Slips

[Horis]

Anyone have experience using slips to landing?

[eman1200]

yep.

[N201MKTurbo]

In my old M20F I did them all the time. Now I have speed brakes, so I use them.

On my instrument check ride in ‘85, I forgot about a crossing altitude. The examiner asked “what altitude were you supposed cross XXX at”? I was about a mile from it and 1000 feet high. While under the hood, I pulled the power to idle and shoved the rudder to the floor. I crossed with the needle centered and about 50 feet high. He said “ well OK, that meets the requirement” and then “I can’t believe you did that”.

[0TreeLemur]

Different models have different limitations.   You should fill in your profile so we know which Mooney model you fly.

[Shadrach]

23 minutes ago, 0TreeLemur said:

Different models have different limitations.   You should fill in your profile so we know which Mooney model you fly.

I’ve heard this before but I’ve never seen the limitation. Which model has this limitation? I went through the limitations sections of several POHs. I saw references to unporting tanks with less than 8 gallons as well as a warning for fuel vapor in the cabin at extreme sight slips. Couldn’t find a limit on slips anywhere. 

[carusoam]

Kind of a loaded question… 

Without mentioning what airframe we are discussing….

The answer is… It depends….

Slips are part of aviation 101’s tool box for energy control…

If you approach the runway either high or fast…. The slip typically gets used to remove excess energy before getting to the ground….

Since this is a cross controlled maneuver… and we are discussing being near the ground… it helps to be familiar with the safety issues that go with the maneuver…

 

Or… are we discussing maintaining the runway centerline with a X-wind…?  This is where we discuss the Crab and Kick techniques… where people crab all the way to the runway… and go into a slip for the final landing phase… thus keeping the aircraft aligned with centerline when the wheels touch down…

 

The most important part of this question… when you fly a LongBody… a slip, with full flaps, can have an aerodynamic anomaly….  The combination of full flaps and X-controls can blanket / eclipse the tail feathers with turbulent air… causing a tail stall…

The results of the tail stall at low altitudes went out of popularity with the game lawn darts…

 

Sooooo….

All LBs received speed brakes as a result….

The use of speed brakes easily removes the excess energy of being high and fast without any of the side effects of being cross controlled…

 

+1, -1 for slips…. Use them properly… always enter and leave the slip with finesse… no need to stomp on the rudder pedals… or let your feet slip off the rudder pedals…. Keep the nose down…

 

PP thoughts only, not a CFI…

Best regards,

-a-

[Ned Gravel]

1 hour ago, Horis said:

Anyone have experience using slips to landing?

Yup.  Simple, easy and safe way way to lose altitude when VFR to enter the pattern without gaining the speed that can create havoc with other aircraft in the pattern.  Sometimes a forward slip on final to stay lined up on the centreline.

I fly a short body - so no longbody issues.

[Shadrach]

9 minutes ago, carusoam said:

Kind of a loaded question… 

Without mentioning what airframe we are discussing….

The answer is… It depends….

Slips are part of aviation 101’s tool box for energy control…

If you approach the runway either high or fast…. The slip typically gets used to remove excess energy before getting to the ground….

Since this is a cross controlled maneuver… and we are discussing being near the ground… it helps to be familiar with the safety issues that go with the maneuver…

 

Or… are we discussing maintaining the runway centerline with a X-wind…?  This is where we discuss the Crab and Kick techniques… where people crab all the way to the runway… and go into a slip for the final landing phase… thus keeping the aircraft aligned with centerline when the wheels touch down…

 

The most important part of this question… when you fly a LongBody… a slip, with full flaps, can have an aerodynamic anomaly….  The combination of full flaps and X-controls can blanket / eclipse the tail feathers with turbulent air… causing a tail stall…

The results of the tail stall at low altitudes went out of popularity with the game lawn darts…

 

Sooooo….

All LBs received speed brakes as a result….

The use of speed brakes easily removes the excess energy of being high and fast without any of the side effects of being cross controlled…

 

+1, -1 for slips…. Use them properly… always enter and leave the slip with finesse… no need to stomp on the rudder pedals… or let your feet slip off the rudder pedals…. Keep the nose down…

 

PP thoughts only, not a CFI…

Best regards,

-a-

Could not find a thing in the M20TN POH from 2006 about slips but maybe I missed it. Does you Ovation have a limitation? 
 

I make no judgement on whether a pilot uses them or not. I’ve read Bob K’s (or was it Bill W) comments on them. I’m just trying to determine if an actual limitation exists or if it is a Mooney proverb.

[steingar]

I think the long body Mooneys have an honest to gosh limitation in slips, read it here somewhere.

[carusoam]

4 minutes ago, Shadrach said:

Could not find a thing in the M20TN POH from 2006 about slips but maybe I missed it. Does you Ovation have a limitation? 
 

I make no judgement on whether a pilot uses them or not. I’ve read Bob K’s (or was it Bill W) comments on them. I’m just trying to determine if an actual limitation exists or if it is a Mooney proverb.

There was an accident during flight testing along the way…. Leading to the loss of a factory test pilot…

Good question… I can’t immediately point to where this comes from…

Transition Training covers the use of Speed Brakes pretty deeply…

When discussed around here…. Some people with more sensitive seats of the pants than I… say that you can feel what is happening… when tested at a safe altitude….

Old and Fuzzy memories only…

Best regards,

-a-

[A64Pilot]

J model slips just fine.

But I know people who slip Fowler flapped Cessna’s with flaps down too, and they shouldn’t so a prohibition in the POH is not a guarantee, but a possibility.

If there is a Prohibition, don’t.

So far as feel I wouldn’t count on it, you may get some buffet, a Cessna it’s my understanding is the only warning you get is when there is nothing but ground in the windshield, I never slipped one, much less had the tail stall so I don’t know. On a Cessna it’s more of an airflow blanking, and the loss of airspeed is why the tail stalls.

Having Certified a few aircraft myself, I can’t imagine any accident during Certification not being put under the magnifying glass, a fatality even moreso.

‘When I was Certifying the S2R-H80, coincidentally Gulfstream was Certifying their G-650, they had a fatality in testing, from over aggressive maneuvers to Certify the aircraft for a shorter field than maybe it should, that ripped through ATL ACO, people I believe were reassigned and the whole Cert program put under the microscope, I think Congressmen got into trouble and all kinds of shakeups.

So long story short I find it incredible if any model Mooney can be tail stalled in a slip without a prohibition in the POH, and secondly if there was an accident much less a fatality and no prohibition.

There would be absolutely no reason for Mooney to not prohibit the maneuver, it wouldn’t hurt sales, the whole Cessna single engine fleet (almost) is prohibited and it’s not hurt sales.

[carusoam]

More on the subject…

 

Ross,

Oddly, I have written a review (for this subject) from an LB POH… quite a while back…. 
February, 2010… right around the time I got the O….

Funny… my writing style hasn’t changed very much…

“

I used sideslips for my M20C often.  Always making sure nose is down and airspeed maintained.  Entering and exiting the slip smoothly / gently.  There is no desire to let the tail wag by over or undercontrolling.

 

PK, I have been reviewing the POH for the M20R (longbody)

 

Slips are mentioned 3 times:

 

cross wind landing, door closing in flight, fuel gauge accuracy only during coordinated flight.

 

It is a normal category airplane, so slips are acceptable (with normal precautions to avoid stall / spin).

 

Otherwise, speed brakes are used for additional speed control.

 

Directly to answer the question: The POH (Section IV - Landing) recommends crab until flare, touch down with slight wing low side slip.  (Caution: YOUR POH may vary)

 

The C and the R seem to be at maximum up trim during the landing phase (with two people on board).

-a-  “

[EricJ]

2 hours ago, Horis said:

Anyone have experience using slips to landing?

This comes up here once in a while and lots of people do them.   I've done some very aggressive slips in my J, and I don't hesitate to do it if need be.   It's an effective technique.

[natdm]

https://img1.wsimg.com/blobby/go/fd03665a-9127-4f79-a429-ee3607a81548/downloads/Bob Krommer on Mooney Slips-Part 1.pdf?ver=1619678278351

 

Good short read about slips in certain Mooney's.

[Shadrach]

1 hour ago, carusoam said:

There was an accident during flight testing along the way…. Leading to the loss of a factory test pilot…

Good question… I can’t immediately point to where this comes from…

Transition Training covers the use of Speed Brakes pretty deeply…

When discussed around here…. Some people with more sensitive seats of the pants than I… say that you can feel what is happening… when tested at a safe altitude….

Old and Fuzzy memories only…

Best regards,

-a-

I've searched for "Mooney Test pilot accident" looking for news and articles. I searched the NTSB data base (the new CAROL system leaves a lot to be desired) and the only one that come up is the unfortunate Stall/Spin during an apparent overhead break at KONY that took Joel Smith (who was sitting right seat) .  I can find no reference to it other than in Mooneyspace lore.

[DonMuncy]

4 minutes ago, Shadrach said:

I've searched for "Mooney Test pilot accident" looking for news and articles. I searched the NTSB data base (the new CAROL system leaves a lot to be desired) and the only one that come up is Joel Smith's unfortunate Stall/Spin during an apparent overhead break at KONY.  I can find no reference to it other than in Mooneyspace lore.

Sorry about being ultra picky. Joel Smith was aboard and died in that accident, but may or may not have been (likely not) piloting the plane.

[Shadrach]

1 hour ago, carusoam said:

More on the subject…

 

Ross,

Oddly, I have written a review (for this subject) from an LB POH… quite a while back…. 
February, 2010… right around the time I got the O….

Funny… my writing style hasn’t changed very much…

“

I used sideslips for my M20C often.  Always making sure nose is down and airspeed maintained.  Entering and exiting the slip smoothly / gently.  There is no desire to let the tail wag by over or undercontrolling.

 

PK, I have been reviewing the POH for the M20R (longbody)

 

Slips are mentioned 3 times:

 

cross wind landing, door closing in flight, fuel gauge accuracy only during coordinated flight.

 

It is a normal category airplane, so slips are acceptable (with normal precautions to avoid stall / spin).

 

Otherwise, speed brakes are used for additional speed control.

 

Directly to answer the question: The POH (Section IV - Landing) recommends crab until flare, touch down with slight wing low side slip.  (Caution: YOUR POH may vary)

 

The C and the R seem to be at maximum up trim during the landing phase (with two people on board).

-a-  “

I have read Bob's comments many times.  They seem contradictory as he states that the planes that require significant nose up trim on approach are most prone. He then says that they could not induce a tail buffet in the J model no matter the configuration. Well most F and J owners will tell you that trim is near or totally full nose up by short final with two folks and light fuel, at least that's how mine is if I want to trim for proper approach speed.  

[Shadrach]

8 minutes ago, DonMuncy said:

Sorry about being ultra picky. Joel Smith was aboard and died in that accident, but may or may not have been (likely not) piloting the plane.

Thanks for the correction.  Edited to better reflect the situation.

[A64Pilot]

Mooney is odd though in the way the stabilator is variable incidence like many Jets.

I don’t understand why people trim for hands off on an approach, I stopped doing that when I found out how much of a handful it made my Maule on a go-around. As I often fly off grass that means wildlife appears on the runway, used to be deer, here it’s sand hill cranes. I feel I need to be set up for a go-around, I even open cowl flaps on final when the prop goes forward.

I don’t touch my trim for takeoff, it’s right where it was for landing and it does take some pull to get her off the ground, but as soon as flaps are up I’m trimming down so I don’t want too much up trim to start with.

Co-incidentally when we get out the elevator is perfectly in line with the stabilator.

The other day at the Fl Mooney lunch fly in I followed a Mooney out for departure, during taxi his elevator was full down, what was that about? can two aircraft have that much difference in trim ?

[carusoam]

5 minutes ago, A64Pilot said:

 

The other day at the Fl Mooney lunch fly in I followed a Mooney out for departure, during taxi his elevator was full down, what was that about can two aircraft have that much difference in trim 

We’re you following a Long Body?

The elevator doesn’t have the bungees of the other Mooneys… so the elevator hangs at the bottom until being raised up…

The elevator of the LB won’t show the trim, the yoke will be pressed against the forward stop….

Best regards,

-a-

[A64Pilot]

4 minutes ago, carusoam said:

We’re you following a Long Body?

The elevator doesn’t have the bungees of the other Mooneys… so the elevator hangs at the bottom until being raised up…

Best regards,

-a-

I believe so yes, one was a Screaming Eagle, but I think he was in lead, one I followed didn’t climb or wasn’t any faster in climb than I was though

[carusoam]

Screamin’ Eagles and Standing Os… both have the power to weight ratio to climb like crazy….

Ordinary LBs climb like most other Mooneys…

All LBs have the same tail structures…

PP thoughts only…

-a-

[jaylw314]

I think the only time I've told my wife "watch this!" in the plane involved a slip.  Getting the expected slam dunk into LAX airspace, I dropped the gear and slipped to lose 4000' in VMC.  I pegged out the VSI at 125 KIAS.

I also slept on the couch that night 

Edited October 11, 2022 by jaylw314

[Yetti]

Yep.  You are minor slipping when you do a one wheel landing.  Handy for buffeting cross wind.  In an F model.  In Texas.  Half flaps.

[Hank]

36 minutes ago, jaylw314 said:

I think the only time I've told my wife "watch this!" in the plane involved a slip.  Getting the expected slam dunk into LAX airspace, I dropped the gear and slipped to lose 4000' in VMC.  I pegged out the VSI at 125 KIAS.

I learned about intra-cockpit communications while testing a strange above-redline EGT by turning the key. Found out three things:

1. The left magneto was dead.
2. Running only on a dead magneto makes the engine go silent, and there is a strong down-pitch to maintain cruise airspeed.
3. Tell others in the plane what you are doing BEFORE demonstrating #2 above! She reacted strongly, with great distaste. But we reached her mother's house anyway, so no couch for me.