And proof that I apparently can learn a lesson.
I flew to Prescott, AZ today. I had to get my transponder’s biennial check and my annual medical exam done. Both my avionics shop and AME are based at the field.
How to Start an R44 Raven II
The first indication that I’d have a less than perfect day came when I started up the helicopter on the ramp at Wickenburg. The main part of the startup procedure on an R44 Raven II goes like this:
- Turn on the master switch. This provides electrical power to the aircraft.
- Push in the mixture to full rich. This enables fuel flow to the engine.
- Turn the key to Prime and count off the seconds. This uses the auxiliary fuel pump to prime the engine. The number of seconds depends on conditions such as outside temperature (cold means more priming) and engine temperature (already warm means less priming). This is something you get a feel for when you fly the same aircraft in all kinds of conditions.
- Turn the key to Both. This turns on both magnetos.
- Pull the mixture completely out. This cuts fuel flow to the engine.
- Push the starter button while slowly pushing in the mixture. The idea is that when the engine catches, the mixture should be full rich. This can be tricky, but most pilots get the hang of it pretty quickly.
When these steps are completed, the engine should be running. You then follow up with a bunch of other stuff to get the blades spinning and everything else working.
This morning, when I pushed in the mixture (step 2), it felt different — like it was scraping on something. It felt okay when I pulled it out again (step 5). Then it felt weird when I pushed it back in (step 6). The engine didn’t catch, so I repeated steps 2 through 6 again with a bit more priming. (It was cold out.) The mixture still felt weird when I pushed it in.
I debated whether I should shut down and talk to my local mechanic, Ed, about it. But then I convinced myself that the stiffness of the mixture cable was probably due to the cold. I finished my warmup and departed to the north.
Flight to Prescott
Prescott is 30 minutes north of Wickenburg. It’s a “mile high” city, with an airport at 5,000 feet elevation. The airport is home to Embry Riddle Aeronautical University, as well as two helicopter flight schools. It’s a busy place, with three runways and a tower that occasionally splits radio coverage to two frequencies to handle the traffic load.
I’ve flown to Prescott more times than I can count over the past nine years. This morning, I planned a direct route. I departed from the ramp at Wickenburg and crossed the runway low level, heading 017°. Then I began my climb toward the first of two mountain ranges I had to cross: the Weavers. I had about 15 miles to climb from 2400 feet at Wickenburg to the 5,500 feet (minimum) I’d need to cross the mountains just east of the flat-topped Antelope Peak.
I was past Wickenburg within minutes, climbing at nearly 500 feet per minute at 100 knots. It was just after 8 AM and the sun was still low in the sky, casting deep shadows on the cactus-studded Sonoran desert below me. I listened to my iPod, catching up on Future Tense podcasts. The miles passed quickly. Soon I was crossing the Weavers and leveling off at 6,000 feet.
Now I was over the high desert, passing Yarnell, Peeples Valley, Kirkland Junction, and Wilhoit. I began another climb, to 7500 feet, to cross over the Sierra Prieta Mountains. There was snow on the north sides of the hills in the mountains below me. Ahead of me was the town of Prescott and the wide, flat areas of the Chino and Prescott Valleys.
I tuned into Prescott’s ATIS and used its altimeter reading to set my altimeter. Then I keyed the mic to call the tower. “Prescott Tower, Helicopter Six-Three-Zero-Mike-Lima is nine to the south with Zulu, request landing at Mile High Avionics.”
“Helicopter Six-Three-Zero-Mike-Lima, Prescott Tower, proceed inbound for landing on the numbers of Runway Three-Zero. Report two miles out.”
I read back the instructions and modified my course to come in from the southeast, pushing down the collective to begin my descent. I was cruising at 120 knots, descending at about 300 feet per minute. My course took me over the south end of Watson Lake and the Granite Dells. I was three miles out and had both the tower and runway end in sight when the tower came back on the radio.
“Helicopter Zero-Mike-Lima, cleared to land on the numbers of Runway three-zero. You can then taxi down the runway to exit at echo-three and taxi to Mile High.”
I read back the important parts of the instructions, wondering whether echo-three was prominently marked. Helicopter pilots rarely deal with taxiway exits, so we don’t usually study airport diagrams to learn them.
I exited at the right intersection and taxied over to the big ramp on the back side of Mile High Avionics’ hangar. I cooled down and shut down. The blades were still spinning as the big accordion doors opened. A short while later, we had the ground handling wheels on the helicopter and were pushing it into the hangar.
Errands in Prescott
It was 8:45 AM and the avionics guys were ready to get to work on my helicopter. My doctor’s appointment was at 10:00 AM right across runway 30. The only way to get there was to make a five-mile drive around the airport.
The avionics guys very kindly gave me a pickup truck to use while they worked on the helicopter. I headed over to the doctor’s office to see if I could get my medical exam taken care of early. It was a good thing I did. The doctor took ill not long after my exam. As I was leaving with my new medical certificate, an ambulance was arriving to take him away.
I’d like to think that taking my blood pressure and having me read an eye chart didn’t give him a heart attack.
I took the pickup to a hardware store in Chino Valley, where I picked up some weed pre-emergent. I have a gravel “helipad” at our Howard Mesa property and we’ve had some serious problems with tumbleweeds there. I wanted to get the problem under control this year.
Then I went to breakfast at the airport restaurant. Bacon, egg, and cheese on an English muffin. Yum.
I was back at the avionics shop by 10:30 AM. The helicopter was done. I paid up and the avionics guys helped me pull the helicopter back outside.
Next Stop, Howard Mesa
When I started up the helicopter, the mixture problem was just as bad as it had been that morning in Wickenburg. But now it wasn’t cold. There was no excuse for it. I was getting concerned.
The tower cleared me to depart to the southwest, parallel to Runway 21, which the planes were using. A plane had just taken off and was climbing out. The controller had me switch to the north tower frequency and that controller instructed me to make my right turn, staying low level to depart to the north. I was at 5300 feet, about two miles north of the airport, when the controller asked what my altitude was. I told him and he replied with “Frequency change approved. Have a good day.”
I thanked him and wished him a good day, thinking that that last exchange had been a little weird.
I listened to an episode of Skeptoid on my iPod as I flew north, over Chino Valley and Paulden. I was heading toward the west side of Bill Williams Mountain and would have to climb to about 7500 feet to get up onto the Colorado Plateau. I was abeam Williams’ Clark Memorial AIrport before I saw it. I was already on frequency and made a courtesy call to the empty airspace.
There was a lot of snow on the ground. I started wondering whether there would be snow on my landing zone. And whether it was wise to spread pre-emergent when I might blow it away when I took off. And whether there was something wrong with my mixture control that would prevent me from starting up when I was ready to leave.
This last thought was weighing heavily on my mind. I didn’t want to get stranded at Howard Mesa. Sure, I could always start up the heat in the shed and wait for Mike to rescue me, but I wasn’t interested in a repeat of my 2004 mesa-top helicopter repair.
I began to slow down and descend when I was still two or three miles out from Howard Mesa. By the time I flew over my place, I was only about 200 feet off the ground. I was surprised to see the windsock hanging almost limp. There were patches of snow on the ground and a series of partially melted animal tracks across the snow-covered driveway. I swung around, made a tight turn to the right, and came in for a final approach from the north. I set down behind the shed, pushed the collective full down, and opened my door to see how my skids were set in the snow and ground. I didn’t want to sink into any muck (again). It looked solid enough.
And then I made a radical decision: I wasn’t going to shut down. Instead, I cooled down the engine and throttled it down to idle RPM. I tightened the cyclic and collective friction. And I stepped out to take care of my chores, leaving the helicopter running.
Now before you other pilots start scolding me, remember this: there was almost no wind and I was on private property in the middle of nowhere with no one around. The cyclic and collective friction on my helicopter do what they’re supposed to; neither control moves when they’re tightened up. The blades had enough spin to keep them from drooping. I was facing where I needed to go, so there was no reason to walk behind the helicopter. There really was no danger. Really.
I offloaded the pre-emergent and brought it into the shed. Then I fetched the two small pieces of furniture I’d come to get. I put one on each of the rear seats, fastening them down with the seatbelts. I climbed back in, double-checked the doors, and fastened my seatbelt. I think I was out of my seat for about four minutes.
I loosened the frictions and spun up. Then I very slowly and carefully lifted the collective, just in case some of that mud was trying to suck me down. The helicopter lifted straight up. I pulled more pitch, pushed the cyclic forward, and took off between two trees.
Mixture Problems Back in Wickenburg
I flew a direct route back to Wickenburg, detouring only a tiny bit around Granite Mountain. I listened to NPR’s Wait Wait…Don’t Tell Me! podcast.
There were three planes in the pattern when I arrived — all flight training planes doing touch and goes on Runway 5. I came in behind the last one and set down on one of the helipads on the west end. When I shut down, I recorded a total of 2.2 hours of flight time for the day.
I fetched my cart and towbar and brought the helicopter back to the hangar. As I was getting ready to back it in, I noticed that oil had been leaking on my muffler. I got down on the ground and took a closer look. Oil was dripping in the vicinity of the starter motor. A leak somewhere. That could explain why I’d been using more oil than usual later. I decided to see if Ed wanted to look at it.
He came over with me. While he was checking that out, I told him about my mixture control. We backed the helicopter into the hangar and he looked underneath while I pulled the control knob in and out. It made a weird kind of squeaking noise when I pulled it out.
Let me explain how the mixture works. It’s a knob that’s attached to a long cable. The knob is in the cockpit. You pull it toward you to cut fuel; you push it in to add fuel. AIrplane pilots know mixture controls very well, since they often have to “lean” the mixture in flight. Robinson pilots don’t do that. It’s either full mixture while flying or pulled mixture when the engine is shut down.
Ed also had a service bulletin to take care of for me. Since he didn’t have any planes to work on, we figured it would be a good time for him to take care of the SB, lubricate the mixture cable, and see if he could find the oil leak.
I spent some time updating my log book, then drove off to get my hair cut. When I got back, Ed shared some bad news. He’d been working on the mixture and, when he pulled it, the cable broke.
With a broken mixture cable, my helicopter wasn’t going anywhere.
A Lesson Learned
I took the news well. You see, I’d spent a good part of the day before writing an article about how inconvenient some mechanical problems can be. I’d concluded that preventative maintenance could have saved me a lot of bother.
In this instance, I’d identified a potential problem with the mixture control. Even though it still worked, I’d asked my mechanic to take a look at it at the first opportunity. Sure, he’d broken it, but if he hadn’t, I probably would have.
And maybe that break would have been on top of a mesa.
Or when taking charter clients to Sedona or the Grand Canyon.
Any mechanical problem that occurs anywhere other than at home base with a mechanic around is a mechanical problem you want to avoid. Writing that article had reminded me of that simple fact.
And I managed to remember it for a full day.
Anyway, we ordered the cable. It should arrive on Thursday. Ed will fix it then. In the meantime, I hope he tracks down that leak.