WHat does this mean?I looked at the approach charts for Philadelphia (KPHL).I never saw this kind of approach before:ILS PRM Rwy 26 SIMULTANEOUS CLOSE PARALLEL Anyone know what all that means?ThanksChris Catalano

Sounds like there are parallel runways at PHL. If two adjacent parallel runways are within 2,500'; the when simultaneous ops are in progess the arrivals are staggered, with a minimum diagonal distance of 1.5 miles spacing.When the distance is greater then 4,300'between runways, the there is no requirement to "stagger" arrivals. Usually in this case there is a special ATC person who can over-ride the Tower frequency. This person watches the arrivals on radar and will abort both when one transgresses into the zone between runways (Denver KDEN has this on 35, 17 L/R).The term you quote "Sim Close Parallel" is (as I understand it, I'm still studying the IR written :) ) is when the spacing between runways is between 2,500' and 4'300'. My notes on this say (a little cryptic!):---------Simultaneous Close Parallel ILS PRM Approaches: PRM = Precision Runway Monitor Uses smart radar and path prediction computer. Each r/w has it

From my reading on the PRM plates of the Jeppesen SimCharts..PRM approaches are used in visual conditions as a way to increase the landing efficiency of a set of close parallel runways. Each parallel approach has it's own very specific breakout procedure, so if a controller sees something amiss, both planes can break out without colliding. I don't think both runways have separate towers and frequencies, but when PRM is in use, pilots must monitor a special approach frequency in addition to the tower. This frequency is listen only, so the pilot will not step on an important break-out emergency call.Technically, I think these approaches "break" the normal rules when it comes to spacing of aircraft. But becuaes of the PRM technology and procedures, they are exempt. That's my non-pilot and non-expert take on it!-GregEdit: Maybe it's not restricted to visual, due to the fact it's an ILS approach. (duh!)

Hey guys,PRM approaches are for runways equipped with ILS or LDA, with centerlines less than 4300' but not less than 3000' apart. SOIA, or Simultaneous Offset Instrument Approaches are used if the centerlines are between 3000' and 750' apart.The previous comments about monitoring a second frequency are correct. Dual VHF comms are REQUIRED to utilize the PRM approach. The PNF will communicate on the appropriate Tower Freq, and simultaneously monitor the PRM controller. If an aircraft penetrates the Non-Transgression Zone between the runways, the PRM controller will issue either a climbing or descending break-out to the non-offending aircraft.Use of the PRM approaches is company and pilot specific. Thats is, an airline as a whole must be approved by the FAA to fly PRM approaches. That authorization is contained in the company's Op-Spec C052. Additionally, each pilot must undergo training before they can accept a PRM approach. Think of it like the training required of a pilot before he can accept a CAT II or III approach.Best Regards,NickBlue Ridge Dx

Thanks Nick (modifying IR written notes). :)Bruce.

As a PHL native I thought I would just add for the record, we do have 3 parallel runways, and occasionally simaltaneous parallel approaches do take place on all 3. 27L is farthest south, then 27R, and finally 26 (5000' commuter runway) is farthest north. The runway thresholds are straggered, with 27L beginning farther to the west, 27R begins about mile east of that, and 26 about another 3/4 miles to the east.27L has a separate tower frequency only used for that runway, while 27R and 26 (plus the intersecting 17/35) share the main tower frequency. I beleive parallel approaches do take place in IFR conditions, but the worst I've seen were parallel approaches in less than 2 mile visibilty during extreme smoke/haze from some forest fires in Canada. I think the 26 Localizer is also not completely alligned with the runway centerline, it may angle slightly to the north to keep 26 traffic slightly farther away from 27R for as long as possible.Joe Wagner

Hi Joe,Interesting info, thanks.I see on SimPlates that the 26 LOC is at 263 degrees, so it's not an LDA (is aligned with the runway). It may be that intercepts to 26 make it look like it's at an angle.I flew into PHL once on UA from DEN. The train transportation into the city is something that many other US airports could do with. A really nice operation.Thanks,Bruce.

Hi,Just wanted to point out that, yes, Simultaneous Close Parallel Approaches are conducted in IFR. Thats kind of the point of the whole excercise. As mentioned above, controllers have special high- resolution radar sets that are used to ensure seperation. There are also very specific 'break-out' procedures in place should an aircraft intrude into the non-transgression zone. And finally, aircrews must undergo specific training in order to accept PRM approaches.If SCPA were limited to VFR conditions, there wouldn't be any need for all that stuff. Just for reference, assuming a CAT C aircraft, the minima for the ILS PRM 27L approach is 250 - 1/2. For the ILS PRM 26 approach, its 250 - 3/4. Those values qualify as Low IFR...And as an aside, I got curious about the runway 26 localizer question. I checked it out and found that the localizer for runway 26 is, in fact, offset 5 degrees. The runway heading is 268, while the localizer inbound course is 263. Hope that helps...Best Regards,NickBlue Ridge Dx

Joe,I re-read your message after I posted my last reply, and I realized that I misread you... :-doh I thought you had said that PRM approaches were NOT conducted in IFR. Hence my reply... Sorry for the mis-understanding...Best Regards,Nick

>I flew into PHL once on UA from DEN. The train transportation>into the city is something that many other US airports could>do with. A really nice operation.That's it, pack it up. The internet is officially over. Somebody is actually PRAISING SEPTA. Publicly. I just can't get over it. (grin)AdrianSimPlates 2004 Author :)