30 June 1961 - The Black Vault

114
The H-43B modified emp~nnage
was developed to correct rotor
blade...to-tail inter.ference which resulted in aircraft groW1ding
and sllsPension of Category II testL'1g en 4 May 1960. 67
Ferrell
and Honaker determined thernodH'ications increased the blade to
tall clearance 5uf.f.1clent to make inter.fe:cenee very remote.
Flying- qua~itlea oi' -the helicopter ~1th modified empennage Viere
acceptable for serVice'use as long as the directional stability
augmentatIon system ',-Ias operating at the optimum setting used by
the _proJect ~testpl10t. HO\-leve·r J Honaker advised that the H-43B
should not be flo,·/O except for :flight te·st or pilot familiarization
wltn an. ihstruc tor pilotabo~rd \·;hen the direc tional stab1lity
augmentation system was not working. 68 For static directional
stabll! t;;~~as
poor during autorotation wi.th the directional
stability augmentation system working and completely unsatisfactory
".,1th it inoperalt1ve.
Add.i tional 2tabillty and control deric lenc le s ~'lere
pOinted
out by test personnel that were particularly apparent 1n low
level ope·rations. But these def'lcienc ies not'"'!thstandlng, the
test dlaclo3ed! the modified H-43B ·~:a ·s a nuch lmprov~d helicopte;:-'
for re Ecue vJork a thigh alt1tude s .
YHU-IB Category I Tests
categor-y I performance, stability and control tests were
CO!":clUC ted en YHU-lB SiN 58-2078 at the AF?'"j'C from 5 OC tober to
1 rJ::vern-~er 1960 to determine if the heli(':optcr met perfor!'1.a.;-,:::2
67. See p . 126 and 127, Hist of the APFTC, Jul - Dec Ij60, for'
a. d i3Cr-iption of' the R-43B and a -report of incidents.
68. He AFPTC-TR-60-21 AddendUln I: H-43B t~odified Empennage
Evaluatio n , i'·:a y 196 1, p. 18. SD l iF. Vol 4. this iH2.t.