LarryJ

Backup charts are still carried as ship sets. Our iPads are required for the various flight manuals. If an iPad fails, malfunctions, or the approved iPad mount is missing or broken then the backup charts must be used by the affected pilot for departure and arrival.

Juventini

Question arose when I sitting in Polaris lounge just beside C18 the other day.
Instead of towing heavies in for next departure, I saw few coming in with it's own engines, mostly from United hangar across the runway. United app indicates some a/c arrived T5 day before, some arrived T5 few hours earlier. So assuming using super tugs is more cost-effective, is there a specific reason not towing a/c but run engines instead?

TA

An airport / ATC question for pilots here:

I often see antennas around large airports that are mounted on platforms/towers, where there are always 4 vertical antennas in a square layout. Do you know what these are (VHF/UHF/other), and is there something to do with the wavelength / type of communications that makes this configuration the rule?

Thanks!

clubord

Not quite sure exactly which ones you're referring to but if your talking about the antennas located in the grass at the end of the runways. Those are for the Localizer/ILS approaches to that runway.

TA

no, what I mean are the antennas seen on the shorter masts in this picture (not the radar and its antennas obviously):



I always see these in sets of 4 and in a square configuration on the tower. Any ideas?

LarryJ

Those are VHF communications antennas.

TA

Right, so why the square configuration always?

ROCAT

It is most likely just stability, but I can ask one of my facilities Navaids personal on my next work day.

PenaltyBox

The requirements to issue a landing clearance are very different between FAA and ICAO rules. Having worked in 2 FAA Towers and 2 ICAO Towers, I could list a bunch of the differences between FAA and ICAO regs.

As ROCAT correctly explained, FAA rules allow tower controllers to anticipate separation meaning that if the controller thinks that the preceding will be clear of the runway by time the succeeding aircraft crosses the landing threshold, the landing clearance need not be withheld. ICAO rules do not allow a landing clearance to be issued until the preceding aircraft is past the landing threshold. Both procedures are equally safe however the ICAO rules require additional radio communications which adds to frequency congestion which isn't always welcome at very busy airports.

Normally, a pilot on an instrument approach, will be instructed to contact the tower at the FAF or approx. 5-6 miles from the runway. If the spacing is 3-4 miles between planes, the tower controller in the US can tell the pilot about the preceding traffic and issue a landing clearance in the same transmission. At an ICAO facility, the controller cannot issue a landing clearance so he/she ends up saying "continue" or "roger" as there is nothing else to say. Once the preceding aircraft crosses the landing threshold, the controller can then go back and clear the 2nd aircraft to land.

I worked at DXB with many ex-LHR and ex-UK controllers and for the most part they took the ICAO restrictive rules a step farther. (It must have been a UK-specific interpretation of the rule and would support your observation.)

Probably out of habit, some of the ex-UK controllers would not issue a landing clearance until the preceding aircraft was clear of the runway which meant that almost all of their landing clearances were issued when an aircraft was on very short final and in many cases, over the approach lights. In my opinion, this is far too late to be giving any control instructions to a flight crew other than "go around".

Say Vandelay

That was exactly my experience. Thank you for the very interesting reply.

COSPILOT

I'm 99% sure the dark rods are grounding rods for lightning protection. The white is the actual antenna.

I will have to share this photo with a company I know that sells lighting protection for a living and confirm.

DCA writer

Last Wednesday's departure from IAH on UA 1011 to IAD was delayed when the pilot announced that we'd have to return to the gate to have some cargo removed. I thought we'd be in a for a long wait as somebody searched for a particular suitcase in the hold of our 767, but instead I watched as rampers opened the cargo door and rolled an LD2 container out and onto a loader, which then hauled the errant cargo away. They closed the door, and this time we departed for real.

I'm pretty sure I've never seen that happen before. Any ideas about what would make it necessary?

DENviaLAX

That's interesting and ive never seen it myself. Could've been some freight or mail that wasn't properly inputted to the CLP. Ive seen where the weights of the mail were quite clearly incorrect, so they hold it off altogether for it to be reweighed. Though it doesn't make sense that it'd be noticed after already loaded and the plane pushed back.

Hard to imagine they would remove a whole can of bags that were supposed to be on that flight. Especially a domestic flight that likely wasn't heavy on freight/mail, where w&b could be an issue and there is no PPBM. The only other thing I can think of is that maybe they loaded a can of bags that were for a different flight onto that plane, then realized it when those bags were missing for their correct flight. That's something you certainly bring a plane back for, though I've never heard of something like that happening, and itd be a colossal screwup for sure. That's only my best guess, though.

goalie

I flew UA936 EWR-SFO yesterday and Ch9 was on and I have a two fold question...

When you request a higher or lower altitude and the controller says "climb and maintain/descend and maintain flight level XXX", is there standard rate of climb/descent and does "descend at pilot's discretion to XXX" also have any pre-determined rate of descent?

The reason I ask is that we were at FL28-0 and cleared to FL 38-0 and I decided to time it on my watch and it was a nice leisurely climb at somewhere between 1,200-1,500 fpm yet when we were in the beginning of the descent to SFO, it was "descend at pilot's discretion to FL30-0" and the descent from FL38-0 seemed much steeper and quicker

LarryJ

When it is a "climb/descend and maintain" clearance they expect ~1000fpm or greater. Sometimes they will specify greater.

When it is at pilot's discretion it is up to the pilots when to descend and at what rate. The only restriction is that once you've reported departing an altitude or flight level you can not return to it.

On arrivals, we will fly a VNAV profile if the ATC clearance allows it. If they descend us early we'll initially descend around 1000-1500 fpm until intercepting the VNAV profile.