DPApilot
GUYSH! GUYSH! GUYSH!
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Below Glideslope but on the PAPI's
- Thread starter RightSeatGirl
- Start date
OldTownPilot
Well-Known Member
Its not really the accuracy but rather the sensitivity. Its easy to over maneuver the airplane as you get closer to the glideslope antenna, especially in light airplanes.
BobDDuck
Island Bus Driver
Over here, it is company policy to back up ALL visual approaches with an ILS (if it's available). If you are using an ILS you must follow the glideslope until inside the middle marker. At that point you are free to deviate to land. HOWEVER... our POI thinks differently, and with her in the jumpseat you follow the glideslope to the ground.
deadstick
Well-Known Member
I remember hearing about the "GS to the ground" bit, and it is possible, but the FOM directs us to do otherwise. The PAPI/VASI is suppose to be an aid. This inside/outside-rinse/repeat method increases the workload unnecessarily. Even the caviat for no VASI/PAPI uses visual cues when a GS is available. Gotta love standardization!
CaptBill
Well-Known Member
When shooting an approach in yucky weather we all know to fly the GS down to DH. I recommend you stay on GS to DH in iffy conditions, even when you pick up the runway, just in case you lose sight of it at some point during the approach. Once you decide to descend below DH, it is perfectly legal and appropriate to fly any visual transition you feel comfortable with including the PAPI. When shooting the ILS 35 into Quito, Ecuador, Continental teaches that once DH (652') has been passed, it is recommended to fly the remainder of the approach using the PAPI for vertical guidance which is about .75 dot below the GS. Since the elevation of the airport is 10,000' this technique allows you to touch down in the first 1000' of the runway. If the GS was flown all the way down, your touchdown point would be about 2200' down the runway. This makes a world of difference in trying to get the airplane stopped in heavy rain or slippery runways. If you have a long runway and don't have a need to get it on the ground, you may want to fly the remaining several hundred feet on the same profile as the GS which would show you slightly high on the PAPI. BTW, the ILS is very accurate right to the ground. After all, it is this same signal that we use for Cat3 autoland approaches.
Once I have decided to land visually, and for whatever reason I will be one dot or below on the glideslope, I just de-tune the localizer so that I don't get the aural warnings. Make sure you don't get distracted screwing around with radios in the last hundred feet or so. Ask the other pilot to inhibit it or simply ignore it. If the localizer is part of the missed approach procedure, you may not want to de-tune it for obvious reasons.
Once I have decided to land visually, and for whatever reason I will be one dot or below on the glideslope, I just de-tune the localizer so that I don't get the aural warnings. Make sure you don't get distracted screwing around with radios in the last hundred feet or so. Ask the other pilot to inhibit it or simply ignore it. If the localizer is part of the missed approach procedure, you may not want to de-tune it for obvious reasons.
FlyChicaga
Vintage Restoration
When did pilots stop trying to land visually?
If we have a PAPI/VASI, awesome. If we have a G/S, awesome. I find there are a few times we have neither, and many times it creates problems. That concerns me. We should be able to visually fly an approach to a runway regardless of the type airplane we are flying. That is why I always brief a few things:
My point is that not every runway we arrive into will have a VASI or glideslope. While we should try to use the resources we have available to us, the most important thing is using our eyes to ensure we are at a safe distance above all obstacles, and that we land in the touchdown zone.
If we have a PAPI/VASI, awesome. If we have a G/S, awesome. I find there are a few times we have neither, and many times it creates problems. That concerns me. We should be able to visually fly an approach to a runway regardless of the type airplane we are flying. That is why I always brief a few things:
- Runway Length
- Runway Width (especially important in Canada)
- Touchdown Zone Elevation
My point is that not every runway we arrive into will have a VASI or glideslope. While we should try to use the resources we have available to us, the most important thing is using our eyes to ensure we are at a safe distance above all obstacles, and that we land in the touchdown zone.
BobDDuck
Island Bus Driver
Matt, that's a very valid point, and I think one of the toughest, normal operations thing I've done recently is shoot a night time visual approach to a runway with no form of guidance at all. We can normally cheat a bit and throw up a FMS generated snowflake, but if the FMS dies, it's just normal MK I eyeballs the whole way down. I'm not sure why you had no reference with the MTVN Visual to 1, cirlce 33 in DCA. There's a VASI on 33 that is pretty easy to pick out within about 30 degrees of the runway.
However, the question posed in this thread was what do you do in instances where you DO have a glideslope to follow. And in the case of 23 in CLT, if you stay on the VASI once you go "visual" you will be anywhere between 1 dot and 2.5 dots off the electronic glideslope and still have 2 red over 2 white.
However, the question posed in this thread was what do you do in instances where you DO have a glideslope to follow. And in the case of 23 in CLT, if you stay on the VASI once you go "visual" you will be anywhere between 1 dot and 2.5 dots off the electronic glideslope and still have 2 red over 2 white.
DE727UPS
Well-Known Member
I can't say as I remember a "G/S call" from the GPWS after transitioning to the PAPI/VASI., maybe it's just Alzhimers. I'd have no problem ignoring the Glide Slope warning and following the VASI. Seems to me most places the electronic G/S and PAPI, agree, so it's a non-issue.
14 CFR 91.129
(e) Minimum altitudes when operating to an airport in Class D airspace. (1) Unless required by the applicable distance-from-cloud criteria, each pilot operating a large or turbine-powered airplane must enter the traffic pattern at an altitude of at least 1,500 feet above the elevation of the airport and maintain at least 1,500 feet until further descent is required for a safe landing.
(2) Each pilot operating a large or turbine-powered airplane approaching to land on a runway served by an instrument approach procedure with vertical guidance, if the airplane is so equipped, must:
(i) Operate that airplane at an altitude at or above the glide path between the published final approach fix and the decision altitude (DA), or decision height (DH), as applicable; or
(ii) If compliance with the applicable distance-from-cloud criteria requires glide path interception closer in, operate that airplane at or above the glide path, between the point of interception of glide path and the DA or the DH.
(3) Each pilot operating an airplane approaching to land on a runway served by a visual approach slope indicator must maintain an altitude at or above the glide path until a lower altitude is necessary for a safe landing.
(4) Paragraphs (e)(2) and (e)(3) of this section do not prohibit normal bracketing maneuvers above or below the glide path that are conducted for the purpose of remaining on the glide path.
91.130 and .131 specify you have to abide by these rules in C and B airspace also.
GS to from FAF to DA(H), then VASI until you need to descend lower.
The regulation makes no mention of a "Precision Approach Path Indicator", just "Visual Approach Slope Indicator". Is the reg intended to separate the two? Anyone know for sure?
-mini
(e) Minimum altitudes when operating to an airport in Class D airspace. (1) Unless required by the applicable distance-from-cloud criteria, each pilot operating a large or turbine-powered airplane must enter the traffic pattern at an altitude of at least 1,500 feet above the elevation of the airport and maintain at least 1,500 feet until further descent is required for a safe landing.
(2) Each pilot operating a large or turbine-powered airplane approaching to land on a runway served by an instrument approach procedure with vertical guidance, if the airplane is so equipped, must:
(i) Operate that airplane at an altitude at or above the glide path between the published final approach fix and the decision altitude (DA), or decision height (DH), as applicable; or
(ii) If compliance with the applicable distance-from-cloud criteria requires glide path interception closer in, operate that airplane at or above the glide path, between the point of interception of glide path and the DA or the DH.
(3) Each pilot operating an airplane approaching to land on a runway served by a visual approach slope indicator must maintain an altitude at or above the glide path until a lower altitude is necessary for a safe landing.
(4) Paragraphs (e)(2) and (e)(3) of this section do not prohibit normal bracketing maneuvers above or below the glide path that are conducted for the purpose of remaining on the glide path.
91.130 and .131 specify you have to abide by these rules in C and B airspace also.
GS to from FAF to DA(H), then VASI until you need to descend lower.
The regulation makes no mention of a "Precision Approach Path Indicator", just "Visual Approach Slope Indicator". Is the reg intended to separate the two? Anyone know for sure?
-mini
EDUC8-or
Well-Known Member
Just like mini posted, it's in the regs. You must follow the electronic GS to DH/DA. We've spent LOTS of time going over this one at our company. Dipping below the GS before that isn't legal and I've seen it done safely and not safely depending on the pilot.
They've actually adjusted the VASI on 23 to coincide more directly with ILS glideslope.
It's your runway, if you can make Mike great, if not just roll it out. There's no need to slam on the brakes, even with someone 2 miles behind you there's enough time to roll it out to Fox without smashing the passengers faces into their tray tables.
They've actually adjusted the VASI on 23 to coincide more directly with ILS glideslope.
It's your runway, if you can make Mike great, if not just roll it out. There's no need to slam on the brakes, even with someone 2 miles behind you there's enough time to roll it out to Fox without smashing the passengers faces into their tray tables.
jtrain609
Antisocial Monster
No doubt, and as Ethan has noted, and I agree with him here, one of the hardest things to do in my mind is fly a jet on a maneuver like that when there's no visual glideslope backup. It's not like it's impossible to do, and in fact it's not and we should all be able to do an approach with no PAPI/VASI, but it certainly ups the challenge a little bit.
The thing I was talking about earlier is the whole Cessna 172 style approach to the ILS. You hit the DH, pull power and dip the airplane below GS, whether it's a PAPI or an ILS GS to land the thing in as short of a distance as possible. Again the only thing I'd be concerned with would be getting outside what the TERPS allows for your mains going below a safe threshold crossing height.
As long as your mains are above that height for the runway, do what you gotta do. But I think it's really easy for a lot of folks to forget that you can have hundreds of feet of aircraft BEHIND you when you're landing, and if you dip the aircraft too low after DH you're going to drag your wheels through the approach lighting system.
Does that make sense? I have a feeling something's getting lost in the translation.
Yeah, but good luck finding any 121 airline with Ops Specs allowing non-stabilized approaches for turboprops.Interesting, FAAO 8900.1 4-221 says
Turboprops are free to do whatever they want, wooo!anic: (I know, this is about visual approaches. I just thought the distinction was unusual.)
A PAPI is a specific type of Visual Approach Slope Indicator. At least that's my understanding. VASI is used in the regs as a generic term for all visual systems, IIRC.
B767Driver
New Member
At my company, this requires a special briefing when the VGSI and G/S are not coincident. We can even exceed 1000fpm to aquire the PAPI guidance in this scenario.
Basically, at DA...you are now maneuvering the airplane visually to the touchdown zone...and can use whatever "NORMAL" maneuvering necessary to achieve that objective.
One word of caution, however. If you are flying a bigger airplane...make sure you study gear heights at the threshold. You will be surprised how low the gear will be and how far behind the cockpit they are. On the glideslope...when the cockpit is 50' over the threshold...the main gear might cross at only 23' or so. Fly one or two dots below G/S...and you may be in danger of not having the gear make it to the pavement!!
In the 767, I never fly below G/S for this reason.
Nick
Well-Known Member
B767Driver -
I recall reading that the threshold crossing height is based on where the glideslope antenna on the airplane would be if the airplane was on glideslope at the TCH. In other words, if the antenna is around the main gear then perhaps the wheels are another 3-10 feet below depending on airplane type.
Does this conflict with your information?
B767Driver
New Member
It all depends where the RA is mounted. On the 767 it's up by the cockpit...and there's 1/3 of a football field between the cockpit and the main gear. So in my situation...it will be substantially more than 3 to 10'.
Fortunately, Boeing gives us a lot of tail and gear clearance data in chart form. It helps to get a better picture on what's going on back there.
B767Driver
New Member
As a side note...I really enjoy these types of productive threads. So much more enjoyable than..."airline vs airline and pilot vs pilot"...stuff!
Yank&BankmyRJ145
New Member
I got a question for everyone? I was flying with a captain this past week, and he was flying all his approaches with the PAPI at 3 red and 1 white. When I noticed the 3 reds, I stated "I see three red one white". He responded with "correct on slope". After we made it back to the gate, I asked him why he was flying 3 red/1 white. His answer was that its the correct way to fly the PAPI in our aircraft.
Now I have not read this anywhere, That I recall. I do remember so stuff about high cockpit aircraft flying the upper slope on a VGSI or 3 white/1 red. But thats for something like a 747, not a EMB-145 right??
Now I have not read this anywhere, That I recall. I do remember so stuff about high cockpit aircraft flying the upper slope on a VGSI or 3 white/1 red. But thats for something like a 747, not a EMB-145 right??
B767Driver
New Member
When I was a commuter check airman...I had a FED line checking me while giving IOE to a new copilot. He flew the PAPI as you described above and I got quite a tail chewing from the FED for letting him fly 3 Low on the PAPI.
Maybe that answers your question. (That FED was a notorious jerk, however, and I believe eventually left the agency.)