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-   -   Using "throttle for GS and stick for AOA" when landing (https://forums.eagle.ru/showthread.php?t=200282)

LJQCN101 01-22-2018 04:29 AM

Using "throttle for GS and stick for AOA" when landing
 
While preparing for the upcoming module, I found this in the NATOPS manual describing landing and takeoff characteristics of F18 FCS:

Quote:

In the takeoff and land modes, AOA and pitch rate feedbacks are used to augment inherent airframe pitch damping and stability. The computer nulls the difference between the trim AOA and actual AOA.

The FCS incorporates full-time AOA feedback in the flaps HALF or FULL mode. For this reason, longitudinal trim is required when changing AOA and/or airspeed. When the aircraft is trimmed to an AOA, it tends to maintain that AOA and some longitudinal stick force or trim is required to fly at another AOA.
So the FCS actually encourages what we known as "throttle for GS and stick for AOA". An increase in throttle would result in a decrease in AOA, which would make the aircraft pull up by itself, so that AOA is maintained.

This would make carrier landing a lot easier than Su-33 IMO.

Emmy 01-22-2018 05:12 AM

Pitch For Airspeed
Power For Altitude (Glide Slope)
http://www.boldmethod.com/learn-to-f...-a-glideslope/

probad 01-22-2018 07:34 AM

uhhhh i think @op has the right understanding of the physics, hes just describing it from an unorthodox perspective

"throttle for GS and stick for AOA" is definitely an invitation for some big misunderstandings

anyways really not sure what this thread is meant to contribute, landing the hornet is a thread already done to death several times over.

LJQCN101 01-22-2018 08:25 AM

Quote:

Originally Posted by probad (Post 3363145)
uhhhh i think @op has the right understanding of the physics, hes just describing it from an unorthodox perspective

"throttle for GS and stick for AOA" is definitely an invitation for some big misunderstandings

anyways really not sure what this thread is meant to contribute, landing the hornet is a thread already done to death several times over.

Just some findings from FCS perspective which I think it's worth to expand when Wags mentioned about PA mode in the mini-updates, in case people find out that FCS is fighting their input;)

pr1malr8ge 01-22-2018 09:59 PM

I've argued this point and well so has the rest of the piloting world and on this forum.

So I've generally always used Pitch for air speed and throttle for "Glide Scope" in my real life flying experience. I have not been fortunate enough to fly PIC of turbine aircraft in the real world. You will notice that a lot of pilots who argue pitch for altitude and throttle for speed fly rather large turbine aircraft. I have deduced that those arguing for P/Alt T/S is the worry about delayed spool-up. Which does make sense. In Piston engines trottle response is pretty close to instantaneous vs Turbines that can and do have rather long response times at/near idle.

But yet I always seem to come across things like this and pilots of large turbine aircraft that say P-airspeed T-Glide scope. My cousin who flew f15cs and now flys a360s stated he uses Pitch for airspeed and throttle for glide scope..

While I cannot specifically state this as "Fact" as I've never flown large aircraft I personally think that those stating Pitch for altitude and Throttle for airspeed due to turbine spool up might not have the best stick and rudder abilities or simply just going by their mandated training from their employer. I feel that if you're needing instantaneous throttle response to stay on glide scope in VMC then they are behind on the aircraft.
How ever. I also can understand why airlines and aircraft with high T/O&L speeds would want the Throttle for speed and Pitch for altitude as its primary basis due to the potential for windshere where throttle response is an absolute must to avoid a sink rate that will result in structural damage or catotropic/death..

just my humble opinion.

Thump 01-23-2018 12:09 AM

Quote:

Originally Posted by pr1malr8ge (Post 3363983)
I've argued this point and well so has the rest of the piloting world and on this forum.

So I've generally always used Pitch for air speed and throttle for "Glide Scope" in my real life flying experience. I have not been fortunate enough to fly PIC of turbine aircraft in the real world. You will notice that a lot of pilots who argue pitch for altitude and throttle for speed fly rather large turbine aircraft. I have deduced that those arguing for P/Alt T/S is the worry about delayed spool-up. Which does make sense. In Piston engines trottle response is pretty close to instantaneous vs Turbines that can and do have rather long response times at/near idle.

But yet I always seem to come across things like this and pilots of large turbine aircraft that say P-airspeed T-Glide scope. My cousin who flew f15cs and now flys a360s stated he uses Pitch for airspeed and throttle for glide scope..

While I cannot specifically state this as "Fact" as I've never flown large aircraft I personally think that those stating Pitch for altitude and Throttle for airspeed due to turbine spool up might not have the best stick and rudder abilities or simply just going by their mandated training from their employer. I feel that if you're needing instantaneous throttle response to stay on glide scope in VMC then they are behind on the aircraft.
How ever. I also can understand why airlines and aircraft with high T/O&L speeds would want the Throttle for speed and Pitch for altitude as its primary basis due to the potential for windshere where throttle response is an absolute must to avoid a sink rate that will result in structural damage or catotropic/death..

just my humble opinion.


It's a question of where on the power curve your aircraft lands. It is not a matter of preference but of physics and how the aircraft performs when configured.

Sierra99 01-23-2018 02:15 AM

Quote:

Originally Posted by LJQCN101 (Post 3363062)
An increase in throttle would result in a decrease in AOA, which would make the aircraft pull up by itself, so that AOA is maintained.

An increase in throttle will reduce DESCENT RATE...if done properly once you have your AOAset you can control descent rate using throttles.

GGTharos 01-23-2018 02:42 AM

Throttle for descent rate, stick for speed. The aircraft will maintain the AoA of you do things right and within limits.

You can do this with any of the PFM aircraft, it's known as the region of reverse command and typically presents itself in low speed, moderate AoA situations.

Piston85 01-23-2018 03:02 AM

All aircrafts are flown that way. From day 1 in flight school you'll be tought to change altitude with power and change airspeed with pitch.

It is inherent to safety procedures.

USMC_Trev 01-23-2018 03:09 AM

Pitch + airspeed = AoA at a given power setting
Power up = decreased rate of descent and AoA decrease at a given pitch
Power down = increased rate of descent and AoA increase at a given pitch.

NOW there is no set formula for this. It changes dynamically with WEIGHT. After you get rid of ordnance and burn fuel it takes less and less power to accomplish these things.

FURTHERMORE - a heavy, draggy jet responds rapidly to power decreases and slowly to power increases.

THEREFORE don't be dumb. Don't try to come back to the boat with racks full of bombs. Dump them unless they are specials. Keep the A2A ordnance. They don't weigh much and aren't draggy like bombs. Dump fuel down to landing weight as you make your turn from the downwind to the 90 if you're still over (or when it's time for the platform call for the Case III recoveries).


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