You seem to be assuming that both aircraft were flying pre-planned routes. As one was apparently a school aircraft, it could well have been doing training manoeuvres in uncontrolled airspace. I learned to fly at Wycombe Air Park and have had that sort of session in that area. Safety depends on continual observation at all times, which can be quite difficult if you're concentrating on flying an unfamiliar manoeuvre or observing your student doing so, and if there is no TCAS or other aids to help you.

The fixed wing a/c is owned by Booker so probably used for training/sightseeing/trial flights. Hence would have been all over the place on manoeuvres, not a fixed route.

Also google "ntsb-see-and-avoid-isnt-enough" (sorry, can't post links :oh:)

Fair enough, but at some point they would have reported their position and intentions.

When flying for training out of Denham, the general direction is North West. This means (solo) students avoid going in Heathrow's airspace (or trying to find the small gap between Wycombe and Heathrow for a route to the south, and avoid going towards Luton. You can head NW and not infringe airspace for quite some time. My first solo navigation was around the Waddeson Manor gardens. It's a busy bit of sky.

A local flight would be reported to ATC on departure. There is no requirement to disuss routings if you are remaining on frequency. I fly off in that direction when I just want a quick trip out and would not describe the route to ATC before departing the circuit.

And mine was Elstree to Stokenchurch and back, passing just north of Wycombe.

one of the nicest guys ive had the pleasure to meet and have a laugh with, including this morning, sadly.

I was flying this morning and what was a "great aviation day" turned into a "a very sad one indeed" then I listened to Radio 4 News at 7pm and it became a "Very angry sad day" why are they allowed to have a "voice of authority" an "expert" talk utter drivel about lodging a flight plan. There are now people all over the world taking gospel from some self serving duffer who likes to "get on the radio" given credibility by the BBC. Surely we must be able to stop the "free press" making things up and fuelling speculation. If you get a chance complain to 03700 100 222 or before you know it some "Expert" will be drawing up "enforced flight plan filing for VFR" RIP

Helifirst
 

A very sad day for WAP today
Our thoughts and prayers are with you tonight

Knowing the registrations of both all is visible on FR24 :(
Sad day for rotor and planks, but rotor while flying on 1000 ft in steady course
had no chance to see above&behind and plank last data was:
2,700 ft Vertical Speed -1,536 fpm

RIP and sincere condolences to all related

On a record:
My Jr, student pilot on the G2 had two close encounters with planks,
having less than 100 h t/t.
It is time for at last FLARM or OGN hardware in case that TCAS is to expensive for GA / ATO-s

No. That is uncontrolled airspace surrounded by half a dozen training airfields and a couple of gliding clubs, as well as being en-route between any number of destinations. What radar service there is would be swamped by regular position reports, which would also be a nuisance to most of the training traffic.

See and avoid, or sense and avoid are the only viable strategies in areas like that.

G

Hi.
Very very bad news for us.
Still not sure how the fix wing lost the altimeter from 2700ft to 1400 ft!

I've been flying in that local area for 30yrs, most of that instructing and some out of Wycombe.

It is very busy airspace but sadly anyone who has been flying long enough has had the odd near miss, this is just a tragic accident.
Getting in my car and driving around the M25 is far more risky.

Forcing GA with compulsory TCAS sort of gadgets will not solve the problem - It will just pander to the 'gadget brigade' who never look out enough, and won't show up the non squawking traffic.

My condolences go out to those involved in this sad accident. RIP.

As has been said, "TCAS" - especially in most GA aircraft is prone to drive a head down and inside - and the display doesn't always give a "class D" bearing on the target especially in a turn. Worse, in a climbing turn the relative vector can be reducing and in error laterally and vertically.

I fly an aeroplane so fitted and that in nil wing can give a ground speed of 3nm/min. The closure on something heading directly towards doing the same is minimal at best - I've seen pilots spend so long trying to identify where the threat is 'on the screen' before looking up and out. It's a mindset of 'automatics' will keep me safe and that is to the detriment of good old fashioned airmanship, situational awareness and TEM principles.

I'm a big fan of TCAS - in a well equipped aircraft with a well trained operator in seat 0A but there are so many other threats that aren't necessarily going to show on the screen - (hang gliders, parascenders etc). Not to mention in a supposedly safe environment (the circuit, perhaps) where the pilot doesn't understand the inhibit function or the capability of the systems that recognise the environment and desensitise themselves leading to too many 'contacts' in a target rich environment that the conflicts become so frequent that the pilot begins to ignore the warnings.

I stand by my statement that, whilst good, it isn't the solution

I've not been involved at Wycombe for a good few years now, despite my moniker.

Having seen this news, and as one who frequently traversed that airspace in club and privately-owned aircraft in years past, I'd just like to pass my condolences to all involved in today's tragedy.

Flightradar 24 (in)accuracy
 

Whilst for the heavier metal (with full GPS location via ADS-B out) flightradar data is very accurate (excluding loss of signal and the estimation which is then involved), smaller GA aircraft data is an approximation at best.

I would urge caution before making statements such as w,xyz fpm descent rate on the 152 prior to impact.

In a simple form: How flightradar generally works for GA aircraft is it requires several ground stations to receive the transponder signal from an aircraft. It then calculates based on the known locations of the ground stations and the differences in the time received between the transponder signal at each of these locations. Over time it can estimate the altitude, speed and direction of the aircraft. For a really basic example of this; turn off your GPS, wifi and bluetooth on your phone and open google maps and look at the margin of error circle around your position.
A lot of the accuracy of this system depends how accurately a user records the positon of their flightradar receiver (typically done manually) and how many different receivers receive each transponder transmission.

I believe (but I don't know for sure about this) - that a lot of "smoothing" or "averaging" is applied to the data received by flightradar to give a sensible relatively consistent reading.
I would expect that in a scenario such as this (sudden loss of signal or wildly varying data for want of a better way of putting it), that the recently reported data by flightradar would be suspect at best. I've looked at the raw data reported by flightradar (CSV format - maybe worth a look for the curious) and I believe there is a reasonable amount of inaccuracy there. I do not know how much.

Note: I do not know the cause of this accident - Nor will I be making any assumptions - I would however urge caution about treating heavily filtered data as 100% accurate.

It is class G airspace. The alternative is controlled airspace. Would you like to pay for a deconfliction service?

A gadget is a self opening bin or a touch sensitive light. TCAS is the ABS on your car or the system that stops trains passing red signals (TPWS if you're interested :8).

When our phones have the power of supercomputers there is no technical reason why EVERY aircraft, including UAVs, can't broadcast its position.

That only leaves geese, but even A320s have problems with them.

I believe with a SkyEcho (ADS-B IN/OUT) device £600 a tablet and SkyDemon you have a TCS device for as little as £1000 with all the benefits of skydemon. Then as long as everyone runs mode S we would all see each other and reduce these sad events happening. This is UK CAA Approved only. Even gliders could run this, has an internal batteries that runs for 6 hour. SkyEcho ? uAvionix

It would appear from the tracks they where both on the same track and the 152 descended onto the helicopter so in each others blind spot very sad day.