Flight 3 - patterns, fly-bys, landings and take offs!

This was THE most challenging flight yet, 11 times around the pattern including 8 landings and 3 go arounds. Towards the end of the 1.6 hours of flying I was starting to get the hang of the approach and the landings were not too bad. But it gets tiring doing that many circuits!

The original plan was to do some stalls, but the visibility has been getting worse with all the wild fires in California at the moment, see the photo to the right to see how strange the sky and the sun look at the moment. Apparently the weather is forecast is predicting more lightning at the weekend, which could mean more fires and bad vis. So instead of stalls I was taught the airport's holding pattern and we were going to do a number of low altitude fly bys. The fly bys went well so we tried a few landings... then a few more... and a few more. At the end of the lesson I was surprised to find out I'd done 8 landings with various degrees of assistance from my instructor Patti. Towards the end they were 99% mine, with some verbal coaching on when to 'flare'. I've just checked the flying handbook and it looks like I've got a few chapters to catch up on: 5) Takeoff and departure climbs, 7) Airport Traffic Patterns, and 8) Approaches and Landings.

Palo Alto Airport Traffic Pattern

The traffic pattern at PAO (and I'm sure most airports) is a rectangle, 800ft up in the air on the bay side, and 1000ft up on the city side. This altitude is called the TPA, Traffic Pattern Altitude. A complete rectangular traffic pattern includes 4 sides (but 5 legs), departure, crosswind, downwind, base and final.

The departure is probably the obvious one, this is straight after take off. At PAO you have a great view of interestingly shaped water features in the mud flats of the bay (see photo). The aim is to climb at Vy = 67 kts, this is the best rate of climb for the 152. When you reach TPA - 300ft (500ft) you make the turn onto the 'crosswind leg'. For the "right closed traffic" pattern this is a medium 30 degree turn which will put you parallel with Dumbarton Bridge (see photo, note the terrible visibility).

The Crosswind leg is a short one, maybe 3 seconds of level flight before the next turn which puts you on the downwind leg. By this time you reach the 800ft TPA and can level off the plane (pitch, power, trim).

During the downwind leg you get a few seconds to relax before starting to prepare for the landing. When you are directly across from the mid point of the runway it's for for a pre-landing flow check: fuel on, flaps up, mix in, throttle 2100, carb heat off. By the time you reach the point where you are abeam the end of the runway ("key position") it's time to prepare for the landing and start the descent.

Descent and Landing

You start the descent with the following: Carb Heat on, throttle at 1700rpm, trim 70knts, flaps 10 degrees. Assuming you have clearance from the control tower you can then turn onto the 'base leg'. If there is no other traffic then this would ideally be when you are at 45 degrees to the end of the runway, for the 152 this is when the runway is fully visible in the back window. After the turn you continue the descent by setting flaps to 20 degrees and lowering the speed to 65 kts with the attitude of the plane (not the rpm). The next turn puts you on 'final' approach, again lower flaps to 30 degrees, lower speed to 60-65 kts and line up with the runway. Assuming a constant speed and pitch, the glide slope and rate of change of altitude are now controlled by the throttle, and this takes some getting used to. As you reach the point just before the runway you cut the throttle back to idle, perform the roundout (or flare) and land the plane.

This last part sounds easy but along with the approach is probably the most difficult thing to master when learning to fly. A smooth landing requires a balance of the right speed, the right descent slope, the right angle of attack and the right timing on the 'flare'. The flare is where the plane is transitioned from the descent angle, to level flight just a few feet above the ground, before pitching back some more to touch the back wheels on the tarmac. The perfect landing would be where the plane almost reaches a stall just as it touches the ground. The most difficult thing here is to get the feeling for when to pull back on the elevator, and this part of the flight is so different to being in the air. The ground comes up to you and moves past you at a high speed, and when you're looking out the front it's difficult to get a sense for how high you are.

Post landing checks

Once you are on the ground it is time to apply the brakes gently then pull off the runway once you are down at taxi speed. Once you are off the runway you can do the post landing checks: flaps up, mix lean (about 1" from fully rich), throttle 1000rpm, carb heat off, landing light off, transponder to standby.

And again...

A lesson like this involves practising again and again. A taxi up to the courtesy line, or straight on to the runway depending on clearance, and flow check: Lights (landing), Camera (transponder Alt), Action (Mix rix) then take off.

Takeoff and aborts

From my experience so far the take off is much easier than the landing. The sequence is full throttle, use the rudder to keep the plane straight and accelerate until you reach Vr = 60 kts at which point you pull back on the elevator and the plane leaves the ground. If there is any problem during the take off, e.g. the engine not sounding right, some obstruction on the runway or an issue with the controls, then you abort the landing but cutting the throttle back to idle, breaking gently and leaving the runway. Also during the acceleration you should perform one last check of the engine instuments: rpm, oil pressure and oil temp before declaring "engine instruments are green".

Crosswinds

If flying wasn't difficult enough, then cross winds add a whole other complication. A crosswind is where you have wind coming across the runway rather then straight down it. This has a tendancy to push the plane to one side and makes the process of takeoffs and especially landings that but more challenging. For take off you tilt the ailerons in the direction of the wind, but landings you need to do some kind of sideslip or crabbed landing approach. This is one area I need more practice as it doesn't feel natural, and the controls are crossed (e.g. right aileron but left rudder).

Radio calls

Some notes for myself about the radio calls used.

When parked up in West Valley you call Palo Alto Ground (125.00) with the following message:

• Palo Alto Ground
• C24351 in west valley
• Taxi with Hotel (or whatever it happens to be)
• Right closed traffic
  

After getting permission from ground you change the radio to the tower frequency (118.60), taxi to the run-up area, perform the run up checks then:

• Palo Alto Tower
• C24351
• Ready at 31 (the runway entrance)

The response from the tower will then be one of the following:

• "Clear for take off" - at which point you do just that
• "Position and hold" - move onto the runway but hold
• "Hold short" - move ot the edge of the runway but don't move onto it, e.g. someone else is coming in to land first
• "Hold position" - stay where you are, don't move
• "Hold position #2" - e.g. you are #2, there is someone else ahead of you in the line

Summary

I learned a LOT of things on this flight, at times it was quite overwhelming but as the landings improved and I learned the flw checks and sequences I got a real sense of achievement and a buzz. After the lesson I felt really tired! It's been a busy week at work and I'd only just flown in from England over the weekend; I need some time to relax before the next lesson!

Flight stats: 1.6hrs flying + 1.4hrs groung, N24351

Lessons covered: 11 (part: rectangular pattern), 12 (part: aim point, low approach),

Next time: Good weather - stalls, bad weather - more pattern work.