Mooney J sticking to runway on take off

[A64Pilot]

16 hours ago, Ragsf15e said:

You really will feel a difference by putting some weight in the baggage compartment and using a more middle cg load as well.

Congrats on the new airplane!

He had 100 lbs of baggage so he should have been pretty neutral if you will.

I normally fly with about 100 lbs in the baggage compt and feel she both flies better that way and seems to even be slightly faster.

A neighbor flies a 182 and carries around two packs of water just for the weight so it’s not just a Mooney thing.

I’d be careful doing that in a Bonanza though.

[A64Pilot]

21 hours ago, PT20J said:

 

2. Many of us prefer Mooney factory test pilot Bob Kromer's "Mooney pull" technique of setting the trim more neutral and beginning the takeoff roll with a pull on yoke, and holding that pull until the airplane rotates, and then releasing it as the airplane reaches climb attitude. This will require no trim change until the flaps are raised.

I don’t think that’s a Mooney thing but is they way I was taught and the way I’ve flown everything nose and tailwheel.

I’ve never flown the Big Iron but I think it’s even they way they do it upon passing Vr, they lift the nose? They don’t let it fly itself off?

However it seems in a Mooney that retracting the flaps does have more of a pitching up moment than average, so not having much nose up trim means you don’t have as much push down until the trim adjusts on takeoff, so it seems even more logical to be trimmed so that a little pull is required for her to fly.

[Pinecone]

20 hours ago, rturbett said:

I'm still looking for the link on where to add the map of where I've been in a Mooney- any hints?

Visited States Map: States Visited Map, States Ive Been To Map, Map of States Visited.

 

[Kelpro999]

 It’s not difficult to verify the nose gear set point if for nothing but piece of mind. Perhaps it’s been through an aggressive attempt at mitigating Mr Toads wild ride. Trim & cg most likely but it’s always good to know.

 

[Ragsf15e]

2 hours ago, A64Pilot said:

He had 100 lbs of baggage so he should have been pretty neutral if you will.

I normally fly with about 100 lbs in the baggage compt and feel she both flies better that way and seems to even be slightly faster.

A neighbor flies a 182 and carries around two packs of water just for the weight so it’s not just a Mooney thing.

I’d be careful doing that in a Bonanza though.

I think he said most of the 100lbs was in the backseat.  If so, cg with 2 adults in the front and 100lbs in the back seat is still pretty far forward.  Move the 100lbs to the luggage, it’ll feel much better.

[Parker_Woodruff]

On 1/8/2024 at 9:08 AM, rturbett said:

With the aircraft loaded well within CG, (two adults, 100lbs baggage mostly in back seat, some in the baggage compartment)  significant force is needed on the elevator to get the plane off the runway and into the air. 

an experienced mooney pilot tried, and noted how tough it was.

I'm looking for potential culprits- the only thing I have come up with is donuts on the nose need to be replaced (mains were done) and I'm wondering if that could lower the angle of attack enough to make us have to pull through it.

we thought the elevator trim indicator might be off- so we put a little extra up in- no real change, and clearly had to hold the nose down once we were in the air.

 

Any thoughts?

Thanks,

Rob

What does the tail section look like from the outside when the trim is in the takeoff position?

You're looking for:

- How do the elevators sit relative to the horizontal stabilizer?

- What's the angle forward of the vertical stabilizer?  If the scheme in your profile picture is current and if it was painted correctly (with the trim in the takeoff position), you'd be able to notice if something was off with the horizontal stabilizer & angle forward of the vertical stabilizer.

 

[hubcap]

A Cessna 172 will fly off the runway when you reach a speed very close to Vr. The angle of attack while in the ground roll is sufficient to cause the plane to fly. 
 

On the other hand you have the Mooney going down the runway and it won’t fly off the runway because the angle of attack while going down the runway isn’t sufficient to cause the plane to fly off with either rotation on the elevator or the “Mooney pull” on the elevator to lift the nose.

The way I prefer to setup my trim is about 1/3 above the top trim line, apply a small amount of back pressure and it flys off the ground at Vr. After flaps up it will require trimming down.
 

The less up trim you set for takeoff will require more back pressure to get airborne at Vr.

[A64Pilot]

16 hours ago, hubcap said:

A Cessna 172 will fly off the runway when you reach a speed very close to Vr. The angle of attack while in the ground roll is sufficient to cause the plane to fly. 
 

On the other hand you have the Mooney going down the runway and it won’t fly off the runway because the angle of attack while going down the runway isn’t sufficient to cause the plane to fly off with either rotation on the elevator or the “Mooney pull” on the elevator to lift the nose.

The way I prefer to setup my trim is about 1/3 above the top trim line, apply a small amount of back pressure and it flys off the ground at Vr. After flaps up it will require trimming down.
 

The less up trim you set for takeoff will require more back pressure to get airborne at Vr.

I think you’re referring to angle of incidence. If a Mooney’s were very low then it would land excessively nose high.

Ref a Maule, where if you do a full stall landing the tailwheel hits with the mains still over a foot off of the ground, BD Maule called it a Ker-plunk landing because when that tailwheel hits it brings the mains down quickly. Maule had a lower angle of incidence seeking a higher cruise speed, which they got.

A Piper Cub by contrast has a high angle of incidence, a big reason why it will fly off at 30 mph or whatever they will, but even with a big motor they won’t go very fast, and the tail will be up high

[Shadrach]

35 minutes ago, A64Pilot said:

I think you’re referring to angle of incidence. If a Mooney’s were very low then it would land excessively nose high.

Ref a Maule, where if you do a full stall landing the tailwheel hits with the mains still over a foot off of the ground, BD Maule called it a Ker-plunk landing because when that tailwheel hits it brings the mains down quickly. Maule had a lower angle of incidence seeking a higher cruise speed, which they got.

A Piper Cub by contrast has a high angle of incidence, a big reason why it will fly off at 30 mph or whatever they will, but even with a big motor they won’t go very fast, and the tail will be up high

Angle of incidence is the angle between the wing chord and the longitudinal axis. Not the ground. The effective AOA at rotaion speed is determined by both by angle of incidence and landing gear geometry. For instance an RV6 and an RV6A have the same angle of incidence but very different AOAs in the 3 point position.

[A64Pilot]

9 minutes ago, Shadrach said:

Angle of incidence is the angle between the wing chord and the longitudinal axis. Not the ground. The effective AOA at rotaion speed is determined by both by angle of incidence and landing gear geometry. For instance an RV6 and an RV6A have the same angle of incidence but very different AOAs in the 3 point position.

I know that but anyone who’s ever flown a nose gear airplane with an underserviced or collapsed front oleo strut knows that the nose down attitude from the gear doesn’t cause any issue. IF and it’s a big if but if the angle of incidence were so low that very little lift were generated then it could, but I’ve never heard of that happening on any aircraft except perhaps those very few that could adjust angle of incidence.

I’d bet lunch that his problem is two fold, first Mooney’s are heavier on the controls than average and trim.

He’s been told twice now I believe to look at where his elevator sits in comparison to the horizontal, I mean it has to be trim, what else could it be?

[Shadrach]

3 minutes ago, A64Pilot said:

I know that but anyone who’s ever flown a nose gear airplane with an underserviced or collapsed front oleo strut knows that the nose down attitude from the gear doesn’t cause any issue. IF and it’s a big if but if the angle of incidence were so low that very little lift were generated then it could, but I’ve never heard of that happening on any aircraft except perhaps those very few that could adjust angle of incidence.

I’d bet lunch that his problem is two fold, first Mooney’s are heavier on the controls than average and trim.

He’s been told twice now I believe to look at where his elevator sits in comparison to the horizontal, I mean it has to be trim, what else could it be?

I agree this is very likely some combination of inexperience and trim position.

[A64Pilot]

54 minutes ago, Shadrach said:

I agree this is very likely some combination of inexperience and trim position.

You know I feel like a fool.

All we needed to tell him was to do a soft field takeoff and see it that fixes it.

[Shadrach]

2 minutes ago, A64Pilot said:

You know I feel like a fool.

All we needed to tell him was to do a soft field takeoff and see it that fixes it.

I feel certain a new Mooney pilot would then shift the conversation to how heavy the elevator feels.

[Pinecone]

FYI, the Aerostar is one plane where the angle of incidence and the gear geometry makes the wing make no or negative lift until you rotate.  No rotate, no take off.

[A64Pilot]

4 hours ago, Pinecone said:

FYI, the Aerostar is one plane where the angle of incidence and the gear geometry makes the wing make no or negative lift until you rotate.  No rotate, no take off.

I can believe that, just looking at a Caribou I wonder the same.

I can see advantage of near zero lift at ground attitude, like more effective brakes etc.

Due to the gear type it’s my understanding that the B-52 and B-47 can’t rotate, so the B-47 sits nose high so it will fly off at that attitude, but on the BUFF they raised the wing angle of incidence to deal with that, if you have the opportunity to watch on departing they do indeed climb nose slightly down , looks weird.

Not sure about the U-2 only time I’ve seen them climb they were going up like a rocket

[PT20J]

I think all airplanes need some elevator input to takeoff properly. 

However, the term "rotation" is really specific to jets. There are certification requirements that the jet begin the rotation maneuver at a specific speed above V₁, at a specified pitch rate, to a specified pitch angle such that the airplane will reach V₂ at or before 35 feet AGL. That's very different than what we do in single engine piston airplanes.

https://www.ecfr.gov/current/title-14/chapter-I/subchapter-C/part-25/subpart-B/subject-group-ECFR14f0e2fcc647a42/section-25.107

 

Edited January 12 by PT20J
Emphasized "properly"

[A64Pilot]

Any small airplane that I’ve flown can easily be trimmed so that they will takeoff without any input elevator wise

I don’t but it’s easily accomplished, in fact everything that I have flown has enough up elevator trim so that if you trim full up at full throttle it will stall.

I did one go-around on my Maule with full up trim, I immediately had to turn loose of the throttle to push the yoke down, but of course had to let go to reduce throttle and roll down trim. It only had manual trim. I know the Maule has a particularly effective trim, but it scared me the pitch up was so extreme. I didn’t need to repeat that maneuver.

I’ve forgotten what the target was but there is a Certification requirement of being able to slow to X airspeed I believe power off, max aft CG and full up trim. I don’t remember it because we easily exceeded it, easy test point no risk. A Thrush also has a very powerful elevator trim, it’s a lever you move that’s located above and aft of the throttle so full up to full down is as fast as shoving the throttle, no rolling a wheel.

You can even of course land most small airplanes with just trim, I say most as I’ve only flown a rather small sample, but it was a stupid pilot trick in a C-152. I had to have 100 hours in airplanes before I could get my a commercial so I did silly things like how high can you get a 152 and how short can you land one etc?

My Mooney and I assume it’s nothing different right after takeoff when flaps are retracted takes a rather substantial amount of down trim, so why would I want to be trimmed so it’s nearly hands off on takeoff? That would just require even more down force until the trim catches up.

[Shadrach]

23 hours ago, Pinecone said:

FYI, the Aerostar is one plane where the angle of incidence and the gear geometry makes the wing make no or negative lift until you rotate.  No rotate, no take off.

It will likely start to wheelbarrow or take off at some point. Neutral AOA on perfectly level ground is one thing, but that’s not representative of real world conditions. 

[Pinecone]

I don't know.  Years ago someone ran one off the end of the runway at KLNS, across the grass, through the airport fence, across a road and into a building.

No, it will not wheelbarrow.  If the wing is at negative AOA, there is no lifting forces.  And the faster you go, the more it gets pushed into the ground.   See aerodynamics on race cars.

[Shadrach]

24 minutes ago, Pinecone said:

I don't know.  Years ago someone ran one off the end of the runway at KLNS, across the grass, through the airport fence, across a road and into a building.

No, it will not wheelbarrow.  If the wing is at negative AOA, there is no lifting forces.  And the faster you go, the more it gets pushed into the ground.   See aerodynamics on race cars.

Now that I think about it, wheel barrowing is a function of tail AOA, not wing AOA. Nevertheless, I don’t think your statement is correct for an air frame with two airfoils. I don’t see how an aircraft in the wheelbarrow position has a positive wing AOA.

[A64Pilot]

2 hours ago, Shadrach said:

It will likely start to wheelbarrow or take off at some point. Neutral AOA on perfectly level ground is one thing, but that’s not representative of real world conditions. 

No, it takes lift to wheel barrow, if anything negative lift will add weight mostly to the mains the faster you go, mostly the mains based on where the center of lift is. negative lift is still lift, just in the opposite direction.

I would suspect with no knowledge that there is still positive lift just not much of it.

on edit reading your above post to wheelbarrow the wing has to be providing lift, just the tail is providing more, enough to put the aircraft in a dive if it had altitude, but as the nose is on the ground it lifts the arse end, remember in level flight the tail produces negative not positive lift, positive lift is pretty unusual in anything resembling normal flight.

If the wing were providing zero lift, then the tail would have to lift the weight of almost the entire aircraft, something I doubt it could do at takeoff or landing airspeed.

[hubcap]

On 1/11/2024 at 1:13 PM, A64Pilot said:

I think you’re referring to angle of incidence. 

I’m sure you are correct. My mistake.

[Smiles201]

Don't know why no one has asked how much the 'two adults' that the OP mentions weighs? Closer to 150 or 250 each? Obviously higher weight especially with seats far forward (short legs) would make any aircraft want to hug the ground.

[A64Pilot]

Went to breakfast this morning, my trim on T/O and landing is set to the M in the word trim on the indicator. 81J, well above the T/O band. I do have to pull to get her to fly, not hard, maybe 5 to 10 lbs? I have no idea if the indicator on mine is the same as other year aircraft.

In flight the trim indicator is set just below the band marked T/O.

I can only imagine if I set mine in the middle of the band marked T/O that it would require a substantial pull to get it to fly.

Foreflight says my CG is at 48.5” full fuel both seats occupied with not small people and 100 lbs in baggage and 5 lbs on the hat rack.

[Pinecone]

On 1/13/2024 at 11:46 AM, Shadrach said:

Now that I think about it, wheel barrowing is a function of tail AOA, not wing AOA. Nevertheless, I don’t think your statement is correct for an air frame with two airfoils. I don’t see how an aircraft in the wheelbarrow position has a positive wing AOA.

Tail normally applies a down force.  You would need a healthy push to get the tail to make upwards lift.

I am talking about NO control input.