Angle, or Vx/Vy on takeoff?

[Boom!]

I'm a low hour student pilot. During ground school both Vx and Vy, and their uses, were drilled into us. Now that I'm flying with an instructor, she has told me to add full power, rotate at Vr, and then pitch for 10° after liftoff. I asked her why I shouldn't simply fly Vx or Vy, and she said she has found the aircraft seems to fly better at a 10° pitch. I can easily do what she says, but I don't want to get any bad habits started.

Is this a big deal, or should I just pitch for 10° and go on?

 

[flyingron]

Vx gives you best angle of climb. Important if you are trying not to hit an obstacle.
Vy gives you best rate of climb. Important if you're trying to get altitude underneath you.
Both are pretty steep and slow. A shallower angle has some other benefits: It lets you see forward better, and it keeps the engine cooler.

You'll have to analyze the situation and pick the best climb regime. Ten degrees sounds pretty flat though.

 

[luvflyin]

I'm a low hour student pilot. During ground school both Vx and Vy, and their uses, were drilled into us. Now that I'm flying with an instructor, she has told me to add full power, rotate at Vr, and then pitch for 10° after liftoff. I asked her why I shouldn't simply fly Vx or Vy, and she said she has found the aircraft seems to fly better at a 10° pitch. I can easily do what she says, but I don't want to get any bad habits started.

Is this a big deal, or should I just pitch for 10° and go on?

What plane do you fly? What speed does 10 degrees give you.

 

[Boom!]

What plane do you fly? What speed does 10 degrees give you.

Cessna 152. I don't remember what speed 10° gives, but I have a flight tomorrow and will make a note of it.

 

[Dan Thomas]

...she said she has found the aircraft seems to fly better at a 10° pitch.

Another instructor making up their own rules. There is a long history of that, and it sometimes results in accidents. Try that 10° pitch in a 150 at gross on a high, hot day and see what happens. Or just push the carb heat back off because the iced-up engine seems to run less roughly that way. Or keep your speed up until you're a foot off the runway "so you don't stall on final," then flare and float, or balloon and maybe land hard, or run off the end of the runway, or wheelbarrow off into the rhubarb, or porpoise until the nosegear breaks, or the tires blow out when you try to stop it. Or make your forced landing in a hayfield with those big round bales and run into one because it's soft and will stop you gently. (No kidding. I heard of a local instructor recommending that. Obviously he'd never walked up to one of those things and beat on it or tried to roll it.)

The stuff in the textbooks has ALL been learned the hard way, with blood and bent metal. You don't have to learn the stuff the hard way. You won't live long enough to learn it all.

 

[flyingron]

Another instructor making up their own rules. There is a long history of that, and it sometimes results in accidents.

While I agree 10 degrees sounds flat, the "book" doesn't say climb at Vy or Vx either. Here are the speeds in the book:

Climb, Flaps Up:
Normal .............................................................................................................. 70-80 KIAS
Best Rate of Climb, Sea Level ................................................................................ 67 KIAS
Best Rate of Climb, 10,000 Feet ............................................................................ 61 KIAS
Best Angle of Climb, Sea Level thru 10,000 Feet ................................................... 55 KIAS

 

[Chrisgoesflying]

I would not do that. I'd go by the book at least until you're 500 ft. AGL. Number one, you do want to gain altitude as efficiently as possible to get space between you and things that could hit you. Number two, your examiner will judge you by published speeds +/- some tolerance (not sure what the latest tolerances are). I personally routinely lower my nose somewhat after I reach 500 ft AGL to keep the engine cooler, increase visibility and such. To be fair, by 1,000 ft. AGL I also reduce manifold pressure and dial back RPM slightly. If you do that during your check-ride and can explain why you do that to the examiner, I doubt they'll ding you for it but I'm sure they will if you completely ignore the book numbers and use some CFI made up process.

 

[dmspilot]

I'm a low hour student pilot. During ground school both Vx and Vy, and their uses, were drilled into us. Now that I'm flying with an instructor, she has told me to add full power, rotate at Vr, and then pitch for 10° after liftoff. I asked her why I shouldn't simply fly Vx or Vy, and she said she has found the aircraft seems to fly better at a 10° pitch. I can easily do what she says, but I don't want to get any bad habits started.

Is this a big deal, or should I just pitch for 10° and go on?

Your instructor is an idiot.

 

[RyanB]

7-10 degrees nose up is about that of Vy and is how I teach instrument students in the event of a missed approach pitch attitude. That said, in your case, I would fly Vy as published. Whatever that speed is for your airplane.

 

[farangutan]

Pitch + Power = Performance. Somewhere around 7.5 degrees and full power yields Vy in most of the Cessna trainers I've been flying lately around sea level in Florida.

 

[Clip4]

I'm a low hour student pilot. During ground school both Vx and Vy, and their uses, were drilled into us. Now that I'm flying with an instructor, she has told me to add full power, rotate at Vr, and then pitch for 10° after liftoff. I asked her why I shouldn't simply fly Vx or Vy, and she said she has found the aircraft seems to fly better at a 10° pitch. I can easily do what she says, but I don't want to get any bad habits started.

Is this a big deal, or should I just pitch for 10° and go on?

If your instructor is advising you to establish a 10° pitch attitude by using the attitude indicator, she is not instructing you properly.

 

[Clip4]

7-10 degrees nose up is about that of Vy and is how I teach instrument students in the event of a missed approach pitch attitude. That said, in your case, I would fly Vy as published. Whatever that speed is for your airplane.

Missed approach, sure because you are training for IMC. For primary flight instruction in VMC
, you should be using integrated flight instruction. This means establishing the pitch which will result in Vy by references outside the cabin and instruments.

 

[flyingron]

7-10 degrees nose up is about that of Vy and is how I teach instrument students in the event of a missed approach pitch attitude. That said, in your case, I would fly Vy as published. Whatever that speed is for your airplane.

Or better yet, fly what the book tells you, rather than either an idiot instructor SGOTI.

 

[farangutan]

That's right, you should be looking outside to establish climb attitude and crosscheck with instruments.

 

[dans2992]

I’d like to point out that in more sophisticated aircraft, when you line up for takeoff and press TOGA, the flight director directs a certain pitch angle. Transition to a specific climb speed is really only done AFTER takeoff and things are stabilized.

So, I’m not so sure if we should be piling on and calling the instructor an idiot. Perhaps there’s something missing in translation here.

Vr for me is 85, and Vy is 122. What do you do after rotation but before 122? Follow the flight director.

 

[MauleSkinner]

Here’s what the ACS says for a normal takeoff…

PA.IV.A.S11 Establish a pitch attitude to maintain the manufacturer’s recommended speed or VY, +10/-5 knots.

PA.IV.A.S12 Configure the airplane in accordance with manufacturer’s guidance.

PA.IV.A.S13 Maintain VY +10/-5 knots to a safe maneuvering altitude

If 10 degrees of pitch does that, you’re golden…assuming the density altitude at which you’re operating is relatively constant. But as @Clip4 noted, this should probably be via an outside pitch reference, occasionally crosschecked against the instruments.

You also need to have a conversation with your instructor…

she said she has found the aircraft seems to fly better at a 10° pitch.

Specifically how does the airplane “fly better” at 10 degrees of pitch, and is there a point at which 10 degrees isn’t a good pitch attitude to use? For example, if you go up to 6000 feet, slow to liftoff speed, and establish 10 degrees pitch with full throttle, does it still “fly better?”

It’s easy to find gouges that work well in specific circumstances, but I used to work for a guy who landed a Baron with about 7 minutes of fuel on board because his flight didn’t match the circumstances that the owner assumed when with “you can fly this airplane for 4 1/2 hours.”

 

[Dana]

In defense of the instructor, she may be saying not so much to pitch to exactly 10°, but to get your eyes outside of the cockpit when close to the ground and establish a pitch attitude that looks right, rather than staring at the instruments and chasing an airspeed number before the airplane has accelerated and climbed out of ground effect. You need to know what a proper climb attitude looks like, without looking at an instrument that may fail. I'm not saying you shouldn't be glancing at the instruments to crosscheck, but it shouldn't be the main way you hold the climb angle. A pitch deviation is immediately obvious if you're looking outside, but an airspeed change is slower to respond.

 

[Tools]

the flight director directs a certain pitch angle.

The flight director CALCULATES a pitch… it changes based on “things”.

Or it may pitch to this or that then adjust for “things”.

Mindlessly going to 10 is, as adequately mentioned, dumb.

Ask them, “why 10?” This will be revealing.

 

[rhkennerly]

I’d get off the instructor’s back.

Numbers or marks on instruments are merely crutches for you to get started. With experience you will develop both a pilot’s “eye” and a pilot’s “feel” for what is right for that specific airplane. Eventually, you will throw away your crutches.

Beginning students have a lot of new and very different inputs and sensations to juggle all at once. A quick check of the artificial horizon while matching it to the actual horizon and glancing at the angle of attack on the wing and comparing it to airspeed are useful benchmarks for learning.

VX is when you need to get over a specific obstacle. Vy is to get to cruise altitude while also making time over the ground. VX or VY all depends on what’s in front of you and what your mission is.

Just starting out, do what your instructors says. Eventually, especially in a C150, you will just “know” when it’s time to rotate, you will learn when the plane “feels” ready to start flying, and you will judge by eye whether or not you are going to clear an obstacle and you will let go of numbers and instruments other than using them as a check on what you are feeling and seeing.

Later in your training, under the hood and such, specific attitude management by instruments will be required. But right now, learn to fly the plane and have a blast. Trust you will throw away your crutches.

 

[geezer]

Learn what pitch angle your training plane has at Vx and Vy, AS YOU SEE IT OUT THE WINDOWS of your trainer. Your focus needs to be out there to stay safe with the traffic and obstructions. That is often referred to as the "Mark 1 eyeball, and swiveling neck".

This may be the intention of this CFI. If so, I agree. Until you are miles from the airport, little time should be focused inside, and that on an accurate scan of the instruments.

 

[dans2992]

The flight director CALCULATES a pitch… it changes based on “things”.

Or it may pitch to this or that then adjust for “things”.

Mindlessly going to 10 is, as adequately mentioned, dumb.

Ask them, “why 10?” This will be revealing.

At least in my aircraft; there is no “calculation” for takeoff pitch. It’s 9-degrees when TOGA is activated pre-takeoff. Period. Per the POH.

 

[dmspilot]

I’d get off the instructor’s back.

I wouldn't. Improper instruction deserves to be admonished.

Numbers or marks on instruments are merely crutches for you to get started.

That would contradict the law of primacy. At no point in the AFH discussion on takeoffs and climbs does it recommend or even allude to using the attitude indicator to establish and hold a specific pitch angle. It is not a valid teaching technique, especially not for a new student "to get started."

 

[rhkennerly]

Folks, this is a c150 we’re talking about. God’s forfend learning to fly the wing, you know without flight directors, artificial horizons, or an airspeed indicator that is not bouncing 10 mph on a hot summer day. Forget the books & the gizmos & learn to pilot the plane.

 

[dans2992]

Folks, this is a c150 we’re talking about. God’s forfend learning to fly the wing, you know without flight directors, artificial horizons, or an airspeed indicator that is not bouncing 10 mph on a hot summer day.

Ok, but you’re going to have to learn something different when it’s 200 and 1/2 and you line up for departure….

 

[dmspilot]

https://www.faa.gov/sites/faa.gov/files/regulations_policies/handbooks_manuals/aviation/airplane_handbook/07_afh_ch6.pdf

 

[RussR]

The flight director CALCULATES a pitch… it changes based on “things”.

Or it may pitch to this or that then adjust for “things”.

Not in TOGA mode in any airplane I ever flown. Its a preset pitch attitude depending on the airplane. For example, 12 deg in the Challenger 605 I flew today

Yes, the FD calculates pitch in other modes (except, of course, Pitch mode) depending on lots of factors, but that's not what the post you were responding to was discussing.

 

[nauga]

The flight director CALCULATES a pitch… it changes based on “things”.

In the G3X at least it's installer-defined during installation and fixed during operation. I'm not aware of any piston single system that has TOGA pitch attitude that varies on engagement (but I'm willing to learn).

Nauga,
who flies the box to avoid the rocks

 

[RyanB]

Missed approach, sure because you are training for IMC. For primary flight instruction in VMC
, you should be using integrated flight instruction. This means establishing the pitch which will result in Vy by references outside the cabin and instruments.

Which is………EXACTLY what I said.

 

[brcase]

My opinion is your instructor is overcomplicating a pretty simple concept and/or likely not explaining or even understanding why.

What she should be saying is after you rotate put the cowling on the horizon. This likely roughly equates to 10 degrees of pitch up on your attitude indicator. But you shouldn't be looking at your attitude indicator. GA attitude indicators simply are not precise enough to use for anything but a general pitch attitude and the Airspeed indicator should be used to refine the actual pitch angle to use.
As an experiment try changing your airspeed only 5 or 10mph using only the attitude indicator. It can be done but, you will quickly find it it easier to do so by looking out the windshield for small and precise attitude changes, resulting in small and precise airspeed changes.

As mentioned some larger aircraft do use pitch attitude vs airspeed. Others actually use an angle of attack indicator. Using pitch vs airspeed is a good way to compensate for various weights and g-loading of an aircraft. A C-150 doesn't change weight enough to make a noticeable difference in the best indicated airspeed, and in a climb the G-load should be anything other than about 1G.

Vy is pretty close to the ideal minimum drag angle of attack resulting in the most excess horsepower resulting in the best climb rate. As weight changes Vy speed changes as does the amount of excess horsepower and resulting climb rate. But angle of attack should remain the same.

Your instructor is technically correct holding a specific attitude in most steady state cases will result in a specific efficiency of the climb. But unless you have a very fancy attitude indicator letting you accurately hold that angle plus or minus a degree or two, you are better off holding it looking out windshield and checking it with airspeed indicator.

Brian
CFIIG/ASEL

 

[RyanB]

What she should be saying is after you rotate put the cowling on the horizon. This likely roughly equates to 10 degrees of pitch up on your attitude indicator.

Bingo!

 

[BillTIZ]

The DPE will expect Vx or Vy airspeeds, not pitch control.
Heaven forbid you ever fly an airplane with no attitude indicator. There are a lot of airplanes out there with no attitude, or pitch indication.

 

[Kenny Phillips]

Nose on horizon, on the ancient 172 I fly. I don't look inside much, except to make sure I'm slow enough for flaps.

 

[Dana]

Vy is to get to cruise altitude while also making time over the ground.

Not quite. Vy is to maximize the rate of climb, to get to altitude in the minimum time. If you're also considering time over the ground, you'll be doing a cruise climb, faster and lower pitch angle than Vy (which is very slow).

Ok, but you’re going to have to learn something different when it’s 200 and 1/2 and you line up for departure….

If the student goes in that direction. Many of us are never in that situation.

What she should be saying is after you rotate put the cowling on the horizon. This likely roughly equates to 10 degrees of pitch up on your attitude indicator. But you shouldn't be looking at your attitude indicator. GA attitude indicators simply are not precise enough...

I agree. But the OP never once mentioned the attitude indicator.

My CFI was fond of covering the instruments, especially the AI and ASI, to force the student to look outside. I guess it stuck; I've never owned an airplane with an AI and an ASI failure (it's happened a couple of times) is an inconvenience, not even a problem and certainly not an emergency.

 

[MauleSkinner]

But the OP never once mentioned the attitude indicator.

Nor did the OP mention looking out the window. Unless it’s clarified, we’re all making assumptions.

 

[dtuuri]

What she should be saying is after you rotate put the cowling on the horizon.

Brian
CFIIG/ASEL

...In spades.

 

[Clip4]

I’d like to point out that in more sophisticated aircraft, when you line up for takeoff and press TOGA, the flight director directs a certain pitch angle. Transition to a specific climb speed is really only done AFTER takeoff and things are stabilized.

So, I’m not so sure if we should be piling on and calling the instructor an idiot. Perhaps there’s something missing in translation here.

Vr for me is 85, and Vy is 122. What do you do after rotation but before 122? Follow the flight director.

I would like to point out that 99% of student pilots are not flying an aircraft with a TOGA button, autopilot and a flight director.

 

[sarangan]

I'm a low hour student pilot. During ground school both Vx and Vy, and their uses, were drilled into us. Now that I'm flying with an instructor, she has told me to add full power, rotate at Vr, and then pitch for 10° after liftoff. I asked her why I shouldn't simply fly Vx or Vy, and she said she has found the aircraft seems to fly better at a 10° pitch. I can easily do what she says, but I don't want to get any bad habits started.

Is this a big deal, or should I just pitch for 10° and go on?

Don't over analyze it. Vy, Vx or a pitch angle are all fine as long as you know what they all do. It is a compromise between forward visibility, climb angle and climb rate. You are not flying an Airbus at the edge of its performance envelope. The goal here is to learn the feel for each configuration. Also, you mentioned "rotate at Vr". I would say you should instead listen to the airplane - it will tell you when it is ready to lift off. At this stage you should be focused on developing that 'feel' instead of hitting precise numbers like a robot.

 

[Mikey52]

The DPE will expect Vx or Vy airspeeds, not pitch control.
Heaven forbid you ever fly an airplane with no attitude indicator. There are a lot of airplanes out there with no attitude, or pitch indication.

Yep, flew cessna ag trucks for a couple years. Sure was tough when you entered a fog bank by accident.

 

[Brad Z]

Your instructor is an idiot.

I’m going to give the instructor some grace and imagine the conversation went something like:

Instructor: ”…okay once established in a climb let’s pitch for Vx of 55 knots until we clear obstacles, which in this plane with this configuration is roughly 10 degrees above the horizon…”
Student: “mmmkay”

What student heard:
Instructor “wah-wah-wah vee ex wah-wah wah 10 degrees wah wah wah…”

But seriously, if her reasoning is “planes fly better at 10 degrees” not taking into consideration performance, weight, density altitude, etc., then yeah she needs some remedial training herself.

I’m glad the student is pushing back and asking here.

 

[Dan Thomas]

What she should be saying is after you rotate put the cowling on the horizon.

If she does that, a tall student might raise the nose to stall attitude. A short student will be flying almost level. Neither are satisfactory.

We all know what Vx and Vy are for, and the airspeed indicator tells us to raise the nose or lower it. We don't need an attitude indicator. The student will quickly learn where the horizon belongs on the nose when he's at the correct airspeed. The POH is too often ignored.

As DMSpilot says, teachings that violate primacy are not smart. They can cripple the student. Primacy is one of the Seven Learning Factors, and is described like this:

PRIMACY - Present new knowledge or skills correctly the first time. (Teach it right the first time.)

(a) When students are presented with new knowledge or skills, the first impression received is almost unshakeable. This means that what you teach must be correct the first time. Students may forget the details of lessons, but will retain an overall image of the skill or knowledge for a long time. Frequently you will be required to perform manoeuvres in the aircraft before a student has had the necessary background training. You must perform those manoeuvres correctly or the student may imitate any errors you make. For example, before the exercise on cross-wind landings, you and your student are required to land in a cross-wind. Any poor example shown at this time would have to be "unlearned" when the exercise came up in a subsequent lesson.