Thursday, August 25, 2016

Partial Panel

Flight Data

Airplane: Piper Cherokee PA-28-161/A N9206N

Hobbs: 1.6

Landings: 1

Instrument Approaches: 3

Flight Overview

Today was partial panel work. The plan was to fly the following approaches: Oceanside VOR missed, Carlsbad ILS missed, Montgomery Field ILS full stop.

During the flight to the first approach, Oceanside, I was expecting that my instructor would introduce a partial panel situation. 

What is Partial Panel?

Partial panel is a simulation of the loss of flight instruments associated with loss of vacuum. The airspeed indicator and attitude indicator become inoperative as a result. The intent is for the student to demonstrate his or her ability to perform flight with less than a full complement of flight instruments while in instrument flight.  The instructor uses a cover which has suction cups attached to it in order to hide an instrument from the student. The student must compensate for the loss of instruments by using other instruments in the panel.

Executing the Partial Panel

We were approaching the Oceanside VOR from the south somewhere close to the V23 airway. I was expecting we would go partial panel at some point prior to crossing the VOR. At the VOR, the approach can be performed by doing a teardrop entry. The holding pattern inbound leg is 90 degrees, the outbound 270 degrees. Approaching from the south, the procedure would be, upon positively passing the VOR, turn left to a heading of 240, fly 1 minute, then turn right to intercept the 90 degree radial to the VOR and complete the approach. 

VOR Approach, Oceanside

Prior to arrival, we were advised that we would be number 2 for the approach and to expect a hold. That added a wrinkle to the process. My instructor decided not to put me into partial panel mode as a result, doing an actual hold is rare and I suspect he wanted to give me that experience without overloading me with the burden of doing it partial panel. However, we were given a descent to 2500 feet and it was obvious that we would not hold, so my instructor hid both the attitude indicator, and the heading indicator.

It's hard to be sure exactly how I dealt with this. I did well enough, plenty of experience scanning instruments over the years probably accounted for the bulk of my approach to compensating. I do know that I replaced the attitude indicator with the turn and slip indicator plus mag compass for turns. As far as the use of the attitude indicator, I suspect scans of airspeed indictor, rate of climb indicator, turn and slip indicator, and altimeter all came into play.

We basically found the field, and the missed approach point, and the panel instruments were uncovered.

Compass Errors

Here are some memory aids about compass errors that I picked up during the preflight discussion:
  • ANDS - accelerate north, decelerate south. On a west or easterly heading, accelerating will cause the mag compass to show a turn to the north, and decelerating will cause the mag compass to show a turn to the south.
  • UNOS - For turns of 90 degrees or more from a west or east heading, undershoot when turning north, overshoot when turning south. How much depends on the latitude where you are flying. Given I am flying at 32 degrees north latitude,  the undershoot or overshoot amount for a 90 degree turn would be equal to the latitude, or about 30 degrees. For less then 90 degrees, interpolate - e.g., 45 degrees would be half, so the amount to undershoot or overshoot would be half of my latitude, about 15 degrees. Yes, at the equator, there is no need to compensate. And things reverse in southerly latitudes. The following video illustrates this:

Wednesday, August 10, 2016

ILS is down. Localizer is up. And where is my DME?

Airplane: Piper Cherokee (PA-28-161/A)
Hobbs: 1.5 hours
Landings: 1

Flight Profile:

Cleared Oceanside Airport
After takeoff, Left turn 270 radar vectors OCN VOR
Climb and maintain 3000 expect 4000 10 minutes after departure
Frequency is 119.6
Squawk 5301

Flight Summary and Lessons Learned

The plan was to fly to OCN missed approach partial panel, then LOC/DME approach Carlsbad CRQ, then ILS Montgomery.
During ATIS prior to engine start, we found out that the ILS at Montgomery was down (for the next couple of days). We queried ground on 118.22 and found out that the localizer was up. So we planned on doing the LOC 28R approach into MYF after approaches to OCN and CRQ. 
We got into the system after takeoff and were told to go to 4000 and we stayed on 270 much longer than usual. During the flight up V23 (or thereabouts, we were told to fly direct to OCN VOR) we noticed there was a lot of traffic going into Oceanside. Eventually the controller we were with told us that there would be a 15 minute delay if we wanted to go to OCN and offered us the ILS to Carlsbad first. And we took it. We got vectored far to the east, but eventually flew the ILS, executed the missed approach, got back with ATC and we started our flight towards the LOC approach at MYF. OCN continued to be busy, so we contacted ATC and updated our plans to omit an approach at Oceanside.
Once the MYF localizer came alive on the nav radios, we noticed there was no DME coming in from the MYF localizer. I tuned the DME to the Julian VOR to see if we could get a read from it and we did. 
Localizer approach, KMYF RWY 28R
After a short while, I looked at my approach plate and noticed the IF (initial fix) at MIBBY was defined by the R-196 radial from Julian. I also looked at the plate and noticed that there was a chart that indicated time to the missed approach point from the FAF (Final Approach Fix). I decided to tune that radial but the problem was between this point on the approach and the FAF, how would I know when I could step down? I could have flown the highest known altitude from the IF to the FAF without any step downs (4200 is the MEA at MIBBY and the MEA at the FAF is 2500) but the descent would have been steep. Because at this point we were given a VFR practice approach, I decided that I could pull out my iphone and use ForeFlight. I overlaid on the sectional map the approach plate, and during the flight on the localizer, I was able to identify roughly where I was relative to various step down fixes.
This all worked fine except for the missed approach point is defined based on DME, which we did not have, or the time from FAF at 80 so knots, which I did not start timing and had to think about once on the ground. My instructor, and the fact we were on a practice approach, allowed us to get this far but by the time I was at the FAF, had this been a real flight, I would have been executing a missed approach. And, really, I can't use an iphone app to navigate. So, what in the end should have happened?

What Should Have Happened

Once we found out we had no DME, which we assumed was available given the localizer approach was up, we should have notified ATC. This hopefully would have led us to getting radar vectors, which were acceptable for this approach (position can be determined by radar or by DME). Whenever equipment for a flight that you expect to have for an IFR flight or approach (and especially if it is required for the approach or by FARs to perform the flight) becomes inoperable, it's time to tell ATC.  With radar position reports in lieu of DME, ATC, and then the tower, would have been able to tell me the critical points on the approach, including the missed approach point.  It would not have been as accurate as DME, but it would have gotten me in.
Of course, other possibilities would have been to go to an alternate, or ask for a visual approach, or given that the ceiling was unlimited and visibility was unlimited, we could have just canceled and flown in VFR (which really is what we were doing anyway given it was a practice approach). We missed out on an opportunity to see what it would have been like to fly with radar position reports probably because we didn't report DME out to ATC. Looking at the NOTAMS after the flight (see below), they advise that the ILS navigation is out of service, and do not mention explicitly that DME situated at the localizer is unavailable.

!MYF 08/010 MYF NAV ILS RWY 28R OUT OF SERVICE 1608091600-1608120100

JLI VORTAC OUT OF SERVICE. 1608081617-1608161617EST

In Real Life, Should I Use My iPhone?

Maybe. It was an amazing thing to see my plane on the map flying down the approach plate. In real life, if DME suddenly went out, tower was closed, I had no radar vectors, and I was in IMC, or conditions were marginal, I would have been talking with ATC and executing a missed approach. In any other case, I would have had the phone out for situational awareness as a cross-check, but the aircraft equipment would have been final authority.

Flying the Clock

One thing I think I am going to try, assuming workload permits and I am well ahead of the plane, is to be aware of the speed and time to MAP from the FAF, and time it. Let's say I am going down the approach and DME goes out at the FAF or beyond. If I am timing that segment of the approach, then I can continue on or above MDA for the time given (e.g., 5 minutes in the case of the approach today into MYF) before executing a missed approach. The ability to do that would allow me to reasonably determine the MAP and might mean the difference between landing and having to execute a missed approach when I otherwise could have landed. I might also have my ipad or iphone out like I did today, as a sanity check for situational awareness.

Wednesday, August 3, 2016

Holding Patterns

Piper Cherokee (PA-28-161/A)
1.5 hours
Flight Profile:
Before departing, I got the following clearance from my instructor (first part of the flight was done under the hood but VFR):
Cleared Rancho Intersection
After takeoff, left turn 270 intercept V23 CARIF intersection
Julian 246 Radial Rancho
Hold west of Rancho
Climb and maintain 3500 feet
Expect Further Clearance 1325 local
After executing the three holds, we would obtain an instrument clearance in the air for ILS Montgomery Field, full stop.
Flight Details:
Today's lesson was holding patterns. The plan was to depart MYF under the hood, intercept V23 and fly to CARIF intersection, and then execute three holding patterns. The first was west of Rancho intersection (344 degree radial from Mission Bay VOR and 246 radial from Julian VOR). These would be right turns (the outbound leg south of the Julian 246). Then we would transition to holding east of Rancho, also right turns, with the outbound leg north of the Julian 246). Finally, we would, at Rancho, attempt to enter a holding pattern with left turns east of the Mission Bay 344 radial). The picture looked something like this:
The three holding patterns
What complicated things a bit was the wind was strong out of the south, and the heading indicator was not functioning properly (after right turns of 180 degrees, which you do constantly in a holding pattern, the heading indicator was off 20 or 30 degrees. It seemed to function ok after left turns). I had to constantly update the heading indicator. Guess I will be ready for next week's partial panel exercise, at least as far as the heading indicator is concerned :-)
Lessons Learned:
  • I identified CARIF by intersecting two radials (Julian 246 and MZB 326 (or V23)). I should have used V23 and DME distance to identify the intersection.
  • It's easy to get confused. I initially held *east* of rancho in pattern 1, not west.
  • In the Cherokee, 3 minutes or so before reaching the holding fix, reduce airspeed (via pitch and power) to about 80 knots and fly the holding patterns at that speed.
  • Don't panic - there is plenty of room on either side of the holding fix for errors. The 1 minute leg timing guarantees you won't be more than 2 minutes from the holding fix.
  • The first fix was entered direct. The second teardrop. When it came time to do the third, which was supposed to be parallel, it was easier for me to visualize teardrop, and that's what I did. I turned north 30 degrees right of what I would have flown for the parallel entry, flew for a minute, then turned back to the inbound leg heading (164). My instructor was happy with that - keep in mind that for the practical test, any method that gets me into the holding pattern is acceptable.
  • I need to pay attention to the nav1/nav2 switch that controls what radio the DME is remoted to. I flew at times with it remoted on nav 2, and was confused by what was happening until my instructor pointed it out. I'm trying to think of a reason I would ever want to have it set on nav 2, so need to add that to my preflight checks.
My notepad after the flight with assignments from ATC
  • The ILS into MYF was uneventful, except once again, given a practice approach. Once again, 4000 feet was last assigned altitude, and this worked well.
  • Needed to do better identifying tuned VORs. I did it on the ground before takeoff (was able to receive both MZB and JUL) but in the air, I seemed to forget the importance, and flew for a while on the wrong VOR. 
  • Calling in for a clearance from the air is pretty easy: "Socal approach, cherokee 9206N in vicinity of Lake Hodges, instrument request" - "Cherokee 9206N go ahead" - "Cherokee 9206N is PA-28-161/A requesting instrument approach montgomery field full stop". After that, basically got cleared to class Bravo, fly VFR, sqwawk and ident, headings and altitudes to the localizer. I was prepared to get a more complete clearance and readback like when calling from the ground but pretty much we just jumped in (I think my instructor called it a "pop-up request" when you get a clearance from the air).
N9206N back on the ground