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convair880mfan
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If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Sun Sep 05, 2021 8:49 pm

This is sort of a hypothetical question since I realize there are many backup navigational instruments on a commercial airliner and the the odds of losing all of them would be astronomical. A private pilot once told me that if he lost all navigation instruments he would look for landmarks on the ground, follow roads and such. Just wondering what airliner pilots would do in that highly unlikely situation? Would ATC help out? What if standby instruments failed? Maybe the situation would be worse at night?

I've read about situations where smoke on a flight deck can make seeing navigational instruments difficult or near impossible. I guess that is a very rare situation too. Would military jets be dispatched to guide a plane in?

Thanks for any responses to this question.
 
GalaxyFlyer
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Sun Sep 05, 2021 9:08 pm

If smoke has reached the level that instruments can’t be seen, you won’t be flying long—it’s likely a serious fire. ATC, in a radar environment, can give vectors to an airport or clear air. Overwater, flight plans are written to provide crews with enough information to dead reckon to near the landfall fix. Lindbergh was only 3 miles off track at landfall. From high levels, you can identify plenty of ground features, if it’s clear of cloud.

Many moons ago, a C-141 crew entered the wrong present position in the INSs. Hours later, handed off to Auckland Control on VHF, repeated attempts without contact, they went back Auckland Radio on HF. Smart radio operator fixed their position after a couple of long counts and a turn, showed them hundreds of miles east of NZ. DF steer got them pointed at NZAA. Landed fairly short on fuel as I heard it.

“How to navigate to Florida?” Old instructor, “at the first ocean turn right and follow the coast til you see palm trees”.
 
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Starlionblue
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Mon Sep 06, 2021 3:11 am

It depends on the situation:
- If you're you're flying VFR, you're navigating via terrain and chart reference anyway. Losing the navigation instruments is not an emergency.
- If you're flying IFR and you're in VMC over land, then it may be a PAN depending on the situation.
- If you're flying IFR and you're in IMC, then it would be PAN or MAYDAY as appropriate depending on altitude, surrounding terrain, and so forth.

Most airliner flights are IFR. However, the chance of losing all navigational equipment is ridiculously remote. You'd need to lose multiple GPS, multiple INS, and multiple nav radios. And you'd still have the whiskey compass.

Night could make it worse. But not always. Lights ensure some stuff can be seen from a much longer distance at night.
Last edited by Starlionblue on Mon Sep 06, 2021 3:20 am, edited 1 time in total.
 
Woodreau
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Mon Sep 06, 2021 3:11 am

convair880mfan wrote:
This is sort of a hypothetical question since I realize there are many backup navigational instruments on a commercial airliner and the the odds of losing all of them would be astronomical. A private pilot once told me that if he lost all navigation instruments he would look for landmarks on the ground, follow roads and such. Just wondering what airliner pilots would do in that highly unlikely situation? Would ATC help out? What if standby instruments failed? Maybe the situation would be worse at night?

I've read about situations where smoke on a flight deck can make seeing navigational instruments difficult or near impossible. I guess that is a very rare situation too. Would military jets be dispatched to guide a plane in?

Thanks for any responses to this question.


UPS 6 - crashed because the pilot could not see their instruments due to smoke in the flight deck.

https://en.wikipedia.org/wiki/UPS_Airlines_Flight_6

Final Report

https://www.gcaa.gov.ae/en/ePublication ... 202010.pdf
 
kevinm03
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Mon Sep 06, 2021 9:56 am

A Swiftair 734 lost most instruments on departure out of SNN a few years ago. It was vectored around for a visual approach.

https://www.youtube.com/watch?v=OQlBGBf ... SAviation-
 
IAHFLYR
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Mon Sep 06, 2021 1:57 pm

GalaxyFlyer wrote:
“How to navigate to Florida?” Old instructor, “at the first ocean turn right and follow the coast til you see palm trees”.


:rotfl: Along those same line and in Florida, many moons ago I was getting ready to fly from Ft. Myers (FMY) to Marathon (MTH) to pick up a couple coolers of lobsters as friends where down there diving for them. As I was leaving home for the airport my Mother called and asked me "how will you ever know where you are in case you run out of gas over the ocean"!!! Simply told her fly directly south and when you see land turn left or right and MTH will appear. She didn't think that was very funny, but oh so true.

Okay back to the topic at hand. As others have mentioned in a RADAR environment us controllers could vector them very easily either with headings or no-gyro vectors in order to direct them to a hopefully a safe landing.
 
GalaxyFlyer
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Mon Sep 06, 2021 2:22 pm

I used go over to CFB Trenton where they still had PAR available. The controllers liked doing them and quite good at it. They’d do “no gyros”, too. The new LTs thought I was torturing them. Then, I’d idle an outboard engine and the torture really began. OEI “no gyro” PARs will test your ability to set the right thrust, make small changes and hand-foot coordination.
 
convair880mfan
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Mon Sep 06, 2021 3:32 pm

IAHFLYR . . ."no-gyro vectors"? What does that mean.
 
IAHFLYR
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Mon Sep 06, 2021 3:45 pm

convair880mfan wrote:
IAHFLYR . . ."no-gyro vectors"? What does that mean.


That means you tell the pilot to turn left/right and they remain in that turn until you tell them to stop turn. We could monitor the track of the aircraft and when headed in the direction we wanted then we'd tell them stop turn. They'd turn at a standard rate of turn which is three degrees/second or as GalaxyFlyer posted about PAR or ASR approaches we may tell them half standard rate turns which normally you would not do until they are established on the final approach course.
 
GalaxyFlyer
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Mon Sep 06, 2021 3:46 pm

IFR turns are standard rate (3* per second) or half standard rate. Controller says “start right turn”, hacks a stopwatch and when time equals number of degrees needed says, “stop turn”. Pilot rolls in and out at the radio calls. Half standard rate turns are on final approach. Needle (in needle, ball and airspeed) show standard rate turn.
 
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fr8mech
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Mon Sep 06, 2021 3:47 pm

convair880mfan wrote:
IAHFLYR . . ."no-gyro vectors"? What does that mean.


As I recall from the “I want to learn to fly” period of my life, in a “no-gyro” approach, you have a total or partial flight instrumentation failure, ATC will provide you all the instruction and guidance you need to get on the ground.

They’ll monitor you, as best they can, on RADAR or even visually, and give you step by step…turn left, stop turn, level wings, etc.
 
convair880mfan
Topic Author
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Mon Sep 06, 2021 10:20 pm

Someone told me that a standard rate turn is a 90 degree turn in around 30 seconds and a half standard rate turn is a 90 degree turn in 60 seconds. But someone else told me if depends on the velocity of the aircraft. ??? Watch planes turn from the airport, it always seems to be around 30 seconds for a 90 degree turn. But that's just appearances.

In Albuquerque, airliners taking off to the east seem to fly east for around 20 seconds and then turn mostly right to avoid the mountain. The turn appears to last about 30 seconds or so although Southwest Airlines jets seem to do it in less time.
 
GalaxyFlyer
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Mon Sep 06, 2021 10:53 pm

By definition, a standard rate turn is 3 degrees/second. At 170 KTAS, a standard rate turn is 25 degrees of bank, the usual limit for flight directors. At 210 KTAS, a standard rate turn requires 30 degrees bank, the usual limit for normal instrument flight. Faster than those speeds and the rate of turn decreases. Once at approach configuration, most Jets will be operating at 210 KTAS, a lower altitudes.
 
Newark727
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Mon Sep 06, 2021 11:25 pm

How easy is it to practice a no-gyro landing? Seems like you'd need a tower that isn't too busy. Is it a training requirement or a just nice-to-have thing?
 
GalaxyFlyer
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Mon Sep 06, 2021 11:42 pm

I doubt it practiced much anymore, I wonder how many pilots today are even briefed in class about GCAs. A pilot only has to bank and roll out on the controller’s call, but how many know about it, I can’t say. I heard a story from India where a Global crew lost the navaids needed for the only approach available and eventually were given a PAR by an IAF controller. Can’t say if it’s true.

In an enroute environment, not a problem, it’s doing no-gyro approaches that’s a challenge.

As I said upthread, I practiced them and taught them at CFB Trenton, years ago, so my LTs knew how.
 
GalaxyFlyer
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Mon Sep 06, 2021 11:45 pm

IAHFLYER,

Do controllers know how to use no gyro procedures?
 
N1120A
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Tue Sep 07, 2021 5:11 am

GalaxyFlyer wrote:
IAHFLYER,

Do controllers know how to use no gyro procedures?


They certainly do. They often even open up military airports on weekends to GA pilots for practice PAR approaches to keep controllers current.
 
IAHFLYR
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Tue Sep 07, 2021 1:42 pm

GalaxyFlyer wrote:
IAHFLYER,

Do controllers know how to use no gyro procedures?


Can't say for certain that approach controllers are that familiar with them now days, though they are in the .65 and they should be familiar just don't think many of the new kids on the block today have ever used them. We used to have a guy some 20 years back when ever a pilot was not following his vectors very well the controller would tell them they would be getting no-gyro vectors and it was actually pretty funny when he told an airline crew the same thing......that sure got a phone call when they landed! :shock:

In the GCA's we of course had to provide no-gyro PAR and ASR approaches for currency and I believe the pilots also had a currency requirement to fly them, but not sure that is correct.
 
GalaxyFlyer
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Tue Sep 07, 2021 2:21 pm

By the ‘90s , GCAs were rare for heavy USAF crews, infrequent and not a specific currency requirement. USN and Canadian bases still had them as regular approaches. I got a ASR at Navy Norfolk and it was good the weather was or wouldn’t found the city, let alone the base. New controller. Did one at Pax River, just the opposite, 200-1/2 and perfect run. Rise to the occasion.

Pease AFB had a ANG ATC unit that worked the summer and gave PARs.
 
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kitplane01
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Thu Sep 09, 2021 3:57 am

I really think you all are missing the big picture.

If many redundant nav systems all fail, the problem is that you have some systemic avionics failure going on. If that many independent nav systems all fail, I'd really really worry about the rest of my avionics and flight instruments and even flight controls. Sabotage, rats eating wires, I dunno. But it's bad, an emergency, land now.
 
GalaxyFlyer
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Thu Sep 09, 2021 10:35 am

kitplane01 wrote:
I really think you all are missing the big picture.

If many redundant nav systems all fail, the problem is that you have some systemic avionics failure going on. If that many independent nav systems all fail, I'd really really worry about the rest of my avionics and flight instruments and even flight controls. Sabotage, rats eating wires, I dunno. But it's bad, an emergency, land now.


There’s several junctions where it’s theoretically possible to lose parts of the system. Risk analysis has over the years made the risk vanishingly. But, to your point, if you are losing avionics, landing will require being in VMC conditions which will, in turn, require luck or skill in basic navigation.
 
FlapOperator
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Re: If a commercial pilot lost all nav instruments, would that be a MAYDAY or PAN situation or neither?

Thu Sep 09, 2021 3:10 pm

GalaxyFlyer wrote:
kitplane01 wrote:
I really think you all are missing the big picture.

If many redundant nav systems all fail, the problem is that you have some systemic avionics failure going on. If that many independent nav systems all fail, I'd really really worry about the rest of my avionics and flight instruments and even flight controls. Sabotage, rats eating wires, I dunno. But it's bad, an emergency, land now.


There’s several junctions where it’s theoretically possible to lose parts of the system. Risk analysis has over the years made the risk vanishingly. But, to your point, if you are losing avionics, landing will require being in VMC conditions which will, in turn, require luck or skill in basic navigation.


To illustrate your point, I heard a story of a A300 going from the US East Coast to a Midwest destination along the Mississippi river which lost all three ADCs in the climb.

They broke out VFR on top for hundreds of miles, and ended up continuing to their destination on the wet compass and intermittent comms, which was forecast to be CAVU. Staying VFR on top at night to a CAVU recovery was a better option than trying to do a pretty degraded and dangerous let down.

Nearest SUITABLE airport and all that.

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