B-26 Question.

[B-17engineer]

I was watching a documentary on the Ju-88 and it talked about how the allies were trying to bring in bombers to match the Luftwaffe bombing capabilities. It first talked about the B-25 and then said," the B-26 was not as versatile and at times hard to handle

What was hard to handle about it? I'm not questioning it, just curious.

 

[vanir]

I've read this before, if I remember right it was a high wing loading for poor low speed handling, and the fact Langley was the first to get them in 1940 and replaced the B-18 with them, which was quite a change (double the landing speed).
The wing was later modified during production, someone more knowledgeable should have details. The B-26 was initially ordered directly off the drawing board and no prototypes were built, though the first production batch was used for testing and training.
At first, due to an initial spate of landing accidents and a poor reputation among 22nd BG pilots for heavy handling, the B-26 got a bit of a reputation as a widowmaker, but later versions are described as excellent and it is often said the reputation was largely undeserving. RAF orders also had the early short wing, so Marauder MkI's had the same early series problems and lack of popularity.

 

[beaupower32]

Accidents
While the B-26 was a fast aircraft with better performance than the contemporary B-25 Mitchell, its relatively small wing area and resulting high wing loading (the highest of any aircraft used at that time) required an unprecedented landing speed (120-135 mph/193-217 km/h indicated airspeed depending on load). At least two of the earliest B-26s suffered hard landings and damage to the main landing gear, engine mounts, propellers and fuselage. The type was grounded briefly in April 1941 to investigate the landing difficulties. Two causes were found: insufficient landing speed (producing a stall) and improper weight distribution. The latter was due to the lack of a dorsal turret; the Martin power turret was not ready yet.

Some of the very earliest B-26s suffered collapses of the nose landing gear. It is said that they were caused by improper weight distribution but that is probably not the only reason. They occurred during low-speed taxiing, takeoffs and landings. Occasionally the strut unlocked.

The Pratt Whitney R-2800 engines were reliable but the Curtiss electric pitch change mechanism in the propellers required impeccable maintenance. Human error and some failures of the mechanism occasionally placed the propeller blades in flat pitch and resulted in an overspeeding propeller, sometimes known as a "runaway prop". Due to its sound and the possibility that the propeller blades could disintegrate, this situation was particularly frightening for aircrews. More challenging was a loss of power in one engine during takeoff. These and other malfunctions, as well as human error, claimed a number of aircraft and the commanding officer of the 22nd Bombardment Group, Col. Mark Lewis.

The Martin B-26 suffered only two fatal accidents during its first year of flights, November 1940-November 1941: a crash shortly after takeoff near Martin's Middle River plant (cause unknown but engine malfunction strongly suggested) and the loss of a 38th Bombardment Group B-26 when its vertical stabilizer and rudder separated from the aircraft at altitude (cause unknown, but accident report discussed the possibility that a canopy hatch broke off and struck the vertical stabilizer).

The B-26 was not an aircraft for novices. Unfortunately, due to the need to quickly train many pilots for the war, a number of relatively inexperienced pilots got into the cockpit and the accident rate increased accordingly. This occurred at the same time as more experienced B-26 pilots of the 22nd, 38th and 42nd Bombardment Groups were proving the merits of the bomber.

For a time in 1942, pilots in training believed that the B-26 could not be flown on one engine. This was disproved by a number of experienced pilots, including Jimmy Doolittle.

In 1942, Senator Harry Truman was a leading member of the Senate Special Committee to Investigate the National Defense Program (the so-called Truman Committee), which was investigating defense contracting abuses. When Truman and other committee members arrived at the Avon Park Army Air Field in Florida, they were greeted by the still-burning wreckage of two crashed B-26s. Truman criticized both Glenn L. Martin and the B-26. Indeed, the regularity of crashes by pilots training at nearby MacDill Field—up to fifteen in one 30-day period—led to the only mildly exaggerated catchphrase, "One a day in Tampa Bay."

The B-26 received the nickname "Widowmaker". Other colorful nicknames included "Martin Murderer", "Flying Coffin", "B-Dash-Crash", "Flying Prostitute" (so-named because it had "no visible means of support," referring to its small wings) and "Baltimore Whore" (a reference to the city where Martin was based).

According to an article in the April edition of AOPA Pilot on Kermit Weeks' "Fantasy of Flight", the Marauder had a tendency to "hunt" in yaw. This instability is similar to "Dutch roll". This would make for a very uncomfortable ride, especially for the tail gunner.

The B-26 is said to have had the lowest combat loss rate of any U.S. aircraft used during the war. Nevertheless, it remained a challenging aircraft to fly and continued to be unpopular with some pilots throughout its military career.

Quoted from Wikipedia. Hope this helps.

 

[MikeGazdik]

What was posted was I most remember reading about the Marauder. I really think it was a leap in performance. From seat of pants flying to flying by the numbers. The performance of the plane was great, but the early planes were very unforgiving of improper handling at the slower speeds during landing and take-off. This was primarily due to the short span of the wings.

Later planes, I forget which mark, had increased span and I think the angle of incidence of the wing to help its low speed regime.

 

[B-17engineer]

Many thanks for the responses guys!

 

[FLYBOYJ]

The B-26 had a very high wing loading and landed very fast when compared to some of the other twin engine aircraft of the day. As I've mentioned repeatedly on this forum, it seem the USAAF did not have an effective twin training program until after the war started. Twin engine aircraft can kill you very quickly, especially during an engine failure during take off.

 

[B-17engineer]

Oh, I see. On take off if the engine failed, what would the aircraft do? So on take off if the engine failed it was a problem, but in the air, like Jimmy Doolittle tested, the aircraft could fly on one engine?

 

[FLYBOYJ]

Oh, I see. On take off if the engine failed, what would the aircraft do? So on take off if the engine failed it was a problem, but in the air, like Jimmy Doolittle tested, the aircraft could fly on one engine?

When a pilot has an engine failure on takeoff in a twin engine aircraft he or she must act quickly to counter the effects of "dead" engine. If nothing is quickly done, the aircraft tends to yaw and roll into the dead engine and can eventually roll upside down. Many people have died in WW2 and even in later years because they weren't properly trained or they did not maintain proficiency in practicing engine out emergencies.


Generally here are the steps involved in countering a lost engine on take off.

1. identify failure
2. Counter yaw with rudder
3. Bank toward dead engine
4. Raise landing gear
5. Lower the nose to ensure airspeed
6. Positively identify the engine and feather the prop. After that shut fuel off to the engine if fire is suspect.

When twin engine aircraft are being developed there are 2 things always determined.

1. Minimum Airborne Control speed - this is the minimum airspeed at which directional control can be maintained under the following conditions: maximum gross weight, center of gravity [C of G] at the maximum aft position, sea level, flaps set to the takeoff position, landing gear retracted, operating engine developing maximum power, critical engine failed and windmilling, a maximum of 5 degrees of bank towards the good engine.

2. Best single rate of climb on one engine - Best rate of climb speed with a single operating engine in a twin-engine aircraft – the speed that provides the most altitude gain per unit of time following an engine failure.


So all this must be considered when loosing an engine on take off when flying a twin engine aircraft.

NOW - as for the B-26. At altitude, can it fly on a single engine? I believe so.

BTW - on the P-38, you had to also REDUCE power on the good engine to ensure proper control if you lost an engine during take off.

 

[B-17engineer]

Many thanks for the explanation! Clears a lot up!