Why only 4650lbs of thrust?

[howie87]

Page 26 of the manual:

 

"The F-5E was powered by a more powerful General Electric J85-GE-21 engine having a 5,329 lbf(2,185 kgf) afterburner thrust"

 

Page 77 of the manual:

 

"The aircraft is powered by two J85-GE-21 turbojet engines equipped with afterburners.

 

Sea level, standard day, static thrust at military (MIL) power is 3250 pounds (1475 kgf) and at maximum afterburner (MAX) power, 4650 pounds (2110 kgf)"

[Donut]

Interesting find.

 

Page 1-14 of the real F-5E manual lists the engine as J85-GE-21 with "sea level standard day static military thrust at military (MIL) power is 3500 pounds (3200 pounds installed), and at maximum afterburner (MAX) power, 5000 pounds (4450 pounds installed)."

 

I cannot explain the different thrust numbers posted in the Belsimtek manual as I do not know what their source was. However, the official manual for the F-5E that I saw was for the F-5E-1 and I believe Belsimtek's version is the F-5E-3. Maybe that explains the different thrust ratings.

[howie87]

Sounds like the difference is probably due to installed vs uninstalled thrust then.

 

I guess we can put the 'higher than official' figure down to a possibly uprated engine in later models too.

[Ramsay]

I guess we can put the 'higher than official' figure down to a possibly uprated engine in later models too.

I couldn't see the uninstalled J85-GE-21 thrust figures in the 1984 flight manual that includes the F-5E-3 details but page 1-32 says

ENGINES

The aircraft is powered by two J85-GE-21 turbojet engines equipped with afterburners (figure 1-30). Sea level, standard day, static thrust at military (MIL) power is 3250 pounds and at maximum afterburner (MAX) power, 4650 pounds.

 

http://www.476vfightergroup.com/downloads.php?do=file&id=445