May 06, 2007

Rough and (Not Quite) Ready

I've set 04E's autopilot for 2,000', and as it's just leveling off after a short climb on an IFR-in-VMC departure from Hayward over the Bay, there's a series of annoying bumps from turbulence, then an enormous thump as I'm pushed down into my seat and we gain 300' in a second or two. Then just as suddenly we're pushed back down past 2,000'… with a major roll towards the left, then right back up to 2,300' banked in the other direction. A small hell breaks loose — simultaneously the autopilot disengages with a loud beep, a synthesized voice somewhere in the panel tells me there's a major trim problem, and NorCal tells me to watch my altitude — he's just had a return showing me well above 2,000'. I brace for more windshear, throttle back a bit, and push the nose over to get back to 2,000'. I don't have time to respond with more than a rushed acknowledgement to NorCal, and a quick look to see how everything's going. Fine, so far, and I'm back on track and altitude. The turbulence continues, but not as bad; a few seconds later I call NorCal and tell the controller there's some major windshear here over the Bay. Yeah, he says, sounding unconcerned, it's the offshore flow, and 04E, climb and maintain 5,000…. After a while, it's quiet again, I gingerly re-engage the autopilot — everything's working just fine — and start enjoying the view and the flying again. A few minutes later I'm over Woodside VOR on my way to Monterey in relatively calm air. It's a beautiful day out there, the sunshine, the Bay, the City up in the distance, the blue Pacific stretching towards Japan, the Coast Range below me….

* * *

I'm on what should really just be a pleasurable IFR-in-VMC flight to Monterey and back in the 04E, one of the club's G1000-equipped 172s. And for the most part it is a pleasurable flight, in beautiful weather over rugged and familiar landscapes. But two things stand out this time: the turbulence (it hit me once more on the way back in almost identical ways, but at a much higher altitude this time), and the mortifying realisation of just how quickly you lose a lot of the IFR "edge" skills when you don't fly IFR very often. I don't mean the basic keep-the-plane-upright or keep-a-decent-heading things (both of which I do roughly but robustly), I mean the sort of thing that happens when you look at the G1000 after twiddling a few knobs and sit there wondering "why the hell is it doing that…?" (without having the presence of mind to think "it doesn't bloody matter!"), or when you hesitate on the radio for a little too long. Nothing major, but it's good to do in-the-system IFR in VMC flights like this for precisely this reason: after a couple of hours doing it for real, but in good weather, the rust starts wearing off. By the time I'm back in Hayward I start feeling pretty good about my IFR flying again; I'll have to drag Boyan out for a decent workout under the Cone Of Stupidity sometime in the next few weeks if he's still around.

In any case, the offshore flow (a very mild version of SoCal's more famous Santa Ana wind) is a definite issue this flight, and not just because of the turbulence — there's a strong gusty crosswind on landing back at Hayward, prompting one of the better crosswind landings I've done in years (a nice one-point landing on the right main and a gentle let-down from that), and on the return leg from Monterey, the crab angle during cruise is very obvious (at one stage near BUSHY intersection the G1000 tells me I have a 40 knot crosswind at almost exactly 90 degrees from the right).

* * *

For the most part during this exercise, the NorCal controllers have been their normal rather pleasant and competent selves, so it's a bit of a shock when I'm given several bad vectors and instructions in a row on the final NorCal frequency — for example, I'm vectored for (and told to join) Hayward's localizer after having requested and been told to expect the GPS 28L approach, and I'm told to descend to an altitude that's several thousand feet higher than I'm already at. At least three times I hear a second controller's voice immediately come on and say something like "04E disregard the previous altitude; descend 4,000" or "04E disregard; direct JOTLI; I'll have the approach clearance for you in a minute…". Trainees, doncha just love 'em?! :-).


Hamish said...

Before anyone asks, yes, the first thing I thought had happened was that I'd hit wake turbulence. But it was too low or out of the way for the usual suspects heading into KSFO or KOAK, and in any case, today was a generally pretty turbulent day — what happened, while a bit extreme, wasn't too far out of the norm for the offshore flow (the bumps and windshear returned periodically throughout the rest of the flight). And it was more of a "woosh!" that a thump...

Shane said...

Hi Hamish,

I flew out of Hayward on Sunday also and I can confirm your story about the turbulence. There were a few moments of deviations +/-20 degree bank and +/-100 feet altitude until we were able to climb above the mountains. It was probably not the best day to be out and about in a 152.

On the positive side, the weather was clear all the way up to Shelter Cover.

Hamish said...

Shane — thanks. From yours and several other real-life and email comments, Sunday was definitely a rough old day to be flying around here….