G450 first officer experiences a taxiway excursion at dvt during a turn from taxiway a to A13. The r...

Narrative:

After normal preflight and engine start operations we received a taxi clearance. Paraphrasing; taxi to runway 25L via taxiway a; A13; hold short of runway 25L. It was the taxi clearance we expected and briefed. As we started the taxi we commenced with the taxi checklist. The taxi checklist was completed. As we approached the 90 degree turn from taxiway a onto taxiway A13 we discussed the narrow taxiway and the tight 90 degree turn. During the turn; even though we favored the left side of the taxiway; the right main wheel went off the taxiway. We contacted ground control for assistance. Suggest an airport operations review of the dvt intersection of taxiway a and A13. Convergence of two narrow taxiways. The inside of the turn is not a smooth arc for transition from taxiway a to A13. The old taxiway had a smooth arc inside of the turn. The taxiway markings are at the very edge of the taxiway with no hard surface margins. The old taxiway had hard surface outside of the taxiway markings creating a margin.for narrow taxiways the crew should use the onboard cameras for situational awareness for wheel/edge proximity.

Original NASA ASRS Text

Title: G450 First Officer experiences a taxiway excursion at DVT during a turn from Taxiway A to A13. The right main gear departs the paved surface during the turn.

Narrative: After normal preflight and engine start operations we received a taxi clearance. Paraphrasing; taxi to RWY 25L via Taxiway A; A13; hold short of RWY 25L. It was the taxi clearance we expected and briefed. As we started the taxi we commenced with the taxi checklist. The taxi checklist was completed. As we approached the 90 degree turn from Taxiway A onto Taxiway A13 we discussed the narrow taxiway and the tight 90 degree turn. During the turn; even though we favored the left side of the taxiway; the right main wheel went off the taxiway. We contacted ground control for assistance. Suggest an Airport Operations review of the DVT intersection of Taxiway A and A13. Convergence of two narrow taxiways. The inside of the turn is not a smooth arc for transition from Taxiway A to A13. The old taxiway had a smooth arc inside of the turn. The taxiway markings are at the very edge of the taxiway with no hard surface margins. The old taxiway had hard surface outside of the taxiway markings creating a margin.For narrow taxiways the crew should use the onboard cameras for situational awareness for wheel/edge proximity.

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	1237474
Time
Date	201502
Local Time Of Day	0601-1200
Place
Locale Reference	DVT.Airport
State Reference	AZ
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Gulfstream IV / G350 / G450
Operating Under FAR Part	Part 91
Flight Phase	Taxi
Flight Plan	IFR
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Engineer
Experience	Flight Crew Last 90 Days 40 Flight Crew Total 6000 Flight Crew Type 4000
Events
Anomaly	Ground Excursion Taxiway

G450 first officer experiences a taxiway excursion at dvt during a turn from taxiway a to A13. The right main gear departs the paved surface during the turn.