Another helicopter overflight

March 6: a nice enough day to be in the garden, rather spoilt by a low-altitude helicopter overflight.


Overflights by helicopters, often at what seem to be a low altitude and on an unusual trajectory, have often caused protests. This afternoon, March 6, I witnessed (and heard) another one, yet was unable to find any trace of it in the detected set of aircraft movements. Since the airport noise commission (CCLNTA : Commission Consultative pour la Lutte contre les Nuisances dues au Trafic Aérien) will be having one of their quarterly meetings tomorrow evening (March 7) I thought that it was a good time to send to them, on behalf of ARAG, a request for a detailed explanation: this request is copied below.

If past experience is any guide, the airport management is unlikely to give out any information. For this reason, I have addressed the request to Skyguide, who have often been rather more forthcoming. I will report what was given as an answer in a future blog. I may also report on the answer to another question that has been sent to this commission, namely what measures are the airport management, together with easyJet Switzerland, taking to try to avoid having a repetition of the disastrous period of last summer.

Have a peaceful night (once all the last incoming aircraft have landed: many will be late!)


Mr Hochstrasser,

Thbis afternoon, 6 March 2011, at our family home at 9a ch Perrault-de-Jotemps, Meyrin, while attending a birthday party for my youngest grandchild the house was overflown at low altitude by a helicopter at precisely 13h06. Because it was directly above, heading on a path roughly slightly East of North, I was unable to see any identification: all that I can say is that the underneath was a dark colour. My observation can be corroborated by several people who were also there.

The microphone of ARAG, at precisely this address, recorded this overflight: I am sure that the airport microphone just a short distance away would also have recorded it.

On checking, via the ARAG Movement enquiry system GAME, all aircraft movements this afternoon, I can find no trace of any movement of a helicopter around that time: the only helicopter recorded in the hour from 13h to 14h was that of the Eurocopter AS-350, HB-ZEI, of Heliswiss Schweizerische Helikopter AG (which is white underneath) at 13h11.

The details of the ARAG microphone, shown below, clearly indicate the noise of the overflight, in between takeoff of LS2078 at 13:04:36 (followed by the quiet landing of EZY2053 at 13:05:08) and the takeoff of LS812 at 13:07:37. Given the precision of this information, I am sure that you can identify what helicopter was flying nearby at that precise time.

My strong suspicion is that this helicopter was flying without an active transponder, in which case (according to many precedents) you may say that you can have no record of its exact trajectory. If, however, it did have an active transponder which was somehow not detected by our identification system, then you would certainly be able to produce a plot of its trajectory.

Since this represents a class of events (helicopter overflights at low altitude, apparently not on a standard arrival or departure route, sometimes without an active transponder) which have caused a number of questions in the past, I hereby request that you investigate this incident with sufficient urgency to report back to the members of the airport noise commission (CCLNTA) at the meeting for tomorrow evening (Monday 7 March). Clearly, your report should answer the following questions.

1. What was the identification of the helicopter observed by us at that precise time?

2. Was this flight somehow connected with the Motor Show currently being held in PalExpo just the other side of the airport?
3. Was the helicopter flying with an inactive transponder: if so then what was the reason and what proportion of helicopter flights likewise fly with an inactive transponder?
4. What was the authorised trajectory path involved (I suspect that it was a departure, but I cannot be absolutely sure)?
5. What measures are you prepared to put into place in order to avoid such incidents (except for special cases such as medical emergencies or reasons of State)?

21:08 Posted in Noise around Geneva airport | Permalink | Comments (0) | Tags: geneva, airport, helicopter, noise | |  del.icio.us | | Digg! Digg |  Facebook

The comments are closed.