CFI Help

[carusoam]

Some summary...

1) know exactly what the stall speed is going to be for the day... configuration, and weight...

2) Modes of braking...

• More flaps and trim... is added braking...
• Gear down is braking...
• Going slowly... back side of the curve... really braking...
• Push the prop all the way in... like downshifting, engine braking...
• Speed brakes...
• Slip... use extra caution, cross controlled, ‘Tis better to be nose down than flat attitude....

3) Energy required for flair... at least 10kias above stall... (?)

4) Constantly assessing the amount of energy you have... know the keys, their altitude, and speed...

5) know when short of energy, what the plan is going to be... remove braking, take a short cut... know your best glide speed and be on it...

6) target everything speed and altitude on final,  this is where the practice gets you to this point...

7) have a plan for how wind is going to affect your energy management... at each key point...

8) Bank angle also is a braking maneuver... deeper angles, more braking... stall speed knowledge is important.

9) Don’t spend too much time flying away from the runway... 8 seconds and turn...

10) Initial energy state... always start the maneuver as close to being on speed and altitude, runway under the wing, at the first key point... if you don’t get this consistently... it just adds to the challenges...

11) do not stall the plane while trying to perfect this maneuver... that would be bad form...

12) practice your instrument scan... always know your altitude and speed.... and Vs which will be quite large...

 

PP summary of what I think I read here... not a CFI...

Best regards,

-a- 

[Ibra]

5 hours ago, carusoam said:

Energy required for flair... at least 10kias above stall... (?)

Could be 5kts to 15kts depending if you start to flare power on/off, smooth flare from 50ft or all in ground affect at 10ft, or windsheer gradient, these could make 500ft landing roll difference 

The easy way to manage excess energy is to come slightly high and slighly slow, push to pick some speed and quick flare to bleed it off, if you come fast and low there is no way you can bleed the energy quickly 

But if there are two things that are specific to Mooney: it hates flaring above 80kts (8000ft runway on calm days) and hates go around bellow 60kts/30ft (committed to land with no flare and no go-around even with full power the nose will be on the ground whatever you do with the stick)   

Edited February 11, 2020 by Ibra

[RobertGary1]

6 hours ago, carusoam said:

6 hours ago, carusoam said:

Some summary...

2) Modes of braking...

• More flaps and trim... is added braking...
• Gear down is braking...
• Going slowly... back side of the curve... really braking...
• Push the prop all the way in... like downshifting, engine braking...
• Speed brakes...
• Slip... use extra caution, cross controlled, ‘Tis better to be nose down than flat attitude....

3)

 

I would add turn base late into that. Remember that the base leg includes the key position where you decide if you are high or low and time your turn to final based on that.  

It was a long time ago but I believe this was the maneuver I had to teach on the ground for my initial cfi   

-Robert 

[ilovecornfields]

I’m not a CFI, but I do have some recent experience with power off 180s:

I tried a bunch of different combinations - gear up, gear down, prop forward, prop back, etc. I don’t think it matters what you choose but for me it all came down to CONSISTENCY. I would choose your landing point (although on the checkride my examiner chose a different one) and once you’re abeam the point - power to idle, pitch to best glide, leave the gear down. The first variable is how long you wait before starting the 180. With light winds 3-4 seconds would work for me and then I would start the 180. As you practice this (I did about 20) you get a feel for what the proper glide angle looks like. If you’re high you can turn a little slower and if you’re low you can turn a little faster. Once the 180 is done, you will get an idea of what the proper angle looks like when you’re lined up. For me, 75 kts over the runway threshold with just barely white over white on the VASI meant I would touch down at my aiming point. 
 

Flaps are the other big variable and once you get used to the proper angle you’ll know when to put in flaps. On my practice runs, I would wait until I was lined up to put the flaps in unless I knew that it’d started the 180 too soon( in which case I’d do it during the turn). I didn’t use speedbrakes on the exam because I was told by another CFI that I would lose “style points” but that’s an option as well for those who have them.

I’d practice the maneuver until it doesn’t intimidate you, but I also wouldn’t stress out too much. If you aced your oral and the rest of the maneuvers, I think it would be rare for an examiner to fail you because you landed 10 ft long.

[bradp]

Agree with consistency - I've been practicing on and off.  I go best glide, prop back, gear UP no flaps.  Continuous glide toward the runway - keep the touchdown at the same visual plane in the windshield - until you have the field made and then use energy dissipating techniques - gear down, flaps, slip, to manage the buffer of energy you've stashed.  You can get rid of energy but you can't take it back.  Anticipating the distance (seconds) from the beginning of your flare to the actual touchdown spot for a given speed is key, so aim a bit ahead.

I have electric gear and the procedure above departs from my SOP (i.e. puts me at risk for a GUL).  Therefore I put my hand on the gear lever and don't take it off until the gear is selected / verified down.

Hope this helps.  Not a CFI.

*** Also remember that the stripes / bars are not 200' long; they are 150' so you got a little wiggle room ***.  https://www.faa.gov/airports/southern/airport_safety/part139_cert/media/aso-airfield-standards-quick-reference.pdf

[Jerry 5TJ]

21 minutes ago, bradp said:

*** Also remember that the stripes / bars are not 200' long; they are 150' so you got a little wiggle room ***.

Those stripes are good for estimating distance regardless of runway width:  The end marking stripes are 150’ long. 

The runway centerline paint stripes are 120’ long with 80’ gaps: The start of one centerline stripe is 200’ from the start of the next centerline stripe.  

(Disclaimer:  I am only a CFI, not an expert in painting runways)

[ilovecornfields]

18 minutes ago, Jerry 5TJ said:

Those stripes are good for estimating distance regardless of runway width:  The end marking stripes are 150’ long. 

The runway centerline paint stripes are 120’ long with 80’ gaps: The start of one centerline stripe is 200’ from the start of the next centerline stripe.  

(Disclaimer:  I am only a CFI, not an expert in painting runways)

Right, but to become a CFI you had to become an expert on runway painting, didn’t you?

[Hank]

25 minutes ago, ilovecornfields said:

Right, but to become a CFI you had to become an expert on runway painting, didn’t you?

I'm not a CFI, but I have repainted the runway numbers and displaced threshhold stripe . . . Took way more paint than I anticipated! This was immediately after I made a night landing in the grass by mistake--runway was 75' wide, lights were 200' wide, pavement was old, grass was dead (winter), and the paint was virtually invisible in my landing light.

[skydvrboy]

Not a CFI, not commercial rated, just a schmuck who wants to be better at these in case the fan ever fails to keep me cool. 

Is best glide speed the same gear up vs down?  Also, is there a way to determine best glide speed for say 1/2 flaps?  I know weight is a factor and it is slower as you get lighter, but I'm unclear on how much slower. 

I'm envisioning a scenario where I've already put the gear down, thought I had the runway made and put in some flaps, and then realize on final I'm coming up short.  What to do... other than the obvious, don't let that happen?

[Jkeene02]

Flaps are a tool in this procedure only use them if you need them 

[Hank]

58 minutes ago, skydvrboy said:

Not a CFI, not commercial rated, just a schmuck who wants to be better at these in case the fan ever fails to keep me cool. 

Is best glide speed the same gear up vs down?  Also, is there a way to determine best glide speed for say 1/2 flaps?  I know weight is a factor and it is slower as you get lighter, but I'm unclear on how much slower. 

I'm envisioning a scenario where I've already put the gear down, thought I had the runway made and put in some flaps, and then realize on final I'm coming up short.  What to do... other than the obvious, don't let that happen?

I've only seen one Vbg in my Owners Manual. If the AC quits, pitch for Vbg and head for somewhere to land. Pull the prop back for more range, the sooner the better. 

Don't add flaps or drop gear until your landing is assured. Do some simulated engine outs to see how to handle it in the pattern. For me, that's the same old same old but turn base just a little sooner than normal. 

If you're coming up a little short, raising flaps will get you a little further. Again, the sooner you make the change, the more distance you will get from it.

Happy practicing, and be safe!

[Yetti]

There was some good commentary on this thread.   I think of landing as managing energy.  There are things that you can do to take away.  Like turning.   I like U turn to land because it is more smooth. Straight, one big constant rate declining turn.  Straight.    Throttle, gear, flaps, going uphill take energy away.   Throttle, going downhill add energy.  

 

[Ibra]

39 minutes ago, skydvrboy said:

Is best glide speed the same gear up vs down?  Also, is there a way to determine best glide speed for say 1/2 flaps?

Theory is that:
- Flaps increases drag/lift coefficients, shifts stall speeds from VS1 to VS0 and may also increase min sink rate
- Gear increases drag coecifient with no matterial impact on lift coeficient and stall speed with no increase min sink rate

If you have the exact data of Rate Of Decent vs Speed few kts above stall and extra 2 points you can plot "polar/power/drag curve" and calculate the best L/D and Vbg in various configs
I would say, Gear down: you will get a lower best L/D and higher Vbg than clean configuration
Flaps: depends how your current clean L/D compares to the ratio of sink rate chnage (fpm) to the change in stall speed

My guess partial 1/2 flaps would allow you to keep flying near best clean L/D but higher speed than Vbg
Full flalps you will loose on best clean L/D and you would fly lower Vbg

Need to do some testing the next time I fly the Mooney but I expect Vbg change along +/-(VS1-VS0) = +/-10kts and L/D from 8 to 6
Also clean and flaps stall speed changes vs weights as well

Disclaimer: PPL only not CFI (but I like flying the Mooney as glider)

1 hour ago, Hank said:

This was immediately after I made a night landing in the grass by mistake

With no painting or numbers that could happens in daylight (don't ask me how I know )

[Ibra]

1 hour ago, skydvrboy said:

I'm envisioning a scenario where I've already put the gear down, thought I had the runway made and put in some flaps, and then realize on final I'm coming up short.  What to do... other than the obvious, don't let that happen?

Resist pulling, just unload the wings and fly faster if you are in ground effect at 80kts you can fly forever in a Mooney

If you fly slow wing wing loaded you will be stalling to the ground on high rate of decent and steep path

Worst case you have speed to laterally avoid obstacles if you undershoot before the hedge

How fast? advance yoke forward until you feel low G floating in the seat 

Done few times in gliders (few scary undershoots )