Hydraulic Flaps Go-Around Procedure

[pilot_jb]

Since the POH doesn't mention a single word about go-around procedure in my '67 M20F, I'd like to know what you all do.  

The main issue I have is that once the hydraulic switch is raised the wind pressure removes all of the flaps almost immediately.  Of course, we were all taught to raise the flaps incrementally, which I am finding to be impossible in this plane, no matter how fast I try to work the lever.  

Are there any tricks, or secrets of which I am not aware? 

[1964-M20E]

@pilot_jb First when on the ground with the flaps fully extended and you release them how long does it take for the flaps to retract?  It should be about  8-12 seconds per Manual 104.

If the flaps retract too fast there is an adjustment on the hydraulic pump for the flaps and the procedure is outlined in the maintenance manual.

See Manual 104 pages 6-14 & 6-15.

If adjusted for about 10 seconds a quick up and down motion of the release handle when flying will  retract about 5 to 10 degrees of flaps.

[pilot_jb]

9 minutes ago, 1964-M20E said:

@pilot_jb First when on the ground with the flaps fully extended and you release them how long does it take for the flaps to retract?  It should be about  8-12 seconds per Manual 104.

If the flaps retract too fast there is an adjustment on the hydraulic pump for the flaps and the procedure is outlined in the maintenance manual.

See Manual 104 pages 6-14 & 6-15.

If adjusted for about 10 seconds a quick up and down motion of the release handle when flying will  retract about 5 to 10 degrees of flaps.

Thanks!  I'll take a look at the manual.  I'll time them tonight, but it seems to me that it's more like 5 seconds...maybe less.  

[1964-M20E]

Yeah if they are that quick adjust them slower.  They will go up quicker in flight with the wind loads.

When going around it feels like you just pulled a rug out from under you when the flaps come up quickly.

[pilot_jb]

5 minutes ago, 1964-M20E said:

When going around it feels like you just pulled a rug out from under you when the flaps come up quickly.

Yep.  It sure does.  

I looked at the maintenance manual, but the revision I have is about the PC system on page 6-14 and there is no page 6-15.  What I have is Rev. H 11/1/85.  

[1964-M20E]

11 minutes ago, pilot_jb said:

Yep.  It sure does.  

I looked at the maintenance manual, but the revision I have is about the PC system on page 6-14 and there is no page 6-15.  What I have is Rev. H 11/1/85.  

OK Should be just before the PC system in section 6 of the manual.  Look for the schematic breakdown of the hydraulic pump.

 

 

 

[steingar]

With the J-bar  go arounds get a mite busy.  I pull the plug on the flaps once climb is established and don't worry about them afterward.

Edited April 17, 2019 by steingar

[Shadrach]

1 hour ago, pilot_jb said:

Yep.  It sure does.  

I looked at the maintenance manual, but the revision I have is about the PC system on page 6-14 and there is no page 6-15.  What I have is Rev. H 11/1/85.  

[Shadrach]

2 hours ago, pilot_jb said:

Since the POH doesn't mention a single word about go-around procedure in my '67 M20F, I'd like to know what you all do.  

The main issue I have is that once the hydraulic switch is raised the wind pressure removes all of the flaps almost immediately.  Of course, we were all taught to raise the flaps incrementally, which I am finding to be impossible in this plane, no matter how fast I try to work the lever.  

Are there any tricks, or secrets of which I am not aware? 

I think a lot of folks overcomplicate this procedure. An F model will climb just fine under most circumstances with full flaps and the gear out. Raise the gear after positive rate is established, then raise flaps after the plane has accelerated to ~80mph. It’s pretty easy. Getting your flaps properly adjusted will make things smoother. A 10 sec retraction on the ground will work out to about 4 in the air.

Edited April 17, 2019 by Shadrach

[pilot_jb]

14 minutes ago, Shadrach said:

Either this is a different version of the manual that I have, or mine is incomplete, because this graphic isn't present.  Anyone have a PDF copy of this manual?

 

[Shadrach]

1 minute ago, pilot_jb said:

Either this is a different version of the manual that I have, or mine is incomplete, because this graphic isn't present.  Anyone have a PDF copy of this manual?

 

I do but it’s the same as this one.

http://67m20e.com/Mooney Parts Manual.pdf

 

[pilot_jb]

4 minutes ago, Shadrach said:

I do but it’s the same as this one.

http://67m20e.com/Mooney Parts Manual.pdf

 

That's the parts manual.  Different book. 

[Shadrach]

16 minutes ago, pilot_jb said:

That's the parts manual.  Different book. 

Sorry...wrong link.

http://67m20e.com/Mooney M20 Series S-MM 1980.pdf

[hmasing]

4 hours ago, Shadrach said:

I think a lot of folks overcomplicate this procedure. An F model will climb just fine under most circumstances with full flaps and the gear out. Raise the gear after positive rate is established, then raise flaps after the plane has accelerated to ~80mph. It’s pretty easy. Getting your flaps properly adjusted will make things smoother. A 10 sec retraction on the ground will work out to about 4 in the air.

That's a bingo.

My F climbs like mad on a go-around with full flaps, so likewise, I get the gear up, and then accelerate to about Vy and retract the flaps.  There's a small dip, but usually not much at all.

[pilot_jb]

16 hours ago, Shadrach said:

Sorry...wrong link.

http://67m20e.com/Mooney M20 Series S-MM 1980.pdf

Thank you very much.  I timed the flaps on the ground last night.  Depending on the speed in which the valve is opened, it was between 7 and 3.5 seconds, but certainly more consistently toward the faster time.  Spoke with my mechanic and we're going to make an adjustment this weekend.  

[Jim Peace]

why go around?

[gsxrpilot]

Why land with the flaps all the way out? 

[DXB]

I've never noticed much of a difference between removing takeoff flaps for a normal takeoff vs. full flaps on a go around.  No way to do it incrementally, and  they do come up quick. I wait for an airspeed of at least 90-100mph and clear of obstacles before retracting in either case - slower speed retractions tend to affect climb performance too dramatically for my comfort and carry less of a stall margin.  

For the hydraulic flap J bar mooneys, the priorities for me after going full power during a go around or missed approach are to  (1) set the appropriate climb attitude despite the trim being too nose up (2) retract the J bar  smoothly.  The speed climbs quickly, so often smooth gear retraction takes a brief push down on the nose to avoid a situation where one is trying to muscle the J bar.  Then deal with secondary considerations of flaps and  retrim to settle into a stable climb- these are generally non-events once the rest is taken care of.  

[Guest]

4 hours ago, gsxrpilot said:

Why land with the flaps all the way out? 

Because Mooney are so fast it’s the only way to slow them down.

Clarence

[carusoam]

+1 on getting the valve adjusted to control the rate of flap retraction.

If you are bumping the control lever to try and control the flap motion, this is a set-up for failure...

There isn’t a benefit to having the flaps snap up into place....

The maintenance manual covers the procedure for making the adjustment.  Including the time need on the ground for set-up... compared to the time you actually get while flying....

Keep in mind what can happen during slow flight, and the flaps go from full down, to snapping full up...

• loss of a big chunk of lift
• change in the center of lift/trim requirement
• change of the stall speed

Find Ross’ video of flap operations while on the ground. A great piece about how they are supposed to work... it is a great lesson.

Setting the flaps up properly is a great project for annual, while accessibility the belly is Best!

Do the flight testing at altitude... the loss of lift is pretty dramatic when the flaps snap all the way up quickly

PP thoughts only, not a mechanic.

Best regards,

-a-

[Shadrach]

Just to close the loop on this thread.  I took my 22 month old on her first front seat flight with Daddy yesterday. I noticed it was about as close to a standard day as one might find "accidentally".  OAT 62df  and a Barometric pressure of 30.00" at our 701msl airport.   We took off with 230lbs of people up front. 20lbs of junk in the back and just under 40 gals on board.  After a quick flight, I decided to do several of the dreaded full flap, touch and gos.  As it turns out, it's the same non event that it has always been.  This time I made a mental note of my observations and aircraft performance on three different take offs'

Climb attitude: as one might expect, full flap, gear down climbs are done at a flatter pitch angle then normal settings. Visibility is quite good over the nose.

Climb speed: Vx and Vy with full flaps and gear down appeared to be nearly the same at just about 85mias.  Lowering pitch angle produced a little extra airspeed but diminished climb performance significantly.

Drag:  At the low speeds that we were using, the drag of the gear had almost no effect on climb rate. The affect of the position of the gear on ROC was <100fpm

Rate of climb:  It is often said that going around with gear down and full flaps is risky or dangerous because the degraded performance.  Indeed performance was degraded but the aircraft still climbed well. We weighed around 2200lbs as loaded and 85mias yielded about 900fpm.  My plane performs fairly close to book climb numbers which at 2300lbs and 1000msl is 1260FPM. I can verify that our first departure climbing clean was  >1100fpm at our 120mias cruise climb. 

The conclusion (as expected), the plane does not climb as well with the gear and flaps hanging out.  However, even with it all hanging out, our climb performance appeared to be better than the C172 that was also in the pattern.  So the take away is what you'd think...If you have to go around in landing configuration, fly the plane, expect it to climb flatter and slower, clean it up when you feel comfortable. No need to be busy. No need rush. The plane will climb better in landing configuration than many other 4cyl birds under ideal circumstances.   I'd not be thrilled to do this exercise at a 6000' DA airport at gross on a hot day, but I would bet that it would still do OK (300-400 fpm) under those circumstances.

Edited April 22, 2019 by Shadrach

[carusoam]

Nice pirep, Ross!

How did the copilot like the front seat?

Somewhere along the way I had my daughter keep wings level using the AI... she wasn’t tall enough to see out the windows... 

Best regards,

-a-

[steingar]

Last time I did a go around with the gear hanging out my aircraft climbed like a dog.  I didn't even make it to pattern altitude and swore I'd never do it again.

[Shadrach]

50 minutes ago, steingar said:

Last time I did a go around with the gear hanging out my aircraft climbed like a dog.  I didn't even make it to pattern altitude and swore I'd never do it again.

 I could say the extra 20hp makes all the difference but I don't think it does.  I think it makes some difference.  An M20C with everything hanging out should easily be able to climb out at >500FPM. 

[steingar]

19 minutes ago, Shadrach said:

 I could say the extra 20hp makes all the difference but I don't think it does.  I think it makes some difference.  An M20C with everything hanging out should easily be able to climb out at >500FPM. 

Perhaps something is wrong with mine.  I was at low altitude and wasn't looking at the VSI, jus the occasional glance at the airspeed to make certain I didn't slow down.  But at 500 ft/min it would have been a comfortable climb to pattern altitude.  Like I said, I never got to pattern altitude.  Maybe I'll try again to see what's going on.  but that will after its annual, it goes in at the first VFR weather I see.