Thankyou Flightrider. It's remarkable what goes on behind the scenes. I've looked at the data for some of the 1980-build Monarch 737-200s and they had even greater MTOWs, coming in at over 56 tons. That must have given them quite an edge over Britannia's 1968 machines.

I'm quite surprised that Braathens managed Oslo to Las Palmas with a 737-200, it's over 2,200 nm, well beyond even the quoted Gatwick to Tel Aviv of 1,900. It was for this particular route that both Spanish and Scandinavian charter carriers kept 3- and 4- engined aircraft in stock.

I was at university in Edinburgh in the early 1970s, which for historical reasons had a substantial Norwegian contingent then. Each start and end of term they chartered from Braathens for Oslo to Edinburgh. When I first was there it was a DC-6B, which for about 120 students needed to do two round trips, and took the whole day to do so. Must have been about 1974 they changed to a 737, which not only managed it in one trip, but I worked out had done an early schedule return from Oslo to Bergen and back, then the Edinburgh rounder, and then a holiday flight to Malaga. It was a notable example of how productivity improved with modern aircraft.

How is the MTOW of a single-design aeroplane varied anyway ? I remember when Air UK Leisure received its 737-400s, there was some company literature (inflight magazine, perhaps) stating that two of their newcomers were a certain weight, but the other two had a higher weight and could therefore go further.

I think the 737, with all its variants, is about as far from a "single-design" as you can get. Even within a single series, the manufacturer will typically offer weight/price options (which will be expanded as development and service experience progresses), and operators also have an incentive to certify individual fleet members at a lower MTOM in order to reduce landing fees, route charges, etc.

An extreme example is the MD-81/82/83 series where recertifying an aircraft from, say, an MD-83 to an MD-82 (or any other combination) is purely a paperwork exercise.

MTOW variation:

Two ways - structural, or paperwork.

The earliest Britannia 737-200 variant had an MTOW of 49442kg, the final batch 55111kg. They were all designated B737-204 (which was only a customer identifier) but were structurally different - stronger spars at least, maybe different gauge skins, perhaps different wheelbrakes (memory has faded on the detail!)

Later, with the B757 fleet, all the -204 were delivered with the same MTOW. I think this was 113398kg, but all were downgraded on paper to 112699, and later some to 103699kg.

Why do that? To save money. In the 1990s, 3 roughly equal items made up 75% of the DOC, namely fuel, en route charges, and landing and handling costs. The other 25% covered purchase, maintenance, insurance, and crew costs, plus overheads. By reducing the declared MTOW, the aircraft moved into a lower weight category and the airline paid less for en route and landing charges. The savings were significant.

The airline could do this without penalty provided that the declared MTOW was adequate for the planned sectors. As the B757 had more than enough range for all the normal Europe/Med destinations, that was OK, until............

We also went as far as Banjul; easy if the MTOW was 112699, but not at 103699. Of course, occasionally the wrong aircraft was allocated through force of circumstances, and a tech stop would be needed in the Canaries both ways - thus negating the savings........

It just shows that Sod's Law will get you whenever it can

Thankyou for your explanations, Dave and Ken. It reminds me of the British Midland Saab 340s, which was a mixed fleet of -As and -Bs. The former flew largely from East Midlands whereas the latter were almost always based at Leeds Bradford. The -B was, I think, fitted with more powerful engines and therefore better suited to LBA's shorter runway, even though they were only operating sectors of just a few hundred miles. The -B might have been a higher weight aircraft too.

On the loos-at-the-back aircraft, if the pilots needed to go back to use these facilities they would have to run the gauntlet of pax comments such as 'who's flying the plane?'. As you can imagine, there were a variety of responses.

Yes, the 340B has a 1,000 lb higher MTOM.

The 737-200s with the twin toilets in the tail was the spec on the early aircraft and was also common across the BA and Sabena 737-200s (which later ended up with European Air Charter). The rear galley was split into two smaller units forward of the toilets, instead of the transverse rear galley on the later Britannia 737s. The earlier variant was a bloody nightmare on which to work, as pretty much any and all activity in the galley stopped every time someone wanted to enter or exit the toilets.

The transverse galley with the toilets placed behind the rear row of seats was a whole lot easier.

If I remember rightly, the Britannia aircraft up to G-AXNC had the split rear galley / toilets in the tail (G-AZNZ was an ex-United aircraft) and from G-BADP onwards, which were the first of the 737-204ADVs, the aircraft had the transverse galley with a lot more stowage space and working space. Of those aircraft, I think G-AVRN kept going for by far the longest of any, but mostly confined to Britannia's LTN-Belfast International scheduled services and the trooping flights in its latter days.

There was a business-oriented BBC TV programme ("The Money Programme", I seem to recall, which did a feature on the Britannia base at Luton. At the time Romeo November was going through a complete D-check, possibly the first that Britannia had done, or done internally. It was described in the programme how extensive the work was. Later there was an article in Flight which covered this overhaul, and stated that the cost had been so extensive (it was seen as a pioneer job) that the decision was not to do them any more, but to sell the aircraft before they approached the hours, and buy replacements. However, having done the job RN was kept on for as long as practical. RN was one of the original 1969 aircraft, this was probably happening in the early 1980s, it was finally disposed at the end of the 1993 season.

It always seemed slightly odd that AVRN kept going for far longer than its sisterships, which I think went off to Presidential in the USA. By the end, RN's capability was degraded so far by the changes in MTOW calculations and increases in notional pax/bag weights that it was incredibly limited in what it could do. The latter-day performance of the rest of the Britannia 737-200 fleet was not helped by the decision to fit TV screens (an early incarnation of IFE!) which added a lot to the dry operating weight - I seem to remember about a tonne - and generally made life all the more difficult.

[Spantax leased a 737 from Presidential one summer and it flew around for the whole summer with the rear doors never being opened, as it was one of the few 737-200s with rear airstairs and they apparently were not certificated for use in Europe! Typical Spantax.]

And if saving D Checks on G-AVRN's sisterships was the price of bringing G-BMMZ into the fleet from Air Tanzania - well, an interesting incarnation of the old phrase "Better the Devil you Know"!

'MZ was an oddball. An Advanced -9 (so non-sparkling performance) with placards in French (AEROFREIN for speedbrake, VOLETS for flaps &c). No performance computer, no area nav capability so direct routings not available.

'MZ was ex-Air Algerie, new 1971, and thence Air Mali, both French-speaking onetime colonies, before coming to Britannia at 15 years old, hence the French placards. That must have been one of the first ADV aircraft. After Britannia it later went on to Europe Aero Services in Perpignan, France's equivalent of Dan-Air for a large charter fleet, oddball old aircraft repository, where the placarding would have come in useful again. If Britannia took it back to Algeria once I wonder who there recognised an old friend !

Had smoke in Flight Deck in MZ when operating Nice to Luton.

Went into Lyon awaiting engineers to rectify caused by CB fault I seem to remember.
Had a bad weather radar too.

I was only very young when Britannia began using LBA in 1976. At the time, not only did I think Britannia was a Spanish company (the significance of the name hadn't dawned on me!) but I didn't realise the 737s they used there were relatively youthful. To begin with, I guess it was BAZG, BAZH and BAZI that did the honours, so all only about two or three years old at the time. We didn't see the non-Advanced models as they couldn't reach the Mediterranean off the then 5400 foot runway. Even when I first came across later models such as BGYK, I wasn't aware how new they were. I guess BKHE and BKHF were the final pair of -200s to join Britannia, apart from BJXJ which came from Dan-Air.

Another of my observations is how, at LBA, Britannia had the place to themselves for ITs for four or five years. Then along came Air Europe in 1980 doing flights to Palma and Barcelona. AE didn't operate through LBA in 1981 but came back for '82. This year also saw Monarch make their LBA debut along with Air Malta. These two might have started flights from Southend at the same time. By 1983, Britannia, Monarch, Air Europe and Air Malta had been joined on ITs by Orion and Dan Air, all flying Advanced 732s off the then 5400 ft runway. Suddenly, all the Tour Operators wanted a slice of the LBA pie and they might not have got it (until the runway was extended) without that aeroplane.

Didn't think the doors and the airstairs were linked - or were the rear airstairs different? And didn't somebody take out the front airstairs to save weight?

B732 rear airstairs were an integral part of the door.

Thanks for that, another school day. And for anybody that wants to know more, here's some details from the example in the Alaska Aviation Museum...

https://www.wy2.org/aircraft/b737/b737-airstair.php

My excuse is the rear door was shut when I was there! :O

I was always fascinated by the 737 forward airstair (and door) extension and retraction. As a piece of mechanical engineering it was a classic.