aircraft wing spars

[autothrottle]

Recently read about spar cap corrosion in a PA28 and was wondering a few things about light aircraft wings.

1)HOW ARE THEY SECURED TO THE FUSELAGE

2)WHAT FATIGUE LIFE WOULD A SPAR ON,SAY,A PA28 HAVE

3)IS THERE A PUBLISHED NO OF HOURS AND LANDINGS BEFORE SPAR REPLACEMENT?

If anyone knows it would help satisfy my curiosity.

[ROLLER STAMP]

SPARCAPS ON PA28,S.
THIS MAINLY AFFECTED EARLY 1960,S CHEROKEES.
TO INSPECT YOU NEED TO REMOVE THE FUEL TANKS..WINGS ARE SECURED TO FUSELAGE BY A ROW OF BOLTS UNDER REAR SEATS ALSO BY 4 BOLTS AT FRONT AND REAR OF WING ROOT ON EITHER SIDE.
AS FAR AS I,M AWARE THERE IS NO FATIGUE LIFE OR RESTRICTION ON HOURS OR CYCLES.
I KNOW OF AN EX SOUTHEND FLYING CLUB CHEROKEE WITH 20,000 HRS TT........

[autothrottle]

Cheers ROLLING STAMP,

Much appreciated

autothrottle

[Tasfast]

In Australia there is a life on the spar cap of 12500 hrs for the PA-28 235

On the subject of spars can anyone give me examples of cracks being found in the spar caps of the Beech Queen Air 65 B80