With a 400m RVR it doesn’t matter what the ceiling is, you are IMC before you start.
A 10km RVR would be VMC even with a 20ft ceiling, providing you don’t climb into cloud. Problem is flying at 20ft AGL is not exactly safe IMO.🙂
I had an instructor on the Tiger Moth who had flown bombers in WWII. He told me that they practised take-offs in the Tiger Moth under the hood. It literally was a hood that covered the entire rear cockpit. The instructor in the front was of course unaffected. He said they used a spirit level (part of the instrumentation in the Tiger Moth) to judge pitch, but I can’t remember how he said they kept the heading steady, as from memory there is only a compass and no gyro instruments (or at least none that would be working from the Venturi tube at that point.) Perhaps they did it from a big rectangular field and heading was not so critical.
And this (2) is where Part-NCO references Part-SPA, which in turn has been linked above.
Yes and Part-SPA lo-vis is aplicable to very few (if any) Part-NCO aircrafts, except lo-vis takeoff.
In 2021 I departed Dortmund EDLW in low enough visibility that the follow me car had to escort me to the hold short line. A dense fog layer had quickly enveloped the valley. I was actually unsure of the German RVR requirements or those of the airport, so I called the tower to ask. They said it was my discretion. The visibility was extremely low, as I could only see the centerline immediately in front of me and could not even see the runway edge lights.
I admit that I was a bit hesitant, mostly because I knew I couldn’t land immediately if needed (however it was VFR a few miles away outside the valley). Possibly this should have stopped me from continuing, but I was and am very comfortable on the gauges, as I got my IR in 2002 and fly IFR all the time. I really didn’t think it was going to be an issue to hold centerline, rotate, and go immediately on the AI. In fact it was a non-issue, and I broke out a few hundred feet later into clear skies.
So I’m a bit torn on this one. If you are very instrument proficient it’s probably not quite “crazy” territory, but I’m not sure I would say “it’s no big deal” either. Happy to hear people criticize my choice, but thought I’d share actual experience.
Happy to hear people criticize my choice, but thought I’d share actual experience.
Few years ago I got lost taxing at LYBE and missed the taxiway on totally fogged apron. Follow-me car led me to runway where RVR was 800 m and cloud base was 100 ft. Rotating in the night to this low layer with reflections coming from different directions wasn’t the best experience.
Well, legalities aside, for safety discussion, I see it like that. If a Boeing 747 operated by a crew not approved for CAT II approaches, or at an airport where no such approach is available, whose takeoff distance (or run, I’m not 100% sure) is about 3 km, can safely take off in 400 m RVR (about 13% of its takeoff requirement) without special equipment nor training, then by the same thought process a light GA that takes off in 400 m can is good to RVR 50 m without special equipment nor training.
Now, the pilot-operator’s risk appetite may not go as far as taking off in a situation where (s)he cannot land back, but that is another issue altogether.
Now, the pilot-operator’s risk appetite may not go as far as taking off in a situation where (s)he cannot land back, but that is another issue altogether.
My SOP in a single engine is 1800m and 1,000’ METAR ceiling.
An engine failure in an MEP in LVP before take off safety speed would be exciting.
" but I can’t remember how he said they kept the heading steady, as from memory there is only a compass and no gyro instruments (or at least none that would be working from the Venturi tube at that point.)"
I understand the instructor flew a circuit to get the gyros working, then handed control of the stationary aircraft to the student with the gyros working.
The instructor would have been in the separate rear cockpit. It had superb all-round vision, with the only blind spot (large) being forward.
Often low RVR is accompanied by humidity which not only covers the windscreen in small water droplets or condensation on the interior. Unless your aircraft has wipers, this can also reduce forward vision.
You only have to drive down a motorway in the fog to see how many drivers think they have X ray eyes. But we all have our own opinions on what or what isn’t safe.
Personally in non professional ga aviation, I would prefer pilots to be responsible for their own safety rather than to rely on regulation.
Although I have an authorisation to take off from Brest under LVTO to 150m, it is not something I would do in an SEP as the options are pretty limited with a loss of power.
This is an interesting discussion to me. As I mentioned in my post, my main concern wasn’t possible loss of control or disorientation, but what to do if I needed to return to land for any reason. I almost certainly would not have departed had there been widespread fog, but in my case there were a number of possible VFR fields within a few minutes flight time. So the real risk would have been loss of power immediately after takeoff.
Truthfully I have had to learn to just accept that in many cases a loss of power after takeoff is going to result in a bad outcome. On two of the three VFR departures from my home base at EHRD there is literally nowhere to put the plane down. The routing flies directly over the Rotterdam city center at low altitude, leaving no options. At my home field in the US where I was based for years, Dekalb-Peachtree (PDK) in Atlanta, you have only buildings or trees in every direction for miles. There’s no chance of putting the airplane down safely. Departing Shoreham on Sunday on 20 left me immediately over the North Sea. Any night or mountain flight leaves you basically in this same position.
The late Richard McSpadden (AOPA Safety Foundation for those who don’t know) always said the safest thing in GA is a proficient instrument rated pilot flying a well maintained aircraft with sufficient fuel in the tanks. I try my hardest to make sure these three are well-covered, by keeping myself instrument proficient and maintaining my airplane to the highest standards. I prepare myself well for every flight, and stay within the boundaries of my own capabilities and those of my airplane. There’s always the possibility that something can go wrong, but for me the risk is a calculated one. I totally get that for some it’s too much; some people don’t fly in IMC, or at night, or over water or mountains. My risk profile would probably be different in an aircraft of unknown maintenance history, but I am intimately familiar with my own.
