PDP 全称Pre-delivery payments。据其全称，可以大概看出它指的是贸易前的预付款的意思。在航空产业中，其常指PDP financing，即与飞机预付款（购买飞机时，买方需要向卖方交纳一定的预付款，一般为飞机价格的30%左右）有关的融资模式，这一模式为飞机制造商与航空公司架起了桥梁，能有效促进航空产业迅速发展。

其英文释义如下：

Pre-delivery payments --- or PDPs --- are progress payments that a purchaser makes to a manufacturer while new aircraft are being built. They represent a significant cash expense for the purchaser, on average amounting to as much as 30% of the price of finished aircraft. Purchasers commonly finance that cash expense using PDP financing.

在传统的PDP融资模式中，一般是lender出借人通过向买方提供secured loan担保贷款而为其提供一定的PDP金额。买方需要在整个贷款期间支付利息，且本金应于贷款对应的飞机交付时予以归还。同时，买方一般会就其在飞机购买协议项下的权利授予出借人留置权，作为collateral抵押物。买方亦会安排与出借方和制造商一起签订三方协议，协议内容应包括制造商知晓并确认出借方享有的留置权以及买方违约后各方关于飞机的其他合同权利等。

以下为相关双语示例：

“Pre-Lease PDP Support Agreement” means the pre-lease PDP support agreement dated 2 June 2017 between the Purchaser and the Seller relating to the pre-delivery payment under the Airbus Purchase Agreement, as amended and supplemented by an Amendment Agreement No.1 dated 2 August 2016 between the Purchaser and the Seller.

“《租赁前PDP支持协议》”指买方和卖方于2017年6月2日就《空客购买协议》项下的预付款签订的租赁前预付款支持协议，及经买卖双方于2016年8月2日签订的修订协议1号进行的修订和补充的版本。