B737-800
Air Traffic Control Fully Certified
Situational Awareness
ATC Issue All Types; Conflict Ground Conflict; Less Severe
General None Reported / Taken
Airport; Aircraft; Human Factors; Procedure
I was providing training on Local 1. The Trainee cleared a PA46 for take off of Runway 19L. Air Carrier X had just landed Runway 19R and was exiting at Taxiway Echo as PA46 was upwind. PA46 was issued a MUSEL6 departure from Clearance Delivery prior to takeoff. When the Trainee cleared PA46; he issued 'fly runway heading' which is what the MUSEL 6 departure does until a mile South of the airport anyway. When Air Carrier X exited; he advised Ground Control that the Malibu overflew him and was low. I observed the Malibu overfly Air Carrier X as it happened and I did not feel it was unsafe. PA46 was definitely much lower than I would expect; as Taxiway Echo is 2;500 feet from the departure end of Runway 19L and the standard climb rate of a PA46 is 1;143 feet per minute. The Malibu was maybe 5 plane heights above Air Carrier X. The Malibu; however; did not appear to be in unsafe proximity to Air Carrier X where I thought either plane was in danger. After the training session; I did not consider it a safety event; so we did not discuss it much. SNA airport is extremely compact and it is not uncommon for aircraft to overfly other aircraft; especially the little planes that depart Runway 19L on a 15 degree left turn and aircraft on Taxiway Alpha. Most aircraft have to taxi down Taxiway Alpha and it is our busiest taxiway and it is directly under the 15 degree left turn off Runway 19L. The difference in this scenario with Air Carrier X was the Malibu's climb rate (he appeared heavy). The only way to avoid this situation is pilot education and awareness. The pilot should have advised us that he was too heavy for Runway 19L. When a plane's climb rate is that much different than expected we have no way of knowing.
SNA Controller described an air/ground conflict when an IFR PA46 departing Runway 19L overflew an air carrier taxiing to the gate on Taxiway E; the reporter surprised by the very slow climb rate of the departing aircraft.