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A jump seat rider hears the ATCT controller at iah and a B737 crew in position cut each other out several times during a busy period.
| Attributes | |
| ACN | 443643 |
| Time | |
| Date | 199907 |
| Day | Wed |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : iah.airport |
| State Reference | TX |
| Altitude | agl single value : 0 |
| Environment | |
| Flight Conditions | VMC |
| Weather Elements | Thunderstorm Windshear |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | MD-80 Super 80 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | ground : holding |
| Flight Plan | IFR |
| Aircraft 2 | |
| Controlling Facilities | tower : iah.tower |
| Operator | common carrier : air carrier |
| Make Model Name | B737 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | ground : position and hold |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | observation : observer |
| Qualification | controller : radar pilot : private |
| Experience | controller radar : 10 flight time last 90 days : 0 flight time total : 400 |
| ASRS Report | 443643 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Events | |
| Anomaly | non adherence : published procedure |
| Independent Detector | other controllera other controllerb other flight crewa other flight crewb other other : 4 |
| Resolutory Action | controller : issued new clearance none taken : anomaly accepted |
| Supplementary | |
| Problem Areas | Flight Crew Human Performance ATC Human Performance |
| Primary Problem | ATC Human Performance |
Narrative:
I was riding jump seat (ATC observer) in an MD80 (aircraft X) departing iah runway 26. We were #8 for departure at XA00 with rapidly approaching thunderstorms sharply increasing the urgency of the actions and xmissions of pilots and controllers alike. Iah tower was scrambling to get arrs down on any available runway while still managing to get departures out. At one point, B737 (aircraft Y) was taxied into position and hold for in trail spacing. After a short delay tower cleared the B737 (aircraft Y) for takeoff without a response. This was reported. The tower urgently requested a radio check from the pilot which was acknowledged. This was followed by yet another takeoff clearance. The pilot then asked for a wind check but his transmission was blocked by the tower. The B737 (aircraft Y) continued to hold awaiting a wind check. Tower figured that they had lost communication again since the B737 (aircraft Y) was not moving and had not acknowledged the takeoff clearance. Both the B737 (aircraft Y) and the tower made repeated attempts to re-establish communication but continued to block each other out. After (what seemed like) several mins, other aircraft on frequency joined in the fray trying to sort things out, but only adding to the confusion. This potentially dangerous situation could have been avoided if anti-blocking devices had been installed on the aircraft radios.
Original NASA ASRS Text
Title: A JUMP SEAT RIDER HEARS THE ATCT CTLR AT IAH AND A B737 CREW IN POS CUT EACH OTHER OUT SEVERAL TIMES DURING A BUSY PERIOD.
Narrative: I WAS RIDING JUMP SEAT (ATC OBSERVER) IN AN MD80 (ACFT X) DEPARTING IAH RWY 26. WE WERE #8 FOR DEP AT XA00 WITH RAPIDLY APCHING TSTMS SHARPLY INCREASING THE URGENCY OF THE ACTIONS AND XMISSIONS OF PLTS AND CTLRS ALIKE. IAH TWR WAS SCRAMBLING TO GET ARRS DOWN ON ANY AVAILABLE RWY WHILE STILL MANAGING TO GET DEPS OUT. AT ONE POINT, B737 (ACFT Y) WAS TAXIED INTO POS AND HOLD FOR IN TRAIL SPACING. AFTER A SHORT DELAY TWR CLRED THE B737 (ACFT Y) FOR TKOF WITHOUT A RESPONSE. THIS WAS RPTED. THE TWR URGENTLY REQUESTED A RADIO CHK FROM THE PLT WHICH WAS ACKNOWLEDGED. THIS WAS FOLLOWED BY YET ANOTHER TKOF CLRNC. THE PLT THEN ASKED FOR A WIND CHK BUT HIS XMISSION WAS BLOCKED BY THE TWR. THE B737 (ACFT Y) CONTINUED TO HOLD AWAITING A WIND CHK. TWR FIGURED THAT THEY HAD LOST COM AGAIN SINCE THE B737 (ACFT Y) WAS NOT MOVING AND HAD NOT ACKNOWLEDGED THE TKOF CLRNC. BOTH THE B737 (ACFT Y) AND THE TWR MADE REPEATED ATTEMPTS TO RE-ESTABLISH COM BUT CONTINUED TO BLOCK EACH OTHER OUT. AFTER (WHAT SEEMED LIKE) SEVERAL MINS, OTHER ACFT ON FREQ JOINED IN THE FRAY TRYING TO SORT THINGS OUT, BUT ONLY ADDING TO THE CONFUSION. THIS POTENTIALLY DANGEROUS SIT COULD HAVE BEEN AVOIDED IF ANTI-BLOCKING DEVICES HAD BEEN INSTALLED ON THE ACFT RADIOS.
Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.