Basic flight behaviour in transition from auto to full flaps

[markturner1960]

Hi all, I am getting back into DCS with the luxury of lockdown time on my hands and loving it.....I am going back to basics and practicing landing patterns and basic nav etc. Trying the VFR shore landing pattern, I was struck by the jet behaviour , which I had not noticed when practicing landings on the carrier as I usually come straight in.....( I know, am working up to the pattern...)

 

What I find is in the transition from auto flaps as I rollout at approx 240knots, drop the gear and apply full flaps, the nose really wants to climb badly and I have to apply lots of forward stick....all the while airspeed is dropping and it’s only as it reaches around 140 it’s that I can get any rapid response from trimming the nose so I am on the donut and can transition to flying on the throttle rather than the stick.....

 

Why is this as it really makes it tricky and not very smooth to slow to on speed flight? Am I missing something?

 

Thanks

[VpR81]

I drop the gear at 240-250 knots and wait for the Hornet to slow down to 180-190 knots before setting flaps to half. Small trim adjustments until the aircraft is down to 160-170 knots and then i set flaps to full. Propably not correct by the book, but works for me.

 

Don't push or pull the stick, adjust AOA with the throttle and small trim adjustments to keep the FPI in the "E" bracket.

Edited April 18, 2020 by VpR81

[5e EVC Chappy]

Hi all, I am getting back into DCS with the luxury of lockdown time on my hands and loving it.....I am going back to basics and practicing landing patterns and basic nav etc. Trying the VFR shore landing pattern, I was struck by the jet behaviour , which I had not noticed when practicing landings on the carrier as I usually come straight in.....( I know, am working up to the pattern...)

 

 

 

What I find is in the transition from auto flaps as I rollout at approx 240knots, drop the gear and apply full flaps, the nose really wants to climb badly and I have to apply lots of forward stick....all the while airspeed is dropping and it’s only as it reaches around 140 it’s that I can get any rapid response from trimming the nose so I am on the donut and can transition to flying on the throttle rather than the stick.....

 

 

 

Why is this as it really makes it tricky and not very smooth to slow to on speed flight? Am I missing something?

 

 

 

Thanks

Perfectly normal behavior. When the flaps are transiting from UP to HALF or FULL the Hornet has a tendency to “balloon”. A slight check forward on the stick is required to counter this tendency and maintain altitude.

 

Sent from my CLT-L04 using Tapatalk

[Zyll]

The above is correct. If you get to doing the break turn (instead of straight in approach), you can lower gear and put flaps to full while on the break, and your balloon will then pull at least partly in the horizontal, which will lessen the jarring effect.

[G B]

I have always immediately dropped gear and full flaps immediately below 250. Never felt any crazy ballooning. Was nice and stable.

[tweet]

Zyll has it spot on. I drop the gear as the jet drops below 300 KCAS in the break and start to trim off stick forces as the airspeed approaches 220-200. That is about the time I usually begin to roll out on downwind. Airspeed is still decreasing but I stop trimming until I'm more or less wings level. By then, in the descent from 800' to 600' I have a better feel for what my AOA is. Power needs to be coming up to arrest the descent and if I over trim I'll find I'm on AOA but way out of trim and need to hold lots of forward stick force to counter the nose coming up with the power. Holding excess stick force, getting level at 600', and picking the right point for the 180 is just too much going on to ensure a good start at the 180. The rest of your turn to final will suffer if you're fighting the jet and not stable on speed and AOA at 600'. Still making corrections in the final turn isn't conducive to a solid pass.

 

The technique of dropping gear and flaps together at 300 KCAS was the key to improving my traps at the boat.

Edited April 18, 2020 by tweet

[oldcrusty]

I have always immediately dropped gear and full flaps immediately below 250. Never felt any crazy ballooning. Was nice and stable.

 

Thanks, GB. I think Kate "promised" work on FCS logic in PA in another thread. I'm not going back to that thread anymore...

[randomTOTEN]

The technique of dropping gear and flaps together at 300 KCAS was the key to improving my traps at the boat.

Maximum landing gear extend/operation speed is 250 knots, so you're overspeeding the gear. 250 is also the maximum for flap extension, but FCS protects the flaps from extending until below 250.

 

 

In DCS the nose gear doors fail at somewhere around 280, so it wouldn't surprise me if you're ripping them off the jet every time you try landing on the boat :D

[markturner1960]

Thanks fellas, will try that......

[CBStu]

I agree on a straight-in approach wait for flaps to 190 or less. I usually go to full, rather than 1/2 and then full, because that way I only need to do the AOA trimming once. Also at the boat w/ the ICLS running, you may not be able to immediately go to full up trim because that will move you above the glide slope line.

[G B]

Maximum landing gear extend/operation speed is 250 knots, so you're overspeeding the gear. 250 is also the maximum for flap extension, but FCS protects the flaps from extending until below 250.

 

 

In DCS the nose gear doors fail at somewhere around 280, so it wouldn't surprise me if you're ripping them off the jet every time you try landing on the boat :D

 

Fun fact: when the Blue Angels perform their Dirty Loop, they enter at up to 310 knots with the gear down (not to exceed that speed throughout).

[oldcrusty]

Fun fact: when the Blue Angels perform their Dirty Loop, they enter at up to 310 knots with the gear down (not to exceed that speed throughout).

 

Is the limit higher for extended gear then extending gear?

[G B]

Is the limit higher for extended gear then extending gear?

 

No. The Blue Angels have special waivers that were granted after very particular flight testing.

[tweet]

I have had exactly zero problems with gear, gear doors, or flaps. The only time I've encountered problems is when I've missed the G key and failed to confirm that the gear is coming up. The other day I got a phone call and paused before raising the flaps after a cat shot. I couldn't figure out why I couldn't exceed .90 mach in an A2A config with a center line tank. No damage despite a 450 KCAS burner climb. I'll experiment with complying with the 250 KCAS limits and see if there is a difference but apparently it's not necessary with the current damage modeling.

[DW2020]

You guys are waaayyyy over thinking this! If you get the angle of attack right, altitude and speed you don't need to mess with flaps or trimming and can drop the Hornet onto the runway very nicely. She is built for carrier landings so has a very solid undercarriage that will sustain a lot mroe force than most aircraft.

[markturner1960]

Yeah, but, you would generally use the gate provided when the gear is down to adjust the trim to the correct angle of attack would you not? Surely correct trim is the proper way to fly the jet on speed?

[Radial9]

 

What I find is in the transition from auto flaps as I rollout at approx 240knots, drop the gear and apply full flaps, the nose really wants to climb badly and I have to apply lots of forward stick....all the while airspeed is dropping and it’s only as it reaches around 140 it’s that I can get any rapid response from trimming the nose so I am on the donut and can transition to flying on the throttle rather than the stick.....

 

Why is this as it really makes it tricky and not very smooth to slow to on speed flight? Am I missing something?

 

Thanks

 

Thanks for posting this, exactly where I'm at with the same issue.

 

No one mentions the use of the speedbrake as they make the break. Do you gentlemen raise the board into the break? Once at 250 IAS does the board go back down or do you let it stay extended?

 

Thanks!

[oldcrusty]

Thanks for posting this, exactly where I'm at with the same issue.

 

No one mentions the use of the speedbrake as they make the break. Do you gentlemen raise the board into the break? Once at 250 IAS does the board go back down or do you let it stay extended?

 

Thanks!

Once you dirty up the boards retract. If you need to extend it momentarily during an approach to a runway you need to hold the switch. When you release the switch the brake retracts.

With the weight on wheels you don't need to hold the brake switch to keep the boards out.

[CBStu]

I see references to using the speedbrake in that first 180 deg but when I do the Banklers carrier trap mission I have never needed it. Pass the carrier at 350 and 800 ft w/ gear and hook already down and flaps already set to full but they won't actually go down til speed drops to 250. Chop throttle to idle at the same time cranking in 30 deg bank and adding a slight pull back on the stick. Somewhere around 1/2 way through the break (why is it called that?) the flaps drop to full. You feel something happening but it's easy to correct for since what would be a huge balloon in straight flight just becomes a slightly tighter turn.

[Swift.]

I see references to using the speedbrake in that first 180 deg but when I do the Banklers carrier trap mission I have never needed it.

 

The reason you find yourself not needing the speedbrake is because you are massively overspeeding your gear by having it out at 350kts, having the gear out will add the extra drag that the speedbrake should be used to provide.

[oldcrusty]

I see references to using the speedbrake in that first 180 deg but when I do the Banklers carrier trap mission I have never needed it. Pass the carrier at 350 and 800 ft w/ gear and hook already down and flaps already set to full but they won't actually go down til speed drops to 250. Chop throttle to idle at the same time cranking in 30 deg bank and adding a slight pull back on the stick. Somewhere around 1/2 way through the break (why is it called that?) the flaps drop to full. You feel something happening but it's easy to correct for since what would be a huge balloon in straight flight just becomes a slightly tighter turn.

 

I'm thinking about doing the break in the vertical. Actually I've done it already... I'd call it case 0.

Oh wait, that's already reserved for the break approaching from downwind direction... done that too:music_whistling:

[markturner1960]

I have been working hard at this the last week and have found the following works best for me:

 

I turn into the break at around 375 - 400kts, speed break out and concentrate keeping the turn level and regular, until 250 kts, then gear down, and carefully watch speed and height as I near the end of the turn.

 

As I roll out, I am aiming for approx. 150kts and nose level. I then retract break, and drop flaps fully.

 

This way, I get virtually no ballooning and its fairly easy to trim and drop to 600 ft as you go downwind.

[CBStu]

I have been practicing too since it was pointed out that I shouldn't be dropping gear at 350. Man it is much harder when you need to watch speed and drop gear at <250 somewhere in the middle of the first 180 turn. Just one more thing to do. It quickly became apparent that I need the speed brake but then I was still too fast as I leveled out. So did another one and found that the speed brake auto retracts I 'think' when the gear drops. So need to pop the speed brake twice? I was getting fairly regular scores in the low 50s and now I am back into the 40s. Dang this is difficult.

[Razor18]

Speed brake will start to retract at 250 kts, unless you hold the brake button open while going through 250. If you hold the button "open" through 250, it will remain open below that, even if you let go the button afterwards.

 

Or from the DCS manual, page 61:

 

"Airborne, when in the AUTO FLAPS UP mode, the speedbrake automatically retracts above 6.0 g or above 28° AOA and, when not in the auto flaps up mode, below 250 knots. The speedbrake will automatically retract if flaps are extended unless the speedbrake switch is held aft. The speedbrake extends with the flaps HALF or FULL so long as the switch is held in EXTEND. The speedbrake can be commanded to extend to any intermediate position but will retract fully with a momentary forward press of the speedbrake switch."

[CBStu]

Thanks Razor. That makes sense.