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Minimum Safe Manoeuvering Speed


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Came back from Bromont yesterday (great two-and-a-bit hours of flying.  One to go.  1/2 to show Serge and one to come home) and this morning I saw this.  We have had lots of discussions on this forum about AoA indicators and I do intend to get one.  But this video describes how the airlines do it.  

Not an instructor, but I like the idea of creating a safety margin (albeit artificially).  So your mileage may vary.  I have modified the Vspeed page in my checklist to add this speed.  Turns out for my E model it is 94 MIAS or 81 KIAS (somewhat higher than Vs).  So my intent is to stay above that speed unless one of the two following conditions is met:

  1. On approach through the FAF, or
  2. Manoeuvering to practice stalls.

One GA fatality every four days?  Enjoy the video.

 

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Excellent video !  A free quality flight instruction...... it was completely engaging.

Terrific minimum safe mauvering speed concept in conjunction with re visiting my back to basics stall prevention refresher information/ techniques from my initial flight instructor Barney Kuhns, Lompoc Aviation, Lompoc, CA, 1973.

Barney was a beyond stickler at always flying the airplane in any situation, regardless of other issues.  It was hammered into my brain!  

As a right seater years ago, with an inexperienced and hesitant left seater, I had occasion to react instantly as an imminent on departure stall was about to occur.  As the non PIC, I instantly pushed the nose over to save the situation.  Thank you Barney!!

Thank you for sharing this video.

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I thought the video was great, but found the opening about airline vs GA "maneuvering speed"  bit misleading. The two groups were answering based on two completely different concepts. The GA pilots thought they were being asked about Va - "design maneuvering speed", which is indeed a maximum. The airline pilots understood they were being asked about "minimum maneuvering speed"  for safe flight.  But I got past that after all media needs to attract right at the beginning.

The rest of it was a bit scary in this sense: I wasn't give a specific number but I was definitely taught the need for maintaining safe airspeed at all times during my primary training 30 years ago. I was also taught the need for a hefty "push" on the yoke in case of a power failure to get to a safe speed and avoid an unintentional stall. One of my DPE friends actually used to test it. During a power-on stall demonstration, he would reach over and pull the power. I've done it to trainees a few times to bring the point home.

The most interesting thing to me about the concept is that I think this is a big part of the FAA's reasons for new "new" slow flight where we pick an airspeed sufficient to avoid hearing the warning and how so many folks, including acknowledged training experts, blasted it.

Edited by midlifeflyer
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Thanks Ned!  For sharing that brief lesson...

A few things that stand out, to me....

  1. A change from... barely recovering, trying to retain altitude... as this was the most important thing back in the day...
  2. to... push the nose over enough to come out of the seat, maintaining energy... as this is the most important thing everyday... as far as laws of physics are concerned... having excess speed is way better than having not enough speed...
  3. How do you know when you have barely enough speed? Will you be looking at your ASI during an unexpected impending stall?
  4. Coming out of the seat is a clear recognizable indicator of the wings being unloaded... 
  5. Maintaining energy is a combination of speed AND altitude... having the wings unloaded, priceless...
  6. In the given scenario... you get six seconds to recognize and decide and act properly...
  7. Since so much time erodes in the recognition phase... push until weightless is a proper response to buy another first down...
  8. Can you tell the Pats are playing? :)

When you survive the stall scenario... you can always trade the extra speed back to altitude... (with a small exchange cost of extra frictional drag loss for being at a higher speed for a brief moment of time... even this loss isn’t much, the time was brief and the speed was probably closer to best glide...)

Some of us had the opportunity to meet the Flight Chops guy at Mooney Summit last year... He has a great personality for this type of aviation media.

PP thoughts only, not a CFI...

Best regards,

-a-

 

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Half way through the video.   I think he sets up the problem a bit out of step.   when we practice stalls, the CFI teach us "to pull a little more back"  When you hear the horn.   this creates a muscle memory to pull back when you hear the horn.   We should be teaching to push down when we hear the horn.   

two years ago on my FR we when through the push hard forward when the engine quits.   I think this should be mandatory training.   in the Mooney it should be instantaneous.    I think this training is what saved me when the engine sputtered in Midland.

I just went through Active Attacker training.   Lizard Brain vs. Human Brain.   The Human Brain goes through Denial, Deliberation, Action.   If you scenario and rehearse  (first half of the video)  You will move through the stages faster which gets rid of the normalcy bias.

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The minimum safe maneuvering speed for a 1966 E is given in round about way in the owner's manual.  The best rate of climb and best glide speeds are the same at 105 mph at gross weight.  I find that 100 mph is a good target as this is also max flap speed.  Hold 100 mph till until you need to slow for final approach speed.  100 mph handles well, has best rate if needed. best glide and max flap speed.

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24 minutes ago, RogueOne said:

I never understood why loss of altitude in a stall recovery was EVER an issue with an instructor. The idea is to get the nose down and gain airspeed and smoothly recover, right?

The standard was with a "minimal" loss of altitude as far back as I can remember. Part of the reason was that the scenario involved being relatively close to the ground. "Landing stall" and "departure stall, not 3,000 feet above the ground where it doesn't really matter.

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I thought the first part of the video talking to pro pilots and GA pilots about maneuvering speed was one of my favorite bits and did make me think. I certainly know what Design Maneuvering speed is and why it's important. But the point that was made to me was that minimum speed should be top of mind.

The other thing I got from this was to "Do" without hesitation.

I enjoyed the video and thought it was quite valuable.

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6 hours ago, Yetti said:

The mooney manual says "no turns in the pattern under 90 mph without flaps deployed"   Follow the Operators Manual.

I searched for the words you quote in POH 1193, which is for my 1965 E model Mooney.  I have a pdf copy of it.

The wording closest to your quote is on page 24:

"It is recommended that the base leg be flown at 90 mph.  Upon turning final, or sooner if necessary, extend the desired amount of flaps.  Flap speed is 100 mph."

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Yetti makes a good point, the take is we’re pulling back on the yoke to make sure we enter the stall..the push to recover, since the video is assuming an inadvertent stall our muscle and mind memory should be trained to push to recover at the first instant, Dan pointed out to push at the first sign of loss of power not the sign of entering the stall actually that’s to late according to him. The new teaching methods to not enter the stall but to recover at the first sign eg a buffer is an attempt to keep our wing energized. The new method along with making the push ASAP makes more sense to me, being an older pilot we should emphasize the points made in the video IMO.

The video was very worthwhile. 

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16 minutes ago, tigers2007 said:

Anyone doing the tape thing? Was I 1.404 x Vs1? Or just use 105mph?


Sent from my iPhone using Tapatalk

I did for over a 15 years while I still had  a dial IAS. When I did it, I used Vy which made the most sense to me as the conditions that I might need it in may require me to get some altitude back. Now with a digital Tape, all my Vspeeds are marked including Vy, so problem solved.

Vg isn't nearly as important to me, since it varies by weight considerably, and not what I consider a minimum speed that I need to reference in severe turbulence as an example. When Vg is needed, such as a glide to a near airport, I usually have some time to consider what to use based on weight.

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2 hours ago, Ned Gravel said:

I searched for the words you quote in POH 1193, which is for my 1965 E model Mooney.  I have a pdf copy of it.

The wording closest to your quote is on page 24:

"It is recommended that the base leg be flown at 90 mph.  Upon turning final, or sooner if necessary, extend the desired amount of flaps.  Flap speed is 100 mph."

Pretty sure it is in my 75 F Operators manual.   It was one of the lines that stuck with me and I adhere to it.   I believe you have the lower flap speed and gear speed.

 

I watched to the end of the video and wholeheartedly agree with what he is teaching.    With the mooney wing and the more power when the fan quits you have to shove the yoke forward.

If you have never done it go up and put it in takeoff configuration and do a couple.     I think this is also a reason to get the gear up soon as the plane is flying.   I saw one video of waiting till all usable runway to pull the gear up.   Just means you are slower and closer to the ground.

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Great video and goes right along with the numerous AOA discussions.  Unload the wing first, then work the problem.  

I apply the same principle in my 310.  Many get killed in a twin for the EXACT reason they do in a single.  The industry calls it a Vmc roll, but it's really nothing more than exceeding crossover AOA.  In a single, it results in a spin; the twin has another engine to help you over the top.  The solution is exactly the same as a single: push forward until the airspeed increases to AT LEAST Vmc, but I like to see Vyse before climbing... and pushing forward that close to the ground is really hard to do.

I just got out of the simulator, at my day job, practicing this very thing.  Glad to see the airlines beginning to focus on stick and rudder skills again!

Just calculated my MMS as 121 MPH.  Strangely enough, that is Vyse in my plane.  Coincidence?  Doubtful....  I typically fly fast anyway, but this is a great number to know!

Edited by Guitarmaster
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32 minutes ago, Yetti said:

I watched to the end of the video and wholeheartedly agree with what he is teaching.    With the mooney wing and the more power when the fan quits you have to shove the yoke forward.

One flight with my wife, I was having weird EGT readings. When it went above redline, I decided to do a mag check. We were in level cruise at 9500 msl, should have been indicating ~145 mph, ~21" / 2500. Ignition Left, engine stopped immediately, plane pitched strongly downward to maintain trimmed airspeed. Ignition Both, came right back on and leveled out. Ignition Right, kept on purring so I left it there and leaned it again. Learned a second lesson:  don't surprise your wife like that!

What creates the need to push on the yoke when this happens in the climb? You do trim for hands-off climb, right? Won't the nose still change pitch to maintain trimmed airspeed? Early in the climb, the trim may not be fully set, though. Is that all? What am I missing?

P.S.--to me, "maneuvering speed" is Va, maximum turbulence penetration speed. MCA is a minimum speed that the FAA no linger requires a demonstration of, although on one flight review I flew my C like that for several minutes, stall horn blaring, changing course left and right as directed. I think the CFI was surprised . . . Now we don't do that anymore.

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10 minutes ago, Hank said:

What creates the need to push on the yoke when this happens in the climb? You do trim for hands-off climb, right? Won't the nose still change pitch to maintain trimmed airspeed? Early in the climb, the trim may not be fully set, though. Is that all? What am I missing?

What creates the need to push the yoke is the upward pitch, inertia and thrust vector change.  Yes, given enough altitude, the airplane will return to stable flight (gliding) at the trimmed speed.  In the meantime, the speed will bleed fast and you are already slow.  Combine that with an inherent fear of hitting the ground and you have the classic, pull back when the airplane is close to stall problem. 

Training is the only thing that will overcome this.  It is well proven, a person will never step up to the task in a fight-or-flight (so-to-speak) scenario.  Instead, they will fall back on their lowest level of training. 

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Just now, Guitarmaster said:

What creates the need to push the yoke is the upward pitch, inertia and thrust vector change.

In level cruise at 170+mph True, I had a lot more i ertia than I do while climbing at 100 mph indicated. But my plane pitched down, rather strongly, immediately (made my wife scream). Why does it not do this when climbing? The only differences between your list and my experience is that I had much less upward pitch and much more inertia. That doesn't add up,mwith triple the inertia, mympitch change should be be slower than in low speed / low inertia situations.

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32 minutes ago, Hank said:

In level cruise at 170+mph True, I had a lot more i ertia than I do while climbing at 100 mph indicated. But my plane pitched down, rather strongly, immediately (made my wife scream). Why does it not do this when climbing? The only differences between your list and my experience is that I had much less upward pitch and much more inertia. That doesn't add up,mwith triple the inertia, mympitch change should be be slower than in low speed / low inertia situations.

Remember, you are trimmed for 170 MPH and your inertia vector is horizontal .  As we all know, the Mooney is a trim hog and in cruise, it is nearly full nose-down trim in cruise (at least my "F" was). Try this... at altitude, set yourself up in an initial climb profile.  Gear and flaps hanging out (if you use them).  You now have an upward inertia vector. Yank the power and watch how fast the speed bleeds.  In addition to this, make a hard floor and envision trees say, 100 feet below you.  The thrust line is a slight downward vector, so at slow speed, high AOA, the engine is pulling downward a bit.  The initial loss of the downward vector will initially create a pitch-up moment.
It's all about AOA and keeping the buffer from critical AOA.  A small change in direction vector with a high AOA (high drag) will move you toward that critical point rapidly.  

Edited by Guitarmaster
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26 minutes ago, Guitarmaster said:

Remember, you are trimmed for 170 MPH and your inertia vector is horizontal .  As we all know, the Mooney is a trim hog and in cruise, it is nearly full nose-down trim in cruise (at least my "F" was). Try this... at altitude, set yourself up in an initial climb profile.  Gear and flaps hanging out (if you use them).  You now have an upward inertia vector. Yank the power and watch how fast the speed bleeds.  In addition to this, make a hard floor and envision trees say, 100 feet below you.  The thrust line is a slight downward vector, so at slow speed, high AOA, the engine is pulling downward a bit.  The initial loss of the downward vector will initially create a pitch-up moment.
It's all about AOA and keeping the buffer from critical AOA.  A small change in direction vector with a high AOA (high drag) will move you toward that critical point rapidly.  

Most of my takeoffs are no flaps, unless I'm heavy or the field is short (like 2000'). Gear is stowed by treetop level, all that drag just slows the climb. From a previous discussion, here are pictures of my typical trim positions:

Takeoff (not heavy):

20160827_100859.thumb.jpg.7f5cc9cc6cc3832bfb1f2d2b9f6dc86c.jpg

Climb:

20160827_114158.thumb.jpg.7f3bfb114ab802512fd8939006e5243f.jpg

Cruise:

20160827_140518.thumb.jpg.25b61e6fefdbc4725956287ea7778984.jpg

20160827_140526.thumb.jpg.470788fde422f0499c23a41e8639da01.jpg

Guess I forgot to get a descent trim picture. 

I still don't understand why pitch changes to maintain speed when the engine quits firing in cruise but not in climb? Unless you are pulling the yoke to climb instead of trimming?

I'll try to remember to do this again going to Summit on Thursday. My wife can help me remember the descent part.  ;)

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