5
$\begingroup$

I am curious to know a couple of things regarding glide-slope:

  1. How often do ATCs encounter flights capturing false glide-slopes?

  2. What is the response expected from ATCs in such a scenario? In other words, is it the duty of ATC to alert the crew of the possibility of a false glide-slope capture.

$\endgroup$
5
  • 1
    $\begingroup$ It might be quite rare. Only two results in an NTSB search, and even those aren't really about that. $\endgroup$ May 28 at 19:55
  • 1
    $\begingroup$ Thank you. I have come across this for the first time in the context of PIA 8303. The link is: airlineratings.com/news/… $\endgroup$
    – Quiescent
    May 28 at 20:22
  • 1
    $\begingroup$ On an ils plate there is a table that computes expected altitude at certain distances from a dme ( usually in 1 mile intervals ). Pilots are expected to compare actual altitude with computed one at least 2 times . $\endgroup$
    – cavver
    May 28 at 21:57
  • $\begingroup$ Agreed. But as in the case of above (PIA 8303) it is a possibility, as was noted in an earlier paper. As this involves landing, not always the crew may have time for re-computation. See: researchgate.net/publication/… $\endgroup$
    – Quiescent
    May 29 at 4:41
  • 1
    $\begingroup$ I realised that my previous comment is wrong , those are specific actions taken by an airline . The incident referred in your link is this : avherald.com/h?article=4641efec/0000&opt=0 . " The revised policy includes a new horizontal landing gate for ILS interception from above; being the earliest of the following: the FAF, 5 DME, 4 NM for VMC operations and 5 NM for IMC operations." $\endgroup$
    – cavver
    May 29 at 7:46

1 Answer 1

7
$\begingroup$
  1. in 10 years of working at a small airport serving commercial airliners never.
  2. ILS is a pilot interpreted landing aid, ATC has no obligation to follow the plane once established on ILS. ATC has the responsibility to vector the plane to such a position and altitude such that the plane can intercept the localiser and glide slope. At airports doing dependant ILS approaches ( 2 aircraft on 2 parallel runways ) ATC follows the distance between planes, not the altitude/glide slope. If providing radar services the ATC vectors the plane until established on the localiser then it's the crews responsibility to follow the ILS procedure.
$\endgroup$
4
  • 2
    $\begingroup$ At least in the USA, however, ATC is responsible for vectoring aircraft to intercept the glideslope outside of the GS-capture point at an altitude not above the glideslope itself (nor below the published minimum intercept altitude). JO 7110.65 5–9–1c. $\endgroup$
    – randomhead
    May 28 at 23:05
  • $\begingroup$ Thank you. Could you please share which country you are referring to? $\endgroup$
    – Quiescent
    May 29 at 4:43
  • $\begingroup$ I will reword my answer in order to be more clear. $\endgroup$
    – cavver
    May 29 at 7:21
  • $\begingroup$ Thank you @cavver $\endgroup$
    – Quiescent
    May 29 at 18:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.