Introduction to Aircraft Structural Analysis (Elsevier Aerospace Engineering)

382 CHAPTER 13 Airframe Loads

Example 13.1
Anaircrafthavingatotalweightof45kNlandsonthedeckofanaircraftcarrierandisbroughttorest
by means of a cable engaged by an arrester hook, as shown in Fig. 13.3. If the deceleration induced
bythecableis3g,determinethetension,T,inthecable,theloadonanundercarriagestrut,andthe
shearandaxialloadsinthefuselageatthesectionAA;theweightoftheaircraftaftofAAis4.5kN.
Calculatealsothelengthofdeckcoveredbytheaircraftbeforeitisbroughttorestifthetouch-down
speedis25m/s.

Theaircraftissubjectedtoahorizontalinertiaforcema,wheremisthemassoftheaircraftanda
itsdeceleration.Thus,resolvingforceshorizontally

Tcos10◦−ma= 0

thatis,

Tcos10◦−

45

g

3 g= 0

whichgives

T=137.1kN

Now,resolvingforcesvertically

R−W−Tsin10◦= 0

thatis,

R= 45 +131.1sin10◦=68.8kN

Assumingtwoundercarriagestruts,theloadineachstrutwillbe(R/ 2 )/cos20◦=36.6kN.

Fig.13.3

Forces on the aircraft of Example 13.1.