Halon1211

https://www.yahoo.com/finance/news/a...122550683.html


I’ve been saying this for a long time, but this is a very good reason why you can’t solely rely on GPS.

you always need a back up system like INS (IRU), VOR or yes ADF.

Not everyone can afford to have an internal navigation system in the airplane.

rickair7777

Yeah we've discussed this issue here in years past.

The FAA at one point intended the eliminate the vast majority of the VOR's. Not sure about TACAN/DME.

Post 9/11, that was re-evaluated and while most ADF's and a few VORs are gone I think the plan now is to keep the system.

GPS is easy to spoof and easier to jam. Mil could in theory do frequency hopping, but that only works if the schedule is promulgated encrypted and 100% of recipients are good guys, which would normally be the case for mil crypto distribution. Can't do that with open access for everybody.

Jamming a VOR would require a large truck with a large diesel generator and large antennas.

JohnBurke

While it can happen anywhere, I've noticed it a lot more around the Ukraine, of late, as well as near Iran, Iraq, and Israel. it may be a loss of signal, or can result in a significant shift in indicated position.

rickair7777

Obviously the later is much more problematic.

Excargodog

ADF? I have to wonder how many people today actually are competent to fly ADF? After the Ron Brown crash in Dubrovnik a study was done indicating that 60% of American ATP rated pilots had not flown an ADF approach in the previous year. I doubt the stats would be nearly that good today. Heck, 82% of the American drivers can't even drive a stick shift. ADF is similarly ancient technology.

BlueScholar

If you continue the open source article it says "While NDB approaches are essentially obsolete in the United States, they are still used widely in other parts of the world. Because of their infrequent use in the United States, many American pilots are not fully proficient in performing them (a NASA survey showed that 60% of American transport-rated pilots had not flown an NDB approach in the last year).[2] The investigation board determined that the approach used was not approved for Department of Defense aircraft, and should not have been used by the aircraft crew.[6] The board determined that the particular NDB approach used required two operating ADFs, the instrument used to fly such an approach, on board the aircraft, but this aircraft only had one ADF installed. To successfully fly the approach, one ADF was required to track the outbound course of 119° from the Koločep NDB (KLP), while another ADF was required to observe when the aircraft had flown beyond the Cavtat NDB (CV), which marked the missed approach point.[7] Further, the board noted that the approach was rushed. The aircraft passed the final approach fix at 80 knots (150 km/h) above the proper approach speed and had not received the proper clearance from the control tower to initiate the approach.[6]"
https://en.wikipedia.org/wiki/1996_C...AF_CT-43_crash

They didn't goof up an NDB approach, they didn't have the proper equipment to fly a procedure in the weather, in the mountains, so they improvised based off an illegal approach plate, had an unstable approach, didn't initiate a missed approach even though they were past the MAP, and smacked into a mountain. That's not the NDB's fault, thats just horrible ADM.

hercretired

not one Airbus at my major Part 121 carrier has an ADF installed.

NDB's are not in the PTS standards anymore (showing my age, "PTS") nor are they taught at all the fancy class cockpit, cadet zero to hero schools.

"Just Fly an NDB" is not an option anymore

hercretired

Ron Brown crash required 2 ADFs to fly the approach.

One was installed

Excargodog

I wasn't for a moment defending the crew. I said they screwed up. The point was that the study showing that 60 % of the US ATPs hadn't flown an NDB approach in a year DATES BACK TO THE TIME OF THE MISHAP. If it was that bad in 1996 how bad must ir be now?

ps2sunvalley

kinda keep some vor is the plan

https://www.faa.gov/air_traffic/flig...ON-Program.pdf