What is the preferred touch and go landing procedure in the F/A-18 Hornet ?

[Frederf]

As far as I'm aware the FCS reset button doesn't do anything with F-18 in flight anyway.

[oldcrusty]

On 6/17/2021 at 7:51 AM, Lex Talionis said:

To help clarify a few things ....

 

...If the plane pitches excessive nose up, do some of that pilot sh!z and fly to mitigate...

 

 

Yes sir, that pilot sh!z is always there.  

When launching from the boat in DCS, the excessive pitch-up might not be that noticeable due to relatively heavy weight. As a matter of fact I always catch myself trying to nudge the stick up a smidgen  before I see VV creeping up. I know, flying off the boat in a Hornet is 'hands off the stick' for a second or two, in RW.

Boltering in DCS requires the aforementioned sh!z, at a much lighter weight.

From what I understand, in RW the pitch CAS controls the initial the pitch-up to 12deg.(?) then preset AOA. (?)

Also after a bolter, when any 2 wheels hit the deck, the pitch CAS resets to a similar pitch-up logic then AOA (?)

I'd appreciate if you could shed some light on this.

[Stearmandriver]

Reasonably sure I've read something similar; pitch trim and/or pitch CAS logic is reset on touchdown to something appropriate for takeoff?

 

Regarding civil aviation accident stats, I'll point out the following: 

 

1.  Until just a couple years ago, loss of control accidents were dramatically outpacing runway events.  It's the heavy emphasis that I've talked about that has changed this. 

 

2.  Regarding the relative fatality rates of the two types of accidents, it's important to remember that LoC accident stats include every type of LoC accident.  Ground loops, blown tires that result in a runway excursion etc... anything like that is counted, as long as it exceeds the (minimal) damage value.  Such events are relatively common and never fatal, thus they dilute the LoC fatality rate. 

 

However, if you break out the different types of LoC accidents, you'll find that the one we're talking about - a high AoA event in flight leading to an accident- is almost ALWAYS fatal.  

[Scaley]

23 hours ago, Frederf said:

As far as I'm aware the FCS reset button doesn't do anything with F-18 in flight anyway.

Correct, once your don't have WonW all it will do is centre the rudder trim and MECH stick position(not modelled in DCS)

[Brass2-1]

@Lex Talionis thanks for diving in with us as always. 
 

 

[Lex Talionis]

I apologize for the aerodynamics diatribe. For those that don't care disregard.

The general premis that the trim button resets the aircraft to some neutral/all applicable setting is simply incorrect. 

There is a difrence between an aircraft being trimmed for its current airspeed/AOA, and setting  "take off trim". The intent behind the trim button (any take off trim setting for any aircraft)  is to set the jet up for predictable behavior for the aerodynamic transition from zero airspeed to rotation on take off. A regime of no aerodynamic control authority to increasing levels of control authority up to full control authority, proper laminar flow over the wings and rotation.

You dont want the stick/yoke trimmed such that just as you gain elevator authority on TO roll, the aircraft prematurely pitches nose up, rotation happens at to slow an airspeed and you stall. You dont know the forces from the trim untill you gain authority, and on a TO that is typically to late to figure out you have not done your TO checks to include setting TO trim.

 

Given the context above:

Depending on the energy state and the various aerodynamic nuances between aircraft (engine spool up times, p factor/ left turning tendencies, landing gear configuration effecting run way ground track ability, if the engine creates a positive/negative pitching moment, etc etc etc etc etc)  ...... during a touch-and-go, some aircraft revert back deeper into that take-off transition than others. Lesser performance aircraft tend to take longer to go from an "approach" energy state, back to a safe "rotation" proper aerodynamic control authority energy state.  So, for some aircraft a "touch and go" is more like an "approach to land- roll a little bit- then a take off again". These aircraft tend to require the re setting of TO trim.

I know there is an actual "roll and go" in aviation vernacular, and i know it may seem as if that is what i am conflating above as a "touch and go". However (pause for effect) given the execution of such is all relative from aircraft performance to aircraft performance, i will define a "touch and go" for this conversation as "retaining the energy to be able to immediately rotate upon landing gear touchdown ". With that definition i also understand some aircraft simply do not have the performance to do a "touch and go" as i defined even though some pilots of those aircraft may call them as such. For this conversation it only proves my point as it is the very example i first provided of a perceived "touch and go" realy being an "approach to land-roll a little bit- take off again"

The hornet can do a "touch and go" as i have defined with kinetic energy to spare (depending on weight) with minimal "roll" proceding rotation. Whats more, you know exactly where the trim is (or should know) as you have been flying "on speed" for the entire approach. The trim button should not be used as you are not "taking off". You  more than have the power to legitimately "touch and go" easly retaining your airspeed/ control authority/etc for the entire evolution. (The main reason the nose climbs so fast after a T&G in the hornet is becase it simply has the performance to do so while retaining the AOA it is trimmed for. *dont conflate "AOA" with "attitude"* The jet is retaining its control authority at the hi attitude, this is a good thing not a bad as so many percieve it to be. Wield the power correctly. This is also where the conversation segways into the proper use of trim, "don't *fly* with the trim" but thats another conversation)

To add (not to create an exception) every touch down at the boat is treated as a missed wire for the very reason of retaining all that energy to make the transition from a descending VSI to an ascending VSI with minimal control authority loss. 

In short, generally, keep the trim you have (given you are in fact trimmed for the correct airspeed/AOA) in a relitively hi (enough) performance aircraft that can more easily retain its energy during a T&G.

 

Hope that helps.

Edited June 23, 2021 by Lex Talionis

[oldcrusty]

Nice explanation.  Just to confirm...  is there any FCS pitchup capture (hands off the stick) that happens right after launch. Of course that could always be effected by pilot input which, if done too early might cause FCS to mitigate that input?  I'm talking immediately after launch before good rate of climb established and gear/flaps go up.

Also, after bolters, if say the pilot kept the stick in neutral, would the FCS initially kept the nose at the similar pitch?  Or, with the jet lifting, does the FCS immediately goes to capturing and maintaining PA AOA?  I think you already answered this, just trying to sort out 'stories' I've heard.

[Lex Talionis]

9 hours ago, Gripes323 said:

Nice explanation.  Just to confirm...  is there any FCS pitchup capture (hands off the stick) that happens right after launch. Of course that could always be effected by pilot input which, if done too early might cause FCS to mitigate that input?  I'm talking immediately after launch before good rate of climb established and gear/flaps go up.

Also, after bolters, if say the pilot kept the stick in neutral, would the FCS initially kept the nose at the similar pitch?  Or, with the jet lifting, does the FCS immediately goes to capturing and maintaining PA AOA?  I think you already answered this, just trying to sort out 'stories' I've heard.

Instead of trying to assume what the FCS is doing, think of it like this ...

 

Configured (when you as the pilot have controll of the trim) the aircraft will always pitch to seek the AOA/airspeed you have trimed it for, regardless what the FCS is doing, regardless if you just did a touch and go, regardless of power, it is transparent to you as the pilot. Dont worry about what the FCS is doing, it was designed to be an extension of the pilot, not a system to be managed.

With all other things equal, longitudinal stability will play out in the hornet as you the pilot would expect it to play out in any other fixed wing aircraft, with or without an FCS, cesna 150 to bell X-15, t45 to f18.

 

To answer the question directly, if you let go of the stick, the plane will seak what it is trimmed for, regardless, ceteris paribus. On a cat shot, the trim is such that the aircraft will pitch nose up if left to its own demise (i.e let go of the stick). Understand, if the throttle is left untouched, the aircraft is accelerating during the entire take off, not only will the aircraft trade kenetic energy for potential to keep what it is trimmed for, the nose will rise exponentially to further trade energy states as the aircrafts kenetic energy state tires to increase. 

 

Hope that helps (there is so much context to this conversation it is hard to keep it "simple". If i am restating things others already know, my apologies, im not trying to insult anyone's inteligence)

Edited June 23, 2021 by Lex Talionis

[oldcrusty]

36 minutes ago, Lex Talionis said:

Instead of trying to assume what the FCS is doing, think of it like this ...

 

Configured (when you as the pilot have controll of the trim) the aircraft will always pitch to seek the AOA/airspeed you have trimed it for, regardless what the FCS is doing, regardless if you just did a touch and go, regardless of power, it is transparent to you as the pilot. Dont worry about what the FCS is doing, it was designed to be an extension of the pilot, not a system to be managed.

(And again without going into the proper use and understanding of trim) With all other things equal, longitudinal stability will play out in the hornet as you the pilot would expect it to play out in any other fixed wing aircraft, with or without an FCS, cesna 150 to bell X-15, t45 to f18.

 

To answer the question directly, if you let go of the stick, the plane will seak what it is trimmed for, regardless, ceteris paribus. On a cat shot, the trim is such that the aircraft will pitch nose up if left to its own demise (i.e let go of the stick). Understand, if the throttle is left untouched, the aircraft is accelerating during the entire take off, not only will the aircraft trade kenetic energy for potential to keep what it is trimmed for, the nose will rise exponentially to further trade energy states as the aircrafts kenetic energy state tires to increase. 

 

Hope that helps (there is so much context to this conversation it is hard to keep it "simple". If i am restating things others already know, my apologies, im not trying to insult anyone's inteligence)

 

 

No worries, simple is always the best... for pilots. Engineers can stare at their equations and try to make it simple for the pilots.  I'm not new to concept of trimming, AOA and other things related to aviation and aviating...  just thought Hornets were a bit 'special', .

Well, back to simming, have to find me some more bugs...

 

[Lex Talionis]

8 hours ago, Gripes323 said:

 

No worries, simple is always the best... for pilots. Engineers can stare at their equations and try to make it simple for the pilots.  I'm not new to concept of trimming, AOA and other things related to aviation and aviating...  just thought Hornets were a bit 'special', .

Well, back to simming, have to find me some more 

 

Sure thing.

Have a good one.

Edited June 23, 2021 by Lex Talionis

[Jackjack171]

On 6/17/2021 at 9:04 AM, Lex Talionis said:

The natops certainly is not an easy read.

 

 It refers to case 1 "as in case1" as an example but does not say it necessarily reverts to case 1 procedures. If it does revert to case 1, the boat is now VMC and procedures for the other cases are no longer used(i.e. "bolter pattern " no longer used). The premis of that paragraph is that the ship is not VFR, there is no VFR pattern, for which you would not go into the VFR pattern after a bolter but instead be vectored back arround (given their phraseology "be vectored into ... "). The "bolter pattern " is like "missed approach instructions" after an IFR approach, but not necessarily a means to enter the VFR landing pattern.

My apologies, my asumption was that we were talking about case 1/VFR landing pattern given we were talking about "breaking" etc. I should clarify, there is no such thing as a "VFR bolter pattern". And there certainly is no expectation to go into a "bolter pattern"  if the VFR traffic pattern is in use (i.e case1)

Case 2 is basically an IFR let down to a VFR pattern.

The context your paragraph is written in is important. 

 I probably missed the context that we were talking about IMC/IFR/ Case3 (if we were). 

Apologies for the confusion.

 

No worries! I was using the following as a way to show that, the word or words "pattern or bolter pattern" are all over some of the manuals. Maybe it was a way to describe the pattern I'm guessing?! So when you said there is no such thing as a "bolter/waveoff pattern", it made me wonder. I guess it is all context however. And yes, NATOPS can be a pain! 

[Pieterras]

On 6/15/2021 at 10:34 PM, Jackjack171 said:

Just to piggy back you, the bolter pattern is 500' for separation since break ALT is 800. I believe it is a climbing left hand turn to 600 to join the downwind with respect to interval, unless you are alone. 

forget the 500.. 

Climb to 600 on BRC,,, turn left with your interval... 
As simple as that.. 

[Chuck_Henry]

To answer the original question - throttles to MIL as soon as you feel the main gears touch the deck and allow the aircraft to rotate on its own. With a positive rate of climb, retract the flaps from FULL to HALF (not necessary, but this minimizes the risk associated with excess drag on the aircraft should an engine fail in the upwind climbout), and reduce power to establish a climb to 600 ft AGL at 150 KIAS or on-speed AOA, whichever is faster (gross weight dependent). There is no hard and fast vertical velocity required for the climb to pattern altitude. I use a 5-degree high FPM. You're only wrong if you blow through 600 ft.