F-5 Center of Gravity

[Terzi]

This video belongs to a modernized Turkish F-5 (double seated):

 

 

It was loaded with 4xMk-82 under the wings and single Mk-84 in the center.

 

Firstly it drops the Mk-84 located in the center (see 0:12). The pilots's reaction translates:

 

- "Wow the airplane got crazy!"

- "It has already pitched up so hard by itself!"

 

This proves that after the center Mk-84 is released, the new center of gravity is located far more behind.

 

I tried the same setup in DCS F-5, and noticed that it doesn't really pitch up after the release. Well it does, but very little.

 

This made me think: Is the current F-5 center of gravity too forward?

 

Another reason why I think that; normally after the F-5 lands, the pilot should keep the nose up for a while for aero-brake. In DCS the nose goes down so fast that you can't really evaluate how much you should pull back before the nose gear touches. On the other hand, you can't really risk pulling up too much to avoid engine scratch. You need some evaluation time. I watched some real life landings and it does not seem like that. It lands and the nose stays up for a good time.

 

Well, these thoughts makes me think that the current center of gravity is a bit forward then it is in real life.

 

I do not certainly claim that it is wrong, but it needs some investigation.

[Nooch]

It's an interesting finding but keep in mind that the dual seat variant should be considered as a different aircraft. Sometimes even the smallest airframe differences can have a noticeable impact.

Edited March 27, 2018 by Nooch

[dolfo]

You are correct that the consequences of expending ordnance in our DCS F-5E are not as severe as they probably should. Reading the -1, Section V, Center of Gravity Limitations, Authorized Configurations for Takeoff, Inflight Carriage & Sequencing Limitations, Employment/Release/Jettison Limits can give us a hint of how much fun it should be to fly the real thing.

 

As for the landing, I find that if the final approach is flown in-trim for the on AOA speed it is very easy to keep the nose up for aerodynamic braking.

[DaveRindner]

Damn! It would be nice to have CCIP/CCRP delivery avionics in DCS: F-5E. Manual DEPR sight is OK for rockets and guns. But bombs really do need CCIP pipper.

[Silver_Dragon]

The Turkey F-5 has A and B version upgrade to the F-5/2000 versions, not a F-5E-3 version. That is outside for a BSK F-5E module.

[GGTharos]

I would say that the video doesn't prove anything ... the pilot is executing his escape maneuver: He drops the bomb and executes a 4g pull-up. There's no way to distinguish this pitch up from anything the bomb may have done.

 

This video belongs to a modernized Turkish F-5 (double seated):

 

Firstly it drops the Mk-84 located in the center (see 0:12). The pilots's reaction translates:

 

- "Wow the airplane got crazy!"

- "It has already pitched up so hard by itself!"

 

This proves that after the center Mk-84 is released, the new center of gravity is located far more behind.