AIM changes - sorting it out

[Jim Heffelfinger]

FAA Safety Team | Safer Skies Through Education



Updated AIM Information
Notice Number: NOTC4145
Recently a pilot informed us of changes to the Aeronautical Information Manual (AIM) concerning the use of lights and transponder while moving on the surface of an airport. This pilot learned from a Designated Pilot Examiner (DPE). Although it is your individual responsibility to stay aware of procedures in the AIM, we thought you would want to know about this particular safety initiative!
The AIM, which is available at http://www.faa.gov/air_traffic/publications/atpubs/aim/Index.htm, is updated in February and July of each year, and included in the last February change was an updated description of the “Operation Lights On” pilot safety program.
In section 4-3-23, Use of Aircraft Lights, paragraphs (c), (e), (f) and (g) describe the use of lights while on an airport. We invite you to go to the AIM and read each of these paragraphs. For example, paragraph (e) states,
Prior to commencing taxi, it is recommended to turn on navigation, position, anti*-collision, and logo lights (if equipped). To signal intent to other pilots, consider turning on the taxi light when the aircraft is moving or intending to move on the ground, and turning it off when stopped or yielding to other ground traffic. Strobe lights should not be illuminated during taxi if they will adversely affect the vision of other pilots or ground personnel.
Furthermore, the use of your transponder while taxiing is recommended in paragraph 4-1-20. It says, in part,
Civil and military transponders should be turned to the “on" or normal altitude reporting position prior to moving on the airport surface to ensure the aircraft is visible to ATC surveillance systems.
We encourage you to keep abreast of the periodic changes to the AIM, and they make it easy by providing a change summary page for each change. We appreciate these items being brought to our attention so that we could share them with you.
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>>>> Please define the difference between strobe and anti-collision lights.

>>>>> Common practice is to place transponder in standby while in close proximity to the field to avoid excessive returns. This new change maintains that all aircraft in taxi and beyond should be transmitting and making the airport a cluster of overlapping codes on the screen.

[Mike M]

interesting that the FAA didn't know it had changed until told by a customer.

[martymayes]

>>>>> Common practice is to place transponder in standby while in close proximity to the field to avoid excessive returns. This new change maintains that all aircraft in taxi and beyond should be transmitting and making the airport a cluster of overlapping codes on the screen.

Never heard of turning the transponder to STBY while close to the field and I been flying for a while. I have seen pilots switch to STBY prior to code changes.....not sure what that was all about.

Prior to the latest "ON" for ground ops change, the AIM said turn the transponder to "ON" as late at practicable before commencing the takeoff roll and switch to OFF or STANDBY as soon as practicable after the landing roll. Was that way for 30+ yrs. Transponder "ON" for surface ops has been pretty common for a while now at airports with ASDE-X and it's been the recommendation for all airports for over a yr now.

[Bob Meder]

>>>> Please define the difference between strobe and anti-collision lights.




Sometimes they're the same. For example, the only anti-collision lights a Diamond has are the wingtip strobes. In other cases, like a newer Cessna, or one with an STC, the anti-collision lighting is the flashing beacon on the tail fin, while the wingtip strobes are supplementary.

In both cases, if the pilot feels that safety is served by turning them off (to avoid blinding someone), then they may.



>>>>> Common practice is to place transponder in standby while in close proximity to the field to avoid excessive returns. This new change maintains that all aircraft in taxi and beyond should be transmitting and making the airport a cluster of overlapping codes on the screen.

I've been flying for about 20 years and instructing for 11 and I've never heard of this, other than the special circumstance of the Oshkosh arrival NOTAM. In fact, if you do it within the 30 mile MODE C veil of a class bravo airport, you could get in real trouble, because, even if you're squawking VFR outside the airspace, ATC systems are still providing separation alerts for IFR traffic, particularly large air carrier aircraft.

[Joe LaMantia]

I was trained to turn the nav and anti-collision lgts on b/4 engine start as part of the cabin pre-flight. Then when I finish the walk-around and pull the aircraft out of the hanger, I get in the airplane and turn on the battery, so now b/4 engine start, I'm all light-up at the hanger taxi way. As for the xponder, I've always turned it on to standby after engine start as part of the avionics set-up prior to taxi. I re-set the xponder to Alt as part of the pre-take-off checklist. Since I fly out of a non-towered airport in class E having the xponder on during taxi seems kinda dumb. I think Bob has a good point regarding Class B, talk about signal overload! Maybe the FAA has some new technology to sort all that stuff out, or maybe the guys re-writing the AIM don't talk to the radar guys.

Joe
:eek:

[Bob Meder]

I don't think I was clear in my post - too many pronouns. What I was saying is that I never heard of the transponder being put in standby near an airport while in flight (other than Oshkosh). In particular, there is no circumstance, other than a transponder putting out false readings, under which you'd put it standby while in flight in Bravo or Charlie airspace.

The practice of putting the transponder in standby mode while on the ground was so ATC wouldn't get proximity alerts from taxiing aircraft, if I understand correctly. I believe that the software has mitigated this, particularly since most large airports now use surveillance systems to aid in avoiding incursions and collisions, particularly in low visibility situations. I'll check with some ATC folks about this on Monday.

[Anymouse]

I have seen pilots switch to STBY prior to code changes.....not sure what that was all about.

Some pilots do this to ensure they don't accidentally transmit a 7x00 code. Personally, I think it's a stupid habit, but whatever floats their boat I guess.

[rosiejerryrosie]

Some pilots do this to ensure they don't accidentally transmit a 7x00 code. Personally, I think it's a stupid habit, but whatever floats their boat I guess. The same thing is accomplished by dialing in the numbers right to left. You never get a chance to inadvertantly enter a 7x00 code as by the time you get to 7 you don't have 00 dialed in as you would have if you went to 71xx from 1200.

[Joe LaMantia]

Does anybody know how far a ground based xponder signal can actually be received? I assume it's line of sight. Thanks Bob for the technology update, I was hoping this new AIM procedure wasn't the result of some internal communication glitch by the FAA. Never thought about putting in the wrong code, but then I'm pretty much lock into 1200.

Joe
:cool:

[WLIU]

I will offer the opinion that running strobes of any sort on the ground when taxiing is very rude to the folks around you who would rather not get blinded. The suggestion that the taxi light be turned on is kinder to your ramp neighbors. That said, most readers here are not flying jets so during daylight hours the folks around you know that you intend to move because they see your prop turning. Daytime light on the ramp is really wasted energy for most of us. Jets are a different story but that is not this audience.

As for running the transponder on the ground, I will theorize that the practice only has value at large air carrier airports equipped with radar that observes the taxi traffic and where a squawk code is issued before you taxi. Everywhere else the practice has no value because the folks in the tower don't have their screen set for that view. The vast majority of towers get a feed from the nearest approach control and only can see traffic arriving and departing their airspace. I sometimes wonder if the folks who write this stuff have every flown anything smaller than a Boeing.

As for transponders being set to standby, I will offer the operational practice that when you are flying formation, as in 2 wingspan separation, the transponder returns merge and the controller sees 1200 instead of the assigned code(s). In this case only the flight lead runs his or her transponder in Mode A or C and the rest of the flight runs standby. For the average pilot where seeing an airplane 1000' away is stressful, setting the transponder to standby only turns you into a primary target. You are still visible to the radar and recorded on tape. The controllers don't change how they warn approaching folks that the traffic pattern is full. Its really an operational don't care.

Be kind to your ramp neighbors and fly safe,

Wes
N78PS

[Anymouse]

Well said Wes.

[Bob Dingley]

Does anybody know how far a ground based xponder signal can actually be received? I assume it's line of sight. Thanks Bob for the technology update, I was hoping this new AIM procedure wasn't the result of some internal communication glitch by the FAA. Never thought about putting in the wrong code, but then I'm pretty much lock into 1200.

Joe
:cool:
How far? When I was flying helos out in the Gulf of Mexico, I regularly observed the xpndr reply light flashing on the deck of a vessel. Less than 100 feet msl, 100 NM south of the coast and snuggled up to the n. side of the vessel's steel structure.

Bob

[Jim Hann]

Y'all are pretty much on it. I've been "reminded" by Ground Control to check the Transponder (TXP) is "Oscar November" at both Anchorage, AK and Louisville, KY when I called for taxi at work (Boeing 7x7). We don't have an "OFF" position on the TXP, and we normally put it in "ALT RPT" position but not TA or TA/RA because we don't want to look at all that clutter until we get near the runway. When I go out to fly the ol' 172 Heavy I follow the checklist it has, which is put the TXP on "ALT" at the runway end for departure.

All of the air carrier size birds I've flown have both a red beacon and white strobes, we never use the strobes on the ground unless crossing an active runway (think about it, I don't want to get hit). Use common sense. If (when?) I get my Cavalier done, it will probably have a system similar to the airliner, because I think that is the safest way to go, red beacon when the engine is running, strobes for in flight, etc. Recognition lights (forward facing white lights like landing lights) are also a good thing when approaching an airport, 'cause if somebody can see them, it means you are headed for them! Our policy at work is landing lights on below 18,000' MSL. Again, you don't need your lights on all the time (those d@mn bulbs are expensive) but use your judgement (pattern ops, busy controlled field, etc.)

Remember also that the AIM is not regulatory, it is just the FAA's recommended way of doing things. Remember too that no amount of lights can protect you from some fool entering the pattern at Warp 9 in a Bonanza/Glasair/Swearingen/Eclipse/Etc, keep looking around like you are flying at night with no lights at all, i.e. invisible!!! Sometimes paranoia can serve you well.

Jim