U90 approach controller describes a confusing reply from his trainee to a pilot. Pilot requested a b...

Narrative:

Training in progress; we were working departure; west radar and satellite combined; moderate VFR conditions. Aircraft X eastbound restricted to 10;000 feet with aircraft Y also eastbound climbing above aircraft X. The trainee restricted aircraft X at 10;000 feet; at some point the pilot asked for a block altitude 9000 feet block 10;000 feet; the trainee responded 'I have your request'; it was never approved. The trainee started to fall behind; there was a lot of frequency congestion on multiple frequencies. The amount of traffic and frequency congestion was beyond the trainee's capability so I took the frequencies. Aircraft X was blocked on the frequency at least once but I knew he was restricted below aircraft Y and I had higher priority transmissions. I heard the controller-in-charge (controller in charge) ask what aircraft X was doing; I saw him at 103 and immediately descended him back to 10;000 feet; I gave him the brasher warning. The pilot stated that I didn't answer him so he decided to climb (paraphrasing). I never saw a loss of separation; the closest altitudes were 10;700 feet and 11;700 feet.although this was not a result of a phraseology error; I did review 'on request' phraseology with the trainee. I don't believe the pilot was confused about the altitude restriction. The pilot did not receive a reply from ATC due to frequency congestion and decided to climb. Even if I would have taken control of the position and frequencies sooner; it would not have prevented this situation because I had other higher priorities. I would recommend monthly or quarterly meetings with the squadrons; an exchange of knowledge; rules and restrictions from both sides (pilots and controllers; not office staff or management) would be beneficial.

Original NASA ASRS Text

Title: U90 Approach Controller describes a confusing reply from his trainee to a pilot. Pilot requested a block altitude; Controller answered 'On request.' Pilot later climbs on his own and separation was lost.

Narrative: Training in progress; we were working departure; west radar and satellite combined; moderate VFR conditions. Aircraft X eastbound restricted to 10;000 feet with Aircraft Y also eastbound climbing above Aircraft X. The trainee restricted Aircraft X at 10;000 feet; at some point the pilot asked for a block altitude 9000 feet block 10;000 feet; the trainee responded 'I have your request'; it was never approved. The trainee started to fall behind; there was a lot of frequency congestion on multiple frequencies. The amount of traffic and frequency congestion was beyond the trainee's capability so I took the frequencies. Aircraft X was blocked on the frequency at least once but I knew he was restricted below Aircraft Y and I had higher priority transmissions. I heard the controller-in-charge (CIC) ask what Aircraft X was doing; I saw him at 103 and immediately descended him back to 10;000 feet; I gave him the brasher warning. The Pilot stated that I didn't answer him so he decided to climb (paraphrasing). I never saw a loss of separation; the closest altitudes were 10;700 feet and 11;700 feet.Although this was not a result of a phraseology error; I did review 'On request' phraseology with the trainee. I don't believe the pilot was confused about the altitude restriction. The pilot did not receive a reply from ATC due to frequency congestion and decided to climb. Even if I would have taken control of the position and frequencies sooner; it would not have prevented this situation because I had other higher priorities. I would recommend monthly or quarterly meetings with the squadrons; an exchange of knowledge; rules and restrictions from both sides (pilots and controllers; not office staff or management) would be beneficial.

Data retrieved from NASA's ASRS site 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.

Attributes
ACN	1232775
Time
Date	201501
Local Time Of Day	1801-2400
Place
Locale Reference	U90.TRACON
State Reference	AZ
Environment
Light	Night
Aircraft 1
Make Model Name	Fighter
Operating Under FAR Part	Part 91
Flight Phase	Climb
Flight Plan	IFR
Aircraft 2
Make Model Name	Medium Large Transport
Operating Under FAR Part	Part 121
Flight Phase	Initial Climb Cruise
Flight Plan	IFR
Person 1
Function	Instructor Approach
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Radar 14 Air Traffic Control Time Certified In Pos 1 (yrs) 6.5
Person 2
Function	Trainee Approach
Qualification	Air Traffic Control Developmental
Experience	Air Traffic Control Radar 1.5
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance

U90 approach controller describes a confusing reply from his trainee to a pilot. Pilot requested a block altitude; controller answered 'on request.' pilot later climbs on his own and separation was lost.