MERGED power curve / floats posts

[TT1900]

One of my job descriptions is a test pilot.

Which aircraft? I’ll make sure to avoid flying them.

The OP’s statement was very poorly worded, but I’m pretty sure everyone here is in agreement on the general premise.

[aeroncasuperchief]

Carrier landing fighter A/C always approach in the backside of the power/lift curve due to the runway being both too short for a normal landing and take-off! That is primarily why it is more difficult than a landing on a 10000 foot runway
WHO in their right mind would tell the navies of the world that they aught to stop carrier landings because it is too dangerous Preposterous!!!

Yes, it is possible to approach and land behind the power curve. Doing so is an advanced technique, fraught with risks if not properly understood and executed. If you're needing to do it to a runway to get in, you're landing that plane on the wrong runway, go around!

Agreed, but most people think that hang-gliding is too risky Bullshit! It is as risky or as safe as I want it to be!
IF one is flying into a 1 way strip and must land in a tailwind, the take-off will be in a headwind and so the runway is too SHORT for a front side of the lift/power curve but is ok for a take-off. It is fine for a backside approach though. This is an example where you cant get in but can get out IF you do not use the tools of the trade and approach in the backside !

DAR, I much respect your abilities and wisdom and wonderfully helpful presence here. If you look honestly at your own ( client caused) accident it is often not the things you train for and get proficient in that will bite you, but rather those mundane things that also may be a part of the "swiss cheese model" that let you down !

[AuxBatOn]

The Be-18 driver that I spoke with over a beer in the OP was likely never on the backside to learn or experience what I am saying . I suspect many pilots are in the same boat.
One of my job descriptions is a test pilot and yes, I do take the A/C to the near limits where I am told, one should never go to !power_curves-300x244.jpg

Interesting. What Test Pilot School did you graduate from and which class? I am a US Naval Test Pilot School graduate. I did investigate power required vs power available on several aircraft: jets, turbo props and piston props.

That is a fact: from non-accelerated flight, if you increase power on the backside, you will accelerate. If you slow down (without using power), you will need to add power to maintain your flight path. Read about flight path stability.

[AuxBatOn]

Carrier landing fighter A/C always approach in the backside of the power/lift curve due to the runway being both too short for a normal landing and take-off! That is primarily why it is more difficult than a landing on a 10000 foot runway
WHO in their right mind would tell the navies of the world that they aught to stop carrier landings because it is too dangerous Preposterous!!!

Yes, carrier-based aircraft fly on the backside during the approach but it has directly nothing to do with landing distance and everything with loads on the structure. You fly as slow as safely possible (on the back side and there are specifications as to how far on the backside and how unstable your speed can be) to reduce the amount of kinetic energy you need to shed (into the aircraft structure) upon touchdown because there is no flare during a carrier landing. FWIW, I flew the Super Hornet with the US Navy.

[digits_]

Carrier landing fighter A/C always approach in the backside of the power/lift curve due to the runway being both too short for a normal landing and take-off! That is primarily why it is more difficult than a landing on a 10000 foot runway
WHO in their right mind would tell the navies of the world that they aught to stop carrier landings because it is too dangerous Preposterous!!!

Yes, carrier-based aircraft fly on the backside during the approach but it has directly nothing to do with landing distance and everything with loads on the structure. You fly as slow as safely possible (on the back side and there are specifications as to how far on the backside and how unstable your speed can be) to reduce the amount of kinetic energy you need to shed (into the aircraft structure) upon touchdown because there is no flare during a carrier landing. FWIW, I flew the Super Hornet with the US Navy.

Isn't that the same though? You want to minimize the landing distance by carrying the minimum amount of energy possible?

[aeroncasuperchief]

Auxbaton--

You don’t add power to slow down. You need more power to maintain a given flight path angle when you slow down would be more appropriate.

Incorrect !
I DO add power to slow down!! You are looking at it (Emphasis) the wrong way . The whole idea behind slow speed backside flight has little to do with maintaining altitude ( who in their right mind loiters over a spot while deep in the backside, it is too effort consuming, power consuming and inherently more risky, for the minimal gain you receive in spotting something at altitude, it is merely a training lesson) but rather establishing a slower speed (that you do not regularily use) with power for the accomplishment of a specific goal. ( like landing)

When you slow down from cruise to best endurance speed, you need LESS and less power. Once you hit the BES, you have the maximum excess power( thrust) avilable but are using the minimum thrust to keep at the same altitude. You CANNOT go below BES without adding power The whole idea with backside use, whether a carrier landing or a 747 landing or my landing in to a short strip is to DESCEND, not maintain altitude and so my only interest is NOT to maintain altitude but rather to descent while establishing AND maintaining the slowest SAFE groundspeed for the conditions.

[AuxBatOn]

Carrier landing fighter A/C always approach in the backside of the power/lift curve due to the runway being both too short for a normal landing and take-off! That is primarily why it is more difficult than a landing on a 10000 foot runway
WHO in their right mind would tell the navies of the world that they aught to stop carrier landings because it is too dangerous Preposterous!!!

Yes, carrier-based aircraft fly on the backside during the approach but it has directly nothing to do with landing distance and everything with loads on the structure. You fly as slow as safely possible (on the back side and there are specifications as to how far on the backside and how unstable your speed can be) to reduce the amount of kinetic energy you need to shed (into the aircraft structure) upon touchdown because there is no flare during a carrier landing. FWIW, I flew the Super Hornet with the US Navy.

Isn't that the same though? You want to minimize the landing distance by carrying the minimum amount of energy possible?

No, because your landing distance is shorten by the fact that you have a hook that catches a cable.

[AuxBatOn]

Auxbaton--

You don’t add power to slow down. You need more power to maintain a given flight path angle when you slow down would be more appropriate.

Incorrect !
I DO add power to slow down!! You are looking at it (Emphasis) the wrong way . The whole idea behind slow speed backside flight has little to do with maintaining altitude ( who in their right mind loiters over a spot while deep in the backside, it is too effort consuming, power consuming and inherently more risky, for the minimal gain you receive in spotting something at altitude, it is merely a training lesson) but rather establishing a slower speed (that you do not regularily use) with power for the accomplishment of a specific goal. ( like landing)

When you slow down from cruise to best endurance speed, you need LESS and less power. Once you hit the BES, you have the maximum excess power( thrust) avilable but are using the minimum thrust to keep at the same altitude. You CANNOT go below BES without adding power The whole idea with backside use, whether a carrier landing or a 747 landing or my landing in to a short strip is to DESCEND, not maintain altitude and so my only interest is NOT to maintain altitude but rather to descent while establishing AND maintaining the slowest SAFE groundspeed for the conditions.

So, in your mind, in straight and level flight (or on a constant flight path angle let’s say 3 deg for argument’s sake, in unaccelerated flight) on the back side if all you so is add power, the result is that you will slow down? Because that is what you are saying.

Which TPS did you graduate from?

[aeroncasuperchief]

to reduce the amount of kinetic energy you need to shed (into the aircraft structure)

Yes, agreed, BUT the reason why you need to shed that kinetic energy is because the carrier is not 10000 feet long AND 400 feet wide. Fighter jets routinely land on 10000 foot runways with higher kinetic energy and without arresting devices because it can be dissipated over a longer length/time
Perhaps another reason is the g-loading on the pilot at a 50 mph higher arrested stop in the same distance?

[aeroncasuperchief]

So, in your mind, in straight and level flight on the back side if all you so is add power, the result is that you will slow down? Because that is what you are saying.

No, I am conveniently leaving out the fact ( for simplicity purposes) that you need fine pitch control ( pitch up) intimately combined with power to enter and maintain backside operations while maintaining altitude, as an example.

[AuxBatOn]

to reduce the amount of kinetic energy you need to shed (into the aircraft structure)

Yes, agreed, BUT the reason why you need to shed that kinetic energy is because the carrier is not 10000 feet long AND 400 feet wide. Fighter jets routinely land on 10000 foot runways with higher kinetic energy and without arresting devices because it can be dissipated over a longer length/time
Perhaps another reason is the g-loading on the pilot at a 50 mph higher arrested stop in the same distance?

Dude, you don’t need to lecture me on how to land a fighter jet: I fly one pretty much every day. Whether you catch the cable at 130 kts or 190 kts doesn’t matterd you will stop. But at 190 kts, if you impact on a 3.5 deg angle and catch the cable, you will likely break the jet.

It’s the exact same reason there is a maximum bring back weight (ie: maximum landing weight) on the carrier.

[AuxBatOn]

So, in your mind, in straight and level flight on the back side if all you so is add power, the result is that you will slow down? Because that is what you are saying.

No, I am conveniently leaving out the fact ( for simplicity purposes) that you need fine pitch control ( pitch up) intimately combined with power to enter and maintain backside operations while maintaining altitude, as an example.

You cannot leave that fact out because the order of things on the backside is extremely important (because you are in an unstable speed regime). While maintaining a constant flight path angle, if you increase power first, you will accelerate. If you want to fly slower, you need to reduce speed (which will reduce your flight path angle) and add power to correct the flight path angle.

[aeroncasuperchief]

IN a steady state altitude, while within the backside regime, if you want to go slower, you need to initially reduce power and pitch up ( almost at the same time) in order to establish a higher AOA and then immediately apply necessary power to maintain altitude at that lower established speed! To increase airspeed in that regime, you need to apply more power first, then immediately pitch down, then readjust pitch and a lower power setting to establish a higher speed ( I know I am speaking to the choir AUX)

[Gannet167]

Yawn. I remember when my mom bought me my first copy of flight simulator. Next tip I'm sure will be "reduce power to speed up".

[AuxBatOn]

aeroncasuperchief: I am still very interested in knowing at which Test Pilot School you completed your formal Test Pilot training.

[aeroncasuperchief]

But at 190 kts, if you impact on a 3.5 deg angle and catch the cable, you will likely break the jet.

I understand!

[aeroncasuperchief]

reduce power to speed up

Well, yes, In the space shuttle, due to the continuously greatly lightening load , you need to reduce thrust, AND you are also accelerating ! Please correct me if I am wrong, all you shuttle pilots... If you didn't reduce power ( thrust), you could not speed up safely, you would break up due to an overly high dynamic pressure!

[aeroncasuperchief]

I have not gone to test pilots school! Do I need to go to one to understand the principles behind slow speed flight, or to actually fly in that regime?

[AuxBatOn]

I have not gone to test pilots school! Do I need to go to one to understand the principles behind slow speed flight, or to actually fly in that regime?

No but you certainly need to to call yourself a test pilot.

[aeroncasuperchief]

A test pilot is a pilot who tests aircraft. Did I need to go to driving school to drive a car? Did I pass the driving test? Would I be a better driver now IF I had gone to driving school 38 years ago?
Do I need to go to tire changing school to be able to change a car tire? Maybe I should start out by changing a go-cart tire first?