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-   -   What was the cockpit design philosophy of McDonnell Douglas? (https://www.pprune.org/tech-log/665601-what-cockpit-design-philosophy-mcdonnell-douglas.html)

777Supremecist 18th April 2025 01:50

What was the cockpit design philosophy of McDonnell Douglas?
 
Every aircraft manufacturer has their own cockpit design philosophy: Airbus's design philosophy revolves around simplification, automation, and pilot assistance, aiming to reduce pilot workload and enhance situational awareness etc. Boeing's design philosophy on the other hand, prioritizes a pilot-centered approach, emphasizing manual controls and pilot intuition, making pilots have full control authority at all times etc. So was McDonnell Douglas's design philosophy? Or more precisely; Douglas's design philosophy, as most of McDonnell Douglas's civilian/airliner aircrafts were originally designed by Douglas.
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EXDAC 18th April 2025 02:30

That's a rather vague question. If you have a specific question on MD-80, MD-11, MD-90, MD-95, or MD-10 perhaps I could answer it as I had some involvement with the development of all those types.

All of the MD commercial aircraft were designed by Douglas Aircraft Company, Long Beach. Boeing had no involvement with the design of any of them although they did re-name the MD-95 to B717 and did send a few people down from Seattle for the flight test program.

You have to get down to specifics e.g, If AP is engaged in ALT HOLD mode in cruise, and available engine thrust is insufficient to maintain altitude and keep airspeed above stall speed, what should the AP do? The choices are 1) lower the nose and maintain safe airspeed or 2) maintain altitude until stall. This was debated with strong opinions for each answer. Douglas decided AP should maintain altitude and allow the aircraft to stall. What label do you put on that design philosophy?

777Supremecist 18th April 2025 04:27


Originally Posted by EXDAC (Post 11869215)
That's a rather vague question. If you have a specific question on MD-80, MD-11, MD-90, MD-95, or MD-10 perhaps I could answer it as I had some involvement with the development of all those types.

All of the MD commercial aircraft were designed by Douglas Aircraft Company, Long Beach. Boeing had no involvement with the design of any of them although they did re-name the MD-95 to B717 and did send a few people down from Seattle for the flight test program.

You have to get down to specifics e.g, If AP is engaged in ALT HOLD mode in cruise, and available engine thrust is insufficient to maintain altitude and keep airspeed above stall speed, what should the AP do? The choices are 1) lower the nose and maintain safe airspeed or 2) maintain altitude until stall. This was debated with strong opinions for each answer. Douglas decided AP should maintain altitude and allow the aircraft to stall. What label do you put on that design philosophy?

I am sorry, I am an amateur in terms of aviation knowledge, neither am I a pilot, and I am also new to this forum, so i don't know how things work here, sorry for being vague. To answer your question; I would say that this is a bit similar to Boeing's design approach. Once again, I am an amateur in aviation, but I once heard from a MD-11 pilot that the MD-11 (for its time) was very advanced and heavily relied on a high degree of automation, and he said that some of it's cockpit quirks were kinda similar to Airbus, more so than Boeing. However, I always used to think that Douglas's design philosophy was similar to Boeing's approach.

galaxy flyer 18th April 2025 12:32

The philosophy before the MD-11 looks to be scatter stuff around. They ran out of room in the DC-9, so when they released they needed a standby compass, they put on cockpit back wall and used a mirror to view it.

alf5071h 18th April 2025 14:40

The idea of a 'flight-deck philosophy' originated with the need to certificate two-crew in the early, smaller, jet aircraft; 737, DC 9, and elsewhere F28, BAC1-11, Mercure. The practicalities in demonstrating acceptable workload became philosophy - our way of doing things.
The emphasis was on the aircraft systems, overhead panel, etc, primarily to satisfy the FAA and thence the US unions.

Later aircraft 737-400, MD 80, (F100, Avro RJ) with updated avionics, autoland, FMS, and EFIS, sought to standardise the operational aspects (arrange the flight-deck) again according to their way of doing things (operational,philosophy). Divisions in this remained with the US unions /airlines as specified by the lead airline's requirements, Boeing or MD (AA large ASI), but less so for other manufacturers.

SAE S7 attempted to agree a common standard, but this was not universally accepted, particularly where sales and certification drove designs, e.g. B 757 / 767 common flight-deck - the Boeing way; pilots fly aircraft, the union way.

During this period and later, Airbus (Europe) developed their own ideas with the A300 becoming two crew (FFCC) and A310.
The integrated philosophy with FBW, EFIS / EICAS for the A320 evolved with the technology and thoughtful observation of non-agreement in SAE 7 discussions.

There was significant effort using the Advanced Flight Deck concept to harmonise the US unions with emerging European views. https://www.vc10.net/Technical/FlightDeckDesign.html


EXDAC 18th April 2025 15:55


Originally Posted by alf5071h (Post 11869540)
Later aircraft 737-400, MD 80, (F100, Avro RJ) with updated avionics, autoland, FMS, and EFIS, sought to standardise the operational aspects (arrange the flight-deck) again according to their way of doing things (operational,philosophy).

As originally certificated the MD-80 had no FMS and no EFIS. It was advanced in other areas as it had Cat 111a autoland and optional dual HUD. It seems remarkable now but the MD-80 was certificated with iron gyros.

Despite the fact that DC-9 had always been 2 crew I remember there was some objection to MD-80 being 2 crew.

moosepileit 18th April 2025 21:15


Originally Posted by galaxy flyer (Post 11869470)
The philosophy before the MD-11 looks to be scatter stuff around. They ran out of room in the DC-9, so when they released they needed a standby compass, they put on cockpit back wall and used a mirror to view it.

If you flew it and forgot, that was the easiest ACCURATE location for the standby compass.
Gave plausible deniability for the glare shield vanity mirrors used to flip up and view said compass, too.

MD-11 reverts nicely from speed on thrust, holding altitude, to wake-up auto throttles, if available but off, to switching to speed on pitch to stay off critical stick shaker by 5 knots.

Same in reverse for over speed. LSAS also in play without auto flight. Come on in for an EET/UPRT session for the PLI use demo.

oceancrosser 18th April 2025 21:24


Originally Posted by galaxy flyer (Post 11869470)
The philosophy before the MD-11 looks to be scatter stuff around. They ran out of room in the DC-9, so when they released they needed a standby compass, they put on cockpit back wall and used a mirror to view it.

Well not exactly correct. It was the same on the DC-8. The “whiskey compass” was far back in the ceiling and each pilot had a small mirror on top of the glareshield. The DC-8s I flew came from several different primary operators and were very different in setup. The overhead panel in one could be mirrored in the next one, i.e. items that were at the front of the panel in one, were at the back in another one. Engine parameters were also different as to which parameters were on the center instrument panel or on the F/E panel. Worst config were the ex Air Canada airplanes that they tried to change to a 2 man cockpit (never worked) with parts from the F/E panel scattered around the pilot stations. Fun time, but when you took one airplane out and another back on the same day, it meant some looking around and adjusting.

Check Airman 18th April 2025 21:33

I suspect the MD80 design philosophy was divinely inspired by Genesis 3, verse 19.

Thankfully by the time the MD11 appeared, they’d become more secular.


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