Friday, September 24, 2010

Cows Get Bigger Too Fast

I arrive early to sign out the airplane and do the walkaround, then Oak comes out to show me the idiosyncrasies of the particular type. Most of it is pretty much what you'd expect of any airplane, but the craziest part is the procedure for checking fuel for contamination. The wingtip tanks are checked in what would I would call the normal way for this type of airplane. You take a fuel tester cup--that's like a drinking tumbler with a spike sticking straight up in the middle and jam the spike into a release valve on the underside of the tank. Fuel spews out into the cup and then you can examine it for impurities. The other tanks work differently. Inside the cabin between and slightly behind the control seats, there are some knobs and if you trace the way the lines go from them you can figure out which connects towards the left and which towards the right. Outside the airplane, on the belly just where your hand right hand would be if you extended it after jamming your left shoulder under the flap are two plastic tubes. (Yeah, surgical tubing sticking out of the belly of the airplane. If it were a dog it would have to wear a plastic cone around its neck so it didn't chew on them). In order to check the fuel in the wing tanks, one person holds a fuel testing cup underneath the tubing while another person inside the airplane selects the tanks and pulls the knobs one at a time to let the fuel drain out. Usually when I test fuel at the bottom of my tanks I drain 25-50 mL. If there's no water or sediment, I move to the next tank. If there is some contamination I take another sample. Here Oak wants me to sample one cup of fuel from each tank, and an additional half cup from the crossfeed line.

I call stop after about 250 mL is in the tester and hold it up. "No, the whole cup," he says. Ah, not "one cup" as in the 250 mL kitchen measure but as in the whole, perhaps 600 mL tester. It has a strainer cap on it, so after examining it I can pour the fuel back into the tanks from the top without risking reintroducing contaminants. This is, don't forget, a little single pilot airplane. And it takes two people to check the fuel. Oh this is done before every flight, too, not just after fuelling or for the first flight of the day.

Our first flight is not IFR, just a flight for me to practice handling engine failures and flying this airplane. Fair enough. He briefs where we will go and what the procedures are, and asks if I have any questions. "Yes, how do we get to and from the runways?" Most of the taxiways seem to be NOTAMed closed. It turns out that everything, from Cessna 152s up to WestJet has to get on and off the runways through taxiway A. That's a lot of backtracking. I don't know how long it's been this way, but the NOTAMs suggest it will continue for at least another month.

I run through all the checks for practice, even though it's a VFR flight. There's no VOT here and I can't ID either of the likely VORs in the area. The CDI comes alive while the NAV flag quivers back and forth but never completely falls out of view, and the Morse code is not audible. The ADF works beautifully, though.

I read the departure briefing as though I am going to depart on an IFR flight and then as I'm taxiing for the runway picturing that in my head, realize that I have read the Abbotsford Seven departure for runway 07 as opposed to the one for runway 19. That's disturbing. I've never done that before. I later figure out what happened. Many airports don't have named departure procedures, and for those that do I've never had them match the runway number. In this case I treated the runway number as redundant information because I already had a seven. When I tell Oak what caused me to do that he says it's common. I caught it because I visualized what I was going to do on departure, and it didn't make sense. It goes to show how important test data is for a program or a technique. I wonder how many departures there are in Canada right now that have the same name as the airport and match a runway number. I wouldn't be surprised if this were the only one.

The rotation speed is given for this airplane as "70-78 kts," with no indication whether this depends on take-off weight, runway surface or what. Turns out that the ideal rotation speed would be 70, but Vmc is 78, and they don't want people flying below Vmc (that's the speed below which the airplane is designated unflyable with an engine failure as maximum power), but they don't want people holding an airplane on the runway when it's ready to fly, because that can also result in loss of control. Sounds like a design problem to me. They should have given the thing a slightly bigger rudder or more rudder travel or whatever it takes to bring Vmc down to match Vr. I'm instructed to make up for this by rotating very slowly beginning at 70 and then keeping the airplane in ground effect until it has passed 78. I try this on my first takeoff and am told to hold it in ground effect a little longer next time.

I have him put me under the hood and we try some simulated engine failures and I do the procedure. I was very slow to simulate feathering on one, not sure why. I'm constantly punching the ceiling or dashboard in the wrong place for controls that aren't where they "should be." The airplane is not too hard to handle on one engine. You can hold altitude with the gear up with the power at 25" x 2500 rpm, but if you let the speed decay below 85 knots you've crawled up the backside of the power curve and it loses altitude rapidly. I should be able to fly this airplane. We go back to the airport to land.

Oak seems surprised that I land it adequately. It's not the greatest: I landed straight and on the mains without undue force, but my nosewheel control should have been better. I felt I set it down too rapidly. It's not brutal though. My mind goes back to the private and commercial flight tests, both of which had poor marks for the final full stop landing. The "oh no, now all I have to do is not screw up the landing" feeling was apparently too much pressure for me back then. Here if I get as far as short final without failing anything, I'll be fine. Oak says the approach was too high. Hmm, I got all the way down to the runway and landed in the designated touchdown zone. I'll try to put it underground next time? (He didn't like my high descent rate).

6 comments:

lahso said...

I'm no fan of instructors who want you to pretend your light piston aircraft is a jet and bring it in on a 3-degree glide path.

Anonymous said...

unless of course the light piston is used to train people in jet operations.

Rob said...

On final I prefer flaps 40 with the rudder pedal on the firewall. Works great in the 172...

Sarah said...

Naw, Rob. Then you have nothing left if the slip & full-flaps aren't enough, except possibly a go-around. Better to be right in the middle of a/c performance so you can correct either way.

Not that it isn't fun. :)

hawk205 said...

sounds like you were flying
click

Rob said...

Sarah... you're absolutely correct, best to be right in the middle. (The shortest runway I normally fly off of is 5,000 feet though).