Plane crash at DCA

[ionel]

1 hour ago, fishbane said:

A few seconds before the collision is not enough time.  The Blackhawk pilots might not have even had time to read the instruction back.  

  If not the extra controller was not what broke the chain of errors. 

I'm sure there will be discussion on staffing as a contributing factor in the final report, but a helicopter and a plane could come into conflict at a time when 1 controller was handling both.  

Yes data seems to show the hit 10 - 15 sec after the "pass behind" instruction.

My original point is it takes generally  takes 3 things to cause the accident chain.  The first single controller didn't cause it but two controllers might have broke the chain, just like any of the other 3 could have broke it.  What if they'd recieved instruction 30 sec earlier?

23 minutes ago, fishbane said:

What basis would the pilots of the plane have to reject the request and say "unable 33?"

Using the earlier math the helicopter would have been 10 mi away from the plane and not directly on front of it either. 

Its not like the pilots have radar in the cockpit showing the position of the helicopter.  The only way for them to know it was there was if they spotted it 10mi away looking outside.

 

 

A pilot can always say "unable" its just you might be asked to make a phone call later to explain.  It's always better to still be around to explain.  The two CRJ pilots discussed before they accepted.

Even small planes have tech in cockpit showing other traffic its just not going to work for traffic at 200' agl.  Also have had for long time tech that shows where you will be in 5, 10 etc minutes.  Tower has it too.

The CRJ had been cleared & accepted circle to land 33 and then cleared to land which means cleared all the way to the ground not just 400'.

[ionel]

Btw:  I had a case sw wind cleared for left downwind 22 and left base which took me over 32.  Regional CRJ type out of Chicago announces "on base"  didn't say what runway.  I immediately asked tower for position (this before new tech) informed as was fine continue close base "clear to land".  Well the regional was turning off base for final 32r  Tower had to make the regional go around cause I was already cleared.  Got a "call tower phone #" after shut down.  Usually you don't want that.  He just wanted to apologize.  I'd have liked to heard the other conversation cause the regional did not make proper position reports.  

I've been into DCA but pre 911.

[fishbane]

1 hour ago, ionel said:

Yes data seems to show the hit 10 - 15 sec after the "pass behind" instruction.

My original point is it takes generally  takes 3 things to cause the accident chain.  The first single controller didn't cause it but two controllers might have broke the chain, just like any of the other 3 could have broke it.  What if they'd recieved instruction 30 sec earlier?

I think adding extra people will could help catch a mistake especially if it just one person doing the job.  It may have changed things, but if this wasn't a mistake and how ATC normally handles the helicopters around DCA then maybe not.  There was a near miss the day before with a helicopter maintaining visual separation which may indicate this kind of handling was routine by ATC.

30s could make a difference.  The initial visual separation request was more than 30s before the crash.  The helicopter likely didn't see the plane then either, so I'm not sure being told to pass behind at that time would make a difference.  If they were in fact looking at the wrong plane they might not do anything different.  If ATC told the helicopter to turn left as you suggested earlier that would avoid a collision if the helicopter turned.  Would it be a normal instruction for a ATC to have a helicopter turn off one of the helicopter paths down the river and to the left would be the city/white house/ect.

2 hours ago, ionel said:

A pilot can always say "unable" its just you might be asked to make a phone call later to explain.  It's always better to still be around to explain.  The two CRJ pilots discussed before they accepted.

Even small planes have tech in cockpit showing other traffic its just not going to work for traffic at 200' agl.  Also have had for long time tech that shows where you will be in 5, 10 etc minutes.  Tower has it too.

The CRJ had been cleared & accepted circle to land 33 and then cleared to land which means cleared all the way to the ground not just 400'.

Certainly they could reject runway 33 and they could have executed a go round after accepting 33.  The NTSB said the pilots briefly discussed the decision to accept 33, but haven't released the CVR transcript.  Wouldn't such discussion be more or less whether the plane was capable of stopping on the runway in the conditions?  A helicopter 10+ miles away wouldn't come up.

The information they would have had displayed regarding the helicopter's position would have been supplied by the helicopter.  It's possible this information was incorrect.  The NTSB said that ATC's display had the CRJ at 200ft, but that they found the plane to be at 325+/-25ft at the time of the collision, so 200ft was clearly incorrect.  Also at the same NTSB press conference the plane's CVR contents were discussed and a TCAS traffic advisory was heard in the cockpit 18s before the collision.  Isn't this late?  I thought TCAS was supposed to issue a TA 40s before a potential collision and an RA 25s before a collision.