When is a near miss?
 

When is passing another aircraft considered a near miss?

I was on Jet2.com LS810 from AGP to MAN on saturday, and at one point a small passenger jet passed to the starboard going in the opersite direction.

As a passenger with no expectation of seeing another aircraft zip past so close, have no idea how far away horizontally or vertically they were, only that they were a little below us and, since I could see the whole thing complete with grubby grey jet exhausts (for all of a second, from my aisle), not going to hit us.

Firstly .... a near misss is when two aircraft " nearly miss" ... that is, hit, but just :E .. so that wasn't you.

Secondly ... aircraft look a lot closer than they actually are when you see them in flight... so, you probably were separated by the required parameters ... but it just doesn't look so.

I had a very unnerving experience on a flight over Portugal. We were at around FL33 when looking out of the starboard window, I saw another aircraft approaching us in a curving trajectory. It actually passed directly under our aircraft and I remember distinctly being able to see clearly the faces of the pilots.

Sadly my camera was in my bag in the overhead locker so I was unable to record the moment. I guess the normal parameters of separation were being observed, but there was definitely a frisson sweeping up my back as the two aircraft converged.

Ok fair enough, it was just a little unexpected to see something moving so fast so close outside, I'm just used to aircraft being several miles away (or lumbering over head, as I live about 3.5 miles from Manchester airport, directly under the usual approach path from Stockport).

I have no doubt that the flight crew had been well aware of the other aircraft for some considerable time before hand, and there was no danger of a collision.

I'm quite prepared to believe it was a perfectly safe distance away. I've turned up a page that says that aircraft shouldn't enter a volume 5 nautical miles (9km) horizontally and 1000 feet (300m) vertically around another.

They were definitely less than 5 nautical miles as at that distance it would have been a pretty small, but it may well have been 300m below us (nice use of mixed units there ;)). As you say judging distance accurately is hard and it is easy to be wrong by a large margin when trying to put a number to it.

Tightslot - nicely summed up.

1000 feet is the minimum vertical separation in many circumstances, about 330 metres, or the equivalent of about 4 - 5 wingspans of something like a 777/747/380 - so it's not that far, but it's regulated and safe. And yes, in the right circumstances you may well see the pilots faces' - what a terrible thought :uhoh:

bpaj - FWIW in some parts of the world in some circumstances,( usually at low altitude) , the approved vertical separation is reduced to 500 feet - now that does look close....and certainly gets the aforementioned TCAS grumbling....

If you want real fun go to States and you'll see heavies doing almost formation approaches to parallel runways (e.g. SFO, IAD), the 5 miles/1000' figure you quote is not a blanket rule.

A 'near miss' is when it was considered that there was a serious risk of collision. I have only ever declared two. One was a military radar error, heavy four jet on heavy four jet, IMC, 5 seconds separation crossing. The other was a light twin against a glider where it shouldn't have been. Now that one was close - 1m :eek:

<<FL33>

That's about 3,300 feet. Did you mean that Dawdler?

<<I've turned up a page that says that aircraft shouldn't enter a volume 5 nautical miles (9km) horizontally and 1000 feet (300m) vertically around another.>>

Not the full story. Separation between two aircraft depends on various factors and can range from 10 miles/2000 feet right down to a few hundred yards and no vertical separation. In busy airspace it is usually 3 miles horizontally or 1000 feet vertically but on the approach to an airport if pilots see other traffic ATC can instruct them to provide their own separation which may be considerably less than that mentioned above.

bpaj Welcome to our 'cabin'. The untrained eye does get confused by two objects moving in 3-D and I am an untrained eye - other than paxing for 45 years.

Last Tuesday, over France at FL380, there was another a/c lower than us and 180 in the opposite direction. Consequently, the closing (ground) speed was about 1,000mph - which made it all happen very fast! The other was probably 1,000ft lower.

This picture illustrates the parallel approach/departure mentioned by wiggy, above.
Photos: Boeing 737-322 Aircraft Pictures | Airliners.net

bpaj, you might try an 'advanced search' of the forum to see other threads about this topic.

TS, when this thread has run it's course, it might one for the FAQ? I have seen this question raised a few times.

Heathrow Director.
 

Yes, sorry I was sure I had hit the "0" button! As I said in my post I imagined that the correct parameters were being observed.

Check that the "0" button works 0 0 0 0 0 0 0 0 0 Yep that seems to be about it.

I did try, but it kept throwing out "near" as too long, short or common and only searching on "miss". Searching for "near miss" (with the quotes) also didn't turn up much helpful. Both searches now turn up this thread first then about the same as before, I also looked for an exact phrase check box...

Well as a long time lurker on these forums, I would like to thank everyone for their fascinating threads (especially the recent 60+ page concorde thread ;)).

Bryn

A passenger telephoned ATC at Heathrow complaining that his flight had been involved in a terrifying near miss and he wanted full details in order to take the matter further. It came as a surprise to us as nothing untoward had occurred. When the gentleman was advised that we were not aware of any problems he claimed that we were "covering up", took my name and said he would send a full report to the appropriate authorities.

The matter was investigated and we came to the conclusion that his flight had turned in the holding pattern at the same time as one above whose track was slightly outside his aircraft. Hence, when the wings were aligned in the same plane there was only around 1000 feet "horizontal" between the two aircraft. I've experienced this myself but luckily I knew what was happening. Presents great photographic opportunities though.

Moral: Trust the people up-front; they know what they're at and the ATC service is reasonably competent too. Well it is now I've gone!

I'll try and define it from a GA viewpoint:

Once, long ago, outbound from Cap Gris Nez in a Cessna Aerobat. Flashing shadow over the roof windows and pressure wave causing the spamcan to drop down a few feet. Slowly turn to passenger who, white-faced, was doing similar to me. "Sheetohgodalmighty", let out in a single breath from him. "jesuswept" in similar fashion from me.
Silence until well over mid-channel then uncontrolled babbling from both of us.
That's a near (hit) miss.

Troll Mode...
 

Provided they are awake and not watching a movies! :p

HTC

Isn't the usual ATC umbrella term an AIRMISS or AIRPROX?

AIRMISS - loss of separation...