Showing posts with label Density Altitude. Show all posts
Showing posts with label Density Altitude. Show all posts

Sunday, February 14, 2010

Flying with the one I love




Nancy and I have been married 31 (and a bit) years - the first and only marriage for both of us. We met in the summer of 1976 at university, and married in 1979 at the start of Nancy's 4th year, which was mid-way through my final year.

I have a very patient wife - some might say that only a very patient person could stay married to me, especially for that long. The most recent test of her patience was watching the bank account drain as I worked through fulfilling my life-long dream of earning my pilot license. But it was my dream fulfillment, and she agreed to the commitment at the start of the journey, so she saw me through it.

The classic question, asked mid-way during 2009: "So, once you get this thing, what are you going to do with it?"

"Why, go flying of course - we are going to go flying."

Fast-forward to January 30 2010, when we scheduled our first flight.

It was appropriate that Nancy would be my first passenger. Technically the flight test examiner is the first passenger, though that designation is there primarily to make it clear that the Transport Canada examiner is not there in a role as a pilot or as an instructor and therefore the PIC is the examinee - all of which is there for liability limiting reasons. Maybe it would be best to call her my first passenger of choice.

And so discussions started. Where do we want to go? What do we want to see? How long do we want to fly? Is this going to be a breakfast flight to a destination, or a sight-seeing flight around the area?

I asked another pilot and instructor at the club, Tony Hunt, about airports within a decent distance that had decent food. Most of the restaurants are of the greasy-spoon variety, and breakfast flights are better in the summertime anyway.

So Nancy and I decided on a local sight-seeing flight, over familiar landmarks, not too long or complex, with lots of novelty.

As always, I had my own objectives for this first flight:


  • Make sure Nancy had an excellent experience. After all the investment of time and effort and money, I did not want this to culminate in one flight which freaked her out, and as a result we'd never fly together again. Smooth, simple, safe, well-explained and no-surprises would be the key criteria.

  • I wanted to fly with precision - holding altitudes, holding headings, final approaches which were stabilized early. In other words, make it look easy and build her confidence.

  • Build my confidence. Just as with any important event, nerves were going to be a factor for me. But I have a decent number of hours, I know how to fly an airplane, I can do this, so quit worrying about it and just go do it.

Flight planning was Friday night. The weather was going to be clear though frightfully cold, the winds were going to be minimal, the jet stream was not overhead, so it was looking like a day with great visibility and minimal or no turbulence.

Route selection was to be local. We live on the west end of Ottawa, and so the route was to be a loop on the northwest side. Once I calculated the total flight time I removed the final leg, there is such a thing as too-much, especially on her first long flight.

Saturday morning: Sky clear, winds were 300 light, temperature was -22C, 30.34". With a density altitude of -5026 feet, the C172 was going to climb like a homesick angel. The club's limitation was a minimum temperature of -25C. Definitely a day to wear layers, especially long underwear (which I wear for every winter flight anyway).

The selected route:


  • CYRO R27, clearing to the west. Fly alongside the Gatineau hills at 2200', providing Nancy with a nice view of the lookouts in Gatineau Park.

  • Turn southwest, fly over Constance Bay to Carp (CYRP). Point out the landforms and towns around CBay, Constance Lake, etc.

  • Descend from 2200' to 1400' over the town of Carp. Fly over the airfield to join the mid-left downwind to a stop&go. Carp is a quiet airport situated in farmland, so it has lots of airspace and not much traffic, a good place to practice circuits with no pressure. I wanted Nancy to see landings, since to an inexperienced passenger seeing the approaching ground get larger through the windscreen is usually one of the more stressful aspects of flying.

  • Backtrack R28. To highlight the performance of the aircraft (and to practice my skill), I briefed her on the short-field take-off technique. No obstacle-clearance required, since I didn't want to surprise her with the extreme nose-up attitude. She was impressed with how quickly we were airborne.

  • Climb straight-out to 1400', circle left to a southeast heading, clear CYRP frequency and talk to Ottawa Terminal, requesting 2000' over Stittsville (our town) then west to Carleton Place for sightseeing. Approved by terminal, I did an enroute climb.

  • Over Stittsville I pointed out a few landmarks, such as the neighbourhood school and the shopping plaza near our house. Nancy traced streets until she figured out where we lived. Pictures were taken.

  • Westbound to Carleton Place. Nancy had the map on her lap, and was correlating landmarks to the map (the world looks very different from even a bit of altitude).

  • Just west of Stittsville to floor of Terminal's airspace changes from 1500' to 2500', radar coverage terminated, and we switched to enroute 126.7. Nancy was relieved, since the radio traffic on Terminal's frequency was constant, and overwhelming her.

  • Highway 7 is being rebuilt to 4 lanes, between the 417 and Carleton Place, and so she was quite interested in trying to figure out the new routing.

  • Just short of CP I turned north, to track along the Mississippi River.

  • Almonte is a great little town (childhood home of James Naismith, inventor of basketball). Nancy didn't figure out which town it was until she cross-correlated with the map (and I pointed out the water tower with the big black letters on the side).

  • Just past Almonte the floor of CYOW's airspace rises from 2500' to 6500', so I climbed to 2800' in anticipation of over-flying Arnprior's airport.

  • Flew past Packenham, between the town and the ski hill.

  • Just east of Arnprior airport (CNP3) we turned northeast, entered the practice area and climbed to 3950' to maximize visibility of Gatineau Park. Told Nancy we were headed to Wakefield to see the covered bridge.

  • Pointed out Meech Lake under the right wing - a very long and narrow lake in Gatineau Park. We've taken the kids swimming there in previous summers.

  • Nancy asked where the covered bridge was located. I told her "look right over the nose", reduced throttle and pushed the nose down - and there it was.

  • Descended to 3000' in a slow descending sweeping turn to the right, so she could have a good look at Wakefield and at the bridge.

  • Flew over the Mont Cascades ski hill. Nancy wanted to have a look at the hill, so I told her to take the yoke and turn it slightly to the left, so we would not fly directly over the hill. Nancy redefined the word "gentle" in a gentle turn. Who knew a C172 would turn with 3 degrees of bank.

  • I took control, dropped the right wing a little so she could see the ski hill. "Oh, that's neat, there is a red helicopter taking off from the ski hill." This observation was made while looking almost straight down, so the heights were clearly not bothering her. We didn't hear any radio calls from the Medevac helicopter, but I made my position reports on frequency. I expect they have TCAS anyway.

  • Enroute descent to 1700' over the Chelsea dam, flying south down the east side of the Gatineau River. Casino and the Parliament buildings were straight ahead.

  • Pre-landing checks complete, landing briefing complete, descend to 1200' and join the straight-in left downwind for CYRO.

  • Normal landing R27.

Radio:


  • This was a busy flight. CYRO - practice area - CYRP- Ottawa Terminal - enroute - Arnprior CNP3 - practice area - CYRO.

Done well:


  • The crosswind landing at Carp CYRP was stunning. Told Nancy exactly what to expect, and I landed exactly on the centre line, no yaw, right wheel first, then the left wheel, and a greaser.

  • Turns were all gentle, 10-15 degrees of bank.

  • No surprises. If I was going to turn, climb, descend, drop a wing so she could have a better look, I remembered to always tell her first.

  • I had a flight plan filed for the route, with calculated times and headings. The only heading I used was Arnprior-Wakefield, the rest of the flight was flown via pilotage (ground landmarks). All the legs were too short to bother calculating ground speed, so I just noted my time at each turn and calculated a delta against my ETA (a minute early here, two minutes late there, ...).

  • I ballooned a bit on the final landing at Rockcliffe, but put in a little power and ultimately greased it. Nancy commented on the smooth landing, and didn't even notice the balloon until I mentioned it.

Lessons learned:


  • I did startle Nancy on the descents. Though I told her we were going to descend, over Carp and approaching Wakefield I reduced power to idle and the nose dipped down to the descent profile. She just didn't think it normal that you would "turn the engine off and the airplane would keep flying". Note to self - use gentle enroute descents where possible when flying new passengers. Otherwise, brief the passenger better.

  • The volume of radio traffic on the Terminal frequency was overwhelming for someone not used to typical radio traffic.

Overall, it was an excellent flight. Nancy enjoyed the eye-candy out the window. Flying over our house was an excellent idea. I did not frighten her. Her comfort grew as the flight moved along, and she was comfortable with looking straight down out the window. Same as being a passenger in the car, she likes to have a map on her lap.

Apparently, she believes I can fly safely. She'll come flying with me again.

It's great to do things as a couple.

Friday, December 12, 2008

A Day of Firsts - Again - December 11

It is not unexpected to constantly experience "firsts" when you're in a new locale, or when you're on a steep learning curve. Today I was on both.

Flight booked from 1-3. I had a preflight briefing from the CFI as my usual instructor was at work (I was working "flex-time"). My plan was to work on the basics. She agreed. Winds were only 6 knots slightly from the right of runway 10, landings were not going to be a problem, so she launched me straight solo. That's a first - every previous solo flight required a checkride for a circuit or three to ensure my skills were within conditions before the self-unloading ballast got out and I went solo.

Temperature yesterday afternoon was -11C, and the air pressure (according to the altimeter when set to runway altitude) was 30.19. While I was physically 382 feet above sea level, I calculated the density altitude to be 3080 feet below sea level. The air was thick (dense), and both the wings and propeller were going to be high performance. I had minimal weight with only myself, and slightly more than a half tank of gas, aboard. This bird was going to climb like a homesick angel.

I had a long list of activities to practice. At first look it seems to be a too-long list, but it was all basic activity (climbs, descents, turns, etc).

Today's plan:
  • Normal take-offs were getting routine, so work on short takeoffs, and soft-field take-offs,
  • Fly to the practice area,
  • Practice the basics - turns to a heading while maintaining altitude, climbs and descents to an altitude while maintaining heading, maintaining altitude while in cruise, do some slow flight manoeuvres. If I was feeling comfortable I'd add steep turns and forward slips.
  • Return to the airport, then practice normal landings.
As the Diamond has a plastic canopy it is necessary to have a nice warm-up before taxiing, otherwise any FOD that hits a cold plastic canopy may pit or shatter, rather than just bounce off. The engine was warm from the previous flight, so the warm-up during the preflight checklists was sufficient.

Taxi was slow and careful - the apron and taxi-way were both snow-covered with occasional bits of bare pavement. The runway was mostly bare, with occasional icy bits. Another first - this was the first time I'd be working on anything except bare pavement.

First take-off was a short-field:
  • Position right at the end of the runway,
  • Elevator full-back, to maximize brake effect,
  • Stand on the brakes,
  • Full power, check guages,
  • Release brakes,
  • Release elevator to neutral, rotate at normal speed (44 knots), climb out at Vx (best angle of climb, 57 knots),
  • When the virtual 50 foot obstruction is cleared, lower nose to climb out at Vy (best rate of climb, 68 knots).
I proceeded solo to the practice area - the third first in a short while. While exciting, it also felt really weird. There was one other aircraft in the practice area, and three others transiting the area, so I claimed a patch of sky over Constance Bay and proceeded to work my plan.

  • Climb to 3500', and level off on a smooth transition (no floating feeling) and without busting through. I did a Vy (maximum rate) climb, and was climbing at 1300 feet per minute. Last summer I was seeing 600 FPM. Went well,
  • Shallow (15 degrees of bank) 360 degree turns in both directions while maintaining altitude. Went well - maintained altitude easily,
  • Medium (30 degrees of bank) 360 degree turns in both directions while maintaining altitude. Turns went well, altitude maintenance was sloppy. Exit on a heading went well. Using external references (the horizon), noted that most of my turns in the circuit were banked about 20 degrees. Since I've spent the last three months in Circuit Hell, thirty degrees of bank was more than I was used to, and a bit uncomfortable, so I decided that medium banked turns were the place to work, and didn't try steep turns (45 degrees, or even 60 degrees) on this flight,
  • Descents were slow. Most (almost all) small GA airplanes have air-cooled engines, so the front cylinders cool quicker than the rear cylinders. Thermal shock occurs when you put the cylinders through hot-cold-hot-cold cycles. With the very cold air, to minimize the thermal shock you want to re-warm the cylinders periodically when in idle conditions (like on a descent), or else just keep some minimal throttle. With the high density air and throttle for 1200 RPM, descents were gentle. It was easy to hit and maintain the desired target altitude,
  • Traffic starting coming in from the north and were announcing that they were passing over Constance Bay (exactly where I was practicing, although I was higher), so it was time to stop playing on the freeway. I set up for slow flight, with gentle turns, and transited down to Kinburn,
  • With the very cold air I decided to not practice forward slips (which is an engine-idle manoeuvre).
By this time I was bored with driving around in the sky, so it was time for some circuits. Descend below 2500 feet (gradual descent) to get under the Ottawa wedding cake, proceed to the town of Carp while continuing to descend down to 1900 feet (1500 feet AGL), pass over the airport, check the runway and the wind-sock, descending turn to circle back to the active side, cross at 1400 feet (1000 AGL), join the mid-left downwind, and practice normal landings, stop&go, and different take-offs.

On every landing it is essential to get stabilized, meaning that you're riding down on rails with only minimal control adjustments, and then only to keep yourself on the rails. I've found that my approaches are horizontally stabilized (tracking the centre-line, and land on the centre of the runway with no yaw), but not vertically stabilized. I tend to start off too high, use minimal power, get too low, bring the nose up to have a lower descent rate, get going a bit slow, then add in some power, arrive at the threshold with minimal energy, and run out of energy and drop (stall out) the last 2 feet to the runway.

It all starts with being too-high at the start of the final approach, so I wanted to get well ahead of the aircraft:
  • Fly the downwind at 110-120 knots, radio calls made, pre-landing checklist done, throttle back opposite the threshold, nose slowly up to maintain altitude and lose speed, reset the elevator trim, flaps to take-off, and then turn to base when at the correct position and speed is 60-65 knots,
  • After the turn to base is complete, flaps down to landing, trim for 60 knots,
  • I'm landing on runway 10 today, so I should be flying 90 degrees from runway heading, or a 190-degree, base leg. Often I will squeeze it to 70-80 degrees, which means I am closer to the runway threshold when turning final, and therefore compressing the final approach,
  • Turn final, make the radio call, and get stabilized both horizontally and vertically,
  • Pick my aiming point (difficult on a mostly snow-covered runway - it's all white), and see if it is static on the windscreen, or if it is tracking up/down (which means you will undershoot or overshoot). Adjust elevator to keep the aiming point stable, adjust power to maintain 60 knots), fly the final. Today the atmosphere was easy - no sink off the end of the runway, and the crosswinds were both mild and non-gusting,
  • Gentle flare to cruise attitude - I had been starting my flare a bit late and was therefore a bit rushed and aggressive,
  • Stop rotating at cruise altitude - no nose-up when rotating to the flare,
  • As the aircraft starts to sink, nose-up to maintain a very gentle sink rate (no sink if just above the runway).
I was doing stop&go (rather than touch&go) landings today, to practice the different take-offs. Post-touchdown, I needed to:

  • Pick an area of the runway which had good traction (or - at least - equal traction for both wheels),
  • Slow down carefully using brakes,
  • Radio the back-tracking call, turn,
  • Complete the pre-takeoff checklist while taxiing back to the take-off position,
  • Set up for the take-off,
  • Launch.
The next four take-offs were all soft-field:

  • On the soft part of the field taxi is done with some power (so you don't get stuck) and full-back elevator (to minimize the weight on the nose-wheel),
  • Turning at the end of the runway is completed without stopping,
  • Smooth application of full power,
  • Nose-wheel will want to come off the runway at much less than rotation speed due to the full-back elevator - when the nose starts to move relax most of the elevator so the nose wheel is only slightly off the runway,
  • At rotation speed (44 knots) lift the nose wheel up, and get the aircraft off the ground. My stall speed is 38 knots with take-off flaps, so we can easily fly at 44 since we're not at maximum weight, we are at full power so the airflow over much of the wing is in the prop-wash and much faster than my airspeed of 44 knots. And because of this aircraft's rapid acceleration we're probably up to 50 knots by the time we lift off.
  • Nose down, and stay in ground effect. This is not a short-field take-off, so there is no urgency to climb out. Accelerate in ground effect to Vy (68 knots), and climb.
Final landing, full stop, taxi to the gas pump, go do paperwork and de-brief.

Time: 1.4 hours solo
Take-offs: 1 short-field, 4 soft-field
Landings: 5 normal

Needs improvement:

  • Because I've spent so much time in the circuit in the last three months, medium and steep turns feel very unusual. Time to become re-acquainted,
  • Altitude tracking on medium turns,
  • Vertical stabilization on final approach. Today was much better, but it still needs practice and improvement to make it slick,
  • Flying downwind and base at 180 degrees and 90 degrees from runway heading. I have a tendency to pinch by 10-20 degrees,
  • On a soft-field take-off, I tend to yaw to the left when leaving the surface. Need more right rudder to counteract the propwash, and perhaps a bit of right aileron to counter-act the cross-wind,
  • On a soft-field take-off, staying within ground effect. I still tend to leap off the runway and get higher than ground-effect. It was especially tough today because of the dense air, which resulted in a very high-performance wing and propeller, and everything happened very quickly.
Needs a re-visit, just because it has been so long:
  • Need more time in very slow flight (50 knots), just to get comfortable with that regimen of flight,
  • Need work on stalls (didn't plan on working on them today),
  • Need practice on forward slips (smooth entry and exit). Didn't work on that today because I had a full workload, and didn't want to thermal-shock the engine,
  • Spiral dives. It has been a long time since I reviewed them. Must have an instructor on board to practice them,
  • Steep turns.
Went well:

  • Getting down to a good altitude at the start of the final approach. I tend to be too high, primarily due to getting behind the airplane in downwind and base. Even with a light load and dense air, today's focus on the pre-final phase of the landing generated very good results,
  • Climbs and descents were good today. But needs more practice, as there remains a tendency to blast through the target altitude on a climb, espceially when things are busy,
  • Slow level flight - 60 knots with flaps in take-off. But it is boring,
  • Gentle turns with altitude tracking and rolling out on a specific heading,
  • Radio work. Solo. With frequency changes,
  • Taxi on a slippery surface,
  • Short-field take-offs,
  • Horizontal stabilization on final approach.
  • Flare - today was much better, no climbing during flare, and the level-off altitude was good,
  • Nose-up during touch-down - I greased all five of today's landings.
Firsts:

  • Taxiways and runways which were not bare pavement,
  • Launched without a checkride,
  • First time solo away from the airport.
Next lesson is next Sunday. It's a short booking period - only 90 minutes - so I'll suggest we focus on slow flight and stalls.