The southern and northern air routes have been reopened but the PCAA collects maximum overflight charges from eastern to western air corridor, sources said.
Sources in PCAA said the authority by collecting US$1 per kilometer on average from each flight using Pakistan airspace generated around Rs. 35 billion per annum on account of overflight charges or fees, of which 60 percent revenue was from eastern to western air corridor, extending to around 10,000 kilometers.
They said that this route was still not reopened for all flights that caused a Rs1.16 billion financial loss to PCAA on account of overflight charges during 20 days of airspace restrictions.
When contacted, PCAA spokesman said that he was not authorized to comment on it.
"Although the Pakistan airspace is expected to be reopened after March 23, 2019, it will not mitigate the financial problems being faced by the airlines, taking long routes to reach destinations as India is reluctant to allow its airspace to be used for the flights originating from Pakistan to the 'Far East' countries," sources said.
Following the increase in duration of flights, some airlines have passed on the impact of rising costs to passengers while other carriers too are contemplating taking this option, sources said.
For the said reason, SriLankan Airlines has suspended its operations from Pakistan till March 30, 2019 and is accommodating its ticketed passengers to other airlines while Thai Airways is en-routing its passengers via Muscat to Bangkok.
Similarly, the cash-starved Pakistan International Airline (PIA) is also being hit harder as its four weekly flights to Kuala Lumpur and two weekly fights to Bangkok along with domestic flights to Sukkur, Bahwalpur, Rahimyar Khan, Sialkot, Dera Ghazi Khan, Gilgit and Skardu have been suspended since the airspace restrictions. "Incurring revenue loss in millions on a daily basis, the national flag carrier is also absorbing additional operational cost of increased flights duration after airspace restriction," PIA spokesman said, adding that the airline had so far passed on only a nominal high cost effect to its passengers under its defined clauses.
"However, the fuel prices have also increased and now the airline has no option but to forward compound effect of high operational cost and fuel prices to passengers if airspace restrictions are not lifted within a week," he added.