It was the hottest weekend of the year and it is only the middle of April. My second day with Paul started at 09:45, Monday 16th April. We sat outside Lashams clubhouse where Paul ran through the days aims:
They were to understand the effect of airstream and slipstream & propwash; the effects of power changes; the effects of using flaps; use of carnurettor heat; the mixture control and the use of mixture control
to make the 3 three main factors of flight control effective when the aeroplane moves it will depen on:
1 the amount of control deflection
2 the airflow over the control surfaces – can be increased by;
a) higher airspeed or b) silpstream from tge propeller
the slipstream from the propellor flows backwards around the aeroplane in a corkscrew fashion. this increases the airflow over the tail section which makes the elevator and rudder more effective and requires less movement by the control wheel. Ailerons are not affected by the propwash as they are outside the airflow slipstream.
When the flowing airflow which is rotating in the corkscrew manner meets the fin it does so at an “angle of attack”. This creates a sideways aerodynamic force which causes a the aeroplane to yaw. This happens when full throttle is applied – increasing airflow and thrust. This affect can be balanced using rudder pressure.
adding power = pitch up / yaw left.
reducing power = pitch down / yaw right
both is the case if rudder trim is neutral and the fuel is equal in each wing
The Mixture:
Rich Mixture (controlling the air/fuel mix) helps the engine generate significant power. varying the mixture setting also helps for fuel efficency when desired. e.g when low on fuel. Mixture is usually kept to rich under normal flying conditions enabling maximum engine performance and safety.
Mixture is set too low during flight can cut the engine off and so should be reduced very slowly until you can feel the engine and the rpm reduce a fraction.
Carburettor:
The air when it is mixed with the fuel in the carburettor is cooled. at varying altitudes if moisture is present it could form ice at temp +25 degrees C. if ice forms, this can block the flow of induction air/fuel to the cylinders, and if throttle is closed for a long time the make sure full carb heat is set
effects of carb ice = drop in rpm – rough running and possible engine stoppage..
Using Flaps:
the flaps are attached to the inboard trailing edge of each wing.They are operated from the cockpit and have various stages, in the PA28 there are 2 stages of flaps. They operate summetrically on each wing. flaps alter the shape of the wing and the airflow around them thus changing the lifting ability of the wing.
they can generate lift at low speed – allows safe flying at low speed and shorter take-off and landing distances – stage 1 and stage 2
increase drag – steepens the descent path on approach to land – usually at stage 2
foward vision – because of the steepen descent path, this lowere the nose attitude.
Operation – make sure you are at the right speed to operate the flaps. Max speed not to exceed with stage 3 of flaps in a PA28 is over 148 knots. safe range to operate stage 1 is around 60-90knots. This can be cross-checked by a white band on th ASI
Limitation – are the flaps working and you can cross check this by looking at them.
There was another element which has slipped my mind but i will add it when i check this with paul.
We taxied to runway 09 and took in the same flightpath as we had on day 1. This time I followed Paul through on the coontrol column with full throttle but steered the PA28 during take off on the runway using the hand control system which is suprising not that difficult and can be mastered. We flew our excerises closer to Lashams over the Popham area. Because it was Monday and a weekday we stayed outside of the military zones and stayed within our boundary. Visibility was not the best so a sharp eye was always kept on our landmark and we always stayed within visual range of Lashams airfield. As visibility was not great Paul made sure that i did the excercises well and we landed back at Lashams – I taxied us back to parking – not at the hanger area but next to the tow glider by the lashams club house.
I got to meet Paul’s stepfather who himself got his RAF wings in the late 50’s and then went onto commercial aviation and is still flying. It was great to meet another experienced pilot.
Lasham to Lasham PA28 G-AXJV
Departure GMT 11:15am – Arrival 11:55pm Total 40mins
Reading and preparation for day 3:- flying straight and level in balance at a selected airspeed & climbing
