Questions, Birdstrikes and Mode S
 

Two quick questions from a current trainee.

Is reporting a bird strike mandatory?? Even if it causes no damage, I know it didn't used to be but hear this may have changed??

And also, can someone explain about how squawks will be allocated when everybody eventually has Mode S. I understand the principle to be that every airframe will have a unique identifer. Will this replace getting assigned a squawk? Will ATCO's be able to issue more squawks so we'll see squawks with 8's and 9's. Any info appreciated, thanks.

On the birdstrike thing, in the UK it is now mandatory. The ANO article 143 says:
Mandatory reporting of birdstrikes
(1) Subject to the provisions of this article, the commander of an aircraft shall make a report to the CAA of any birdstrike occurrence which occurs whilst the aircraft is in flight within the United Kingdom.
(2) The report shall be made within such time, by such means and shall contain such information as may be prescribed and it shall be presented in such form as the CAA may in any particular case approve.
(3) Nothing in this article shall require a person to report any occurrence which he has reported under article 142 or which he has reason to believe has been or will be reported by another person to the CAA in accordance with that article.
(4) A person shall not make any report under this article if he knows or has reason to believe that the report is false in any particular.
(5) In this article “birdstrike occurrence” means an incident in flight in which the commander of an aircraft has reason to believe that the aircraft has been in collision with one or more than one bird.

On the mode S thing, who knows!! Lots of the promises of things that mode was supposed to bring don't seem to be coming to fruition. The last I heard about the the airframe ID (the 24-bit address), there were concerns that equipment was being moved from one airframe to another and so confidence was being lost inn the ability to know the airframe ID in the long-term. Most plans for short-term idents appear to revolve around the aircraft ID feature on-board aircraft (i.e. the box that the crew are supposed to put the current callsign into) although early studies have shown that this is oftenm incorrectly entered.

And, as far as I know, no 8s or 9s in squawks because of the coding used to send the data - there was another thread on this topic a week or three ago.

Yes. Flights remaining within Mode S coverage will get a conspicuity squawk (I think it's 1000, details on Eurocontrol WWW site) for Mode A. However, the crew will still have to set their callsign in the Mode S box at the beginning of the flight (unless the FMS sets it automagically, I guess). It'll take a long while before there are many flights that qualify for this though.

Very funny. ;)

Octal coding therefore squawks 0 - 7?

All correct, the Mode S conspicuity code will be A1000, if the flight ID has been verified against the aircraft identity in the flight plan. SSR codes are octal to 0 - 7 it is. Unwanted returns will be filtered out using other conspicuity codes, mictolights etc.

Having watched a forum for spotters about Mode S its clear that a number of factors have arisen.

A number of the 24 bit codes are miscoded, with some aircraft having two different codes, one in each transponder

When subject to change to the state of registry an aircraft still retains the code of the former country.

Both of these I would have thought would be hard to detect and even harder to police.

I agree its hard to police :mad: There is a programme (airborn monitoring programme) that watches this very closely and produces a report every month that is very detailed. There are available on the Eurocontrol site (AMP reports). The trend is improveing but there is still a lot of work to be done in the procedures area and educating aircrews to same.