RNP

ASpilot2be

Qbicle seat warmer
This new technology is freaking sweet:rawk:

An Alaska Airlines technical pilot came in today and gave a presentation on it. It is amazing what they can do with this technology:crazy:
 

BobDDuck

Island Bus Driver
I think they are RNP Type 1 which means you need to at least use an FD or have the AP fly it.
 

fish314

Well-Known Member
For those flying a Saab that has less avionics than an ATP Seminole, what is RNP??
First, a disclaimer: my understanding of this stuff is cursory only. So this is just a basic overview. Check the TSO's for the latest and greatest.

Stands for "Required Navigation Performance". Essentially, it means that the aircraft's navigation systems are precise enough to keep it within a particular distance of where the system "thinks" it is 95% of the time. So for example if the system is RNP .3 that means the aircraft ACTUALLY IS within .3 nm of the computed position 95% (or 98%, 99% or whatever) of the time (or with 95%, 98%, etc. statistical certainty).

So there are these new GPS-type approaches where the autopilot flies the aircraft on a curvilinear path (a curved path to the runway), and to be allowed to fly them your aircraft needs to meet a particular set of avionics requirements (like .1 RNP or something, not sure). But basically the autopilot flies this curved path to the runway around mountains or through a canyon, etc.
 

JoelT

Well-Known Member
At my airline we are required to have the autopilot on until no later than fifty feet below MDA.
 

Nick

Well-Known Member
Perplexed

At my airline we are required to have the autopilot on until no later than fifty feet below MDA.
By 'on until no later than' does that mean that the autopilot stays on until 50' below MDA?

At 49 feet below MDA you can't click it off yet because you have to have it on.

At 50 feet below MDA you have to click it off because you can't have it on at 51 below MDA.

:confused:
 

WAFlyBoy

Well-Known Member
I rode on a Southwest jumpseat a while back and the flight crew was telling me about this new RNP stuff. Apparently their company is equipping their older 737s to be RNP compliant and they expect to save a lot of fuel by flying these procedures.

When I got home I looked up the company that's designing these procedures, and found they're headquartered about 2 miles from my house. Some interesting reading about RNP:

http://www.naverus.com/About_RNP.htm
 

bdhill1979

Gone West
First, a disclaimer: my understanding of this stuff is cursory only. So this is just a basic overview. Check the TSO's for the latest and greatest.

Stands for "Required Navigation Performance". Essentially, it means that the aircraft's navigation systems are precise enough to keep it within a particular distance of where the system "thinks" it is 95% of the time. So for example if the system is RNP .3 that means the aircraft ACTUALLY IS within .3 nm of the computed position 95% (or 98%, 99% or whatever) of the time (or with 95%, 98%, etc. statistical certainty).

So there are these new GPS-type approaches where the autopilot flies the aircraft on a curvilinear path (a curved path to the runway), and to be allowed to fly them your aircraft needs to meet a particular set of avionics requirements (like .1 RNP or something, not sure). But basically the autopilot flies this curved path to the runway around mountains or through a canyon, etc.
correct

.3 RNP is the lowest we will see (at least in the civilian world) according to the FAA "most pilots and autopilots are not capable of .1 RNP"

In practical terms RNP means what makes a full scale deflection on your CDI. .3 RNP means that either side of your CDI to full scale equals .3 miles, for a total of .6 miles

The FAA is doing seminars about this and I HIGHLY recommend people attend if they can. I learned a whole lot from it.

They said there will be NO NEW ILS funds without special authorization. no more Mx for NDBs. VORs will be scaled down to a skeleton enroute structure.

EVERYTHING will be GPS within 10 years
 

SurferLucas

Southern Gentleman
Horizon is in the process of updating all the FMS's on the Q400 to become WAAS compliant (even recieving an FAA grant for it). We have some RNP approaches that we "could" do (PDX/SUN come to mind), but the current version of the FMS will not allow it. During recurrent sim, we had to fly one of the RNP approaches into PDX...worked pretty sweet to say the least!
 

JoelT

Well-Known Member
We can go down to .16 RNP.

To answer the other question about the use the autopilot, we have to leave it on while in IMC. Then, we have to click it off no later than fifty feet below DA.
 

bdhill1979

Gone West
We can go down to .16 RNP.

To answer the other question about the use the autopilot, we have to leave it on while in IMC. Then, we have to click it off no later than fifty feet below DA.
I am guessing that .16 is a company thing, approved by the FAA sort of deal?
 

BobDDuck

Island Bus Driver
GPS is a type of RNAV. So is LORAN and INS/IRU.

RNP is a measurement of RNAV tolerances, both in terms of position and percentage of time.

RNAV procedures are predicated on an aircraft meeting a certain level of RNP.
 

Rayflyoz

New Member
Horizon is in the process of updating all the FMS's on the Q400 to become WAAS compliant (even recieving an FAA grant for it). We have some RNP approaches that we "could" do (PDX/SUN come to mind), but the current version of the FMS will not allow it. During recurrent sim, we had to fly one of the RNP approaches into PDX...worked pretty sweet to say the least!
:yeahthat: We flew them in sim the other month. The AP stays on unitll DH. I find it funny though. We(QX) spent a hole bunch of money getting RNP and now with the new FMS software we lost approval. And dont plan to get it back in favor for WAAS.
 

Cheechako

Well-Known Member
Alaska has a few approaches that are to .11 RNP. I've flown a bunch of them, but am no expert. I think the tolerances are predicated on satellite coverage. Less satellites = higher RNP minimums. I've personally never seen a lack of coverage. Velo's been at this a lot longer than me, so he may chime in on this.

Here are some examples of RNP approaches:
 

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bdhill1979

Gone West
Alaska has a few approaches that are to .11 RNP. I've flown a bunch of them, but am no expert. I think the tolerances are predicated on satellite coverage. Less satellites = higher RNP minimums. I've personally never seen a lack of coverage. Velo's been at this a lot longer than me, so he may chime in on this.

Here are some examples of RNP approaches:
Just don't forget to cross MORON at 220 or less
 

JLF

Well-Known Member
Opens the opportunity to call the captain a MORON if I want:

"Hey MORON, 220 kts!"
I'd probably phrase it as, "Hey, MORON 220 kts!" :D

Those approaches look like a lot of fun. Especially in a CAT C, or D airplane.
 
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