0
$\begingroup$

I have been reading over the UK Airprox annual report of 2021 and it states:

In 2021 – 76% of all events and 83% of all aircraft-to-aircraft events took place at or below 3000ft altitude.

In 2021 – 76% of all events and 95% of all aircraft-to-aircraft events took place in Class G Airspace

In 2021 – 21 out of 22 Category A aircraft-to-aircraft Airprox involved GA Sports and Recreational light aircraft.

Now as someone that spends 90% of their flying time in Class G airspace, below 3,000ft (because higher than that phone signal doesn't work, which means I lose Skydemon and SafeSky on my tablet) in light aircraft, this concerns me.

My question: Would it be safer to fly over 3,000ft, which would sacrifice use of the Safesky app and navigation aids, rather than use these apps but below the altitude in which 83% of near misses occur?

I am aware I could buy a sky echo device or similar, but they are expensive and cumbersome. Also, most air prox incidents actually involved both aircraft having detection equipment installed and active anyway.

Improve this question
$\endgroup$
6
  • 3
    $\begingroup$ Hypothetically, if 'only' 100-83=17% of accidents take place above 3kft, but only 10% of GA flights are above 3kft, that would make flight above 3kft more dangerous. That is to say, these statistics are meaningless on their own. Another example: maybe (probably?) most airproxes are in the traffic pattern of airports, so then your cross country altitude doesn't factor into safety at all. $\endgroup$
    – Sanchises
    Commented Oct 16, 2023 at 12:18
  • 2
    $\begingroup$ Here's another statistic, about 75% of my flying time is under the LTMA which has a floor of 2500ft :( I'd love to fly above 3kft $\endgroup$
    – Jamiec ♦
    Commented Oct 16, 2023 at 12:34
  • $\begingroup$ @Jamiec why don't you? $\endgroup$
    – Cloud
    Commented Oct 16, 2023 at 13:21
  • $\begingroup$ @Cloud Because the LTMA is class A. With the 200ft guidance that means I stay well below 2300ft for much of the time out of necessity $\endgroup$
    – Jamiec ♦
    Commented Oct 16, 2023 at 13:49
  • 1
    $\begingroup$ @Cloud, from your body content, it looks like you're specifically asking about mid-airs, but your general title is about all GA. Could you define "safer"? It might make it easier to get you a salient response to your question, so we can distinguish between sampling bias (many (most?) GA pilots cruise below 3k, and all pilots fly below 3k' at some point in their flight) vs. the safety metric you're concerned about. $\endgroup$
    – Kenn Sebesta
    Commented Oct 16, 2023 at 14:13

2 Answers 2

Reset to default
4
$\begingroup$

Most GA mid-airs (maybe nearly all) are airplanes on convergent tracks roughly in the same direction. Such situations happen where airplanes converge either near airports, or around landmarks that are popular sight seeing spots (which can be even worse because airplanes converge and hang around for extended periods, and pilots generally aren't making position calls).

So the risks are more geographical than altitude related, and the most dangerous phase of flight is usually approaching the airport and in the circuit.

That being said, in general, "altitude is life" in the same vein that speed is life, in that you have more options when something goes wrong, and as far as running into people goes, the "Big Sky" concept of collision probability moves in your favour. Fewer micro/ultralights and paramotors etc.

For example, if I'm cruising somewhere at 1500 or 2000 ft, in addition to watching for paramotors and geese, I'm scanning for landable areas all the time. Less so above 3000. So in general, higher is safer all around (unless you caught fire I suppose).

Problem with systems like SafeSky and FLARM is they only work on targets equipped with transponders, and lots of aircraft aren't. They need to be treated like the passenger who sees something and taps you on the shoulder. Useful, but not something to rely on to keep you alive, and you need to act like they're not there even when they are.

Improve this answer
$\endgroup$
6
  • $\begingroup$ Thanks John, I do wonder - why don't the CAA just make transponders a legal requirement? $\endgroup$
    – Cloud
    Commented Oct 16, 2023 at 13:28
  • 1
    $\begingroup$ Transponders require an electrical system, or a large battery to operate @Cloud. They add weight as well, so your gliders and ultralights aren't going to be able to carry them. Plus, they aren't some magic safety bullet, your best safety system is the mk1 eyeball and your neck on a swivel. $\endgroup$
    – GdD
    Commented Oct 16, 2023 at 13:43
  • 1
    $\begingroup$ +1 for the sentence alone Useful, but not something to rely on to keep you alive, and you need to act like they're not there even when they are. $\endgroup$
    – Jamiec ♦
    Commented Oct 16, 2023 at 13:51
  • $\begingroup$ @Cloud apart from technical reasons, some mentioned by GdD, there is also a costs aspect. I think a certified transponder/ads-b transmitter + certified gps + installation starts at above 2500 EUR/USD/GPB. For the lower end of the aviation spectrum (e.g. a motorised paraglider) that is significant part of the total costs of the equipment, including the aircraft. $\endgroup$
    – DeltaLima ♦
    Commented Oct 16, 2023 at 14:19
  • 2
    $\begingroup$ @Cloud You already have to have an encoding transponder to fly in transponder airspace. In uncontrolled airspace, such a mandate would just drive more people out of aviation, with not all that much benefit, because mid airs are not that common. One here, one there, well within the calculated risk balance consideration you take when you do a "dangerous" activity like flying. $\endgroup$
    – John K
    Commented Oct 16, 2023 at 18:50
2
$\begingroup$

Given the choice of:

  1. more altitude and no electronic conspicuity
  2. less altitude and electronic conspicuity

I would take option 1 any day over option 2. Get your eyes outside the cockpit, have everyone on board do the same. There is no substitute for a good lookout. The EC device does not and never will pick up all traffic.

The time when you might benefit most from having that EC device working is when you're approaching and in the circuit, and then you are at a lower altitude anyway. Your statistic:

76% of all events and 83% of all aircraft-to-aircraft events took place at or below 3000ft altitude.

Will be because, as we know, most incidents happen around busy areas like the ATZ.

Improve this answer
$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .