Not so iInteresting DC-9 facts, if you are a dog lover
Discussion
The forward cargo compartment on the DC-9 was the only designated area to transport pets due to it being pressurized and heated. In the event of a fire the procedure was to shut off the air supply since it had no suppression capabilities. To prevent the airflow there was a switch on the overhead panel. The switch was known colloquially as the 'puppy snuffer' switch.
The DC-9 (and the DC-8, MD-80, MD-90 and B717) have their backup magnetic 'whisky' compass mounted behind the pilots on the rear cockpit bulkhead up near the ceiling since this was the location with the least magnetic and electrical interference. The compass card is printed 'backwards' and the pilots use little flip-down mirrors if they need to see it.
The cockpit window latches and other minor controls on the DC-9 family use the round handles that were originally used for the DC-3's engine controls. The emergency landing gear unlock/deploy latches and handles are the DC-3's ordinary landing gear controls repurposed.
The cockpit window latches and other minor controls on the DC-9 family use the round handles that were originally used for the DC-3's engine controls. The emergency landing gear unlock/deploy latches and handles are the DC-3's ordinary landing gear controls repurposed.
On some parts of the route system (mountains) the DC-9 didn't have enough power (single engine) to maintain obstacle clearance altitude off airways. Meaning when operating over this segment a more direct routing clearance had to be declined to remain within the drift down profile.
Pressurization was rather primitive in that the outflow valve closed with main gear strut extension. It was at that very moment 108 people started trying to clear their ears. Boeings pressurize on the ground eliminating the pressure bump.
Pressurization was rather primitive in that the outflow valve closed with main gear strut extension. It was at that very moment 108 people started trying to clear their ears. Boeings pressurize on the ground eliminating the pressure bump.
Eric Mc said:
The tooling up costs is incurred by Douglas in anticipation of DC-9 production had such a negative impact on the company that they almost went bust. They were only saved by being bought out by the Mc Donnell aircraft company in 1966.
IIRC from reading this somewhere ages ago (I'm sure you'll be able to correct me if I'm wrong) that this was because of a rather British Leyland-like process where the DC-9 was originally meant to be closely derived from the DC-8 (as the 727 - and parts of the 737 - was from the 707) but by the time they'd 'adapted' the DC-8 fundamentals to become a smaller T-tailed rear-engined jet and the marketing department had insisted on various changes there was virtually nothing in common, hence why the tooling costs were such a burden. To be honest, I am not sure why they got the tooling costs so wrong. They had also had to do a lot of remedial work on the DC-8 design to get it to perform to the original specification as sold to the launch customers. These combined issues put Douglas into a significantly weak trading position.
2xChevrons said:
The DC-9 (and the DC-8, MD-80, MD-90 and B717) have their backup magnetic 'whisky' compass mounted behind the pilots on the rear cockpit bulkhead up near the ceiling since this was the location with the least magnetic and electrical interference. The compass card is printed 'backwards' and the pilots use little flip-down mirrors if they need to see it.
The cockpit window latches and other minor controls on the DC-9 family use the round handles that were originally used for the DC-3's engine controls. The emergency landing gear unlock/deploy latches and handles are the DC-3's ordinary landing gear controls repurposed.
Recently watched a video on YT of chap sat in the cockpit of an MD-80 going through various little things like these. I particularly like the switches and how they use a massive variety so that the pilot can know what switch is which just by touch. The cockpit window latches and other minor controls on the DC-9 family use the round handles that were originally used for the DC-3's engine controls. The emergency landing gear unlock/deploy latches and handles are the DC-3's ordinary landing gear controls repurposed.
This is the video https://www.youtube.com/watch?v=7R0CViDUBFs
Eric Mc said:
To be honest, I am not sure why they got the tooling costs so wrong. They had also had to do a lot of remedial work on the DC-8 design to get it to perform to the original specification as sold to the launch customers. These combined issues put Douglas into a significantly weak trading position.
Boeing nearly came a cropper with the 747 as well. Making aeroplanes is a dicey business.Yertis said:
Eric Mc said:
To be honest, I am not sure why they got the tooling costs so wrong. They had also had to do a lot of remedial work on the DC-8 design to get it to perform to the original specification as sold to the launch customers. These combined issues put Douglas into a significantly weak trading position.
Boeing nearly came a cropper with the 747 as well. Making aeroplanes is a dicey business.start with a large one...
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