Retracting Flaps or Gear First - Video From Bonanza Society

[Lax291]

Sorry to light this fuse, but interesting video from the American Bonanza Society. Wondering if it changes people's thoughts on how they handle a go-around?  Would be interesting to see the same test in a Mooney. 

 

[hazek]

Nice post. I was thinking about making the same one when I saw that video. And I already know who will chime in with his 6000+TT of Bravo experience advising to go Gear UP first to keep things simple 

Anyway, it was interesting to see in the real world how much drag each device produces. Would be cool to do the same test on our Mooneys. I might try this once just for fun. But if it's comparable it partially explains why at least the Bravo POH calls for the sequence to be: 

1. flaps APP
2. gear UP
3. flaps UP

The mystery from the POH and in comparison to the video is why flaps APP then gear UP and only then flaps UP. My thought is, perhaps, at least in the Bravo, the reason is the pitching moment. Retracting flaps is an up moment and retracting the gear is a down moment. And since on a full power go around and trimmed for landing one would already be fighting a pitch up, retracting the gear before fully retracting the flaps can help fight it. Another reason might be that on the Bo the timings are different. I'm not sure but it seems to me their flaps and gear retract much slower than on my plane at least. I don't know how much of a protection to a stall is to keep flaps APP until gear is retracted but that could also be a reason for this sequence.

In my limited practical experience that POH procedure seems to work well at least on the Bravo. Admittedly though I have not yet done a post flare and bounce go around but only a few go arounds still in the approach on short final.

[cbarry]

If folks were as conscientious about applying power sequentially and in stages,  as they are about cleaning up the drag components, I believe most go arounds would be a non-event. In other words , “Balls-to-the-walls” as a first thought might not always be the best.  I’m not an instructor, just trying to be a conscientious Mooney driver.  

[gabez]

this was one test in one plane in one specific weather and weight condition. I wouldn't mess with the POH

[Pinecone]

My M20K 252/Encore POH says flaps to TO after climb is established, then gear, then rest of flaps.  I do wish that I had a flap preselect, that is, 3 position switch, Up, TO, Full.

 

[EricJ]

2 hours ago, cbarry said:

If folks were as conscientious about applying power sequentially and in stages,  as they are about cleaning up the drag components, I believe most go arounds would be a non-event. In other words , “Balls-to-the-walls” as a first thought might not always be the best.  I’m not an instructor, just trying to be a conscientious Mooney driver.  

I do gear first for this reason, sometimes even before any power application, unless I'm too close to the ground.      The gear-in-transit-up speed on my airplane is not far from instrument approach speed, and when I first got the airplane it'd blow the breaker if you tried to pull the gear up at anything over 90 knots (it's better now).   On a go-around or a missed approach it made it difficult to apply full power and not pitch up excessively to keep the speed down, so I got used to either pulling the gear up first, or going to about half power, stabilizing, then gear up, then full power and deal with whatever the flaps need.

There's such a variety in airplane behavior and good practice for stabilizing things that I don't think there's one rule to apply to everything.

[Marc_B]

I'll have to try out the speed drop with full flaps, I don't know the answer to that.  But I'll say that dropping gear roughly drops speed 25 kts and it's more or less similar to the effect of speed brakes in my M20K.

** I wish the video had done the reverse...stabilize in the landing configuration and then go to approach flaps and see how much speed added; then go back to landing and raise gear and see how much speed added.  I also would have liked to see the delta speed for approach flaps at 120 to full flaps at 120 (the video used zero to full).

But I'm sure full flaps have LOADS of drag as that was a "tool in the toolbag" for power off 180's: if you were high you could drop the flaps and point the nose at the ground and it wouldn't pick up more kinetic energy, but if you didn't have flaps in you'd just trade potential energy for kinetic energy, speed up and just float.

Regardless of what you do.  The moral of the story is have a plan and practice it.  A go around shouldn't be a "surprise" as what happens.  In my mind this should be a well honed skill by every pilot! 

Personally, I was trained by @donkaye, MCFI so I'm a gear first kinda guy.  But on an instrument approach I'm also a 10 deg flaps kinda guy so the pitch up moment with power added is non-existent.  ...So in that respect, maybe I'm a flaps, gear, flaps guy and just have the first step already staged! 

[TheAv8r]

I think this changes depending on if you have electric gear vs. manual gear and hydraulic flaps. The manual gear is very very hard to get up if you're fast, and slowly retracting the hydraulic flaps can be tricky, so on a go-around what I teach is go full power, establish a positive rate of climb, get the gear up first, pitch for Vy and climb-out, then incrementally get the flaps up.

[Marc_B]

One of @201er's polls.  It looked like from the responses that it's almost 50:50 with a preference towards gear first.

I think the general gist of gear vs flaps is if you are full flaps AND properly trimmed...raising the flaps first on a go around with full power can be a handful. Raising the gear while simultaneously trimming down, then reducing the flaps makes for a safer go around.

So the answer isn't just dependent on what reduces more drag.

[201er]

All it takes is flaps up to T/O and adjust the trim to turn the dreaded go-around into a normal takeoff.

[hazek]

31 minutes ago, 201er said:

All it takes is flaps up to T/O and adjust the trim to turn the dreaded go-around into a normal takeoff.

Surprisingly, this is what hit me a bit earlier reading the replies to this thread!

[midlifeflyer]

5 hours ago, gabez said:

this was one test in one plane in one specific weather and weight condition. I wouldn't mess with the POH

In this case the test conforms to what the POH says. It's "gear first" which is "messing" with the POH.

[Yetti]

The take off was explained to me like this by Mooney Safety Instructor.    Lift off, gear up, dip level for a second to pick up speed and get the wing flying, then go up.   The Mooney wing needs good airflow to get flying.

Go around should be the same. first off due to habit.   

I had this conversation with the another Safety Instructor last Thursday.   The key being to fly level/aviating after applying power after a go around instead of trying to go up.   Collect your wits about you then start doing things like gear up then flaps up.

Mooney wing airfoils are NACA 63-215 wing root and NACA 64-412 at the tip

The Beechcraft Bonanza does not have a specific, named airfoil. Instead, it utilizes a modified NACA 23015 airfoil

 

 

[PT20J]

2 hours ago, 201er said:

All it takes is flaps up to T/O and adjust the trim to turn the dreaded go-around into a normal takeoff.

This has always been my practice in every airplane I've flown -- get the airplane in the takeoff configuration first.

I believe that NACA wind tunnel data shows that flap parasitic drag for a single slotted flap increases parabolically with deflection angle. So raising the flaps to the TO position will get rid of most of the flap drag. I also find it easier to manage the trim if I don't bring all the flaps up at once.

Most of the time we have plenty of excess power available and climb performance is not highly dependent on technique. But perhaps technique might become more important at high density altitude with a normally aspirated engine. Presumably the flight test pilots took that into consideration when developing the POH.

The first 15 degrees of flaps in my M20J don't have much drag and only reduce the level stall speed by 1 KCAS. The main effect is to provide a more nose down attitude. Full flaps reduce the level stall speed by 7 KCAS which is a greater reduction than most GA airplanes. So, full flaps in a Mooney are effective lift and drag producers. The flap drag can mask the gear drag at low speeds which is likely a contributing factor to pilots not noticing that the gear is not down during landing.

It's easy to raise flaps to the TO position without looking at the flap position indicator in a plane with electric flaps that does not have the switch with the TO position: Just count "one thousand-one, one thousand-two..." while raising the flaps and stop when you get to the count you have determined raises them to the TO position. It'll be close enough. 

 

[Pinecone]

5 hours ago, Marc_B said:

** I wish the video had done the reverse...stabilize in the landing configuration and then go to approach flaps and see how much speed added; then go back to landing and raise gear and see how much speed added.  I also would have liked to see the delta speed for approach flaps at 120 to full flaps at 120 (the video used zero to full).

The problem with that is, at what power setting?

By doing it the way they did, they were just looking at the drag, not related to power

I agree that they should have looked at flaps 0 - TO, 0 - Full, TO - Full

[Pinecone]

1 hour ago, PT20J said:

I also find it easier to manage the trim if I don't bring all the flaps up at once.

This can be a very big factor.  Our planes have a pretty substantial pitch change with flap changes.

[M20F]

TO flaps till assured of landing and then go to full flaps.  For a F half flaps (take off) is additional lift. 

[Pinecone]

1 hour ago, Yetti said:

Go around should be the same. first off due to habit.   

That can be a big factor.  When I was in USAF UPT I was on duty in the RSU when we had a T-38 gear up.  As a witness I got interviewed and was invited to the mishap board debrief.  But I disagree with their findings.

In the T-38 a touch and go was full power (no afterburner), lift off, positive rate - gear up then flaps up.  The last two were not really separated, you put the flap handle up as soon as you could get your hand to it.

The go around was throttle to about straight up and then gear up/flaps up.  No check for positive rate as you were already flying and there was enough power to arrest the sink.

In the mishap, the plane was a solo student.  The aircraft ahead of him in the pattern flew a wide and long pattern, so he saw the conflict and called going around.  The controller saw what was happening and told him to continue and make the wide guy go around.  The mishap plane landed with gear and flaps down, then retracted the gear, settling onto the runway.

I truely believe that the pilot's mind was set to Go Around and his hands did a Go Around and not a Touch and Go.

This primacy is also why I am a big fan of gear before flaps.  In a Mooney you really should notice if you are trying to go down and not speed up and have both gear and flaps up.

[IvanP]

I have practiced few go-arounds in Bravo and unless I need to climb fast to clear obstacle, I do  not use full power - 30" MAP is usually enough to get away from the ground and establish positive rate of climb, retract flaps to T/O while trimming down, then gear up , then flaps up and set up in the pattern for another try. 

[M20F]

44 minutes ago, IvanP said:

I do  not use full power - 30" MAP is usually enough 

What I thought everyone flew their Mooney’s 100% power, 100% of the time, 300 degrees LOP!! 

[skykrawler]

Balked landing procedures:

King Air :  full power, airspeed vref, establish normal climb when clear of obstacles: flaps to approach config , gear up when positive climb established, flaps up above Vyse.

B737:  power, Flaps 15, positive climb - gear up, then flaps on schedule with speed.

B757:  power, Flaps 20, positive climb - gear up, then flaps on schedule with speed.

Cessna CE560:  Max power, Flaps approach, gear up, climb at V2, V2+10 flaps up.

Beech B58: prop forward, power max allowable,  96 kts, flaps up, gear up, cowl flaps.

Cessna Latitude 680A:  TO/GA button, throttles Take Off,  pitch to 7.5,  Flap Handle 2,  speedbrake -ret,  speed Vapp, positive rate gear up,  above Vapp+10 and > 400ft flaps up.

 

I see a pattern here.

I believe the idea is to not raise the gear to protect against sinking to the ground when raising the flaps in a low energy state.

 

[N201MKTurbo]

I’ve never actually been taught any particular methods for going around, but I’ve always done it the same way. 
 

Power up till the yoke pressure gets a bit high. This will arrest the descent. Then trim nose down then full power. Gear up. Once you get 100 feet or so, flaps up. This whole partial flaps thing seems silly in a Mooney. A Cessna 310 is another story, it has real flaps.

You can do all of this in about 10 seconds without rushing.

[midlifeflyer]

8 minutes ago, 0TreeLemur said:

If our Mooney flap selector had an T/O flap detent, I agree.   But when  you gotta spend 4-5 seconds watching the indicator to stop them at half it can't be a normal takeoff.

Don’t you count off the seconds?

[0TreeLemur]

9 minutes ago, midlifeflyer said:

Don’t you count off the seconds?

Nope.   I go power, pitch/trim, establish climb, flaps, then gear.  I'm not talented enough to count seconds through all that.  If I stop flap retract at something close to T/O I'm lucky.  My point was more that I wish they had built a T/O trim detent into our flap controls.

[Hank]

9 hours ago, 0TreeLemur said:

My point was more that I wish they had built a T/O trim detent into our flap controls.

A friend of mine had a 75F, with 3 flap detents on the side of the quadrant--Up, Takeoff and Landing. Sadly, the flaps could not be positioned anywhere else. 

Landing his F was considerably different than landing my C with infinitely adjustable flaps, as I often bump the switch gently on final to maintain glideslope.

For go arounds, I push Full Power first, gear up when positive rate on climb, and flaps whenever I think about them. But I rarely use Full Flaps, so it's much less of a deal for me.