Another useful idea from Bob Kromer at Summit

[exM20K]

The M20TN POH has this in the climb tables:

 

I assume these values are arrived at via flight test.  POH guidance is to leave gear and flaps alone until clear of obstacle.  I'm glad they did this in the POH; note the huge span of liftoff speeds.

-dan

 

Edited October 5, 2018 by exM20K

[Bob - S50]

1 hour ago, Mooneymite said:

Nope.

Alrighty then.  I guess there is only one way to fly an airplane.  I stand corrected.

[Mooneymite]

23 minutes ago, Bob - S50 said:

Alrighty then.  I guess there is only one way to fly an airplane.  I stand corrected.

There are thousands of ways to fly an airplane, but some are better than others.  Physics, not opinions matter in cases of performance.

At an airline with thousands of pilots, there would be thousands of ways to fly, but an airline establishes SOPs, or "best practices" based on what optimizes and provides the safest operation.  Bob Kromer has the numbers to prove what's best in this particular operation.

Coincidentally, his technique matches what my old airline determined was best/safest....and that's how we flew.  Opinions didn't hold much sway.

[gsxrpilot]

On today's flight Austin to Hot Springs, we lifted off at about 100 lbs under gross. I tucked the gear away as soon as the weight was off the wheels and stowed the flaps as soon as we'd cleared the power lines off the end of the runway. We climbed at Vy all the way to 11,500. There were scattered cumulonimbus in all directions and a steeper climb got us through them and on top while staying VFR. CHT's stayed cool <350, the whole way up.

We were at 1000 AGL by the time we made the crosswind to downwind turn.

All in all it worked out pretty well.

[Bob - S50]

Just thought I'd pass along the opinion of another well known pilot:

John Deakin on Vx and Vy

Edited October 6, 2018 by Bob - S50

[Bob - S50]

Just for grins, here is another:

More John Deakin

[carusoam]

Wow, I have not seen Mr. Keller’s video before...

The engine noise and stall horn sounding, happen very close together... as the training suggests.

no time to wait...

Thanks for sharing that,

-a-

 

[hoot777]

Hey guys and gals I’m an old.  - just turned 64 and not bold pilot and fly for a little company out of Atlanta.  We climb as quick as we can to 1000 agl higher if obstacles before we touch the power or lower the nose. Get away from the ground then accel and climb.  Fly safely

[Bob - S50]

OK.  I was just trying to give people a different perspective and point out that there is more than one way to fly/use an airplane.  Flying is situational and much of how you make the airplane do what you want is technique.  Just like saving/investing for retirement and beyond, how you do it depends a lot on your objectives and risk tolerance.  I don't fly my airplane like the engine is going to quit at any second.  If I did...

After takeoff I would always be looking to get to the point where the impossible turn was possible as soon as possible.  I would never cross any inhospitable terrain unless there was a freeway below me.  I would never fly at low altitudes.  All traffic patterns would be flown at idle all the way to touchdown because if they weren't that means that at some point I would not be able to get to the runway if the engine quit.  I would never fly a straight in (which you do almost every time you do an instrument approach) because I would not be able to make the runway if the engine quit.  I would lose a little of the functionality and reason for flying instead of driving.

Personally, I fly the airplane like the engine is going to keep running and the alternator is going to continue to produce electricity.  I fly my plane to get to my destination with a compromise of speed, efficiency, and risk management.  I assume everybody else does too.

Consider your objective, manage the risk, and fly your plane accordingly.

[donkaye]

On 10/4/2018 at 5:06 AM, mike_elliott said:

Bob Kromer and I have talked a number of times about the best[1] way to climb in a Mooney. As others have said so eloquently, Temps are a limiting, but not necessarily THE governing factor. Obstacles are primary with Temps secondary. Get out of the kill zone quickly (below 800'), then set up for cruise climb. 160 of you saw this slide last Saturday.

[1] Everyone has their idea of best way, this is the way I subscribe as does a number of Mooney CFI's and engineering test pilots. The POH should govern the operation of your aircraft.

There are a number of airports where an engine failure could lead to a catastrophe due to lack off a good alternative landing place.  KRHV is a good example of that situation.  I recommend climbing at Vx to 1,000 feet to get the highest within the closest distance to the airport in such situations.

[Mooneymite]

1 hour ago, hoot777 said:

Hey guys and gals I’m an old.  - just turned 64 and not bold pilot and fly for a little company out of Atlanta.  We climb as quick as we can to 1000 agl higher if obstacles before we touch the power or lower the nose. Get away from the ground then accel and climb.  Fly safely

That little company out of ATL wouldn't be Delta, would it?  

Yeah.  Every Delta takeoff is V2+ something to 1000'.  There's always this "imaginary" 50' obstacle that looks like a set of goal posts.  On your next Delta flight, watch and see how smoothly, imperceptibly the pros do it.

(I do not work for Delta....., so I'm guessing here.)

[jetdriven]

There is an NADP1 and NADP2 departure. The former is V2+15 nominally, until 800 AFE then retract flaps and go to clean maneuvering speed until 3000 AFE then 250 kt. This is actually cheaper and more efficient than the NADP2 which is V2+15 until 3000’, then cleanup and 250kt.  Both of these are noise abatement procedures. You’re always guaranteed single engine  obstacle clearance and performance. 

In either regard they usually make the first turn at 400’ AFE when VFR and 1000’ AFE under IFR. 

In a piston airplane i climb at Vx-Vy, depending on terrain, to a certain height, depending on options, then accelerate to 120kt cruise climb... usually at 1000’ AFE. 

Edited October 6, 2018 by jetdriven

[Bob - S50]

1 hour ago, donkaye said:

There are a number of airports where an engine failure could lead to a catastrophe due to lack off a good alternative landing place.  KRHV is a good example of that situation.  I recommend climbing at Vx to 1,000 feet to get the highest within the closest distance to the airport in such situations.

I disagree to a certain extent with this idea.  Vx is only about 10 knots higher than the 1G, wings level stall speed.  If the engine quits at that speed and low altitude, say below about 200' AGL, you'll have to shove the nose down so far to keep the airplane flying that you won't be able to flare.  It will just be a matter of whether you hit the runway stalled and pancake or hit it nose low trying to flare.

If you had said accelerate to maybe Vy or Vy+10 until about 200' and then pull up to Vx and exchange airspeed for altitude then I would probably agree that would be a reasonable technique.  Of course, it will only work if the engine quits before you run out of runway in front of you or after you have enough altitude to make the impossible turn.  Between those two points in time you are no better off as far as picking a place to land.

[Mooneymite]

17 minutes ago, Bob - S50 said:

I disagree to a certain extent with this idea.  Vx is only about 10 knots higher than the 1G, wings level stall speed.  If the engine quits at that speed and low altitude, say below about 200' AGL, you'll have to shove the nose down so far to keep the airplane flying that you won't be able to flare.  It will just be a matter of whether you hit the runway stalled and pancake or hit it nose low trying to flare.

If you had said accelerate to maybe Vy or Vy+10 until about 200' and then pull up to Vx and exchange airspeed for altitude then I would probably agree that would be a reasonable technique.  Of course, it will only work if the engine quits before you run out of runway in front of you or after you have enough altitude to make the impossible turn.  Between those two points in time you are no better off as far as picking a place to land.

But isn't this precisely the scenario Bob Kromer was addressing with his performance analysis?  Altitude over airspeed.....  

[jaylw314]

2 hours ago, donkaye said:

There are a number of airports where an engine failure could lead to a catastrophe due to lack off a good alternative landing place.  KRHV is a good example of that situation.  I recommend climbing at Vx to 1,000 feet to get the highest within the closest distance to the airport in such situations.

I think I read an article from AOPA Pilot toying with the idea of making an early 45^o turn downwind on takeoff, instead of flying the runway heading.  This effectively gives you separation from the runway so you have room to turn back--in a sense, you'd only have to make one turn to land in the downwind direction (instead of two), and if you were high enough, you'd have less distance to cover in the pattern to land in the normal direction.  Obviously not a good idea with other aircraft in the pattern.

Damned if I can find that article, though.

[Hank]

2 hours ago, Bob - S50 said:

I disagree to a certain extent with this idea.  Vx is only about 10 knots higher than the 1G, wings level stall speed.  If the engine quits at that speed and low altitude, say below about 200' AGL, you'll have to shove the nose down so far to keep the airplane flying that you won't be able to flare.  It will just be a matter of whether you hit the runway stalled and pancake or hit it nose low trying to flare.

If you had said accelerate to maybe Vy or Vy+10 until about 200' and then pull up to Vx and exchange airspeed for altitude then I would probably agree that would be a reasonable technique.  Of course, it will only work if the engine quits before you run out of runway in front of you or after you have enough altitude to make the impossible turn.  Between those two points in time you are no better off as far as picking a place to land.

 

2 hours ago, Mooneymite said:

But isn't this precisely the scenario Bob Kromer was addressing with his performance analysis?  Altitude over airspeed.....  

Yes, this is exactly how Bob Kromer ran into trouble, and is the flight profile that he no longer uses for that reason. Fast and low presents few options, but he made it back to the field dodging trees and hills only because his engine was still making a little power (~20-30% IIRC). He advises strongly to fly Vx to clear obstacles, then Vy to at least 1000 agl, transitioning to cruise climb above that if and when desired. My cruise climb is Vy, CHT permitting (which is almost always).

Fly safe out there!

[mike_elliott]

5 hours ago, donkaye said:

There are a number of airports where an engine failure could lead to a catastrophe due to lack off a good alternative landing place.  KRHV is a good example of that situation.  I recommend climbing at Vx to 1,000 feet to get the highest within the closest distance to the airport in such situations.

Vx to clear obstacles, Vy out of the kill zone, and think of anything below 1K feet as just that. You dont have altitude to help you out with options. Get out of this zone as fast (soon) as possible (best rate)

[Bob - S50]

Yes, Vx if there is truly an obstacle at the end of the runway.  But as John Deakin said, you probably made an error in judgement by landing there in the first place if you really need Vx to clear an obstacle.

But if there IS NO obstacle, just no good place to land off airport, why fly Vx right from takeoff?  And why can you only fly either Vx or Vy?  Why not a bit of both?  Flying is not black and white.  Get enough speed so you can recover if the engine fails,  once you have enough altitude (200'?) then you can transition to Vx if it is really that important to you to stay a couple hundred feet closer to the runway.

There are just too many variables to define a 'best' technique that applies to all situations.

[mike_elliott]

I like to preface most of my instructional rants with it is your airplane and you can fly it as you see fit. That said, Vy is a data point, a tested best rate of climb speed. This number is not in question, but a proven, tested speed and it is what it is. My personal and professional preference, and the preference of possibly the best Mooney test pilot I know, Mr. Bob Kromer, is to climb to a safe altitude at the best rate of climb (Vy) , to insure as little time as possible in a dangerous zone, which if something were to happen can really really hurt. I am delighted to find it is not just me, but other Mooney specialist CFI's are adhering to this "get out of the kill zone quick" practice. Perhaps Mr. Mike Miles would chime in, he has a few Brazilian test fight hours in Mooneys also, but Ill bet he would agree. I might not be right, but the numbers back me up.

[81X]

On 10/4/2018 at 8:06 AM, mike_elliott said:

Bob Kromer and I have talked a number of times about the best[1] way to climb in a Mooney. As others have said so eloquently, Temps are a limiting, but not necessarily THE governing factor. Obstacles are primary with Temps secondary. Get out of the kill zone quickly (below 800'), then set up for cruise climb. 160 of you saw this slide last Saturday.

[1] Everyone has their idea of best way, this is the way I subscribe as does a number of Mooney CFI's and engineering test pilots. The POH should govern the operation of your aircraft.

I like this approach with a slight variance.  If I'm in Kansas, transitioning to "cruise climb" seems fine at 1000 feet since there will likely be plenty of forced landing sites should the need arise.  However, if taking off from an urban or an area with plenty of terrain, it's Vy up until I'm comfortable where forced landing sites become more numerous due to glide range, and then it's cruise climb.  In my 231, I just set the AP on 500FPM which usually works out to 120Kts- a decent enough climb rate, good forward progress, and good engine cooling here in the south.  

[Bob - S50]

And after all this discussion, remember Vx and Vy vary as the weight of the airplane changes.  The book numbers are at max gross.  If you are solo with only partial fuel, both speeds will be several knots slower than the book values.  For example, if I calculate it correctly, although Vy is 88 KIAS at SL for my full loaded 2740 lb J, Vy at SL for a lightly loaded 2200 pound J would be about 79 KIAS.

[Dave Morris]

After reading all this and watching the video, it strikes me that Vx climb puts you above the airport in a position from which you must make much steeper turns, 270, and then 90, and if you overshoot as the pilot in the video did, back and forth to line up with the runway again. A 40 degree banked turn adds 12mph to your stall speed. Maybe it's a good idea to think not in terms of "altitude is better" but rather how far out would I want to be in order that a best glide return to the runway can be accomplished without having to make dangerous maneuvers.

[Hank]

It's not a Vx climb to 1000 agl, it's a Vx climb to clear obstacles [used to have trees at the departure end], then a Vy climb to 1000 agl, getting you the altitude you need to turn back quicker and reducing the time that you are vulnerable. "Those trees" were close enough to create a displaced threshold when landing the other direction, but on departure [3000' field] they were only a concern when I was loaded heavy. But I still climbed at Vx to get comfortably above them before lowering the nose to Vy. Because I value my hind end . . .

Ya'll fly safe!

[Cooperd0g]

On 10/7/2018 at 10:16 AM, Bob - S50 said:

And after all this discussion, remember Vx and Vy vary as the weight of the airplane changes.  The book numbers are at max gross.  If you are solo with only partial fuel, both speeds will be several knots slower than the book values.  For example, if I calculate it correctly, although Vy is 88 KIAS at SL for my full loaded 2740 lb J, Vy at SL for a lightly loaded 2200 pound J would be about 79 KIAS.

This is why I love AOA and wish it was a standard thing for light civil aircraft. 

[testwest]

Here is a picture showing the Vz profile. Sorry it's a brand B......

In a nutshell it shows a Vy climb to nominally pattern altitude (assuming there are no obstacles requiring a short duration Vx climb to clear), then acceleration to Vz. That speed is about 1.3 times published gross weight Vy. No need to adjust for weight, temp, etc....when the airplane becomes performance limited you revert to a 500fpm climb until speed is Vy, then Vy. That performance limit is indicated by the change in slope of the Vz line on the right side of the picture.

Edited November 18, 2018 by testwest