Bobster2 From , joined Dec 1969, posts, RR: Posted (7 years 1 month 1 week 3 days 18 hours ago) and read 3479 times:
I've seen a number of incident investigation reports where they say the CVR had no usable data because nobody pulled the circuit breakers after the incident. The CVR then continued running until the voice recording was overwritten. The reports don't appear to be blaming anybody for this, they simply state the fact that it happened. These are all cases with no fatalities and little or no damage to the airplane, however they were still serious enough to be investigated by authorities and the CVR would have been useful.
So I'm wondering who, if anybody, would be required to preserve the CVR data before it gets overwritten? One example that I have in mind is the recent incident of an airliner landing on a taxiway. Is there a rule for that covers this situation? Or is it left to the judgement of the airline personnel and/or management?
EMBQA From United States of America, joined Oct 2003, 9348 posts, RR: 12 Reply 1, posted (7 years 1 month 1 week 3 days 17 hours ago) and read 3459 times:
I've never heard of one case that you mention above, but in most cases the aircraft is destroyed and the CVR/FDR is ripped from the plane so there is no reason to pull CB's. If power is lost for any reason the CVR/FDR will stop recording. If the aircraft has been involved in an event that is serious enough, most time it's SOP for the Crash-Rescue the disconnect the batteries.. thus killing power. If for some reason that power is not lost, and if the recorder is requested, Maintenance will pull the CB's and remove the CVR/FDR
[Edited 2006-11-02 00:13:04]
"It's not the size of the dog in the fight, but the size of the fight in the dog"
SP90 From United States of America, joined May 2006, 388 posts, RR: 0 Reply 2, posted (7 years 1 month 1 week 3 days 17 hours ago) and read 3452 times:
I heard its easy for pilots landing on 16R to land on taxiway T by mistake up in SEATAC. 16L/16R and T are all flush when approaching from the north. The taxiway is concrete and the runway is blacktop, add a little glare and it just seem like the better choice.
474218 From United States of America, joined Oct 2005, 6340 posts, RR: 9 Reply 3, posted (7 years 1 month 1 week 3 days 17 hours ago) and read 3437 times:
Quoting Bobster2 (Thread starter): I've seen a number of incident investigation reports where they say the CVR had no usable data because nobody pulled the circuit breakers after the incident.
Had it happen on a TWA L-1011 tail drag incident at JFK. Pilot really messed up and did not follow the landing check list ended up doing a "full flap no slat" landing after the slats locked due to a mechanical asymmetry brake trip. Pilot never asked FE for standard "14 greens" which verifies all slats have extended. He stayed in the flight station long after everyone left then pulled circuit breaker after he was sure all pre landing conversations were gone.
Bobster2 From , joined Dec 1969, posts, RR: Reply 4, posted (7 years 1 month 1 week 3 days 17 hours ago) and read 3431 times:
Quoting EMBQA (Reply 1): in most cases the aircraft is destroyed
I'm talking about cases where the airplane continues in service. A rejected takeoff is one example. A near collision on the runway is another. One case involved a violent maneuver during a go-around followed by a safe landing. They may be serious enough to warrant a major investigation, but before the investigation commences, the airplanes have gone to be repaired or they continued normal operation. The short lifetime of the CVR combined with the delay in starting the investigation is the problem.
I only mentioned the taxiway landing incident because it has happened a number of times at various airports with no injuries or damage to the planes. There is no power loss to stop the CVR, no crash crews, no military divers at the bottom of the ocean, the planes just continue service.
Charlienorth From United States of America, joined Jun 2006, 1098 posts, RR: 5 Reply 6, posted (7 years 1 month 1 week 3 days 17 hours ago) and read 3424 times:
Usually in an event like these,a request will be made for maintenence to remove the CVR and/or the DFDR,sometimes it's an internal investigation by the airline,in the event it's an incident where the fed's are involved there's a procedure in the airline's GMM or Ops spec,these spell out exactly what to do.Hope that helps some.
OPNLguy From , joined Dec 1969, posts, RR: Reply 7, posted (7 years 1 month 1 week 3 days 15 hours ago) and read 3403 times:
I think you're talking two separate issues here, deactivation after certain kinds of events, and physical removal from the aircraft.
Deactivation can easily be accomplished by pulling the applicable circuit breaker(s) and that will preclude the recording over the event by ambient sounds occurring after the event. I can readily recall where a Valujet DC-9 that had a landing accident at BNA (landed short of 02L due ground spoiler deployment in-inflight, got airborne again, and came around to the right for a straight-in to 31 and stopped it there on the runway). Someone didn't pull the CVR breaker, and the original event was recorded over. The move from :30 minute CVR recordings to 2 hour recordings provides a little more time to secure things, as well as to record more of what happened prior to the event itself.
As far as removal goes, maintenance (company or contract) can do that, and chain-of-custody procedures followed as a part of whatever degree of investigation results.
Bobster2 From , joined Dec 1969, posts, RR: Reply 8, posted (7 years 1 month 1 week 3 days 15 hours ago) and read 3396 times:
Quoting EMBQA (Reply 5): Most of the cases you mentioned would not warrent pulling the CVR
But who makes that decision? Presumably the pilots. But what rules, if any, do they have to follow? Is there an FAA rule that spells out clearly under what circumstances the pilots must pull the breakers and request that the CVR be removed? Is there a company SOP that spells it out?
At the time of the incident, there is not yet an investigation. So I'm wondering what rules cover the time period between the incident and the investigation. Is anybody accountable for what happens during the 2 hours while the CVR is being erased?
T prop From United States of America, joined Apr 2001, 1015 posts, RR: 1 Reply 9, posted (7 years 1 month 1 week 3 days 14 hours ago) and read 3377 times:
Quoting Bobster2 (Reply 8): But who makes that decision? Presumably the pilots. But what rules, if any, do they have to follow? Is there an FAA rule that spells out clearly under what circumstances the pilots must pull the breakers and request that the CVR be removed? Is there a company SOP that spells it out?
When to remove the recorders for an incident is usually spelled out in the airlines GMM and Ops manuals. These manuals are written by the airlines themselves and then reviewed and approved by the FAA. If it's not a crash and the aircraft is at an airport, maintenance personel will remove the recorders per the GMM. The crew is responsible for pulling the CVR breaker. I would imagine the recent CO incident at EWR where the aircraft landed on a taxiway would warrant removal of the recorders.
BTW, the audio on the CVR is easily erased by meeting certain conditions and then pressing the erase button on the CVR panel in the cockpit.
Charlienorth From United States of America, joined Jun 2006, 1098 posts, RR: 5 Reply 15, posted (7 years 1 month 1 week 3 days 1 hour ago) and read 3243 times:
On the newer aircraft there are items that can be downloaded without removing units,these usually requested by the co. if there is thought of an overtemp of an engine or overtorque in a t-prop,on the Airbus you can retreive info on a turbulence event or heavy landing,depending on the number's received these can make the difference between a simple log-book sign off or an airframe inspection.I've been involved in removing Cvr and Fdr ffrom an aircraft that had a landing accident (non-fatal,aircraft was out of svc for six months)the Director of Maint. called me,told me who to meet,check the person's I.D. (NTSB) and make sure you get a written confirmation from the guy,no problem.