Flap Retract on Takeoff

[carusoam]

That’s a great follow-up, Moontown...

That’s in the fix as soon as practable category...

Be extra careful when taking flaps out...  when the snap back at that speed...
 

During slow flight, such as a go around... it could be disastrous...

Pp thoughts only, not a CFI...

Best regards,

-a-

[Tcraft938]

Very interesting post. My checkout in the C last year I was told if no significant obstacles get positive climb and under control out manual gear up and that 85mph or a little less is optimum speed to do that with least effort. If ready with trim the pitch change not bad and you will be accelerating through 90-95 mph by then and put the flaps up pitch to hold that speed until 500’ AGL so can return if needed and then let it accelerated to 110 to 120 mph for cooling (I’m breaking in a new engine so cool is the focus). Climb rate is very good at that speed. 
I recently did a couple of takeoffs with flaps up. I did not notice any real change in the amount of runway used. I got to a higher altitude by the end of the runway than with using flaps and it rotated and lifts off the runway much smoother than with flaps. I’m sure flaps are better if heavy and/or hot or obstacles, but at our low level 4000’ paved runway and just me and one other I will likely keep the flaps stowed much if the time. The only thing I don’t like about that is it changes a routine and easy to forget them some day when I use them 

[Hank]

2 hours ago, Tcraft938 said:

I recently did a couple of takeoffs with flaps up. I did not notice any real change in the amount of runway used. I got to a higher altitude by the end of the runway than with using flaps and it rotated and lifts off the runway much smoother than with flaps.

My standard takeoff in my C is no flaps, trim set a tiny bit nose up from the Takeoff mark. Positive rate, on course,  gear up. Worked well at my 3000' long obstructed home field for 7 years.

When heavy (going on vacation, or 4 adults for dinner), add Takeoff flaps and put trim on Takeoff mark. When I'm looking down at the trees, flaps up.

It's worked well for me even when departing GSP (12,000 feet long, no flaps needed).

Thoughts and experiences of a PP, not CFI . . . .

[carusoam]

12 hours ago, Tcraft938 said:

Very interesting post. My checkout in the C last year I was told if no significant obstacles get positive climb and under control out manual gear up and that 85mph or a little less is optimum speed to do that with least effort. If ready with trim the pitch change not bad and you will be accelerating through 90-95 mph by then and put the flaps up pitch to hold that speed until 500’ AGL so can return if needed and then let it accelerated to 110 to 120 mph for cooling (I’m breaking in a new engine so cool is the focus). Climb rate is very good at that speed. 
I recently did a couple of takeoffs with flaps up. I did not notice any real change in the amount of runway used. I got to a higher altitude by the end of the runway than with using flaps and it rotated and lifts off the runway much smoother than with flaps. I’m sure flaps are better if heavy and/or hot or obstacles, but at our low level 4000’ paved runway and just me and one other I will likely keep the flaps stowed much if the time. The only thing I don’t like about that is it changes a routine and easy to forget them some day when I use them 

There are actual methods of measuring T/O performance...

Going on a feeling, or what you notice is going to lead to disappointment...

Its possible your flaps don’t change anything very much...

Use an app like CloudAhoy combined with a portable waas gps...

You can generate real data, on your plane, while you fly it...

With that data you can clearly see if they work, don’t work, or how much they work...

Hard to really trust POH data written in the 60s... when POH data didn’t get filled in until the mid 70s....
 

Use the app  To compare Your plane against actual data...

Why this is important... you have a new engine being broken in... collect data to see how it is really performing... know that you Got your money’s worth...   
 

Nothing cooler than that...

Speaking of cooler... got an engine monitor watching your chts?
 

PP thoughts only, not a techno guy...

Best regards,

-a-

[Tcraft938]

Not the latest engine monitor but I do have the data. I have a sheet where I record the various parameters for each phase of flight. 384 in the climb is highest CHT I have seen.  Cylinder 3 is consistently the warmest in climb by about 25 degrees. Cruise everything settles to around 310 to 330.  TAS is at book or better at 75% any altitude. Climb is better. However it is new scimitar prop so that could change things some. Fuel burn climb and cruise data indicate it is making the power or more. So far very happy with Penn Yan Aero and the support they provide. 

[carusoam]

Often, during the break-in flights of new or OH’d cylinders...

The CHTs take a noticeable drop signifying the break-in has been effective... something to do with the rings matching the cylinders better...

I was hoping to see this occur during my break-in flights... Thought it would get caught on the monitor...  I think what happened.... the break-in was mostly completed before the engine left the factory...  

Best regards,

-a-

[brndiar]

I recently did a  takeoff with flaps up  at MTOW.

.... Concrete RWY, cca 6500 ft long, 25C OAT, Airport 2500 at ft altitude.... slowly rising terrain in the direction of the start.....

...I will never ever start without a flaps  at MTOW, regardless of the lenght of the RWY.....

 

lg,

m

[MBDiagMan]

I flew my Johnson Bar C differently from my electric gear F.  At that point, with most of my time in a Cessna 140, my attitude was “I don’t need no stinking flaps!”  The routine I developed with it was to get the gear up at about 80 to make it an easier tug.  I didn’t use flaps.  After hurting my shoulder and being forced into an electric gear plane, a respected an retired career pilot friend flew with me and got into my head that I was now flying a complex airplane ad should fly it like one.  So, I still had the gear retraction in my routine And would bring it up upon seeing positive rate of climb.  After gear made it up and a red light, I would dump the flaps.

Today, I have gotten where I might use 1/4 flaps on takeoff and I might not, but when I do that’s when I get rid of them.  The F is gaining speed well during climb, so I may have 90 or more by the time I retract flaps.

What my pilot friend and Don Maxwell added to my routine was full flap landings.  I had lots of trouble at first, but full flaps and near full nose up trim I can get it down and bleed off speed until it settles.  Thanks to these two guys I feel more at home in something besides a little taildragger.

[BigTex]

I've read somewhere that full retraction of the flaps should be around 12 seconds.  In my plane, it was closer to two seconds!  So unless I wanted to have a laundry problem with my passengers I had to milk the flaps up (assuming I used them at all).  Well during my last annual, the mechanic noticed that the rod leaving my flap pump was bent.  After attempting to fix it, he ended up sending it to LASER to be rebuilt.  Now, my laps retract very close to the 12 second time-frame.  It's so nice to be able to bring the flaps up without feeling like your on a Disney amusement ride!

Edited August 29, 2020 by BigTex

[N201MKTurbo]

1 hour ago, BigTex said:

I've read somewhere that full retraction of the flaps should be around 12 seconds.  In my plane, it was closer to two seconds!  So unless I wanted to have a laundry problem with my passengers I had to milk the flaps up (assuming I used them at all).  Well during my last annual, the mechanic noticed that the rod leaving my flap pump was bent.  After attempting to fix it, he ended up sending it to LASER to be rebuilt.  Now, my laps retract very close to the 12 second time-frame.  It's so nice to be able to bring the flaps up without feeling like your on a Disney amusement ride!

That’s an easy adjustment on the pump. The adjustment is very sensitive. If you pull up on the flaps with a fair amount of pressure (very scientific) you can simulate air loads and get it very close to how it will behave in the air.

[BigTex]

It's kind of what you get used to right?  I've always known forever that I could have that adjusted but never got around to having it done.  Also, all the adjustments in the world would not fix a bent flap Pump Rod (referring to my Mooney, not me!  ).   Not until I had to have it overhauled did I experience how flaps were supposed to retract!