Bombers and Agility

[GrauGeist]

In regards to the Air Ministry's 100 foot wingspan limit - this was to limit the size of the aircraft and had nothing to do with hangar access, as many of their large hangar buildings had 112 to 120 foot door spans.

There is a great explanation of both the 100 foot requirement as well as the origin of the myth found here:
Folding wings on British bombers

 

[MacHeath]

The Short Stirling, being built out of the same material as Short Brothers and Harland at Belfast built the Titanic and her sisters from, where Stirlings were manufactured, was quite robust and was known to be quite manoeuvrable for such a big aircraft and could be thrown around with ease. Something to do with its short wingspan, so I believe.

I guess they had to be manoeuvrable as they suffered high losses in early sorties and individual aircraft were pulled out of service because of unreliabilities and defects at the manufacturer level... Not a great start.

Some years ago I read an interview with a Stirling pilot, he said it was a fantastic aircraft, and could out turn an ME 110 night fighter, given the 110 would be heavily loaded with aerials possibly extra cannons etc I can believe it.

 

[JDCAVE]

In regards to the Air Ministry's 100 foot wingspan limit - this was to limit the size of the aircraft and had nothing to do with hangar access, as many of their large hangar buildings had 112 to 120 foot door spans.

There is a great explanation of both the 100 foot requirement as well as the origin of the myth found here:
Folding wings on British bombers

No. That is not what is said in that post and it also lacks an authoritative reference. a post on this forum cannot be assumed to be correct without referencing primary source material

Sounds like GrauGeist should complete further research on this topic and report back. Note that errors and speculation are often later claimed as evidence when they are nothing of the sort.

 

[GrauGeist]

No. That is not what is said in that post and it also lacks an authoritative reference. a post on this forum cannot be assumed to be correct without rerencing primary source material

Sounds like GrauGeist should complete further research on this topic and report back. Note that errors ano speculation are often later claimed as evidence when they are nothing of the sort.

If you disagree, then it is up to you to prove me wrong.

 

[Shortround6]

One thing I discovered from looking at flight test data is that pilot technique can make a vast difference in the loads for exactly the same maneuver, at least in the world of rotorcraft. When I was at Sikorsky, the flight test engineers would tell of a USArmy test pilot who would perform buttonhooks (basically, overfly a spot at high speed, pull up and turn sharply and return to the same point from a different angle) and show lower vibratory loads on the airframe than some "green" pilots would in level flight. Of course, helicopters are weird (albeit more awesome than fixed-wing ones), but I think the same would apply to fixed-wing aircraft: a more experienced pilot could "throw" an airplane around in ways that seem more violent than a less-skilled one and actually put less stress on the airframe. Witness what somebody like Bob Hoover could do with a business twin.

The NACA put a recording G meter in a pylon racer(or more than one) back in the 30s, one of the ones that leaves a trace mark on paper. They found that the instantaneous G loading for a 180 degree nominal 2 G turn could vary from +6 Gs to negative 0.something ( I don't have it in front of me at the moment) as the pilot adjusted his turn. As the plane bleed off speed and the turn radius decreased the pilot would let off on the elevators sometimes causing a momentary (fraction of a second) negative G and then would bounce up again as the pilot reapplied the elevator to maintain the turn. Ground observers thought the turn/s were being flown smoothly.

 

[pbehn]

And 617 used Lancs as Pathfinders so that suggests extreme maneuvers were approved in that unit at least

And then comes the question what is an extreme manoeuvre? A Tallboy was so heavy planes werent supposed to be parked with them in for long, even gentle manoeuvres could strain the wings. As per JDCAVE's post if you are about to be shot down you may risk throwing out operating procedures, pilots routinely flew severely damaged aircraft on 3 or 2 engines not knowing what the damage was in many cases.

 

[JDCAVE]

And then comes the question what is an extreme manoeuvre? A Tallboy was so heavy planes werent supposed to be parked with them in for long, even gentle manoeuvres could strain the wings. As per JDCAVE's post if you are about to be shot down you may risk throwing out operating procedures, pilots routinely flew severely damaged aircraft on 3 or 2 engines not knowing what the damage was in many cases.

617 wasn't a Pathfinder Squadron. And they didn't use Lancasters as Pathfinders either. On occasion, on V-1 sites, the OC of 617, W/C Cheshire used first Mosquitoes, and later, Mustangs for low level marking for 5-Group. But it would be incorrect to say 617 used Lancasters as Pathfinder aircraft or the Squadron as a Pathfinder unit because it wasn't. It was a Special Duties Squadron, used for special targets or critical operations.

 

[pbehn]

617 wasn't a Pathfinder Squadron. And they didn't use Lancasters as Pathfinders either. On occasion, on V-1 sites, the OC of 617, W/C Cheshire used first Mosquitoes, and later, Mustangs for low level marking, for 5-Group. But it would be incorrect to say 617 used Lancasters as Pathfinder aircraft or the Squadron as a Pathfinder unit because it wasn't. It was a Special Duties Squadron, used for special targets or critical operations.

I didnt say they were, although on occasions I believe 617 Mosquitos did act as pathfinders for the raid on Mailly le Camp etc.

 

[GrauGeist]

I didnt say they were, although on occasions I believe 617 Mosquitos did act as pathfinders for the raid on Mailly le Camp etc.

There were several squadrons that operated Lancasters as a pathfinder, though.

 

[JDCAVE]

I didnt say they were, although on occasions I believe 617 Mosquitos did act as pathfinders for the raid on Mailly le Camp etc.

Sorry. No you didn't but the fellow you quoted did, and I wanted to correct that.

 

[pbehn]

Sorry. No you didn't but the fellow you quoted did, and I wanted to correct that.

I think its only a partial correction, I read two books by the same author, one on the Lancaster in General and one on 617 squadron in particular. I believe there were some raids where 617 did act as pathfinders first with Mosquitos using TIs and then with bombers to give a clear aiming point for the bomber stream behind.

 

[MiTasol]

617 wasn't a Pathfinder Squadron. And they didn't use Lancasters as Pathfinders either. On occasion, on V-1 sites, the OC of 617, W/C Cheshire used first Mosquitoes, and later, Mustangs for low level marking for 5-Group. But it would be incorrect to say 617 used Lancasters as Pathfinder aircraft or the Squadron as a Pathfinder unit because it wasn't. It was a Special Duties Squadron, used for special targets or critical operations.

My apologies for getting the unit wrong - Old Timers disease I guess

 

[Dimlee]

Bingo. Wood and moisture do not cooperate, and there's no magic paint to fix that. Wood expands and contracts with temperature, which will break any finish on it regardless of moisture absorption. And then once that finish cracks, guess what? We've introduced moisture into the equation. Now, the temperature ranges between sea-level and 30k are going to tax that finish, and you've got two temp cycles for every flight.

That's a lot of shrinking and swelling to tolerate, for the paint that's keeping the water from rotting the wood. There's not going to be nearly as much lifespan in such a plane compared to aluminum etc.

Just a general remark, not about aviation. Wood in shipping survives for many years despite a lot of moisture and temperature changes and vibrations and various loads. The paint is not reliable indeed but good varnish does the job.

 

[MiTasol]

And there are many old wooden aircraft still flying close to 100 years after they were built.

 

[FLYBOYJ]

And there are many old wooden aircraft still flying close to 100 years after they were built.

There are - but most are meticulously maintained and stored in a control environment. The only place for wood in a modern combat aircraft is maybe the inside of a glove box or cabinet on a larger aircraft. The P-3 initially had floorboards made of wood, they eventually rotted away.

 

[FLYBOYJ]

Just a general remark, not about aviation. Wood in shipping survives for many years despite a lot of moisture and temperature changes and vibrations and various loads. The paint is not reliable indeed but good varnish does the job.

True but comparing the wood used in ships against the wood used in aircraft, the stresses, construction and operating environments, it's apples and oranges.

 

[pbehn]

I worked for a while on corrosion testing in Saudi Arabia, so I read a bit about it. The environment there is similar to being on the deck of an aircraft carrier. 100% humidity means that every morning anything metal is covered in moisture and the sand there contains a percentage of salt. Frequent sand storms elsewhere fill the air with fine dust so things are permanently being covered in a saline solution and frequently given a sand blast that will take any paint cover off and make headlights useless. BiffF15 Were F15s in KSA given any special treatments for this?

 

[Greg Boeser]

There are - but most are maliciously maintained and stored in a control environment. The only place for wood in a modern combat aircraft is maybe the inside of a glove box or cabinet on a larger aircraft. The P-3 initially had floorboards made of wood, they eventually rotted away.

Maliciously maintained.

 

[JDCAVE]

I stand corrected.

I have reviewed the ORB's for 617 Squadron which reveal that 617 Squadron's marking was directed at its own raids, except for a period in April 1944, when 5-Group began to do it's own marking. On March 27, 1944, 617 took 2 mosquitoes on charge, and Cheshire received instruction on how to fly the a/c. On April 5, 1944 145 aircraft from 5-Group bombed Toulouse, with W/C Cheshire marking the target at low level, and 2 Lancasters from the squadron dropping "spot fires", all marking done by 617. According to Middlebrook and Everitt, the attack was brilliantly executed. Further attacks that month (617 Squadron plus a force of Lancasters from 5-Group) included St. Cyre, April 10; Juvisy, April 18; La Chapelle, April 20; Brunswick, April 22 and Munich, April 24. Oboe Mosquitoes from 8-Group also participated on the Juvisy and La Chapelle raids. Also during April, 97, 83, and 627 Squadrons of the Path Finder Force – 8 Group – were 'loaned' to 5 Group in April 1944 against the strong opposition of the Pathfinders' commander, Donald Bennett. The squadrons remained Pathfinders, carrying out pathfinder duties, and as such were still eligible for the full award of the Pathfinder badge. Additionally, I know that 5-group operated with Mosquitoes on some targets, but it is not clear to me whether these were attached to the existing pathfinder Lancaster squadrons in the group , or whether these were from separate squadrons.

Edit: 627 Squadron transferred to 5-Group from 8-Group, April 1944 and equipped with Mosquitoes. There may have been another, but for some reason I have not yet come up with an order of battle for 1945.

Not withstanding the above, after the raids in April 1944, 617 Squadron went back to its specialist duties, mostly on its own or with a contribution from 9-Squadron. In May 1944, it was not operational except for a 4 Mosquito Sorties, as the crews undertook training for Operation Taxable, the Windowing operations designed to mimic an invasion fleet moving towards the French Coast between Boulogne and Le Havre. Other than the brief stint as on pathfinder duties for 5-Group in April 1944, I would not classify the squadron as being "Pathfinders". The ORBs for June-July 1944 reveal they operated on their own. That's not to say they didn't, from time-to-time, operate in concert with the rest of 5-Group, but if you think about it, if you are dropping expensive Tallboys on targets, it should be done without other aircraft stirring up the dust and interfering with your marking, while you are trying to line up the target.

Jim

 

[FLYBOYJ]

Maliciously maintained.

LOL - damned spell check!