Midair collision between Helicopter and CRJ (AA5342) at Washington (DCA)

[marki]

For helicopter pilots:

What is the error range of altimeters?.
X00feet indicated = X 00 feet +/- actual?

How easy is it to maintain altitude at X?. Is there an allowed variability?

Altimeters for helicopters typically have an error range of **±50 to ±100 feet** under normal conditions, meaning an indicated altitude of X00 feet could be X00 ±50-100 feet. Maintaining altitude is challenging due to helicopter instability, but pilots generally aim to stay within **±100 feet** of their target altitude, with tighter tolerances in instrument flight. Environmental factors and pilot skills significantly influence precision. NVGs can give altered height perception as well.

 

[bad]

Helicopter or fixed wing it’s fair to say they are the same ie highly accurate, but they require accurate local air pressure data which is why QNH is always mentioned. If the pilot does not have the right QNH dialled in, you get errors ….

I agree with Markis10 above; altimeters in helicopters and fixed-wing aircraft are highly accurate but depend on correct QNH (local air pressure) settings. If the pilot dials in the wrong QNH, the altitude reading will be inaccurate, emphasizing the need for precise QNH updates from ATC to ensure safe operations. How many times has this gone in the other direction, however? Some maps are outdated, and the topography will also be. To make the alarm go away (PULL up), the pilot zeros the QNH. Therefore, annoying alarm distractions will be silenced until CFIT is too late.

 

[Quickstatus]

NTSB reporting CRJ altitude (from FDR plus or combined withADS-B) to be 325Ft +/- 25ft close to point of collision.

So I come back to the question: how easy is it for a helicopter like this one to maintain 200ft altitude while flying - assuming manually operated flight and at night using NVG?

 

[RSD]

I agree with Markis10 above; altimeters in helicopters and fixed-wing aircraft are highly accurate but depend on correct QNH (local air pressure) settings. If the pilot dials in the wrong QNH, the altitude reading will be inaccurate, emphasizing the need for precise QNH updates from ATC to ensure safe operations. How many times has this gone in the other direction, however? Some maps are outdated, and the topography will also be. To make the alarm go away (PULL up), the pilot zeros the QNH. Therefore, annoying alarm distractions will be silenced until CFIT is too late.

Any need to shout it in bold?

 

[marki]

Any need to shout it in bold?

By the looks of it, the intention was supposed to be the other way around, a simple mistake, I guess, easy enough to do.

i.e., "I agree with Markis10 above; "people can be way too sensitive to such minor transgression nowadays. Sign of the times? Cough cough; I am no slouch when it comes to transgressions either. I agree with Markis10 as well because the slip of the fingers can be so devastating in these circumstances.