PNR AND PET explanation & solution

[aviator86]

G Day

I am doing self study for DGCA exams, reference material around me - GSP Navigation, Flight Planning, Radio Aids, Oxford ATPL, and Suriender's notes.

I am not able to solve few problems in PNR and PET which I came across in surinder's notes, i just don't understand the steps I tried to look up in other text books I have but couldn't find any explanation or similar problems. I am quite good with basic problems like from point A to B with just one wind vector, am posting the problems here someone please explain how to solve them.

1) Find Dcp, Tcp, Dpnr , Tpnr (assume engine failure at PNR and a/c returns on reduced TAS)
Distance - 1200nm
Track - 090
w/v - 090/20kts for 1st 600nm
w/v - 125/40kts for rest of the distance
TAS - (N)420kts, (R)260kts
FOB - 4300kg
Reserve - 1150kg
Fuel Burn - (N)975kg/hr, (R)550kg/hr.

[aviator86]

Another problem

2)
Distance - 990nm
Track - 160
w/v - 360/25kts for 600nm
w/v - 180/10 for renaming distance
TAS - (N)300kts, (R)190kts
FOB - 3500kg
Reserve - 700kg
Fuel Burn - (N)770kg/hr , (R)410kg/hr

Find - Dcp, Tcp, Dpnr, Tpnr
(assume engine failure at PNR and a/c returns with reduced TAS)

[aviator86]

3)
Flying from A to C via B. In case of engine failure a/c is to land at B.
-> Find Dcp & Tcp from A. (assume engine fails after B)
-> Find Dpnr & Tpnr.
(assume engine fails at PNR and a/c returns on reduced TAS to B)

FOB - 5200kg
Reserve - 700kg
Fuel Burn - (N)1425kg/hr, (R)820kg/hr
TAS - (N)420kts, (R)255kts
A to B -> Track - 090, w/v - 125/35, Distance - 460
B to C -> Track - 115, w/v - 135/18, Distance - 670
C to B -> Track - 295, w/v - 135/18, Distance - 670
B to A -> Track - 270, w/v - 125/35, Distance - 460