Holding Pattern

On Saturday I completed another instrument lesson. This time the subject was holding patterns. Having done my reading I understood all the theory but we started with a short ground lesson on the various details of how to enter and fly a holding pattern.

Holding patterns are an important part of IFR flight. In practice their use is rare but when delays happen you cannot just pull over in the air so proficiency is a must. The skills you practice in learning the holding pattern are also useful for flying approaches. In visual conditions you can simply choose a reference point on the ground and circle if an airport experiences a delay. However, in instrument conditions you need to be able to remain oriented without any visibility.

After the ground discussion we moved to the Frasca simulator. This is a non motion simulator which is good for practicing the mechanics of entry into the hold because we can practice it from several different directions. Unfortunately the Frasca is also quite touchy and due to some uncommanded pitch excursions (presumably a dirty potentiometer in there somewhere). So after an hour of sweating in the sim we decided it was time to go out and practice a hold in the Cardinal.

After starting up I called Nashua ground and requested a squawk code from Boston Approach for practicing holds on the VOR or GPS-A approach into Nashua (if the link expires, you can retrieve it from AirNav). For our purposes we performed this approach with the VOR. The approach itself is based on the Manchester VOR which is actually located south of Manchester Airport in Londonderry, NH.

After takeoff I put on the foggles, began a right turn, and then planned my entry into the hold at the Manchester VOR. Since my course direct towards the VOR would take me over the VOR then outside the hold I planned a parallel hold entry. The meant that immediately after passing over the VOR I would turn to a 066 heading to fly outbound parallel to the inbound holding course on the non-holding side. Then I would turn left around 210 degrees to re-intercept the inbound holding course on a 246 heading. At this point the VOR is providing course guidance so using that I know I am flying on the correct radial towards the VOR. When the VOR indicator flips from “To” to “From” the holds continues with a 180 degree turn to the outbound course. After rolling out on the outbound heading I start a timer for one minute and hold the course. Once a minute has elapsed another 180 degree right turn is started. If all is well as the turn completes I will re-intercept the inbound course, start my timer again, and the timer will have elapsed one minute by the next time the VOR indicator flips. Phew! Now do it again! The result is a nice racetrack.

The hold depicted on the Nashua VOR-A approach plate. Right hand turns, one minute legs, inbound course 246 degrees on the 066 Radial of the MHT VOR.

Winds were pretty strong, around 27-30 knots at altitude and a direct crosswind to the hold. In order to avoid being blown off course the headings were modified to point into the wind – towards the northwest. Since it was a direct crosswind the leg timings worked out to around one minute in each direction so the timing did not need to be adjusted. But each time we came back around in the hold the VOR again provides course guidance on the inbound course. This gives a reference point to how well our wind correction angles were working. It was hard work. Each time around the hold the wind correction angles were adjusted a bit more. The air was bumpy too.

After many, many holds in the turn without losing situational awareness and without losing track of the VOR Doug suggested I fly the VOR-A approach back to Nashua. Perfect! My first approach in the Cardinal. We advised the controller who cleared us to descend in the hold down to 2000 feet. Now I had to keep flying the hold while descending. Once reaching 2000 feet we were cleared for the VOR-A approach which continues by following the 246 inbound course on the MHT-066 radial but this time I did not turn right to continue the hold and instead continued following the course outbound from the VOR.

As we exited the controller said “nice work in the hold.” Doug pointed out that the controller has seen lots of people fly this hold for practice today and we weren’t doing so bad given the fierce cross winds! If you don’t correct for the winds properly your hold ends up looking like spaghetti on the controller’s scope so this was good praise. I felt overwhelmed but Doug said I was doing an excellent job in the hold.

After passing the MHT VOR on the approach inbound to Nashua a descent to 900 feet is authorized. This is a “non-precision” approach which means it does not feature vertical guidance. So as soon as you pass the “Final Approach Fix” (the MHT VOR) you are authorized to descend down to 900 feet and continue forward at that altitude until you make visual contact with the airport. Passing the FAF inbound I put out flaps 10 degrees and put down the landing gear and adjusted pitch and power for a 1000 foot per minute descent. A bit over a minute later I leveled at 900 feet and held it there. The VOR needle remained nicely centered – I was nailing the approach so far! At the 90 knot approach speed it is around five and a half minutes of flying from FAF to the Missed Approach Point which is directly above Nashua airport.

The VOR-A does not take you in aligned with any particular runway (that’s why it is the VOR “Alpha” and not “VOR Runway 32″ which is a different approach at Nashua using the Lawrence VOR). This is called a circling approach and means that after reaching the airport you are expected to circle around and land on whichever runway makes the most sense. At the Missed Approach Point Doug told me to take my Blockalls off and for the first time in over an hour I looked outside. I was pleasantly surprised to see we were directly over Nashua airport! I held the altitude at 900 (somewhat below a normal visual pattern altitude) and flew a left circle to land around for runway 32. The approach was very well executed.

I wish I could say I made a perfect landing but instead the combination of gusty crosswinds and the sun directly in my eyes (especially after an hour of close focused blockalls!) led me to bounce it and I decided to shove the throttle forward for a Go-Around. I made my decision without much thought and announced it matter of factly. The Go-Around was well executed and I pulled up flaps and gear and made a right pattern at the request of the Tower controller. This time things looked much nicer. I made an excellent landing on 32, right on the center. Doug pointed out that often it takes some adjustment from the close focused instrument work with outside visual work required for a landing, and I agree. I’ll get better with practice! This is just the first of many instrument approaches to come in the Cardinal.

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