P-47 Elevator Effectiveness & Stick Forces

[ACG_Cass]

It appears as though the elevator effectiveness and stick forces for the P47 at speeds below 350 mph (airspeed) are too low and high respectively. 

 

There are two similar tests on longitudinal stability and stalling characteristics of the P-51H and the P-47D30. The P-51H had a fair few changes but was lighter and used an almost identical elevator configuration. I think it's safe to assume the forces were similar to that seen on the D. 

 

https://ntrs.nasa.gov/api/citations/20050028754/downloads/20050028754.pdf - Measurements of the Longitudinal Stability and Control and Stalling Characteristics of a North American P-51H Airplane (AAF No. 4-64164)

 

https://ntrs.nasa.gov/api/citations/20090022749/downloads/20090022749.pdf - Flight Measurements of Flying Qualities of a P-47D-30 Airplane (AAF No. 43-3441) to Determine Longitudinal Stability and Control and Stalling Characteristics

 

Conditions:

Forward Centre of Gravity, low altitude:

 

Forward centre of gravity, high altitude

Read center of Gravity, low altitude

Rear centre of gravity, high altitude (P-51 is a middle centre of gravity configuration)

Forces comparison at different center of gravity configurations (different speeds, but a comparison and good data)

 

 

 

 

P-47 Data on force per g vs mach:

Stick free comparison at low alt:

stick free comparison at high alt:

 

There are stick fixed tests for the P-51H that show a reduction in force, but these were not shown for the P47 unfortunately. 

 

 

 

Edited January 24, 2022 by ACG_Cass

[ACG_Cass]

The P47 has a lower lift coefficient, is heavier and has a higher wing loading than the P-51 so for it to be able to pitch itself to the AoA required with similar forces, shows it had some very powerful and light elevators. What also might be at play here is the lift capabilities of the tail. 

 

This will obviously be very difficult to find but in the below document we get an estimation at a specific AoA based off the similarities to the NACA 0006 profile. 

 

https://ntrs.nasa.gov/api/citations/19930092906/downloads/19930092906.pdf

 

 

 

 

 

Edited January 22, 2022 by ACG_Cass

[Rache-der-Boote]

Are you saying that there is something wrong with the P-47?