[Tex/LaTex] Remove headrule from a specific page or from chapter’s title page and keep footrule


i tried this answer here memoir class but does not work in my case,I managed to remove the header but could not remove the headrule, here is my MWE:

\patchcmd{\chapter}{\thispagestyle{plain}}{\thispagestyle{fancy}}{}{}%to make chapter's first page fancy
\usepackage{fancyhdr}%to add horizental link to header&foofter
\fancyhead[RE]{\footnotesize\itshape header}      
\renewcommand{\footrulewidth}{0.2pt}%the widht of header line
\renewcommand{\headrulewidth}{0.2pt}%the widht of header line
%==========to make chapter title fancy===========
\makeatletter%to make chapter titles fancy
{\normalfont}{\filright\enspace \@chapapp~\thechapter\enspace}
{20pt}{\Huge\bfseries\filcenter}%20pt the small line that close the box
{0pt}{-20pt}{20pt}%{}{between header and box}{space after box}
%====to remove the header====
\chapter{Head rule}
\section{Head rule}


Best Answer

you can do it by make width=0