Jump to content

Recommended Posts

Posted (edited)

General thread title as there are a few items.

1) Turn performance.

The aircraft seems to lose far too much speed during a +4.0 g level turn at max continuous thrust (102.0%, clean jet).

Video of real thing:

Try doing in the sim what he does here to "look at the weather", and the aircraft in the sim loses speed from 460 kts (CLEAN! In the video he has stores) down to 350 kts. Even running the engine beyond limits won't prevent the deceleration.

This has major consequences for ability to effectively dogfight.

 

2) Adverse yaw.

When making very very small control inputs in roll, the aircraft appears to have more adverse yaw than roll, and so it is possible to quite significantly shake the aircraft left/right in yaw with the stick, while there is almost zero perceptible change in roll angle.

 

3) Trim

If I set trim as required (2 units nose-up) for takeoff in any configuration, this is excessive and results in large pitch up without being countered by a large forward stick input.

In most flight regimes, almost regardless of aircraft speed, I have found it necessary to trim +0.0 units for best controllability, including various takeoff and landing configurations.

Edited by Tiger-II
  • Like 1

Motorola 68000 | 1 Mb | Debug port

"When performing a forced landing, fly the aircraft as far into the crash as possible." - Bob Hoover.

The JF-17 is not better than the F-16; it's different. It's how you fly that counts.

"An average aircraft with a skilled pilot, will out-perform the superior aircraft with an average pilot."

Posted (edited)

1) The video doesn't show what the ambient conditions were, the rpm reached or the gross weight. Not enough information to compare turn rate.

3) Trim should be set to 2 degrees nose-down, for shore procedures. That being said trimming nose down is also not working well. Rotating the nozzles down should result in a pitch up moment which doesn't seem to be modelled.

Edited by lukeXIII
Posted (edited)

[quote]Not enough information to compare turn rate. [/quote]

I'm not talking turn rate. Not at all!!! I'm referring to how fast the aircraft loses airspeed in the sim pulling a LEVEL +4.0 g turn!!! In the video, he is pulling a CLIMBING +4.0 g turn and maintains airspeed. IMPOSSIBLE in the sim with a clean jet.

In the video he has some stores - you can see them in certain shots.

Our aircraft is under-performing significantly.

Edited by Tiger-II
  • Like 1

Motorola 68000 | 1 Mb | Debug port

"When performing a forced landing, fly the aircraft as far into the crash as possible." - Bob Hoover.

The JF-17 is not better than the F-16; it's different. It's how you fly that counts.

"An average aircraft with a skilled pilot, will out-perform the superior aircraft with an average pilot."

Posted (edited)
1 hour ago, lukeXIII said:

How much fuel does he have?

2:07 5000lb bingo warning, Loch Ness, 450 GS @ 500ft AGL
5:20 3000lb bingo warning, end, 5 g max, reduce speed to 420 GS
5:40 Bombing Range, WYPT 5

The clip is from the end of "Harrier: The Vertical Reality (Documentary 1996)" RAF Wittering (Peterborough) to Scotland.

Assuming the external shots (49:27) are of the same flight, it looks like they were carrying 2x wing tanks (and perhaps 2x AIM-9 on the outrigger pylons ?) with simulated weapons/drops.

 

Edited by Ramsay
  • Like 1

i9 9900K @4.8GHz, 64GB DDR4, RTX4070 12GB, 1+2TB NVMe, 6+4TB HD, 4+1TB SSD, Winwing Orion 2 F-15EX Throttle + F-16EX Stick, TPR Pedals, TIR5, Win 11 Pro x64, Odyssey G93SC 5120X1440

Posted

Beat me to it @Ramsay! Thanks!

Hopefully there is enough information now for Razbam to be able to do something.

  • Like 1

Motorola 68000 | 1 Mb | Debug port

"When performing a forced landing, fly the aircraft as far into the crash as possible." - Bob Hoover.

The JF-17 is not better than the F-16; it's different. It's how you fly that counts.

"An average aircraft with a skilled pilot, will out-perform the superior aircraft with an average pilot."

Posted
6 hours ago, Tiger-II said:

[quote]Not enough information to compare turn rate. [/quote]

I'm not talking turn rate. Not at all!!! I'm referring to how fast the aircraft loses airspeed in the sim pulling a LEVEL +4.0 g turn!!! In the video, he is pulling a CLIMBING +4.0 g turn and maintains airspeed. IMPOSSIBLE in the sim with a clean jet.

In the video he has some stores - you can see them in certain shots.

Our aircraft is under-performing significantly.

 

+1, impossible to do in DCS whatever the payload 🙂

  • Like 1
Posted
On 8/24/2022 at 9:41 PM, Tiger-II said:

Try doing in the sim what he does here to "look at the weather", and the aircraft in the sim loses speed from 460 kts (CLEAN! In the video he has stores) down to 350 kts. Even running the engine beyond limits won't prevent the deceleration.

It's clearly not impossible, as the video above shows.

Posted
1 hour ago, Spirale said:

No payload....3000 lbs fuel only....no bombs at all

I tested it yesterday with ~7000lbs fuel, 1x TPOD, 1x Gun Pod, 4x Mk82, 2x Sidearm and lost about 20kts during a 180° 4G turn @102%. @full power during the turn, I did not lose speed.

Posted
On 8/29/2022 at 8:23 AM, felixx75 said:

I tested it yesterday with ~7000lbs fuel, 1x TPOD, 1x Gun Pod, 4x Mk82, 2x Sidearm and lost about 20kts during a 180° 4G turn @102%. @full power during the turn, I did not lose speed.

20 kts is a lot. What was your entry speed? Altitude?

All my missions are set up for STP (Standard Day temperature/pressure). No wind.

Motorola 68000 | 1 Mb | Debug port

"When performing a forced landing, fly the aircraft as far into the crash as possible." - Bob Hoover.

The JF-17 is not better than the F-16; it's different. It's how you fly that counts.

"An average aircraft with a skilled pilot, will out-perform the superior aircraft with an average pilot."

Posted

entry speed 460kts, no wind, 20°C, ~5000ft, 29.92

And no, in this configuration (weight), 20kts is more than ok. You told us in your first post, you would lose 110kts in a clean configuration...

On 8/24/2022 at 9:41 PM, Tiger-II said:

the aircraft in the sim loses speed from 460 kts (CLEAN! In the video he has stores) down to 350 kts

 

  • Like 1
Posted
On 8/29/2022 at 5:30 PM, Spirale said:

No payload....3000 lbs fuel only....no bombs at all

It was with fuel tanks and aim9's, similar to what was in the video as pointed out by Ramsay. Same conditions but clean you can sustain 460 knots whilst pulling up to 6g.

  • Like 1
  • AlphaJuliet changed the title to [INVESTIGATING] Flight Dynamics
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...