Posts about: "VFR" [Posts: 146 Page: 8 of 8]¶

Those are addressed in some of the 75-odd Findings statements.

But all of those deficiencies arguably added up to the stated Probable Cause: "the lack of effective pilot applied visual separation by the helicopter crew, which resulted in a mid-air collision"

flyingformoney777 provides a summary of the NTSB Board Meeting.
Runs 25 minutes.

I would argue that both NTSB and Flying for Money used complacency when the term Normalization of deviance,

Flying for Money articulates that the cost of admission into the airspace for VFR traffic was pilot initiated visual separation.

I don't understand why the helicopter routes do not have a lateral dimension i.e. track via XXX, remain EAST of a line XXX to XXX. Defined lateral dimensions then allows lateral separation applied to be based on a thinner line, rather than a broad line as per the current charting.

Shows the age of the hardware used in FAA . But using the current method is also a choice ,
The standard way to couple frequencies in ATC is what was avail in DC , you can transmit on both, listen to both simultaneously but not retransmitting on both . potentially reducing eventual blocked transmissions , or at least improves the detection of blocked transmissions .
in ATC , VHF anti blocking systems are being discussed since Tenerife ( 1977) , CONTRAN was the first one , tested but never really implanted , ,later some copies were made , introduced here and there but with a switch to disable, when traffic got too high ,. not sure what the situation is today but I doubt it changed much. ( waiting to be contradicted)
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In the air , most new 8,33 VHFs have a "dual" function , where you can listen to 2 frequency simultaneously , but when the master is receiving , the slave is blocked out , some have a replay function but useless in flight , especially when flying manual VFR at 200 ft .. I doubt this would have made any difference in this case . Plus it would not solve UHF/VHF ground coupling issue.

This was supposed to be a checkride including Night vision Goggle usage and a bunch of submittals regarding the use and accuracy of the bardo metric altimeter system, and not much, if anything regarding the radar altimeter system accuracy.
The UH-60 Maintenance Test Flight Manual includes a barometric altimeter accuracy check, which is accomplished by calling the tower for the local altimeter setting, set the altimeter accordingly and comparing the altimeter readout to the elevation of that heliport/airport. THE ACCEPTED MAXIMUM ERROR IS 70 FEET. So, the baro altimeter readout can be 70 ft off and you are OK to fly: VFR or IFR.

The radar altimeter ( APN-171 or later APN-209 ) accuracy is similar at +/- 3 ft then 3% of indicated altitude, so, for the H-4 Route Maximum altitude of 200 ft. The Rad Alt could be as much as 9 ft off.

The NVGs do show Rad Alt.

Haven\x92t seen any submittal indicating the Rad Alt was inoperative or unusable.

None of the references to NVGs in the hearing made mention of a HUD capability.

The Helicopter Operations presentation included a slide stating that pilots are "Trained to use barometric altimeter to navigate helicopter route ceilings".

When the altimeter setting is placed in the aircraft on the ground, the pilot should take note of how much difference there is from actual field elevation and then consider what should be done for compensation for any error. On most VFR flights, a 100' error does not have much relevance. On the other hand, if you were to know that you are going to pass extremely close to something that you do not want to be close to, then it can become significant. An example might be for the people who like to fly 100 feet vertically from airspace that they are not allowed to enter. This situation might be another example where good airmanship can make a difference(specifically to compensating for an altimeter error).

I have not read this report, as I am deep into many other ones these days but I did take a quick glance on page 242 that was referenced and it talks about altimeter additive errors. The report states: "The allowable tolerances are additive, with the total error having the potential of exceeding 100 ft.". The report also states: "The NTSB concludes that, due to additive allowable tolerances of the helicopter\x92s pitot-static/altimeter system, it is likely that the crew of PAT25 observed a barometric altimeter altitude about 100 ft lower than the helicopter\x92s true altitude, resulting in the crew erroneously believing that they were under the published maximum altitude for Route 4".

My question to other people on this thread is: Did the NTSB do some sort of evaluation of this particular helicopter in order to come to a reasonable conclusion that all errors were in such a way that they were all in the direction of resulting in the helicopter being higher than indicated as opposed to errors potentially cancelling each other out(or partially so)?