Flaps management

Hi !

After reading belsimtek and real manual I have understood that:

UP: fast cruise for long distance or maximum endurance without store.

FIXED: maximum endurance flight at low speed with store loaded.

AUTO: "is normally used for all phases of maneuvering flight from takeoff thru landing."

So does AUTO is used in air-ground and/or air-air combat phases ? It seems that yes but it's not really clear.

Yes basically the intent would be to run in flaps Auto in all phases of flight unless you are specifically looking for Max range or endurance.

Ok that's clear, thanks !

I would keep the "UP" position handy for the extreme situation where you're in a low energy state and you need to do a quick zero g unload to gain energy as quickly as possible.

You'll want to have the flaps and slats up, not interfering with the airflow creating unnecessary drag.

You will lose bit more altitude during the zero g unload but you should accelerate faster.

Sorry, but what's the difference between UP and FIXED? Aren't they fixed in the up position?

From Belsimtek manual:

FXD Flaps

In fixed flaps setting, flaps are automatically positioned by the CADC:

 

 12°/8° position – when flying at altitudes below 32,000 feet above sea level;

 0°/8° position – when climbing through 32,000 feet (±2000 feet);

 12°/8° position – when descending through 28000 feet (±2000 feet);

 0°/0° position – when approaching 550 KIAS or 0.95 IMN, regardless of altitude.

 

If flaps fail to retract, an audible warning signal sounds. The audible warning is silenced by retracting the flaps or pushing the warning silence button located next to the gear lever.

From real manual:

Fixed Flaps

Fixed flaps provide reduced fuel consumption

and improved buffet control when the aircraft

is flown at reduced speed for maximum endurance

with stores loaded. In fixed flaps setting,

flaps are automatically positioned by the

CADC to half (12° /8°) below approximately

32,000 fe~t MSL and shift to one-quarter

(0° /8°) when climbing thru 32,000 feet (±2000

feet). On descent, the flaps shift back to half at

approximately 28,000 feet MSL (±2000 feet).

Flaps automatically retract to up approaching

550 KIAS or 0.95 IMN, regardless of altitude.

If flaps fail to retract upon reaching this speed,

a steady audible warning signal sounds. The

audible warning is silenced by retracting the

flaps or pushing the warning silence button located

next to the gear lever.

:book:

Sorry, but what's the difference between UP and FIXED? Aren't they fixed in the up position?

Fixed flaps follow a speed/altitude schedule for determining flap position.

Please see Page 111 of the BST F-5E Flight Manual.

In combat action you have to play with the Flap Handel, the automatic never know if the Pilot want accelerate fast or go for the next high G Turn.

Only Auto bring's disadvantage because the Flaps works also as big Speed Brake.

In Flaps AUTO the flap scheduling is also AOA based so a healthy push for a Zero G unload should result in flaps going to zero. No need imo to consider selecting up with Flaps AUTO for an unload. Have a look in game in external view, reducing AOA and pushing to 0 G results in complete retraction of both Leading edge and trailing edge.

From the F5EN manual describing Auto operation:

2.11.3.3 Auto flaps

Automatic flap operation is normally used for all phases of maneuvering flight from takeoff through landing. With AUTO

selected, flaps automatically position to up (0°/0°), half (12°/8°), three- quarters (18°/16°), or full (24°/20°) by signals

from the AOA switching unit and the CADC. Above 550 KIAS or 0.95 IMN, the CADC prevents extension of the flaps

by the thumb switch regardless of AOA. If the flaps are already extended when approaching 550 KIAS or .95 IMN,

they automatically retract to full up. If the flaps fail to retract approaching this speed, a steady audible warning will

sound. The audible warning is silenced by retracting the flaps or pushing the warning silence button located next

to the gear lever. See figure 2-22 for auto flap shift schedule. Flaps automatically position to full down any time the

gear lever is in the LG DOWN position or the gear alternate release handle is pulled. The flap indicator will also transition

from AUTO to FULL. A failure within the AOA switching unit (indicated by illumination of the AOA/FLAPS caution

light), or a CADC failure causes the flaps to freeze in their attained position. If only the AOA switching unit fails, control

of flaps is regained through the FXD or UP settings of the thumb switch or use of the flap lever. With CADC failure,

only the UP setting of the thumb switch or use of the flap lever controls

In Flaps AUTO the flap scheduling is also AOA based so a healthy push for a Zero G unload should result in flaps going to zero. No need imo to consider selecting up with Flaps AUTO for an unload. Have a look in game in external view, reducing AOA and pushing to 0 G results in complete retraction of both Leading edge and trailing edge.

 

From the F5EN manual describing Auto operation:

 

2.11.3.3 Auto flaps

Automatic flap operation is normally used for all phases of maneuvering flight from takeoff through landing. With AUTO

selected, flaps automatically position to up (0°/0°), half (12°/8°), three- quarters (18°/16°), or full (24°/20°) by signals

from the AOA switching unit and the CADC. Above 550 KIAS or 0.95 IMN, the CADC prevents extension of the flaps

by the thumb switch regardless of AOA. If the flaps are already extended when approaching 550 KIAS or .95 IMN,

they automatically retract to full up. If the flaps fail to retract approaching this speed, a steady audible warning will

sound. The audible warning is silenced by retracting the flaps or pushing the warning silence button located next

to the gear lever. See figure 2-22 for auto flap shift schedule. Flaps automatically position to full down any time the

gear lever is in the LG DOWN position or the gear alternate release handle is pulled. The flap indicator will also transition

from AUTO to FULL. A failure within the AOA switching unit (indicated by illumination of the AOA/FLAPS caution

light), or a CADC failure causes the flaps to freeze in their attained position. If only the AOA switching unit fails, control

of flaps is regained through the FXD or UP settings of the thumb switch or use of the flap lever. With CADC failure,

only the UP setting of the thumb switch or use of the flap lever controls

 

But in Combat envoirment allways have some G load, not sure how good the Auto flaps react when you want to accelerate in a slight turn should be tested .

In Flaps AUTO the flap scheduling is also AOA based so a healthy push for a Zero G unload should result in flaps going to zero. No need imo to consider selecting up with Flaps AUTO for an unload. Have a look in game in external view, reducing AOA and pushing to 0 G results in complete retraction of both Leading edge and trailing edge.

It could be that you will already be in a zero G state a tad before the AoA is low enough for the CADC to send the "UP" command to the surfaces.

Its well worth testing the reaction time of the CADC.

S!

So...

Up. Equivalent to non flaps.

Fixed. Flaps exgended.

Auto. The aircraft handle it at will, depending on speed, AoA etc.

Fixed. Flaps exgended.

not quite...

Fixed works according to the extend schedule from the manual posted above by diditopgun:

FXD Flaps

In fixed flaps setting, flaps are automatically positioned by the CADC:

 

 12°/8° position – when flying at altitudes below 32,000 feet above sea level;

 0°/8° position – when climbing through 32,000 feet (±2000 feet);

 12°/8° position – when descending through 28000 feet (±2000 feet);

 0°/0° position – when approaching 550 KIAS or 0.95 IMN, regardless of altitude.

 

If flaps fail to retract, an audible warning signal sounds. The audible warning is silenced by retracting the flaps or pushing the warning silence button located next to the gear lever.

From the stick time I have so far on this brilliant module I have come to the following conclusions on how to best use the flap switch:

AUTO: only during take offs and landing

UP: as soon as I am combat ready! SPEED = LIFE!

FXD: only to get that slight edge in the turn when you are committed against an adversary, and also when maneuvering close to the ground to reduce AoA needed for avoiding the ground when energy is low.

Beware of staying in AUTO and getting into a dogfight! those big flaps will come down and bleed you out of energy before you complete even one circle...

S!

I've been wondering about dogfighting in up or fixed. Leaving them in auto all the time, I tend to bleed energy way too fast to even fight the MiG21 in a turn fight or scissors.

Hi !

 

After reading belsimtek and real manual I have understood that:

 

UP: fast cruise for long distance or maximum endurance without store.

 

FIXED: maximum endurance flight at low speed with store loaded.

 

AUTO: "is normally used for all phases of maneuvering flight from takeoff thru landing."

 

So does AUTO is used in air-ground and/or air-air combat phases ? It seems that yes but it's not really clear.

Correct me if i'm worng, but from my understanding:

AUTO: for take offs and landings

UP: Above 260 knots

FXD: For maximum fuel efficiency, when no sudden or sharp manuevers needed (during dogfight or evasive maneuvers, for example)

not quite...

 

Fixed works according to the extend schedule from the manual posted above by diditopgun:

 

 

 

 

From the stick time I have so far on this brilliant module I have come to the following conclusions on how to best use the flap switch:

 

AUTO: only during take offs and landing

UP: as soon as I am combat ready! SPEED = LIFE!

FXD: only to get that slight edge in the turn when you are committed against an adversary, and also when maneuvering close to the ground to reduce AoA needed for avoiding the ground when energy is low.

 

Beware of staying in AUTO and getting into a dogfight! those big flaps will come down and bleed you out of energy before you complete even one circle...

 

S!

Been wondering about this as well ...Thanks...

I tried some testing last night in 2.0, and it's really hard to tell if acceleration is appreciably better and turn speed is maintained better when in flaps UP vs flaps AUTO.

I did some dogfights with a MiG-21 AI (excellent skill lvl), and I did better when starting at high speed and keeping flaps in the UP position - I maintained higher speed, but wider turns. I did not do any accurate evaluation of turn speed and turn radius, and I'd be very interested to see if anyone can figure out a good way to do this.

My biggest problem is that once I get on the MiG-21's tail, it extends and just runs away. Even if I only give it guns, in an attempt to try and force it into a sustained turn fight, it will run, and I can't get any good testing done. Any hints on how to force the AI behavior into something more demanding on the flight performance of the F5?

get into any MP server with Mig21 and F5 only. Against Human, IF the Mig21 go to turning combat, you need the AUTO setup if not, you will fall while he gets your 6. If you are in AUTO, he never will beat you in turning combat.

Mig 21 has to go vertical to get adventage.

My biggest problem is that once I get on the MiG-21's tail, it extends and just runs away. Even if I only give it guns, in an attempt to try and force it into a sustained turn fight, it will run, and I can't get any good testing done. Any hints on how to force the AI behavior into something more demanding on the flight performance of the F5?

Hahaha, I had the same result. Except the MiG eventually turned back and shot me in the face with an Aphid. My P5 wouldn't guide on his lit burner, from 3.5 miles.

More testing. I think I'll set up a switch on my HOTAS for that flap slider though.

-Jeff

from this post:

http://forums.eagle.ru/showthread.php?p=2853169

 

 

Comparing the charts seem that those rivals have very similar turning performance in almost all the envelope..U will need very fine and sensitive hand to manage energy.

I guess we will have very "sporty" dogfights over there :thumbup::thumbup:

 

Pity we cant feel the Gs on our bodies, cause from my experience phisical preparation is what often make the difference in those circumstances. :smilewink::joystick:

But from what I have experienced so far, I get better sustained turn rate with flaps in FXD rather then AUTO.

It would be interesting to do a circle competition between two F-5: one with flaps on AUTO the other with flaps on FXD and see who has better turn performance.

S!

Following this for future reference.

I cannot shoot down an AI mig-21 in a neutral guns only matchup. I have tried different flaps settings and seem to have no significant turning advantage. Usually the situation devolves into the two jets opposite eachother in a two circle fight while Im at 250 kts or less and the mig will zoom 5000 feet.

Based on Vladimir Kondaurov's accounts, having the flaps extended was the way to go below 400kts. I will try to make some layman-scientific turning results with tacview.

Key word which must be remembered is "schedule" as "fixed schedule" and "auto schedule." Fixed does not mean fixed to a single configuration but tied to a fixed schedule based on few parameters. Auto schedule is tied to a schedule based on different parameters like AOA.

UP

• 00° LEF, 0° TEF
  
• Maximum range (all loads)
  
• Maximum endurance (clean)
  

FIXED

• Scheduled by altitude
  
• 12° LEF, 8° TEF at low altitude
  
• 00° LEF, 8° TEF at high altitude
  
• Low-high changeover 32+-2 kft
  
• High-low changeover 28+-2 kft
  
• 00° LEF, 0° TEF >500kt or M0.95
  
• Maximum endurance (stores)
  

AUTO

• Scheduled by airspeed, AOA, and AOA trend
  
• LEF/TEF set 00/0, 12/8, 18/16, or 24/20 by schedule
  
• 00° LEF, 0° TEF >500kt or M0.95
  
• Maximum turn performance
  
• Reduced cruise range
  
• Full deployment with landing gear handle down
  

OK I found real 1984 manual which has this "E-3/F-2" style auto flap system. The five configurations of the LEF and TEF are called up, quarter, half, three-quarters, and full. The commanded UP position is limited to up. The command FIXED allows up, quarter, and half. The commanded AUTO allows all configurations except quarter.