips in a short body E or C

[Pilot boy]

About 9 days out from my commercial check ride and I recently discovered how useful forward slips off for the power off 180 in order to hit the 1,000 ft markers.  I have browsed through the the forums and found various estimates....but would like more direct answers.  What is a safe full cross controlled slip speed in a 64 M20E or C short body?

I often come in with no flaps at best glide of about 95 to 100 mph for the maneuver.  This is well above stall speeds in the POH for no flaps for normal bank angles up to 45 degrees so it gives me some margin with the zero flaps.   This is with no slip performed just a normal no flap circular landing for the power off.  So what would be a safe number to use for a fully cross controlled slip with no flaps?  With takeoff flaps?  This is my usually configuration on final for the power off.  Rarely do I use full flaps as the float become more unpredictable it seems though I will use it if I’m way too high.
Today I performed several forward slips around the 90 to 105 mph range with either 15 degree flaps or no flaps and no issues....is 90 a good bottom limit or should I keep it higher? It really helps if I’m coming in too high for the power off when flaps and gear alone won’t save it.  
does anyone have any factory test pilot numbers for what’s a safe margin.  I have the smaller rudder also.

[carusoam]

Speed enough to avoid cross-controlled stalls….

Being crossed controlled is somewhat like hitting the brakes…. Keep the nose down, or you may slow very quickly…

When discussing cross controlled Mooney flying… it may help to know if you have the full long rudder… or the short rudder…

When flying an M20B…you get a short rudder with a short rudder throw….

 

Is there any ASI error noted for slips? Is it different to the left or to the right?

Great question… I haven’t seen a specific answer before…

Also keep in mind… entering and exiting the cross controlled state…  extra points for smoothness are awarded while entering and exiting… no stomping or slipping off the pedals…

PP thoughts only, not a CFI…
 

Best regards,

-A-

[MBDiagMan]

I have never paid much attention to airspeed when slipping because it won’t be correct anyway.  Before my first Mooney I had slipped my Cessna 140 a gazillion times and on my private checkride in it, the DPE yelled “keep that nose down” at the top of his lungs when I was demonstrating a slip.   Any time I slip now I hear his words, so I always keep the nose down.

When Bob Cabe brought my C to me and did my familiarization training, I had flown a good bit with him when I came in high and asked him if I could slip a Mooney.  He said “sure, you can slip this one all you want.  I was on final, so I was probably doing 80 or less, so I just laid it over, kept the nose down and slipped it like it was my little taildragger.   I think that slipping is something you do much more by feel than by instruments.  If you’re properly established on base or final, you will be at a good slip speed.  I usually am slipping on final.  Often I start the slip when I’m turning final and just hold in some bank as I straighten up for final.  Actually after having gotten more Mooney time, I don’t remember coming in high and needing to slip recently.

[DXB]

Forward slip is an awesome tool on final for short bodies with gear down, full flaps, throttle idle.  You can point the nose down hard and burn a ton of altitude without gaining speed - I think I've generally been in the 85-95mph range when using it - that's the speed range the plane seems to settle into, but I haven't given it much thought really. As long as you point the nose down firmly (the whole point of the maneuver), it won't get TOO slow.  I vaguely recall the long bodies have a potential tail stall issue when below 90kts in a forward slip, but not our planes. 

Forward slip without full flaps doesn't make a ton of sense to me...

Edited July 9, 2021 by DXB

[David Lloyd]

Last year doing a flight review, young instructor said pick a place on the runway for a spot landing.  I picked the thousand foot marker and with just a little slip, nailed it.  Then a soft field.  A little slip, bit of power at the last second and greased it on the same spot.  Then he wanted a power off.  From my normal tight pattern, I turned base just past the end of the runway.  Gear, then flaps, still high so I used all the rudder and slipped it to the ground.  Same spot.  The instructor said he never saw anyone on their own use full rudder to slip. Great tool to make the airplane do what you want, where you want.  I was light, 75mph indicated, nose must be down!  If you try to level with full crossed controls, the airspeed will bleed off in the blink of an eye and bad things will happen.

[luv737s]

Slip all the time.  It is a fundamental maneuver taught to ALL private pilot students prior to SOLO.  My C slips just fine at 80 MPH.  If you forgot HOW to do a slip re-read the FAA handbook or go out with a CFI and practice, flight review is a great opportunity.  

Mike

 

[Yourpilotincommand]

10 hours ago, Pilot boy said:

About 9 days out from my commercial check ride and I recently discovered how useful forward slips off for the power off 180 in order to hit the 1,000 ft markers.  I have browsed through the the forums and found various estimates....but would like more direct answers.  What is a safe full cross controlled slip speed in a 64 M20E or C short body?

I often come in with no flaps at best glide of about 95 to 100 mph for the maneuver.  This is well above stall speeds in the POH for no flaps for normal bank angles up to 45 degrees so it gives me some margin with the zero flaps.   This is with no slip performed just a normal no flap circular landing for the power off.  So what would be a safe number to use for a fully cross controlled slip with no flaps?  With takeoff flaps?  This is my usually configuration on final for the power off.  Rarely do I use full flaps as the float become more unpredictable it seems though I will use it if I’m way too high.
Today I performed several forward slips around the 90 to 105 mph range with either 15 degree flaps or no flaps and no issues....is 90 a good bottom limit or should I keep it higher? It really helps if I’m coming in too high for the power off when flaps and gear alone won’t save it.  
does anyone have any factory test pilot numbers for what’s a safe margin.  I have the smaller rudder also.

To nail my pwr off 180s in my 66E, I’d give 2 flap pumps, 2 trim ups abeam the touch down point, pitch for 90mph, drop gear, then slip on short final as needed as I’m usually a little high, maintaining airspeed.. it’s been awhile since my commercial checkride, buts how I think I did it.. I need to go out and practice again. If you think you’re coming up a little short, pull the prop back, but be ready to shove it back in for a go around.

[Shadrach]

15 hours ago, DXB said:

Forward slip is an awesome tool on final for short bodies with gear down, full flaps, throttle idle.  You can point the nose down hard and burn a ton of altitude without gaining speed - I think I've generally been in the 85-95mph range when using it - that's the speed range the plane seems to settle into, but I haven't given it much thought really. As long as you point the nose down firmly (the whole point of the maneuver), it won't get TOO slow.  I vaguely recall the long bodies have a potential tail stall issue when below 90kts in a forward slip, but not our planes. 

Forward slip without full flaps doesn't make a ton of sense to me...

There’s been two occasions where I have used full cross controlled descent without flaps. Both were situations where either ATC or an over confident copilot put us in a situation with a surplus of altitude (>4000ft) and a shortage of distance (<5mls) from the threshold. So, one reason to slip without flaps is when you need to bleed energy immediately. In a descent at 160KIAS, leveling off and waiting for the speed to bleed down to the white arc consumes significant amount of distance and time that could be used to bleed off excess energy. 
 

Edited July 10, 2021 by Shadrach

[Ragsf15e]

2 hours ago, MBDiagMan said:

I have never paid much attention to airspeed when slipping because it won’t be correct anyway.  Before my first Mooney I had slipped my Cessna 140 a gazillion times and on my private checkride in it, the DPE yelled “keep that nose down” at the top of his lungs when I was demonstrating a slip.   Any time I slip now I hear his words, so I always keep the nose down.

When Bob Cabe brought my C to me and did my familiarization training, I had flown a good bit with him when I came in high and asked him if I could slip a Mooney.  He said “sure, you can slip this one all you want.  I was on final, so I was probably doing 80 or less, so I just laid it over, kept the nose down and slipped it like it was my little taildragger.   I think that slipping is something you do much more by feel than by instruments.  If you’re properly established on base or final, you will be at a good slip speed.  I usually am slipping on final.  Often I start the slip when I’m turning final and just hold in some bank as I straighten up for final.  Actually after having gotten more Mooney time, I don’t remember coming in high and needing to slip recently.

It might not be as accurate, but normal airspeed is a reasonable target for slipping.  As others said, nose down and around your typical final airspeed of 80ish mph is good.  Few knots faster is fine, never slower than normal final airspeed.

[Pilot boy]

13 hours ago, carusoam said:

Speed enough to avoid cross-controlled stalls….

Being crossed controlled is somewhat like hitting the brakes…. Keep the nose down, or you may slow very quickly…

When discussing cross controlled Mooney flying… it may help to know if you have the full long rudder… or the short rudder…

When flying an M20B…you get a short rudder with a short rudder throw….

 

Is there any ASI error noted for slips? Is it different to the left or to the right?

Great question… I haven’t seen a specific answer before…

Also keep in mind… entering and exiting the cross controlled state…  extra points for smoothness are awarded while entering and exiting… no stomping or slipping off the pedals…

PP thoughts only, not a CFI…
 

Best regards,

-A-

Short rudder.  It’s at the end of the original post I called it the small rudder!  The one that begins above the tail nose one.  Not much rudder power for me.

[Pilot boy]

4 hours ago, DXB said:

Forward slip is an awesome tool on final for short bodies with gear down, full flaps, throttle idle.  You can point the nose down hard and burn a ton of altitude without gaining speed - I think I've generally been in the 85-95mph range when using it - that's the speed range the plane seems to settle into, but I haven't given it much thought really. As long as you point the nose down firmly (the whole point of the maneuver), it won't get TOO slow.  I vaguely recall the long bodies have a potential tail stall issue when below 90kts in a forward slip, but not our planes. 

Forward slip without full flaps doesn't make a ton of sense to me...

Yeah I guess I just like the combo of half flaps and a slip when I’m a little too high....and then more for the controllability of the flare and preventing float.  Full flaps seems to give me too much float and makes the precision landing a bit trickier for commercial ACS.  
I sometimes do full flaps and slip if I’m really high though as well.  Then take some flaps out once in ground effect lol.  This causes me to drop when I need to.  
The hydraulic flaps are fun to play with in ground effect.  I’ve found if I come in too short w like zero or 2 pumps of flaps....adding full flaps really helps to extend the float in ground effect even though you get some drag.  You still get a couple hundred feet more float by not stalling until Vso at 57 mph.

[Pilot boy]

4 hours ago, David Lloyd said:

Last year doing a flight review, young instructor said pick a place on the runway for a spot landing.  I picked the thousand foot marker and with just a little slip, nailed it.  Then a soft field.  A little slip, bit of power at the last second and greased it on the same spot.  Then he wanted a power off.  From my normal tight pattern, I turned base just past the end of the runway.  Gear, then flaps, still high so I used all the rudder and slipped it to the ground.  Same spot.  The instructor said he never saw anyone on their own use full rudder to slip. Great tool to make the airplane do what you want, where you want.  I was light, 75mph indicated, nose must be down!  If you try to level with full crossed controls, the airspeed will bleed off in the blink of an eye and bad things will happen.

That’s impressive slow for the slip.  I don’t know if I’d want to do 75 there!  

[Pilot boy]

13 hours ago, Yourpilotincommand said:

To nail my pwr off 180s in my 66E, I’d give 2 flap pumps, 2 trim ups abeam the touch down point, pitch for 90mph, drop gear, then slip on short final as needed as I’m usually a little high, maintaining airspeed.. it’s been awhile since my commercial checkride, buts how I think I did it.. I need to go out and practice again. If you think you’re coming up a little short, pull the prop back, but be ready to shove it back in for a go around.

I found if you need more float, I add 2.5 more pumps (full flaps) and you’ll float another 100 to 200 ft and make the mark... but only once you are in ground effect should you go full flaps...as the drag action of full flaps is reduced in the ground effect.  I just figured this out the other day when I was practicing, it saved one of my power offs and kept me in ACS boundaries.

[Pilot boy]

14 hours ago, luv737s said:

Slip all the time.  It is a fundamental maneuver taught to ALL private pilot students prior to SOLO.  My C slips just fine at 80 MPH.  If you forgot HOW to do a slip re-read the FAA handbook or go out with a CFI and practice, flight review is a great opportunity.  

Mike

 

Yep, I am working on commercial so I have done many slips in a Cessna but I wanted direct Mooney info for the short bodies so I don’t have troubles.  I had read some models have major issues with slips but this mostly seems to apply to the newer models not the old shirt bodies.  

[carusoam]

Long bodies, full flaps, and full slips…

Have been replaced by speed brakes….

The airflow over the tail has been known to get eclipsed by the flaps in a slip…

Tail stalls near the ground are a set up for lawndarting…

Nobody likes lawn darts anymore…

 

So…

If not sure if you are flying a Long Body…. Look for the speed brakes…

If your ship has speed brakes… it may not be a long body… 

But, with speed brakes deployed, you probably don’t need a slip either…

 

Nothing more powerful than turning the plane sideways to the apparent wind…

Remember maneuvering speeds and its limitations while planning this stuff out… as you may be considering full deflection of the flight control surfaces… 

 

PP thoughts only, not a cfi…

Best regards,

-a-

[DXB]

On 7/9/2021 at 9:45 AM, Shadrach said:

There’s been two occasions where I have used full cross controlled descent without flaps. Both were situations where either ATC or an over confident copilot put us in a situation with a surplus of altitude (>4000ft) and a shortage of distance (<5mls) from the threshold. So, one reason to slip without flaps is when you need to bleed energy immediately. In a descent at 160KIAS, leveling off and waiting for the speed to bleed down to the white arc consumes significant amount of distance and time that could be used to bleed off excess energy. 
 

Is a forward slip safe above maneuvering speed? 160kias seems rather fast to use full rudder deflection.

[Shadrach]

3 hours ago, DXB said:

Is a forward slip safe above maneuvering speed? 160kias seems rather fast to use full rudder deflection.

Well I was not suggesting a rapid full deflection cross control slip while descending in the yellow. In fact, I don’t think the plane would sustain that kind of speed in a slip unless you were at or above cruise power. I was merely suggesting that waiting for the white arc could eat up miles that could be other wise used to scrub energy. You make a good point and one worth exploring.  Maneuvering speed is based on weight so that the aircraft stalls before hitting designed load limits, but by definition it limits “full” deflection of control surfaces above maneuvering speed. So I would say that by definition, that full deflection above maneuvering speed is contrary to the definition. On the other hand, a properly entered slip is a gentle maneuver, no need for abrupt movements or stress.  So the question is what is the max speed appropriate for conducting full forward slips? I don’t know. Maybe that’s maneuvering speed (130MCAS in my plane) or below.  I would suggest that power off slips are not likely to be much above 130 because of the drag. This is another one to explore in the air.

[luv737s]

If you are slipping any plane at maneuvering speed or above, you are really screwing up and you need to plan better.  And don't tell me "ATC screwed me", you can ask for maneuvering vectors to help get you down or go missed!  The original thread was about slipping on final not flying a 133 MPH final and trying to slip to lose some altitude. If you are fast and high on final...go around and fix your pattern.   I am also envious of my Mooney brothers with speed brakes.  I am training a Columbia 400 pilot and he is figuring out how the speed brakes can be used, wish my C had them!!  Every Boeing pilot out there knows the value of speed brakes cause you don't slip jets!!

Mike

[carusoam]

Mike,

I equally got caught up in the frenzy… of thread creep….

 

But this time I stopped writing…   

Best regards,

-a-

 

The unfinished ideas I couldn’t work into the conversation…   

 

Oddly enough…

We started out discussing dissipating energy, rapidly.

Landing gear needs to be extended to do so…

 

Speed brakes can be deployed at Vne…. To get down to Vlo…

 

If a real emergency…

Pulling MP, and pushing the prop control in… maximizes engine braking…

[EricJ]

6 minutes ago, luv737s said:

Every Boeing pilot out there knows the value of speed brakes cause you don't slip jets!!

Mike

Carlos Dardano did. 

[MBDiagMan]

On 7/9/2021 at 10:51 PM, carusoam said:

Long bodies, full flaps, and full slips…

Have been replaced by speed brakes….

The airflow over the tail has been known to get eclipsed by the flaps in a slip…

Tail stalls near the ground are a set up for lawndarting…

Nobody likes lawn darts anymore…

 

So…

If not sure if you are flying a Long Body…. Look for the speed brakes…

If your ship has speed brakes… it may not be a long body… 

But, with speed brakes deployed, you probably don’t need a slip either…

 

Nothing more powerful than turning the plane sideways to the apparent wind…

Remember maneuvering speeds and its limitations while planning this stuff out… as you may be considering full deflection of the flight control surfaces… 

 

PP thoughts only, not a cfi…

Best regards,

-a-

Yes, I would have never spent money to add speed brakes UNTIL I bought a plane with them already installed.  They add so many different tools to the box that I don’t know how I got along without them.  I slipped my F when I first got it, but once I started using the speed brakes for different things, I dont remember the last time I slipped it.

[MBDiagMan]

On 7/9/2021 at 10:51 PM, carusoam said:

Long bodies, full flaps, and full slips…

Have been replaced by speed brakes….

The airflow over the tail has been known to get eclipsed by the flaps in a slip…

Tail stalls near the ground are a set up for lawndarting…

Nobody likes lawn darts anymore…

 

So…

If not sure if you are flying a Long Body…. Look for the speed brakes…

If your ship has speed brakes… it may not be a long body… 

But, with speed brakes deployed, you probably don’t need a slip either…

 

Nothing more powerful than turning the plane sideways to the apparent wind…

Remember maneuvering speeds and its limitations while planning this stuff out… as you may be considering full deflection of the flight control surfaces… 

 

PP thoughts only, not a cfi…

Best regards,

-a-

Yes, I would have never spent money to add speed brakes UNTIL I bought a plane with them already installed.  They add so many different tools to the box that I don’t know how I got along without them.

[M20F]

While you can stall at any attitude and speed, you aren’t going to stall in a forward slip with the nose down. 
 

Slip into the fuller tank, if you slip into a fairly empty tank you are probably going to lose the  motor.  Boost pump plus letting off the slip brings it right back.