Cloud on the Ranges

The large cloud we avoided enroute

This is the story of a private flight from Temora to Richmond encountering adverse weather, various aircraft and how air traffic control can help, including audio from Sydney Radar 124.55Mhz courtesy of Air Services Australia.

It was return trip to Richmond from NATFLY at Temora on 3rd April 2010 in aRockwell Commander 114. Darin was pilot in command with 2 passengers, Alan and Steve. Just after Young (just east of Temora) we avoided a large cumulonimbus cloud. We continued normally at around 5500ft AMSL.

Approaching the western side of the Blue Mountains, a few miles north of Katoomba were were faced by a wall of low cloud. The cloud base covered the majority of the range tops and although some avenues looked promising, as we approached them it got worse.

Initial weather view

Listen to Darin’s recorded radio transmissions on Sydney radar 124.55MHz (courtesy Air Services Australia). The audio includes the controller helping us and another other aircraft in the area. The other aircraft headed for Bankstown attempts VFR on top but is not recommended by the controller. You’ll notice other aircraft also helping with weather observations. Without the help of Sydney radar we would have probably diverted to Bathurst (which almost happened).

The initial views looking across the ranges toward the east look like there’s enough room to get under the cloud base, but on closer inspection the visibility was less than than the minimum for VFR. In the initial weather view photo you’ll notice a hard shadow line running across the top of the ranges where the thick cloud starts. Because it was late afternoon it was quite dark under there and trying to find a path under the cloud and through to the other side was not possible. We had to find a valley!

Powerlines highlighted

As we passed over Little Hartley we noticed power lines which fall from the top of the cliff face (on the eastern side) down to the flats (shown here, highlighted in red). After noticing these power lines, I also put Alan (in the right hand seat) and Steve (in the back seat) on the lookout for any other power lines due to our low altitude constraints under the cloud base.

Wall of cloud

Flight path over the Blue Mountains

From our point of view, at this stage, the south looked more promising (as Alan also suggested) but after I heard a call from a helicopter at Riverside Oaks advising that things looked clear to the north we completed a figure eight pattern then headed further north over higher terrain. After reaching Bells Line of Road, near Lithgow, things weren’t looking promising and our height above terrain was reduced to under 500ft so I advised Sydney Radar that we would head for Bathurst. The visibility to the west was always good and I always made sure that I kept that option open at all times.

Just as I started making a turn for Bathurst, Sydney Radar came back to us with hope, advising us of a path taken by previous aircraft, just south of Katoomba. After checking the fuel status, I decided we’d go down and take a look. At first I wasn’t confident of the weather holding out as I beleive the cloud base was falling. I headed for the north western fork of Warragamba dam. As we approached, I could identify a hole under the cloud base, an obvious dip in the terrain. This was our best chance of making it over the ranges. Although the visibility wasn’t great as we approached the point, it never reached anything close to VFR minimums. One of my thoughts at this stage was whether I could conduct a 180 degree turn if the weather caved in through the valley. Fortunately, visibility remained ok as we entered through the hole. This hole of hope was located in an area named Wild Dog Mountains, real tiger country, and no place to put down in an emergency.

The hole

On entry to the Wild Dog Mountain area, we spotted the waters of Warragamba Dam. It was at this point visibility increased tremendously and we could see most of the Sydney basin as other pilots had described previously. Steve was quick enough to turn around and take a quick snap of where we managed to sneak through the hole. At no time did we encounter any precipitation, thankfully. The next looming issue was daylight, and we were starting to run out of it. As you can see from “the hole” photo, the ground is quite dark due to the cloud cover and also from the sun going down. The photo was taken at approximately 18:15 local AEDST 3rd April 2010 (UTC +11) or 7:15 Zulu. Last light for that day at Richmond was 0815 UTC. It must also be taken into consideration that because the mountains block the last bits of light coming from the sun setting in the west, it does appear somewhat darker earlier. Adding to this earlier darkness was the solid low cloud cover.

As we left Sydney Radar, we were making a cruise decent into Richmond. The tower was down and it was a CTAF(R) zone, so we didn’t have any air traffic delays. We arrived in the circuit area at 07:26Z and were landed on the runway at 7:30:04Z. As we were putting the aircraft to bed it was becoming dark, and by the time we left the club house it was dark. Remember to always leave some margin before last light for this kind of circumstance.

The only thing I wished I had of done, is taken my own gut feeling along with Alan’s, to go further south initially, which would have led us to “the hole” alot earlier. The earlier advice from the helicopter pilot didn’t turn out to what we expected. All in all it was a good flight experience and a learning experience and I hope everyone who reads this can learn something from it.

Please add any comments you wish below.

Photos

Photos courtesy of Steve Brown. Map images courtesy of Google Earth.

Download

Available for download is the Google Earth KMZ file of our flight path in 3D on the day.