When retract gear at take off at short fields

[NicoN]

There is a interesting discussion going on on beechtalk about the right order and timing to retract gear and flaps during a short field take-off.

The opinion of some speakers is that a gear in transition creates far more drag and kills climb performance than a fully extended gear.

So, they recommend not to touch the gear until you reach your safe altitude.

 

Does this only apply to Bonanzas or is the Mooney also suffering while the gear is in transition?

At least for me (with an M20K) the take-off performance is dependant on keeping the MAP below limits. Though, I think I personallay waste more performance on the startup-run than later in the air.

 

 

[GeeBee]

It depends. On the Beech airplanes (except for Sierra and Duchess), the inner gear doors open and create an increase in drag during retraction, somewhat substantial I might add.. So leave them down. On a Mooney, the only direction for drag to go on retraction is to decrease, so suck them up right away although if you are that close on performance, you probably should not be operating out of that field. Also your attention is better placed on airspeed control than looking for the gear switch. 

 

[Hank]

My gear are up by treetop level anyway, regardless of runway length. Transit is only a few seconds, unless you have the 40:1 gears which take a few more seconds.

Left mine down once on a busy IMC departure from a rare towered field, took a minute to determine the cause for my abysmal climb rate in the clouds--raised the gear and went right up.

So my experience is that climb rate is much better with the gear up.

[David Lloyd]

Another factor with the Beechcraft, the 12 volt Bo's retract time was about 10 seconds. Clear the trees then retract the gear.

[steingar]

If the aircraft has the J-bar there is little choice.  Gotta get the gear up before the airplane gets too fast.  Of course, the swing is sufficiently fast to not generate much in the way of drag.  Pity the Bo drivers, they don't have J-bars.

[RobertGary1]

Mentally you don’t want to establish an automatic reaction between leaving the runway and pulling up the gear. The habit of grabbing it without thinking can bite you at some point. So you want to wait long enough to transition your thought process from take off to climb. I’ll often tell students to take a relaxing breath, do a gauge scan (including positive rate) and then pull them up. 
 

-Robert 

[Hank]

11 minutes ago, RobertGary1 said:

Mentally you don’t want to establish an automatic reaction between leaving the runway and pulling up the gear. The habit of grabbing it without thinking can bite you at some point. So you want to wait long enough to transition your thought process from take off to climb. I’ll often tell students to take a relaxing breath, do a gauge scan (including positive rate) and then pull them up. 
 

-Robert 

Yep. Lift off, verify track, verify positive rate, move that little round white knob and climb for Vx, relaxing to Vy when clear of obstacles. 

[Andy95W]

But what about using flaps on takeoff?  Will that change the sequence? 

[BradB]

Retracting the gear depends on the airplane and the mechanism.  The Mooney gear transitions so quickly, that you can get it up and back down in a hurry if needed.   In the Meridian, it is a 7 second process in each direction.  It also requires a 90 degree turn of the nose wheel as it comes up or down.    This results in a definite yaw motion during the transition.  I’m not sure that it is enough to significantly affect performance during the climb, but I tend to leave the gear down until there is no useable runway left for me to use if I had to land.  

And for question 2:  Gear then flaps.

Fly Safe,

Bradb

2006 Meridian N951TB

Former Acclaim

[RobertGary1]

28 minutes ago, BradB said:

And for question 2:  Gear then flaps.

 

On my Commercial multi checkride on a go around I raised the gear before the flaps because the gear handle is much closer and my DPE freaked out. Then he talked about how scary it was to do it in that order and asked if the POH prohibited it. I asked my MEI about it afterwards and we both scratched out heads. This DPE was certainly not a normal guy so it could have been him or maybe there is some mystery out there I just haven't discovered yet. Only reason anyone uses this guy is because he's the only one that isn't booked out 6-8 weeks.

 

-Robert

Edited October 22, 2019 by RobertGary1

[BradB]

Go Around is a different animal than takeoff.  You’ll have more flaps.

Go-Around = Flaps. Gear. Flaps. Flaps.   (I have 3 flap positions.  In the Mooney I did Flaps. Gear. Flaps.)

Maybe one of the other Acclaim drivers will pitch in and explain how dramatic the pitch up is with power addition on the go around.  It isn’t subtle.  I believe it’s was discussed on another thread in the past.  

Bradb

2006 Meridian N951TB

 

Edited October 22, 2019 by BradB

[Deb]

For the Ovation 2 there is a note on the “Takeoff Distance” chart stating:

Landing gear: Down until obstacle cleared

and in the Normal Procedures, Takeoff checklist:

Edited October 22, 2019 by Deb
Added: Normal Procedures, Takeoff checklist

[skydvrboy]

If it's truly a short field (under 1500' of runway or 50' obstacles within 2,500' near sea level) this is what I do...

• Leave the ground ASAP
• Stay in ground effect
• Make sure you aren't going to settle back to the runway (still in ground effect)
• Bring the gear up (still in ground effect)
• Accelerate to Vx (still in ground effect)
• Climb above the obstacle(s)
• Accelerate to Vy
• Dump the flaps

If I'm at a high density altitude, takeoff is with no flaps to reduce drag and in order to climb out of ground effect.

[BradB]

There you go @Deb , confusing us with facts.

Although, that is listed under the “conditions” box.   To me this indicates that you can expect that performance in those conditions.    It doesn’t say that changing “conditions” won’t improve performance.    Maybe, higher headwind.  Maybe, gear up sooner.    Maybe temporary decrease in gravity.

And not to be picky, but the chart you show also seems to be for ‘Hard surface - normal takeoff.’   I think the OP is looking for Max performance takeoff/climb data.

My POH lists my maximum landing performance data without the use of reversing the prop.   That certainly shortens the roll-out, but under ‘conditions’ - No Prop Reverse.

I’m always open to being wrong.

Bradb

 

Edited October 22, 2019 by BradB

[midlifeflyer]

6 hours ago, steingar said:

If the aircraft has the J-bar there is little choice.  Gotta get the gear up before the airplane gets too fast. 

Definitely well before Vy. But isn't Vx for obstacles about 80? That's slow enough to make later gear retraction an option.

[steingar]

Just now, midlifeflyer said:

Definitely well before Vy. But isn't Vx for obstacles about 80? That's slow enough to make later gear retraction an option.

If you're trying to get over obstacles off a short field you want to be as slick as you can get.  Gear generates oodles of drag.  Don't believe me?  Try leaving it down some time.  If you want out of a shot occluded field you clean up the airframe quick as you can, you'll have that much more energy to muscle yourself out of there.  The J-bar is a dream come true in such situations, gear comes up super fast.  If I'm in that big a hurry I get the gear up just as soon as I'm certain I'm not going to settle back down.

I'll be the first to admit I don't do this often.  I didn't buy  Mooney to land in mudholes in the wilderness.

[Guitarmaster]

Put the gear handle up at the beginning of the takeoff roll and let the squat switch take care of it.

[Obviously this a joke]. Sometimes I have to clarify.

Sent from my Pixel 2 XL using Tapatalk

[Gone]

5 hours ago, BradB said:

Go Around is a different animal than takeoff.  You’ll have more flaps.

Go-Around = Flaps. Gear. Flaps. Flaps.   (I have 3 flap positions.  In the Mooney I did Flaps. Gear. Flaps.)

Maybe one of the other Acclaim drivers will pitch in and explain how dramatic the pitch up is with power addition on the go around.  It isn’t subtle.  I believe it’s was discussed on another thread in the past.  

Bradb

2006 Meridian N951TB

 

Brad:  Not the same issue for short body Mooneys with a Johnson bar.  Two pumps of flaps (10 degrees or so) is the same for takeoff as for go round (and standard approach) in my E model.  More flaps do not create more lift - just more drag.  

For me, gear up on running out of runway room (or need to keep it down) or 500', whichever comes first and flaps at 1000'. Altitude is life.  If I am worried about clearance and/or climb performance, Vx,  if not, Vy.  At 1000', retract flaps, lower nose to get to Carson speed climb (= best glide (Vy) X 1.316 = 105 mph X 1.316 = 135 mph or so).  See Norm Howell's thesis paper on it.

 

[Yetti]

Plane comes up. pause. Gear comes up.  slight nose down, get the wing flying.  nose up.  pause flaps up.

[Hank]

12 minutes ago, Yetti said:

Plane comes up. pause. Gear comes up.  slight nose down, get the wing flying.  nose up.  pause flaps up if used.

FTFY.  

[midlifeflyer]

3 hours ago, steingar said:

If you're trying to get over obstacles off a short field you want to be as slick as you can get.  Gear generates oodles of drag.  Don't believe me?  Try leaving it down some time.  If you want out of a shot occluded field you clean up the airframe quick as you can, you'll have that much more energy to muscle yourself out of there.  The J-bar is a dream come true in such situations, gear comes up super fast.  If I'm in that big a hurry I get the gear up just as soon as I'm certain I'm not going to settle back down.

I'll be the first to admit I don't do this often.  I didn't buy  Mooney to land in mudholes in the wilderness.

I don't disbelieve you at all.  Notice the comment I was specifically responding to.

[Shadrach]

9 hours ago, RobertGary1 said:

On my Commercial multi checkride on a go around I raised the gear before the flaps because the gear handle is much closer and my DPE freaked out. Then he talked about how scary it was to do it in that order and asked if the POH prohibited it. I asked my MEI about it afterwards and we both scratched out heads. This DPE was certainly not a normal guy so it could have been him or maybe there is some mystery out there I just haven't discovered yet. Only reason anyone uses this guy is because he's the only one that isn't booked out 6-8 weeks.

 

-Robert

Freaking out over that makes one wonder how he would handle an actual emergency. It makes perfect sense to raise gear first and it’s not uncommon.

[Shadrach]

5 hours ago, midlifeflyer said:

Definitely well before Vy. But isn't Vx for obstacles about 80? That's slow enough to make later gear retraction an option.

94mph or 82kts is Vx in my F.  Not a problem to retract at that speed but noticeably different from retracting at say positive rate. I think the difficulty in retracting the gear at higher speeds is overstated though it does get heavy as you approach V_LO

[PT20J]

13 hours ago, RobertGary1 said:

On my Commercial multi checkride on a go around I raised the gear before the flaps because the gear handle is much closer and my DPE freaked out. Then he talked about how scary it was to do it in that order and asked if the POH prohibited it. I asked my MEI about it afterwards and we both scratched out heads. This DPE was certainly not a normal guy so it could have been him or maybe there is some mystery out there I just haven't discovered yet. Only reason anyone uses this guy is because he's the only one that isn't booked out 6-8 weeks.

 

-Robert

In most airplanes, it makes sense on a go around to get the airplane set up in the initial climb configuration as quickly as possible. Usually, the flaps move quicker than the gear, so the landing flaps come off first and then the gear comes up. It’s just more efficient that way. Another reason for this order is that larger, heavier airplanes will continue down hill for a bit even as go around power is added and pitch adjusted for climb and you don’t want to raise the gear until you are sure you are not going to contact the runway. In the DC-3 for instance a go around initiated much below 200 feet will frequently result in a touch and go.  In a light twin at low altitude, and beginning the go around from DA or greater, it doesn’t really matter. But for a go around from 50’ at high density altitude, flaps first might be a better idea. 

Skip

 

Edited October 23, 2019 by PT20J

[carusoam]

the important thing to know is...

To get POH performance, you have to follow POH procedure...

 

It is possible to get better performance than POH... but that requires proof that you can get by being a test pilot...

Do your test data collection before using ideas you found on BT...

We know gear doors cause a fair amount of drag...

They cause the challenge of raising the gear when going too fast... the doors are mounted at a slight outward angle... they very much power the downward pull of the gear at speed...

 

Realistically, departure and clearing trees... the airspeed isn’t fast enough to cause a lot of drag...

 

I’m pretty sure the T/O procedure is being simplified so we don’t accidentally Mooney dip into the trees... or be off speed while doing other things...

Missing paying attention during this critical phase can prove disastrous...

Use the precision required to achieve the performance that is required...

 

A long body has inner gear doors...probably negligible added drag being added during the gear stowage...

 

Best to follow the POH steps to achieve POH performance...

Always use the entire runway... running into trees has ended a couple of MSer flights before their time...

PP thoughts only, not a CFI...

Best regards,

-a-