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Posted

Sorry, I was just trying to make the slightly snarky point that if you always land slow enough to make the horn go off (flaps anyone?) then you don’t need to triple check it before attempting  slow flight. 

im also going to make the unfounded but generally accepted point that most landing accidents happen at or after touchdown, and therefore that regardless of the length of the runway or the weather conditions, touching down at a slower speed (ie fulL flaps) is always preferable (Except in windy conditions in high wing airplanes where the main wing can blanket the straight- tail empennage, or icing)

  • Like 1
Posted
13 minutes ago, rbp said:

Sorry, I was just trying to make the slightly snarky point that if you always land slow enough to make the horn go off (flaps anyone?) then you don’t need to triple check it before attempting  slow flight. 

im also going to make the unfounded but generally accepted point that most landing accidents happen at or after touchdown, and therefore that regardless of the length of the runway or the weather conditions, touching down at a slower speed (ie full flaps) is always preferable (Except in windy conditions in high wing airplanes where the main wing can blanket the straight- tail empennage, or icing)

It wasn't just your post. It's the direction the thread is going.  How does one triple check the stall horn without flight testing (slow flight and stall)?  So triple checking the horn before attempting slow flight would involve slow flight and stall testing.

Also, on the rare occasion that I do a no flap landing, I still typically get a horn chirp before touchdown it just happens at a higher speed and pitch angle than it would with flaps.

  • Like 1
Posted (edited)

A lot of interesting comments on this long thread.  I'll share one more thought after reading the last few.  My stall warning chirps all the time on final if I'm in the 85 mph range.  Drives me crazy; makes the passengers nervous (I have to explain it every time).  I rarely if ever hear it in the flare or during touch down.  I'm sure some of that is technique (like everyone has said) but I'm wondering if ground effect does make a big difference related to the horn activating during touch down.  

Here are the numbers we recorded the last time we "tested" the stall horn and actual stall at altitude.  

  Stall Horn Buffet/Break
Clean 84 70
TO Flaps 83 67
TO Flaps + Gear 84 68
LND Flaps + Gear 82 65
 
 


 

Edited by DCarlton
Posted (edited)
13 minutes ago, Shadrach said:

It wasn't just your post. It's the direction the thread is going.  How does one triple check the stall horn without flight testing (slow flight and stall)?  So triple checking the horn before attempting slow flight would involve slow flight and stall testing.

I was responding to the suggestion of flying a 360 turn with the stall warning going.    I think that's a great idea as long as the stall warning is going off sufficiently prior to stall, which can be easily checked by doing a coordinated straight-ahead stall.   If somebody unaware were to take an airplane where the stall horn doesn't have much margin to stall speed and immediately seek the stall horn while doing a 360 turn, it could add more risk than they may be expecting.

I think it's a good, practical idea to check it, not a bad direction for the thread.

Edited by EricJ
Posted
26 minutes ago, DCarlton said:

A lot of interesting comments on this long thread.  I'll share one more thought after reading the last few.  My stall warning chirps all the time on final if I'm in the 85 mph range.  Drives me crazy; makes the passengers nervous (I have to explain it every time).  I rarely if ever hear it in the flare or during touch down.  I'm sure some of that is technique (like everyone has said) but I'm wondering if ground effect does make a big difference related to the horn activating during touch down.  

Here are the numbers we recorded the last time we "tested" the stall horn and actual stall at altitude.  

  Stall Horn Buffet/Break
Clean 84 70
TO Flaps 83 67
TO Flaps + Gear 84 68
LND Flaps + Gear 82 65
 
 


 

that seems fast for the horn to go off. My M is 73 in the flare 

  • Like 2
Posted
37 minutes ago, EricJ said:

I was responding to the suggestion of flying a 360 turn with the stall warning going.    I think that's a great idea as long as the stall warning is going off sufficiently prior to stall, which can be easily checked by doing a coordinated straight-ahead stall.   If somebody unaware were to take an airplane where the stall horn doesn't have much margin to stall speed and immediately seek the stall horn while doing a 360 turn, it could add more risk than they may be expecting.

I think it's a good, practical idea to check it, not a bad direction for the thread.

Fair enough. I will take my literary references and my sense of humor elsewhere...:P

I'll just add that the difference in stall speed wings level and 20° of bank is 2mph.  I don't rely on the ASI for that kind of precision.  I just stay out of the buffet.

  • Like 1
Posted
2 minutes ago, Shadrach said:

Fair enough. I will take my literary references and my sense of humor elsewhere...:P

Aw, I probably missed something...

Posted
4 hours ago, EricJ said:

Aw, I probably missed something...

John Yossarian is the protagonist in Joseph Heller's novel Catch 22.  Its a great book that was made into a very good movie.  I would recommend both, but the movie is very user friendly and has lots of great aviation footage and a star studded 1970s cast. Alan Arkin’s portrayal of Yossarian is genius. 

  • Like 1
Posted (edited)
18 minutes ago, Shadrach said:

John Yossarian is the protagonist in Joseph Heller's novel Catch 22.  Its a great book that was made into a very good movie.  I would recommend both but the movie is very user friendly and has lots of great aviation footage. Alan Arkin portrayal of Yossarian is genius. 

Oh, I did notice that.   Read the book, saw the original movie, still have a copy of the Flying mag article they did on how the flying scenes were done in Mexico, which was also pretty interesting, including how the hand from the dummy jammed the elevator in the raft scene and nearly caused an incident.   I've not seen the newer one.

Edit:  BTW, it was Frank Tallman flying the L-5 for the scene.
 

 

Edited by EricJ
  • Like 1
Posted
2 minutes ago, EricJ said:

Oh, I did notice that.   Read the book, saw the original movie, still have a copy of the Flying mag article they did on how the flying scenes were done in Mexico, which was also pretty interesting, including how the hand from the dummy jammed the elevator in the raft scene and nearly caused an incident.   I've not seen the newer one.
 

 

I’ve not seen the newer one either, but I can’t imagine that it’s better.  1970s were the golden age of modern cinema. 

  • Like 2
Posted
6 hours ago, rbp said:

Sorry, I was just trying to make the slightly snarky point that if you always land slow enough to make the horn go off (flaps anyone?) then you don’t need to triple check it before attempting  slow flight. 

im also going to make the unfounded but generally accepted point that most landing accidents happen at or after touchdown, and therefore that regardless of the length of the runway or the weather conditions, touching down at a slower speed (ie fulL flaps) is always preferable (Except in windy conditions in high wing airplanes where the main wing can blanket the straight- tail empennage, or icing)

Uh, technically, ALL landing accidents happen at or after touchdown ;)

  • Haha 3
Posted (edited)

Went to the airport to see if I could adjust my stall warning switch IAW the service manual now that I know it's coming on about 5 mph too high (around 15 mph above stall).  Please see pic.  IF it's attached by screws and not rivets, and IF I could get the paint cleaned out well enough to loosen them, I'm guessing the screws are corroded in place (and the heads are really small).  I'm inclined to leave it alone unless I'm in annual and have a potential replacement.  I'll just have to explain to passengers why it's chirping all the way down short final.  At least I know it's coming on approx 5 mph too fast now.... thanks to the feedback on MS.   

  Stall Horn Buffet/Break
Clean 84 70
TO Flaps 83 67
TO Flaps + Gear 84 68
LND Flaps + Gear 82 65
 

 

M20F STALL SWITCH.jpg

Edited by DCarlton
Posted (edited)
25 minutes ago, DCarlton said:

Went to the airport to see if I could adjust my stall warning switch IAW the service manual now that I know it's coming on about 5 mph too high (around 15 mph above stall).  Please see pic.  IF it's attached by screws and not rivets, and IF I could get the paint cleaned out well enough to loosen them, I'm guessing the screws are corroded in place (and the heads are really small).  I'm inclined to leave it alone unless I'm in annual and have a potential replacement.  I'll just have to explain to passengers why it's chirping all the way down short final.  At least I know it's coming on approx 5 mph too fast now.... thanks to the feedback on MS.   

  Stall Horn Buffet/Break
Clean 84 70
TO Flaps 83 67
TO Flaps + Gear 84 68
LND Flaps + Gear 82 65
 

 

M20F STALL SWITCH.jpg

On my J the only access to the back side of that, to get to the nuts behind those screws (they're not captive fasteners, sadly), is through an inspection plate straight aft of it.   It's not a short reach and it's really a pain to get to.   If you do decide to adjust it, realize that it will likely mean multiple trips iterating to get it close enough, which means multiple contortion sessions trying to get to the fasteners inside the wing.   I have fairly long, skinny arms, and it's still a nasty job.   For somebody with shorter or bigger arms, I wouldn't recommend it unless completely necessary.   As always, ymmv.   I'm not certain how the earlier airplanes differ, other than your airplane has four screws, mine only has two.  

Also, before loosening it to make adjustments, mark the corners with a sharpie so you can tell whether and how much it actually moved during the adjustment.

 

Edited by EricJ
Posted
3 minutes ago, EricJ said:

On my J the only access to the back side of that, to get to the nuts behind those screws (they're not captive fasteners, sadly), is through an inspection plate straight aft of it.   It's not a short reach and it's really a pain to get to.   If you do decide to adjust it, realize that it will likely mean multiple trips iterating to get it close enough, which means multiple contortion sessions trying to get to the fasteners inside the wing.   I have fairly long, skinny arms, and it's still a nasty job.   For somebody with shorter or bigger arms, I wouldn't recommend it unless completely necessary.   As always, ymmv.   I'm not certain how the earlier airplanes differ, other than your airplane has four screws, mine only has two.  

Also, before loosening it to make adjustments, mark the corners with a sharpie so you can tell whether and how much it actually moved during the adjustment.

 

Appreciate the reinforcement.  I noticed how far aft the inspection panel is.  Sounds like leaving it alone is the best option.  It works and it works consistently.  I don't mind it at all flying but you do have to explain to passengers (not a major issue).  

  • Like 1
Posted
30 minutes ago, DCarlton said:

Went to the airport to see if I could adjust my stall warning switch IAW the service manual now that I know it's coming on about 5 mph too high (around 15 mph above stall).  Please see pic.  IF it's attached by screws and not rivets, and IF I could get the paint cleaned out well enough to loosen them, I'm guessing the screws are corroded in place (and the heads are really small).  I'm inclined to leave it alone unless I'm in annual and have a potential replacement.  I'll just have to explain to passengers why it's chirping all the way down short final.  At least I know it's coming on approx 5 mph too fast now.... thanks to the feedback on MS.   

  Stall Horn Buffet/Break
Clean 84 70
TO Flaps 83 67
TO Flaps + Gear 84 68
LND Flaps + Gear 82 65
 

 

M20F STALL SWITCH.jpg

Are you saying that your stall horn sounds at 82mias and the plane breaks at 65mias? What did the plane weigh? Both of those numbers seem high.

Posted (edited)
1 hour ago, Shadrach said:

Are you saying that your stall horn sounds at 82mias and the plane breaks at 65mias? What did the plane weigh? Both of those numbers seem high.

That's what the data shows.  Can't tell you how much it weighed.  Data was taken in 2018 but I'm planning to do it again.  I'm guessing it had around 50 gals of fuel and about 400 lbs of bodies.  Stall numbers don't seem too far off when compared to the ASI.  

ASI.jpg

Edited by DCarlton
Posted
38 minutes ago, DCarlton said:

That's what the data shows.  Can't tell you how much it weighed.  Data was taken in 2018 but I'm planning to do it again.  I'm guessing it had around 50 gals of fuel and about 400 lbs of bodies.  Stall numbers don't seem too far off when compared to the ASI.  

ASI.jpg

That’s not too far off.  I ran the numbers for that weight in my plane and came up with the following:

A12B6374-71A0-43B7-8F65-1624378C4658.jpeg.7969452685d8ad6ece5eedc99f0eb985.jpeg

Posted
43 minutes ago, Shadrach said:

That’s not too far off.  I ran the numbers for that weight in my plane and came up with the following:

What IS off for.him is when the stall horn sounds, 15 mph above stall. The Mm posted above says it should sound 5-10 before stall.

  • Like 1
Posted
19 minutes ago, Hank said:

What IS off for.him is when the stall horn sounds, 15 mph above stall. The Mm posted above says it should sound 5-10 before stall.

Indeed a horn 18mias above stall is significant. If my horn sounded at 82mias it’d drive me crazy. The POH’s recommended “generic” final approach speed is 80mias. 

Posted

I'm gonna try 90 configured at the FAF to the MAP (with 2 pumps or take off flaps), 85 across the fence (with 3-4 pumps of flaps), and 80 at the threshold.  Stall warning won't be that bad; just chirpy.  Landings should be easier and slower than I've been doing it.  Worked well yesterday.  Appreciate everyone's input.  

Posted
13 hours ago, DCarlton said:

A lot of interesting comments on this long thread.  I'll share one more thought after reading the last few.  My stall warning chirps all the time on final if I'm in the 85 mph range.  Drives me crazy; makes the passengers nervous (I have to explain it every time).  I rarely if ever hear it in the flare or during touch down.  I'm sure some of that is technique (like everyone has said) but I'm wondering if ground effect does make a big difference related to the horn activating during touch down.  

Here are the numbers we recorded the last time we "tested" the stall horn and actual stall at altitude.  

  Stall Horn Buffet/Break
Clean 84 70
TO Flaps 83 67
TO Flaps + Gear 84 68
LND Flaps + Gear 82 65
 
 


 

I am a rookie and have little experience in piston airplanes, but flying final with the stall warning chirping gives me the Heebie Jeebies.

Posted
30 minutes ago, DCarlton said:

I'm gonna try 90 configured at the FAF to the MAP (with 2 pumps or take off flaps), 85 across the fence (with 3-4 pumps of flaps), and 80 at the threshold.  Stall warning won't be that bad; just chirpy.  Landings should be easier and slower than I've been doing it.  Worked well yesterday.  Appreciate everyone's input.  

so plane stalls at 62mias at MGW. You’re choosing to be 18mph above MGW stall as you come into ground effect when lighter than gross. Your already too fast and ground effect will exacerbate the issue, If you weigh in at a normal 2 people and fuel weight for an F‘ you will likely be more than 20mph above stall at the threshold or around 1.4-1.5Vso  across the numbers. May I ask what is driving your decision making? Do you think the FAR/AIM recommendations are not conservative enough?

 

Posted (edited)
1 hour ago, Shadrach said:

so plane stalls at 62mias at MGW. You’re choosing to be 18mph above MGW stall as you come into ground effect when lighter than gross. Your already too fast and ground effect will exacerbate the issue, If you weigh in at a normal 2 people and fuel weight for an F‘ you will likely be more than 20mph above stall at the threshold or around 1.4-1.5Vso  across the numbers. May I ask what is driving your decision making? Do you think the FAR/AIM recommendations are not conservative enough?

 

I don’t see 62 on my ASI or in my test data.  I see 64ish to 68ish.  More like 12 mph above the buffet at the numbers for my airplane.  1.2 is about 80.   Will see how it feels.  Baby steps.  With full flaps maybe a tad slower.  

Edited by DCarlton
Posted
8 minutes ago, DCarlton said:

I don’t see 62 on my ASI or in my test data.  I see 64ish to 68ish.  More like 12 mph above the buffet at the numbers for my airplane.  1.2 is about 80.   Will see how it feels.  Baby steps.  With full flaps maybe a tad slower.  

It’s should be in your POH. Perhaps your ASI is in need of calibration.

86605B42-55CB-46B8-BF46-6676F4A429B4.jpeg.18dd8f9f02bf6a9dd680343912c8e4f1.jpeg

 

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