Peter wrote:
In my 22 years I’ve never known anyone who did a precautionary landing – in a fixed wing aircraft
Lots of those in Norway pre-GPS. I would guess pre-online weather also was a factor. People just got lost, typically in less than optimal weather. Then what options do you have? For a start it is a very upsetting feeling not knowing where you are (where did I go wrong? was the plan wrong, was it the wind, did I mistake N for S, did I note the time wrong etc etc). Done that a couple of times, but managed to figure it out, largely because the weather was not all that bad. People landed on fields, roads. Even football fields and docks have been used 
Lots of other were not that lucky.
With GPS those kind of accidents/incidents are all gone (being lost). Still there have been some. I think engine trouble is the usual cause, or some other stuff not working properly. I have had a couple of those also, but those tends to occur soon after take off. More like oops, something is wrong here, must turn around and land. I don’t know what to call that. Some kind of precautionary landing perhaps? One time, the temp was way off the scale just after take off. I told the tower exactly that, and said I had to land. When landing I was met with a couple of big fire trucks Was it emergency, was it precautionary?
Where to draw the line between a precautionary landing and an emergency landing? It really isn’t clear, because the specter of precautionary landings is wide. To land at an airfield to tie down the luggage better to prevent things from happening, is very different from landing on a piece of road because the engine isn’t giving full power. It’s not clear, and it’s a decision that has to be done by the PIC in a potentially very stressful situation. Largely unnecessary IMO. If you are stressed out, call an emergency is my opinion. If in doubt, there is no doubt etc.
alioth wrote:
I decided to make a precautionary landing at the next airfield to check it out rather than ignoring it.
I think that is called a diversion – by precautionary landing UK CAA means lands in a field…
Peter wrote:
In my 22 years I’ve never known anyone who did a precautionary landing – in a fixed wing aircraft.
I’ve done one. I was doing an IFR trip from Houston Gulf to Amarillo in an early Cessna 182 (I don’t recall the model, but it was before they had back windows), which I had flown just twice before this trip. I’d made an early morning start (5 am or something like that), and Amarillo was the first fuel stop and where I’d pick a friend up en route to Salt Lake City.
The early C182 has quite small fuel tanks, and somewhere between Waco and Amarillo, the fuel gauges were showing less fuel than what I calculated I ought to have. When it comes to fuel, I always believe the most pessimistic thing. I had looked in the tanks before departure and they looked full. I decided to make a precautionary landing at the next airfield to check it out rather than ignoring it. Good job I did – I fuelled the plane and it took about 10 gallons more than I expected – and I discovered the difference between “it looks full” and “it actually is full” on the visual check.
For the reasons mentioned, i opted for the nearest airfield with a proper hard runway.
Safe for the landing; easy to get out if as harmless as expected; easy for an ambulance if needed; and well known, so no need to describe a complex path to it.
I understand PAN MEDICAL, but i still do not know for sure, if that was a precautionary landing, too. I guess, yes.
Peter wrote:
Mayday, and land at an airport. The ambulance can get there quick, which won’t usually be the case with some field. Many/most fields are actually completely inaccessible to a vehicl
As an emergency physician who has actually treated patients on the tarmac of a major airport more than once, let me add this somewhat tongue-in-cheeck comment:
For the ambulance it might actually be easier to reach your aircraft if you put it down on some stretch of motorway or other major road. Actually getting inside the security perimeter of a major airport turns out to be not that easy even with blue lights flashing and sirens blaring. The security staff, having seen too many movies, seem to automatically assume all ambulances are actually manned by disguised terrorists and really do take a lot of time to check your vehicle before letting you airside. Last time (earlier this year) we waited some 30 Minutes or so…
I know of 2 Pa28 precautionary landings, one in a field, one on a beach, due to weather. Both flew out. Not a problem.
I’ve contemplated a precautionary landing 3 times, orbiting. Each time an escape route cleared and I escaped.
VFR below cloudbase which covers the valley hills, combined with showers moving across the valley makes this situation unpredictable.
After my only powered aircraft accident, I flew it home on a A&P issued certificate, after his temporary repair, restricted to the flight to the repair facility. (Stronsay, Orkney to Inverness.)
In maybe 2008 a pilot from a neighbouring airfield landed in a field near Dijon because he felt very unwell. It turned out to be the start of a heart attack, so he did the right thing. I can’t find a report, so it either wasn’t judged an accident or it’s an urban myth.
There may be a direct correlation between the likelihood to land in a field, and the ability to get out of a field (STOL, trailer)
It can’t be an easy decision to make. With an engine failure the decision is made for you For certain types of accidents, e.g. VFR IMC CFIT or partial power loss, more awareness on precautionary landings might make a difference to accident rates. On the other hand, so might diverting or turning back earlier.
I’m puzzled too by this idea of a medical urgency. If they need treatment, an airport is the place to be. Even if it’s an uttanded grass strip, I can get the ambulance to be on the way while I’m in the air, or at worst when I get on the ground and they’ll know where to go.
Otherwise, what? Needs a pee or worse, or feeling sick? If it’s comes to it I’d rather clean up a mess IN the plane than a mess OF the plane. Hard to imagine what lies in between.
arj1 wrote:
@Peter, is it actually a mayday? I thought that unless it is an aircraft in distress (or flight crew), it should be pan-pan.
I have it mind it is “PAN MEDICAL”. But as Peter says, for a medical emergency (not urgency) of a passenger, nobody will make you trouble for doing a MAYDAY.
Peter wrote:
Mayday, and land at an airport.
I’m not sure what ch.ess meant by “medical urgency”, I clearly understood a far more minor thing than you did. But if an ambulance is needed, or even just professional medical help beyond “first aid out of box”, I would say definitely a “real airport” if any is nearby, they will have EMTs (emergency medical technicians) or paramedics RIGHT THERE AT THE AIRPORT, bored out of their mind waiting for an emergency to happen (which will probably be the same person as the firefighters). Make use of them.
Either will do, IMHO. Nobody will question your decision.
In my radio exam, 22 years ago, I was taught that if I see a raft in the water or hear an ELT beacon, I should set 7700 and declare a mayday and pass on the location etc.
