Connect and get the inside scoop on Airline Companies

Welcome to Airline Pilot Forums - Connect and get the inside scoop on Airline Companies

If this is your first visit, be sure to check out the FAQ. Join our community today and start interacting with existing members. Registration is fast, simple and absolutely free.


User Tag List

Post Reply
 
Thread Tools Search this Thread
Old 04-25-2021, 04:34 AM   #1  
Gets Weekends Off
Thread Starter
 
Spin's Avatar
 
Joined APC: Jun 2010
Posts: 124
Default F-4 not horizontal stabilizer

Does someone know why the F-4 horizontal stabilizer is not horizontal?
Spin is offline  
Old 04-25-2021, 04:45 AM   #2  
Gets Weekends Off
 
jaxsurf's Avatar
 
Joined APC: Jul 2018
Posts: 183
Default

Probably made them anhedral to get them out of the turbulent air caused by the wings at high angles of attack/landing. Angling them down lets them stay in smooth air and not lose any effectiveness from the turbulent air caused by the wings.

Or maybe the engineers thought it would be a cool looking counterpoint to the dihedral wing tips.
jaxsurf is offline  
Old 04-25-2021, 04:46 AM   #3  
Gets Weekends Off
 
M696's Avatar
 
Joined APC: Dec 2012
Position: 747
Posts: 103
Default

The anhedral tail was incorporated into F-4 to get horizontal stabilizers assisting the vertical stabilizer. The main vertical stabilizer was utterly useless in high angles of attack as it had work in the wake of the fuselage. By designing an anhedral tail they added more lateral surface to the aircraft.
M696 is offline  
Old 04-25-2021, 04:51 AM   #4  
Gets Weekends Off
 
Peabody17's Avatar
 
Joined APC: Jun 2019
Position: Right Seat
Posts: 166
Default

And the F-4 uses stabilators, not horizontal stabilizer and elevators.
Peabody17 is offline  
Old 04-25-2021, 05:51 AM   #5  
Gets Weekends Off
 
jaxsurf's Avatar
 
Joined APC: Jul 2018
Posts: 183
Default

https://www.hq.nasa.gov/pao/History/SP-468/ch11-5.htm

Says this in paragraphs 5 and 6:

A large anhedral angle (negative dihedral angle) of the horizontal tall in combination with a sharply defined positive dihedral in the outer wing panels are two conspicuous identifying features of' the aircraft. These two features are related to the position of the exhaust nozzles located only a short distance behind the low-mounted wing. To avoid impingement problems with the hot jet exhaust, the tail surfaces are mounted on an aft fuselage extension above the nozzles. As indicated by early wind-tunnel studies, the resultant high position of the horizontal tail in combination with the wing-shape parameters led to undesirable nonlinear pitching-moment characteristics at high angles of attack. The large anhedral angle, or droop, of the horizontal-tail surfaces greatly improved the pitching-moment characteristics, as well as increasing directional stability. To achieve the proper balance in dihedral effect for the integrated aircraft configuration, however, a large positive dihedral angle was incorporated in the outer panels of the wing. In addition, the wing dihedral elevated the wingtip vortexes relative to the horizontal tail and further improved the pitching-moment characteristics of the aircraft.
jaxsurf is offline  
Old 05-03-2021, 11:20 AM   #6  
Gets Weekends Off
 
galaxy flyer's Avatar
 
Joined APC: May 2010
Position: Baja Vermont
Posts: 4,627
Default

Probably act just like the fins on the back of later Learjets.
galaxy flyer is offline  
 
 
 

 
Post Reply
 



Thread Tools Search this Thread
Search this Thread:

Advanced Search


Related Topics
Thread Thread Starter Forum Replies Last Post
Luggage Works Stabilizer strap seminolepilot Regional 2 10-05-2015 11:06 AM
Vertical Stabilizer Icing? (Or Lack Thereof) mswmsw Technical 10 10-06-2011 08:43 PM
Uh oh... 787 horizontal stabilizer issue... solinator Hangar Talk 4 06-25-2010 12:27 PM
Tail Stall vs. Wing Stall A320fan Flight Schools and Training 50 04-21-2010 08:53 PM
Horizontal Stabilizer (Tail) Stall Warning block30 Technical 34 10-24-2009 09:48 PM


All times are GMT -8. The time now is 09:24 PM.